Commit Graph

34154 Commits

Author SHA1 Message Date
Rafael J. Wysocki c81b30c895 Merge branch 'pm-cpufreq'
* pm-cpufreq: (24 commits)
  cpufreq: intel_pstate: Fix EPP setting via sysfs in active mode
  cpufreq: intel_pstate: Rearrange the storing of new EPP values
  cpufreq: intel_pstate: Avoid enabling HWP if EPP is not supported
  cpufreq: intel_pstate: Clean up aperf_mperf_shift description
  cpufreq: powernv: Make some symbols static
  cpufreq: amd_freq_sensitivity: Mark sometimes used ID structs as __maybe_unused
  cpufreq: intel_pstate: Supply struct attribute description for get_aperf_mperf_shift()
  cpufreq: pcc-cpufreq: Mark sometimes used ID structs as __maybe_unused
  cpufreq: powernow-k8: Mark 'hi' and 'lo' dummy variables as __always_unused
  cpufreq: acpi-cpufreq: Mark sometimes used ID structs as __maybe_unused
  cpufreq: acpi-cpufreq: Mark 'dummy' variable as __always_unused
  cpufreq: powernv-cpufreq: Fix a bunch of kerneldoc related issues
  cpufreq: pasemi: Include header file for {check,restore}_astate prototypes
  cpufreq: cpufreq_governor: Demote store_sampling_rate() header to standard comment block
  cpufreq: cpufreq: Demote lots of function headers unworthy of kerneldoc status
  cpufreq: freq_table: Demote obvious misuse of kerneldoc to standard comment blocks
  cpufreq: Replace HTTP links with HTTPS ones
  cpufreq: intel_pstate: Fix static checker warning for epp variable
  cpufreq: Remove the weakly defined cpufreq_default_governor()
  cpufreq: Specify default governor on command line
  ...
2020-08-03 13:12:36 +02:00
Rafael J. Wysocki 5b5642075c Merge branches 'pm-em' and 'pm-core'
* pm-em:
  OPP: refactor dev_pm_opp_of_register_em() and update related drivers
  Documentation: power: update Energy Model description
  PM / EM: change name of em_pd_energy to em_cpu_energy
  PM / EM: remove em_register_perf_domain
  PM / EM: add support for other devices than CPUs in Energy Model
  PM / EM: update callback structure and add device pointer
  PM / EM: introduce em_dev_register_perf_domain function
  PM / EM: change naming convention from 'capacity' to 'performance'

* pm-core:
  mmc: jz4740: Use pm_ptr() macro
  PM: Make *_DEV_PM_OPS macros use __maybe_unused
  PM: core: introduce pm_ptr() macro
2020-08-03 13:11:39 +02:00
Ingo Molnar 992414a18c Merge branch 'locking/nmi' into locking/core, to pick up completed topic branch
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-08-03 13:00:27 +02:00
Linus Torvalds c6fe44d96f list: add "list_del_init_careful()" to go with "list_empty_careful()"
That gives us ordering guarantees around the pair.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-02 20:39:44 -07:00
David S. Miller bd0b33b248 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Resolved kernel/bpf/btf.c using instructions from merge commit
69138b34a7

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-02 01:02:12 -07:00
Andrii Nakryiko 73b11c2ab0 bpf: Add support for forced LINK_DETACH command
Add LINK_DETACH command to force-detach bpf_link without destroying it. It has
the same behavior as auto-detaching of bpf_link due to cgroup dying for
bpf_cgroup_link or net_device being destroyed for bpf_xdp_link. In such case,
bpf_link is still a valid kernel object, but is defuncts and doesn't hold BPF
program attached to corresponding BPF hook. This functionality allows users
with enough access rights to manually force-detach attached bpf_link without
killing respective owner process.

This patch implements LINK_DETACH for cgroup, xdp, and netns links, mostly
re-using existing link release handling code.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200731182830.286260-2-andriin@fb.com
2020-08-01 20:38:28 -07:00
Linus Torvalds ac3a0c8472 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Encap offset calculation is incorrect in esp6, from Sabrina Dubroca.

 2) Better parameter validation in pfkey_dump(), from Mark Salyzyn.

 3) Fix several clang issues on powerpc in selftests, from Tanner Love.

 4) cmsghdr_from_user_compat_to_kern() uses the wrong length, from Al
    Viro.

 5) Out of bounds access in mlx5e driver, from Raed Salem.

 6) Fix transfer buffer memleak in lan78xx, from Johan Havold.

 7) RCU fixups in rhashtable, from Herbert Xu.

 8) Fix ipv6 nexthop refcnt leak, from Xiyu Yang.

 9) vxlan FDB dump must be done under RCU, from Ido Schimmel.

10) Fix use after free in mlxsw, from Ido Schimmel.

11) Fix map leak in HASH_OF_MAPS bpf code, from Andrii Nakryiko.

12) Fix bug in mac80211 Tx ack status reporting, from Vasanthakumar
    Thiagarajan.

13) Fix memory leaks in IPV6_ADDRFORM code, from Cong Wang.

14) Fix bpf program reference count leaks in mlx5 during
    mlx5e_alloc_rq(), from Xin Xiong.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (86 commits)
  vxlan: fix memleak of fdb
  rds: Prevent kernel-infoleak in rds_notify_queue_get()
  net/sched: The error lable position is corrected in ct_init_module
  net/mlx5e: fix bpf_prog reference count leaks in mlx5e_alloc_rq
  net/mlx5e: E-Switch, Specify flow_source for rule with no in_port
  net/mlx5e: E-Switch, Add misc bit when misc fields changed for mirroring
  net/mlx5e: CT: Support restore ipv6 tunnel
  net: gemini: Fix missing clk_disable_unprepare() in error path of gemini_ethernet_port_probe()
  ionic: unlock queue mutex in error path
  atm: fix atm_dev refcnt leaks in atmtcp_remove_persistent
  net: ethernet: mtk_eth_soc: fix MTU warnings
  net: nixge: fix potential memory leak in nixge_probe()
  devlink: ignore -EOPNOTSUPP errors on dumpit
  rxrpc: Fix race between recvmsg and sendmsg on immediate call failure
  MAINTAINERS: Replace Thor Thayer as Altera Triple Speed Ethernet maintainer
  selftests/bpf: fix netdevsim trap_flow_action_cookie read
  ipv6: fix memory leaks on IPV6_ADDRFORM path
  net/bpfilter: Initialize pos in __bpfilter_process_sockopt
  igb: reinit_locked() should be called with rtnl_lock
  e1000e: continue to init PHY even when failed to disable ULP
  ...
2020-08-01 16:47:24 -07:00
Linus Torvalds 0ae3495b65 for-linus-2020-08-01
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Merge tag 'for-linus-2020-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread fix from Christian Brauner:
 "A simple spelling fix for dequeue_synchronous_signal()"

* tag 'for-linus-2020-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  signal: fix typo in dequeue_synchronous_signal()
2020-08-01 16:40:59 -07:00
Christoph Hellwig ef1dac6021 modules: return licensing information from find_symbol
Report the GPLONLY status through a new argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-08-01 16:05:02 +02:00
Christoph Hellwig cd8732cdcc modules: rename the licence field in struct symsearch to license
Use the same spelling variant as the rest of the file.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-08-01 16:05:02 +02:00
Christoph Hellwig 34e64705ad modules: unexport __module_address
__module_address is only used by built-in code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-08-01 16:05:01 +02:00
Christoph Hellwig 3fe1e56d0e modules: unexport __module_text_address
__module_text_address is only used by built-in code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-08-01 16:05:00 +02:00
Christoph Hellwig a54e04914c modules: mark each_symbol_section static
each_symbol_section is only used inside of module.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-08-01 16:05:00 +02:00
Christoph Hellwig 773110470e modules: mark find_symbol static
find_symbol is only used in module.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-08-01 16:04:59 +02:00
Christoph Hellwig 7ef5264de7 modules: mark ref_module static
ref_module isn't used anywhere outside of module.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-08-01 16:04:55 +02:00
Ingo Molnar 63722bbca6 Merge branch 'kcsan' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/core
Pull v5.9 KCSAN bits from Paul E. McKenney.

Perhaps the most important change is that GCC 11 now has all fixes in place
to support KCSAN, so GCC support can be enabled again.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-08-01 09:26:27 +02:00
Valentin Schneider f4470cdf10 sched: Document arch_scale_*_capacity()
Rather that hide their purpose in some dark, damp corner of Documentation/,
add some documentation to the default implementations.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200731192016.7484-2-valentin.schneider@arm.com
2020-08-01 09:19:43 +02:00
David S. Miller 69138b34a7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2020-07-31

The following pull-request contains BPF updates for your *net* tree.

We've added 5 non-merge commits during the last 21 day(s) which contain
a total of 5 files changed, 126 insertions(+), 18 deletions(-).

The main changes are:

1) Fix a map element leak in HASH_OF_MAPS map type, from Andrii Nakryiko.

2) Fix a NULL pointer dereference in __btf_resolve_helper_id() when no
   btf_vmlinux is available, from Peilin Ye.

3) Init pos variable in __bpfilter_process_sockopt(), from Christoph Hellwig.

4) Fix a cgroup sockopt verifier test by specifying expected attach type,
   from Jean-Philippe Brucker.

Note that when net gets merged into net-next later on, there is a small
merge conflict in kernel/bpf/btf.c between commit 5b801dfb7f ("bpf: Fix
NULL pointer dereference in __btf_resolve_helper_id()") from the bpf tree
and commit 138b9a0511 ("bpf: Remove btf_id helpers resolving") from the
net-next tree.

Resolve as follows: remove the old hunk with the __btf_resolve_helper_id()
function. Change the btf_resolve_helper_id() so it actually tests for a
NULL btf_vmlinux and bails out:

int btf_resolve_helper_id(struct bpf_verifier_log *log,
                          const struct bpf_func_proto *fn, int arg)
{
        int id;

        if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID || !btf_vmlinux)
                return -EINVAL;
        id = fn->btf_id[arg];
        if (!id || id > btf_vmlinux->nr_types)
                return -EINVAL;
        return id;
}

Let me know if you run into any others issues (CC'ing Jiri Olsa so he's in
the loop with regards to merge conflict resolution).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-31 17:19:47 -07:00
Catalin Marinas 4557062da7 Merge branches 'for-next/misc', 'for-next/vmcoreinfo', 'for-next/cpufeature', 'for-next/acpi', 'for-next/perf', 'for-next/timens', 'for-next/msi-iommu' and 'for-next/trivial' into for-next/core
* for-next/misc:
  : Miscellaneous fixes and cleanups
  arm64: use IRQ_STACK_SIZE instead of THREAD_SIZE for irq stack
  arm64/mm: save memory access in check_and_switch_context() fast switch path
  recordmcount: only record relocation of type R_AARCH64_CALL26 on arm64.
  arm64: Reserve HWCAP2_MTE as (1 << 18)
  arm64/entry: deduplicate SW PAN entry/exit routines
  arm64: s/AMEVTYPE/AMEVTYPER
  arm64/hugetlb: Reserve CMA areas for gigantic pages on 16K and 64K configs
  arm64: stacktrace: Move export for save_stack_trace_tsk()
  smccc: Make constants available to assembly
  arm64/mm: Redefine CONT_{PTE, PMD}_SHIFT
  arm64/defconfig: Enable CONFIG_KEXEC_FILE
  arm64: Document sysctls for emulated deprecated instructions
  arm64/panic: Unify all three existing notifier blocks
  arm64/module: Optimize module load time by optimizing PLT counting

* for-next/vmcoreinfo:
  : Export the virtual and physical address sizes in vmcoreinfo
  arm64/crash_core: Export TCR_EL1.T1SZ in vmcoreinfo
  crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo

* for-next/cpufeature:
  : CPU feature handling cleanups
  arm64/cpufeature: Validate feature bits spacing in arm64_ftr_regs[]
  arm64/cpufeature: Replace all open bits shift encodings with macros
  arm64/cpufeature: Add remaining feature bits in ID_AA64MMFR2 register
  arm64/cpufeature: Add remaining feature bits in ID_AA64MMFR1 register
  arm64/cpufeature: Add remaining feature bits in ID_AA64MMFR0 register

* for-next/acpi:
  : ACPI updates for arm64
  arm64/acpi: disallow writeable AML opregion mapping for EFI code regions
  arm64/acpi: disallow AML memory opregions to access kernel memory

* for-next/perf:
  : perf updates for arm64
  arm64: perf: Expose some new events via sysfs
  tools headers UAPI: Update tools's copy of linux/perf_event.h
  arm64: perf: Add cap_user_time_short
  perf: Add perf_event_mmap_page::cap_user_time_short ABI
  arm64: perf: Only advertise cap_user_time for arch_timer
  arm64: perf: Implement correct cap_user_time
  time/sched_clock: Use raw_read_seqcount_latch()
  sched_clock: Expose struct clock_read_data
  arm64: perf: Correct the event index in sysfs
  perf/smmuv3: To simplify code for ioremap page in pmcg

* for-next/timens:
  : Time namespace support for arm64
  arm64: enable time namespace support
  arm64/vdso: Restrict splitting VVAR VMA
  arm64/vdso: Handle faults on timens page
  arm64/vdso: Add time namespace page
  arm64/vdso: Zap vvar pages when switching to a time namespace
  arm64/vdso: use the fault callback to map vvar pages

* for-next/msi-iommu:
  : Make the MSI/IOMMU input/output ID translation PCI agnostic, augment the
  : MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID bus-specific parameter
  : and apply the resulting changes to the device ID space provided by the
  : Freescale FSL bus
  bus: fsl-mc: Add ACPI support for fsl-mc
  bus/fsl-mc: Refactor the MSI domain creation in the DPRC driver
  of/irq: Make of_msi_map_rid() PCI bus agnostic
  of/irq: make of_msi_map_get_device_domain() bus agnostic
  dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus
  of/device: Add input id to of_dma_configure()
  of/iommu: Make of_map_rid() PCI agnostic
  ACPI/IORT: Add an input ID to acpi_dma_configure()
  ACPI/IORT: Remove useless PCI bus walk
  ACPI/IORT: Make iort_msi_map_rid() PCI agnostic
  ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic
  ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC

* for-next/trivial:
  : Trivial fixes
  arm64: sigcontext.h: delete duplicated word
  arm64: ptrace.h: delete duplicated word
  arm64: pgtable-hwdef.h: delete duplicated words
2020-07-31 18:09:39 +01:00
Ingo Molnar 28cff52eae Merge branch 'linus' into locking/core, to resolve conflict
Conflicts:
	arch/arm/include/asm/percpu.h

As Stephen Rothwell noted, there's a conflict between this commit
in locking/core:

  a21ee6055c ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables")

and this fresh upstream commit:

  aa54ea903a ("ARM: percpu.h: fix build error")

a21ee6055c is a simpler solution to the dependency problem and doesn't
further increase header hell - so this conflict resolution effectively
reverts aa54ea903a and uses the a21ee6055c solution.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-31 12:16:09 +02:00
Marco Elver 92c209ac6d kcsan: Improve IRQ state trace reporting
To improve the general usefulness of the IRQ state trace events with
KCSAN enabled, save and restore the trace information when entering and
exiting the KCSAN runtime as well as when generating a KCSAN report.

Without this, reporting the IRQ trace events (whether via a KCSAN report
or outside of KCSAN via a lockdep report) is rather useless due to
continuously being touched by KCSAN. This is because if KCSAN is
enabled, every instrumented memory access causes changes to IRQ trace
events (either by KCSAN disabling/enabling interrupts or taking
report_lock when generating a report).

Before "lockdep: Prepare for NMI IRQ state tracking", KCSAN avoided
touching the IRQ trace events via raw_local_irq_save/restore() and
lockdep_off/on().

Fixes: 248591f5d2 ("kcsan: Make KCSAN compatible with new IRQ state tracking")
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200729110916.3920464-2-elver@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-31 12:12:03 +02:00
Marco Elver 0584df9c12 lockdep: Refactor IRQ trace events fields into struct
Refactor the IRQ trace events fields, used for printing information
about the IRQ trace events, into a separate struct 'irqtrace_events'.

This improves readability by separating the information only used in
reporting, as well as enables (simplified) storing/restoring of
irqtrace_events snapshots.

No functional change intended.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200729110916.3920464-1-elver@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-31 12:11:58 +02:00
Vincent Whitchurch ee896ee805 tracing: Remove outdated comment in stack handling
This comment describes the behaviour before commit 2a820bf749
("tracing: Use percpu stack trace buffer more intelligently").  Since
that commit, interrupts and NMIs do use the per-cpu stacks so the
comment is no longer correct.  Remove it.

(Note that the FTRACE_STACK_SIZE mentioned in the comment has never
existed, it probably should have said FTRACE_STACK_ENTRIES.)

Link: https://lkml.kernel.org/r/20200727092840.18659-1-vincent.whitchurch@axis.com

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 22:54:50 -04:00
Chengming Zhou c5f51572a7 ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines
When inserting a module, we find all ftrace_ops referencing it on the
ftrace_ops_list. But FTRACE_OPS_FL_DIRECT and FTRACE_OPS_FL_IPMODIFY
flags are special, and should not be set automatically. So warn and
skip ftrace_ops that have these two flags set and adding new code.
Also check if only one ftrace_ops references the module, in which case
we can use a trampoline as an optimization.

Link: https://lkml.kernel.org/r/20200728180554.65203-2-zhouchengming@bytedance.com

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 22:45:31 -04:00
Chengming Zhou 8a224ffb3f ftrace: Setup correct FTRACE_FL_REGS flags for module
When module loaded and enabled, we will use __ftrace_replace_code
for module if any ftrace_ops referenced it found. But we will get
wrong ftrace_addr for module rec in ftrace_get_addr_new, because
rec->flags has not been setup correctly. It can cause the callback
function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called
with pt_regs set to NULL.
So setup correct FTRACE_FL_REGS flags for rec when we call
referenced_filters to find ftrace_ops references it.

Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com

Cc: stable@vger.kernel.org
Fixes: 8c4f3c3fa9 ("ftrace: Check module functions being traced on reload")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 19:35:19 -04:00
Kevin Hao 96b4833b68 tracing/hwlat: Honor the tracing_cpumask
In calculation of the cpu mask for the hwlat kernel thread, the wrong
cpu mask is used instead of the tracing_cpumask, this causes the
tracing/tracing_cpumask useless for hwlat tracer. Fixes it.

Link: https://lkml.kernel.org/r/20200730082318.42584-2-haokexin@gmail.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0330f7aa8e ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 19:35:04 -04:00
Kevin Hao a9d0ba6772 tracing/hwlat: Drop the duplicate assignment in start_kthread()
We have set 'current_mask' to '&save_cpumask' in its declaration,
so there is no need to assign again.

Link: https://lkml.kernel.org/r/20200730082318.42584-1-haokexin@gmail.com

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 19:35:04 -04:00
Yonghong Song 4fc00b79b8 bpf: Add missing newline characters in verifier error messages
Newline characters are added in two verifier error messages,
refactored in Commit afbf21dce6 ("bpf: Support readonly/readwrite
buffers in verifier"). This way, they do not mix with
messages afterwards.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200728221801.1090349-1-yhs@fb.com
2020-07-31 00:43:49 +02:00
Ingo Molnar c1cc4784ce Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull the v5.9 RCU bits from Paul E. McKenney:

 - Documentation updates
 - Miscellaneous fixes
 - kfree_rcu updates
 - RCU tasks updates
 - Read-side scalability tests
 - SRCU updates
 - Torture-test updates

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-31 00:15:53 +02:00
Romain Perier 12cc923f1c tasklet: Introduce new initialization API
Nowadays, modern kernel subsystems that use callbacks pass the data
structure associated with a given callback as argument to the callback.
The tasklet subsystem remains one which passes an arbitrary unsigned
long to the callback function. This has several problems:

- This keeps an extra field for storing the argument in each tasklet
  data structure, it bloats the tasklet_struct structure with a redundant
  .data field

- No type checking can be performed on this argument. Instead of
  using container_of() like other callback subsystems, it forces callbacks
  to do explicit type cast of the unsigned long argument into the required
  object type.

- Buffer overflows can overwrite the .func and the .data field, so
  an attacker can easily overwrite the function and its first argument
  to whatever it wants.

Add a new tasklet initialization API, via DECLARE_TASKLET() and
tasklet_setup(), which will replace the existing ones.

This work is greatly inspired by the timer_struct conversion series,
see commit e99e88a9d2 ("treewide: setup_timer() -> timer_setup()")

To avoid problems with both -Wcast-function-type (which is enabled in
the kernel via -Wextra is several subsystems), and with mismatched
function prototypes when build with Control Flow Integrity enabled,
this adds the "use_callback" member to let the tasklet caller choose
which union member to call through. Once all old API uses are removed,
this and the .data member will be removed as well. (On 64-bit this does
not grow the struct size as the new member fills the hole after atomic_t,
which is also "int" sized.)

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Co-developed-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-30 11:16:01 -07:00
Kees Cook b13fecb1c3 treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()
This converts all the existing DECLARE_TASKLET() (and ...DISABLED)
macros with DECLARE_TASKLET_OLD() in preparation for refactoring the
tasklet callback type. All existing DECLARE_TASKLET() users had a "0"
data argument, it has been removed here as well.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-30 11:15:58 -07:00
Andrii Nakryiko 1d4e1eab45 bpf: Fix map leak in HASH_OF_MAPS map
Fix HASH_OF_MAPS bug of not putting inner map pointer on bpf_map_elem_update()
operation. This is due to per-cpu extra_elems optimization, which bypassed
free_htab_elem() logic doing proper clean ups. Make sure that inner map is put
properly in optimized case as well.

Fixes: 8c290e60fa ("bpf: fix hashmap extra_elems logic")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200729040913.2815687-1-andriin@fb.com
2020-07-30 01:30:22 +02:00
Linus Torvalds d3590ebf6f audit/stable-5.8 PR 20200729
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Merge tag 'audit-pr-20200729' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit fixes from Paul Moore:
 "One small audit fix that you can hopefully merge before v5.8 is
  released. Unfortunately it is a revert of a patch that went in during
  the v5.7 window and we just recently started to see some bug reports
  relating to that commit.

  We are working on a proper fix, but I'm not yet clear on when that
  will be ready and we need to fix the v5.7 kernels anyway, so in the
  interest of time a revert seemed like the best solution right now"

* tag 'audit-pr-20200729' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  revert: 1320a4052e ("audit: trigger accompanying records when no rules present")
2020-07-29 12:35:36 -07:00
Willy Tarreau f227e3ec3b random32: update the net random state on interrupt and activity
This modifies the first 32 bits out of the 128 bits of a random CPU's
net_rand_state on interrupt or CPU activity to complicate remote
observations that could lead to guessing the network RNG's internal
state.

Note that depending on some network devices' interrupt rate moderation
or binding, this re-seeding might happen on every packet or even almost
never.

In addition, with NOHZ some CPUs might not even get timer interrupts,
leaving their local state rarely updated, while they are running
networked processes making use of the random state.  For this reason, we
also perform this update in update_process_times() in order to at least
update the state when there is user or system activity, since it's the
only case we care about.

Reported-by: Amit Klein <aksecurity@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-29 10:35:37 -07:00
Ahmed S. Darwish af5a06b582 hrtimer: Use sequence counter with associated raw spinlock
A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.

Use the new seqcount_raw_spinlock_t data type, which allows to associate
a raw spinlock with the sequence counter. This enables lockdep to verify
that the raw spinlock used for writer serialization is held when the
write side critical section is entered.

If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-25-a.darwish@linutronix.de
2020-07-29 16:14:29 +02:00
Ahmed S. Darwish 025e82bcbc timekeeping: Use sequence counter with associated raw spinlock
A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.

Use the new seqcount_raw_spinlock_t data type, which allows to associate
a raw spinlock with the sequence counter. This enables lockdep to verify
that the raw spinlock used for writer serialization is held when the
write side critical section is entered.

If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-18-a.darwish@linutronix.de
2020-07-29 16:14:27 +02:00
Ahmed S. Darwish b75058614f sched: tasks: Use sequence counter with associated spinlock
A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.

Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.

If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-14-a.darwish@linutronix.de
2020-07-29 16:14:26 +02:00
Paul Moore 8ac68dc455 revert: 1320a4052e ("audit: trigger accompanying records when no rules present")
Unfortunately the commit listed in the subject line above failed
to ensure that the task's audit_context was properly initialized/set
before enabling the "accompanying records".  Depending on the
situation, the resulting audit_context could have invalid values in
some of it's fields which could cause a kernel panic/oops when the
task/syscall exists and the audit records are generated.

We will revisit the original patch, with the necessary fixes, in a
future kernel but right now we just want to fix the kernel panic
with the least amount of added risk.

Cc: stable@vger.kernel.org
Fixes: 1320a4052e ("audit: trigger accompanying records when no rules present")
Reported-by: j2468h@googlemail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-29 10:00:36 -04:00
Hari Bathini f891f19736 kexec_file: Allow archs to handle special regions while locating memory hole
Some architectures may have special memory regions, within the given
memory range, which can't be used for the buffer in a kexec segment.
Implement weak arch_kexec_locate_mem_hole() definition which arch code
may override, to take care of special regions, while trying to locate
a memory hole.

Also, add the missing declarations for arch overridable functions and
and drop the __weak descriptors in the declarations to avoid non-weak
definitions from becoming weak.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602273603.575379.17665852963340380839.stgit@hbathini
2020-07-29 23:47:53 +10:00
Qais Yousef 13685c4a08 sched/uclamp: Add a new sysctl to control RT default boost value
RT tasks by default run at the highest capacity/performance level. When
uclamp is selected this default behavior is retained by enforcing the
requested uclamp.min (p->uclamp_req[UCLAMP_MIN]) of the RT tasks to be
uclamp_none(UCLAMP_MAX), which is SCHED_CAPACITY_SCALE; the maximum
value.

This is also referred to as 'the default boost value of RT tasks'.

See commit 1a00d99997 ("sched/uclamp: Set default clamps for RT tasks").

On battery powered devices, it is desired to control this default
(currently hardcoded) behavior at runtime to reduce energy consumed by
RT tasks.

For example, a mobile device manufacturer where big.LITTLE architecture
is dominant, the performance of the little cores varies across SoCs, and
on high end ones the big cores could be too power hungry.

Given the diversity of SoCs, the new knob allows manufactures to tune
the best performance/power for RT tasks for the particular hardware they
run on.

They could opt to further tune the value when the user selects
a different power saving mode or when the device is actively charging.

The runtime aspect of it further helps in creating a single kernel image
that can be run on multiple devices that require different tuning.

Keep in mind that a lot of RT tasks in the system are created by the
kernel. On Android for instance I can see over 50 RT tasks, only
a handful of which created by the Android framework.

To control the default behavior globally by system admins and device
integrator, introduce the new sysctl_sched_uclamp_util_min_rt_default
to change the default boost value of the RT tasks.

I anticipate this to be mostly in the form of modifying the init script
of a particular device.

To avoid polluting the fast path with unnecessary code, the approach
taken is to synchronously do the update by traversing all the existing
tasks in the system. This could race with a concurrent fork(), which is
dealt with by introducing sched_post_fork() function which will ensure
the racy fork will get the right update applied.

Tested on Juno-r2 in combination with the RT capacity awareness [1].
By default an RT task will go to the highest capacity CPU and run at the
maximum frequency, which is particularly energy inefficient on high end
mobile devices because the biggest core[s] are 'huge' and power hungry.

With this patch the RT task can be controlled to run anywhere by
default, and doesn't cause the frequency to be maximum all the time.
Yet any task that really needs to be boosted can easily escape this
default behavior by modifying its requested uclamp.min value
(p->uclamp_req[UCLAMP_MIN]) via sched_setattr() syscall.

[1] 804d402fb6f6: ("sched/rt: Make RT capacity-aware")

Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200716110347.19553-2-qais.yousef@arm.com
2020-07-29 13:51:47 +02:00
Qais Yousef e65855a52b sched/uclamp: Fix a deadlock when enabling uclamp static key
The following splat was caught when setting uclamp value of a task:

  BUG: sleeping function called from invalid context at ./include/linux/percpu-rwsem.h:49

   cpus_read_lock+0x68/0x130
   static_key_enable+0x1c/0x38
   __sched_setscheduler+0x900/0xad8

Fix by ensuring we enable the key outside of the critical section in
__sched_setscheduler()

Fixes: 46609ce227 ("sched/uclamp: Protect uclamp fast path code with static key")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200716110347.19553-4-qais.yousef@arm.com
2020-07-29 13:51:47 +02:00
Peter Zijlstra 4fd5750af0 sched,tracing: Convert to sched_set_fifo()
One module user of sched_setscheduler() was overlooked and is
obviously causing build failures.

Convert ring_buffer_benchmark to use sched_set_fifo_low() when fifo==1
and sched_set_fifo() when fifo==2. This is a bit of an abuse, but it
makes the thing 'work' again.

Specifically, it enables all combinations that were previously
possible:

  producer higher than consumer
  consumer higher than producer

Fixes: 616d91b68c ("sched: Remove sched_setscheduler*() EXPORTs")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20200720214918.GM5523@worktop.programming.kicks-ass.net
2020-07-29 11:43:53 +02:00
Dan Williams 48001ea50d PM, libnvdimm: Add runtime firmware activation support
Abstract platform specific mechanics for nvdimm firmware activation
behind a handful of generic ops. At the bus level ->activate_state()
indicates the unified state (idle, busy, armed) of all DIMMs on the bus,
and ->capability() indicates the system state expectations for activate.
At the DIMM level ->activate_state() indicates the per-DIMM state,
->activate_result() indicates the outcome of the last activation
attempt, and ->arm() attempts to transition the DIMM from 'idle' to
'armed'.

A new hibernate_quiet_exec() facility is added to support firmware
activation in an OS defined system quiesce state. It leverages the fact
that the hibernate-freeze state wants to assert that a memory
hibernation snapshot can be taken. This is in contrast to a platform
firmware defined quiesce state that may forcefully quiet the memory
controller independent of whether an individual device-driver properly
supports hibernate-freeze.

The libnvdimm sysfs interface is extended to support detection of a
firmware activate capability. The mechanism supports enumeration and
triggering of firmware activate, optionally in the
hibernate_quiet_exec() context.

[rafael: hibernate_quiet_exec() proposal]
[vishal: fix up sparse warning, grammar in Documentation/]

Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Co-developed-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2020-07-28 19:28:32 -06:00
Andrii Nakryiko 310ad7970a bpf: Fix build without CONFIG_NET when using BPF XDP link
Entire net/core subsystem is not built without CONFIG_NET. linux/netdevice.h
just assumes that it's always there, so the easiest way to fix this is to
conditionally compile out bpf_xdp_link_attach() use in bpf/syscall.c.

Fixes: aa8d3a716b ("bpf, xdp: Add bpf_link-based XDP attachment API")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200728190527.110830-1-andriin@fb.com
2020-07-29 00:29:00 +02:00
Christoph Hellwig 274b3f7bf3 dma-contiguous: cleanup dma_alloc_contiguous
Split out a cma_alloc_aligned helper to deal with the "interesting"
calling conventions for cma_alloc, which then allows to the main
function to be written straight forward.  This also takes advantage
of the fact that NULL dev arguments have been gone from the DMA API
for a while.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
2020-07-28 13:42:15 +02:00
Miaohe Lin 21a6ee14a8 sched: Remove duplicated tick_nohz_full_enabled() check
In sched_update_tick_dependency() there's two calls that check
whether nohz_full is enabled: tick_nohz_full_cpu() does it
implicitly, while there's also an explicit call to tick_nohz_full_enabled().

Remove the duplicated, open coded check.

[ mingo: Amended the changelog. ]

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1595935075-14223-1-git-send-email-linmiaohe@huawei.com
2020-07-28 13:27:54 +02:00
Masami Hiramatsu 112a0e4171 kprobes: Remove unnecessary module_mutex locking from kprobe_optimizer()
Since we already lock both kprobe_mutex and text_mutex in the optimizer,
text will not be changed and the module unloading will be stopped
inside kprobes_module_callback().

The mutex_lock() has originally been introduced to avoid conflict with text modification,
at that point we didn't hold text_mutex.

But after:

  f1c6ece237 ("kprobes: Fix potential deadlock in kprobe_optimizer()")

We started holding the text_mutex and don't need the modules mutex anyway.

So remove the module_mutex locking.

[ mingo: Amended the changelog. ]

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Link: https://lore.kernel.org/r/20200728163400.e00b09c594763349f99ce6cb@kernel.org
2020-07-28 13:19:05 +02:00
Ingo Molnar e89d4ca1df Linux 5.8-rc7
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Merge tag 'v5.8-rc7' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-28 13:18:01 +02:00
Colin Ian King f6dfbe31e8 bpf: Fix swapped arguments in calls to check_buffer_access
There are a couple of arguments of the boolean flag zero_size_allowed and
the char pointer buf_info when calling to function check_buffer_access that
are swapped by mistake. Fix these by swapping them to correct the argument
ordering.

Fixes: afbf21dce6 ("bpf: Support readonly/readwrite buffers in verifier")
Addresses-Coverity: ("Array compared to 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200727175411.155179-1-colin.king@canonical.com
2020-07-28 12:40:10 +02:00
Amir Goldstein b9a1b97725 fsnotify: create method handle_inode_event() in fsnotify_operations
The method handle_event() grew a lot of complexity due to the design of
fanotify and merging of ignore masks.

Most backends do not care about this complex functionality, so we can hide
this complexity from them.

Introduce a method handle_inode_event() that serves those backends and
passes a single inode mark and less arguments.

This change converts all backends except fanotify and inotify to use the
simplified handle_inode_event() method.  In pricipal, inotify could have
also used the new method, but that would require passing more arguments
on the simple helper (data, data_type, cookie), so we leave it with the
handle_event() method.

Link: https://lore.kernel.org/r/20200722125849.17418-9-amir73il@gmail.com
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2020-07-27 23:25:50 +02:00
Amir Goldstein 7dbe608016 audit: do not set FS_EVENT_ON_CHILD in audit marks mask
The audit group marks mask does not contain any events possible on
a child so setting the flag FS_EVENT_ON_CHILD in the mask is counter
productive.

It may lead to the undesired outcome of setting the dentry flag
DCACHE_FSNOTIFY_PARENT_WATCHED on a directory inode even though it is
not watching children, because the audit mark contribute the flag
FS_EVENT_ON_CHILD to the inode's fsnotify_mask and another mark could
be contributing an event that is possible on child to the inode's mask.

Furthermore in the following patches we want to use FS_EVENT_ON_CHILD
for non-dir inodes for other purposes so stop using the flag.

Link: https://lore.kernel.org/r/20200722125849.17418-4-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2020-07-27 23:16:33 +02:00
Amir Goldstein 82ace1efb3 fsnotify: create helper fsnotify_inode()
Simple helper to consolidate biolerplate code.

Link: https://lore.kernel.org/r/20200722125849.17418-5-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2020-07-27 23:13:51 +02:00
Al Viro 1e6986c9db regset: kill ->get()
no instances left

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27 14:31:12 -04:00
Al Viro 7717cb9bdd regset: new method and helpers for it
->regset_get() takes task+regset+buffer, returns the amount of free space
left in the buffer on success and -E... on error.

buffer is represented as struct membuf - a pair of (kernel) pointer
and amount of space left

Primitives for writing to such:
	* membuf_write(buf, data, size)
	* membuf_zero(buf, size)
	* membuf_store(buf, value)

These are implemented as inlines (in case of membuf_store - a macro).
All writes are sequential; they become no-ops when there's no space
left.  Return value of all primitives is the amount of space left
after the operation, so they can be used as return values of ->regset_get().

Example of use:

// stores pt_regs of task + 64 bytes worth of zeroes + 32bit PID of task
int foo_get(struct task_struct *task, const struct regset *regset,
	    struct membuf to)
{
	membuf_write(&to, task_pt_regs(task), sizeof(struct pt_regs));
	membuf_zero(&to, 64);
	return membuf_store(&to, (u32)task_tgid_vnr(task));
}

regset_get()/regset_get_alloc() taught to use that thing if present.
By the end of the series all users of ->get() will be converted;
then ->get() and ->get_size() can go.

Note that unlike ->get() this thing always starts at offset 0 and,
since it only writes to kernel buffer, can't fail on copyout.
It can, of course, fail for other reasons, but those tend to
be less numerous.

The caller guarantees that the buffer size won't be bigger than
regset->n * regset->size.  That simplifies life for quite a few
instances.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27 14:31:07 -04:00
Al Viro dc12d7968f copy_regset_to_user(): do all copyout at once.
Turn copy_regset_to_user() into regset_get_alloc() + copy_to_user().
Now all ->get() calls have a kernel buffer as destination.

Note that we'd already eliminated the callers of copy_regset_to_user()
with non-zero offset; now that argument is simply unused.

Uninlined, while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27 14:31:07 -04:00
Al Viro b4e9c9549f introduction of regset ->get() wrappers, switching ELF coredumps to those
Two new helpers: given a process and regset, dump into a buffer.
regset_get() takes a buffer and size, regset_get_alloc() takes size
and allocates a buffer.

Return value in both cases is the amount of data actually dumped in
case of success or -E...  on error.

In both cases the size is capped by regset->n * regset->size, so
->get() is called with offset 0 and size no more than what regset
expects.

binfmt_elf.c callers of ->get() are switched to using those; the other
caller (copy_regset_to_user()) will need some preparations to switch.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-27 14:24:50 -04:00
Amir Goldstein b54cecf5e2 fsnotify: pass dir argument to handle_event() callback
The 'inode' argument to handle_event(), sometimes referred to as
'to_tell' is somewhat obsolete.
It is a remnant from the times when a group could only have an inode mark
associated with an event.

We now pass an iter_info array to the callback, with all marks associated
with an event.

Most backends ignore this argument, with two exceptions:
1. dnotify uses it for sanity check that event is on directory
2. fanotify uses it to report fid of directory on directory entry
   modification events

Remove the 'inode' argument and add a 'dir' argument.
The callback function signature is deliberately changed, because
the meaning of the argument has changed and the arguments have
been documented.

The 'dir' argument is set to when 'file_name' is specified and it is
referring to the directory that the 'file_name' entry belongs to.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2020-07-27 18:32:47 +02:00
Marc Zyngier aa251fc5b9 genirq/debugfs: Add missing irqchip flags
Recently introduced irqchip flags lack the corresponding printouts in
debugfs. Add them.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/874kpvydxc.wl-maz@kernel.org
2020-07-27 16:20:40 +02:00
Thomas Gleixner f0c7baca18 genirq/affinity: Make affinity setting if activated opt-in
John reported that on a RK3288 system the perf per CPU interrupts are all
affine to CPU0 and provided the analysis:

 "It looks like what happens is that because the interrupts are not per-CPU
  in the hardware, armpmu_request_irq() calls irq_force_affinity() while
  the interrupt is deactivated and then request_irq() with IRQF_PERCPU |
  IRQF_NOBALANCING.  

  Now when irq_startup() runs with IRQ_STARTUP_NORMAL, it calls
  irq_setup_affinity() which returns early because IRQF_PERCPU and
  IRQF_NOBALANCING are set, leaving the interrupt on its original CPU."

This was broken by the recent commit which blocked interrupt affinity
setting in hardware before activation of the interrupt. While this works in
general, it does not work for this particular case. As contrary to the
initial analysis not all interrupt chip drivers implement an activate
callback, the safe cure is to make the deferred interrupt affinity setting
at activation time opt-in.

Implement the necessary core logic and make the two irqchip implementations
for which this is required opt-in. In hindsight this would have been the
right thing to do, but ...

Fixes: baedb87d1b ("genirq/affinity: Handle affinity setting on inactive interrupts correctly")
Reported-by: John Keeping <john@metanate.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/87blk4tzgm.fsf@nanos.tec.linutronix.de
2020-07-27 16:20:40 +02:00
peterz@infradead.org ed00495333 locking/lockdep: Fix TRACE_IRQFLAGS vs. NMIs
Prior to commit:

  859d069ee1 ("lockdep: Prepare for NMI IRQ state tracking")

IRQ state tracking was disabled in NMIs due to nmi_enter()
doing lockdep_off() -- with the obvious requirement that NMI entry
call nmi_enter() before trace_hardirqs_off().

[ AFAICT, PowerPC and SH violate this order on their NMI entry ]

However, that commit explicitly changed lockdep_hardirqs_*() to ignore
lockdep_off() and breaks every architecture that has irq-tracing in
it's NMI entry that hasn't been fixed up (x86 being the only fixed one
at this point).

The reason for this change is that by ignoring lockdep_off() we can:

  - get rid of 'current->lockdep_recursion' in lockdep_assert_irqs*()
    which was going to to give header-recursion issues with the
    seqlock rework.

  - allow these lockdep_assert_*() macros to function in NMI context.

Restore the previous state of things and allow an architecture to
opt-in to the NMI IRQ tracking support, however instead of relying on
lockdep_off(), rely on in_nmi(), both are part of nmi_enter() and so
over-all entry ordering doesn't need to change.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200727124852.GK119549@hirez.programming.kicks-ass.net
2020-07-27 15:13:29 +02:00
Greg Kroah-Hartman eea2c51f81 Linux 5.8-rc7
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Merge 5.8-rc7 into driver-core-next

We want the driver core fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-27 12:39:54 +02:00
Rafael J. Wysocki 80e3036866 Merge back cpufreq material for v5.9. 2020-07-27 12:34:55 +02:00
Greg Kroah-Hartman 65a9bde6ed Linux 5.8-rc7
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Merge 5.8-rc7 into char-misc-next

This should resolve the merge/build issues reported when trying to
create linux-next.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-27 11:49:37 +02:00
John Stultz 8d16f5b979 genirq: Export irq_chip_retrigger_hierarchy and irq_chip_set_vcpu_affinity_parent
Add EXPORT_SYMBOL_GPL entries for irq_chip_retrigger_hierarchy()
and irq_chip_set_vcpu_affinity_parent() so that we can allow
drivers like the qcom-pdc driver to be loadable as a module.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: iommu@lists.linux-foundation.org
Cc: linux-gpio@vger.kernel.org
Link: https://lore.kernel.org/r/20200710231824.60699-3-john.stultz@linaro.org
2020-07-27 08:55:03 +01:00
John Stultz 8a667928cf irqdomain: Export irq_domain_update_bus_token
Add export for irq_domain_update_bus_token() so that
we can allow drivers like the qcom-pdc driver to be
loadable as a module.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: iommu@lists.linux-foundation.org
Cc: linux-gpio@vger.kernel.org
Link: https://lore.kernel.org/r/20200710231824.60699-2-john.stultz@linaro.org
2020-07-27 08:55:02 +01:00
Zenghui Yu 45e9504f10 genirq/irqdomain: Remove redundant NULL pointer check on fwnode
The is_fwnode_irqchip() helper will check if the fwnode_handle is empty.
There is no need to perform a redundant check outside of it.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200716083905.287-1-yuzenghui@huawei.com
2020-07-27 08:55:02 +01:00
Pavel Machek 7665a47f70
signal: fix typo in dequeue_synchronous_signal()
s/postive/positive/

Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
Link: https://lore.kernel.org/r/20200724090531.GA14409@amd
[christian.brauner@ubuntu.com: tweak commit message]
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-26 23:57:52 +02:00
Ingo Molnar aadfc2f957 entry: Correct 'noinstr' attributes
The noinstr attribute is to be specified before the return type in the
same way 'inline' is used.

Similar cases were recently fixed for x86 in commit 7f6fa101df ("x86:
Correct noinstr qualifiers"), but the generic entry code was based on the
the original version and did not carry the fix over.

Fixes: a5497bab5f ("entry: Provide generic interrupt entry/exit code")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200725091951.744848-3-mingo@kernel.org
2020-07-26 15:42:20 +02:00
Andrii Nakryiko aa8d3a716b bpf, xdp: Add bpf_link-based XDP attachment API
Add bpf_link-based API (bpf_xdp_link) to attach BPF XDP program through
BPF_LINK_CREATE command.

bpf_xdp_link is mutually exclusive with direct BPF program attachment,
previous BPF program should be detached prior to attempting to create a new
bpf_xdp_link attachment (for a given XDP mode). Once BPF link is attached, it
can't be replaced by other BPF program attachment or link attachment. It will
be detached only when the last BPF link FD is closed.

bpf_xdp_link will be auto-detached when net_device is shutdown, similarly to
how other BPF links behave (cgroup, flow_dissector). At that point bpf_link
will become defunct, but won't be destroyed until last FD is closed.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200722064603.3350758-5-andriin@fb.com
2020-07-25 20:37:02 -07:00
Song Liu 2b9b305fcd bpf: Fix build on architectures with special bpf_user_pt_regs_t
Architectures like s390, powerpc, arm64, riscv have speical definition of
bpf_user_pt_regs_t. So we need to cast the pointer before passing it to
bpf_get_stack(). This is similar to bpf_get_stack_tp().

Fixes: 03d42fd2d83f ("bpf: Separate bpf_get_[stack|stackid] for perf events BPF")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200724200503.3629591-1-songliubraving@fb.com
2020-07-25 20:16:36 -07:00
YiFei Zhu dfcdf0e9ad bpf/local_storage: Fix build without CONFIG_CGROUP
local_storage.o has its compile guard as CONFIG_BPF_SYSCALL, which
does not imply that CONFIG_CGROUP is on. Including cgroup-internal.h
when CONFIG_CGROUP is off cause a compilation failure.

Fixes: f67cfc233706 ("bpf: Make cgroup storages shared between programs on the same cgroup")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200724211753.902969-1-zhuyifei1999@gmail.com
2020-07-25 20:16:36 -07:00
YiFei Zhu 7d9c342789 bpf: Make cgroup storages shared between programs on the same cgroup
This change comes in several parts:

One, the restriction that the CGROUP_STORAGE map can only be used
by one program is removed. This results in the removal of the field
'aux' in struct bpf_cgroup_storage_map, and removal of relevant
code associated with the field, and removal of now-noop functions
bpf_free_cgroup_storage and bpf_cgroup_storage_release.

Second, we permit a key of type u64 as the key to the map.
Providing such a key type indicates that the map should ignore
attach type when comparing map keys. However, for simplicity newly
linked storage will still have the attach type at link time in
its key struct. cgroup_storage_check_btf is adapted to accept
u64 as the type of the key.

Third, because the storages are now shared, the storages cannot
be unconditionally freed on program detach. There could be two
ways to solve this issue:
* A. Reference count the usage of the storages, and free when the
     last program is detached.
* B. Free only when the storage is impossible to be referred to
     again, i.e. when either the cgroup_bpf it is attached to, or
     the map itself, is freed.
Option A has the side effect that, when the user detach and
reattach a program, whether the program gets a fresh storage
depends on whether there is another program attached using that
storage. This could trigger races if the user is multi-threaded,
and since nondeterminism in data races is evil, go with option B.

The both the map and the cgroup_bpf now tracks their associated
storages, and the storage unlink and free are removed from
cgroup_bpf_detach and added to cgroup_bpf_release and
cgroup_storage_map_free. The latter also new holds the cgroup_mutex
to prevent any races with the former.

Fourth, on attach, we reuse the old storage if the key already
exists in the map, via cgroup_storage_lookup. If the storage
does not exist yet, we create a new one, and publish it at the
last step in the attach process. This does not create a race
condition because for the whole attach the cgroup_mutex is held.
We keep track of an array of new storages that was allocated
and if the process fails only the new storages would get freed.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/d5401c6106728a00890401190db40020a1f84ff1.1595565795.git.zhuyifei@google.com
2020-07-25 20:16:35 -07:00
Song Liu 5d99cb2c86 bpf: Fail PERF_EVENT_IOC_SET_BPF when bpf_get_[stack|stackid] cannot work
bpf_get_[stack|stackid] on perf_events with precise_ip uses callchain
attached to perf_sample_data. If this callchain is not presented, do not
allow attaching BPF program that calls bpf_get_[stack|stackid] to this
event.

In the error case, -EPROTO is returned so that libbpf can identify this
error and print proper hint message.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723180648.1429892-3-songliubraving@fb.com
2020-07-25 20:16:34 -07:00
Song Liu 7b04d6d60f bpf: Separate bpf_get_[stack|stackid] for perf events BPF
Calling get_perf_callchain() on perf_events from PEBS entries may cause
unwinder errors. To fix this issue, the callchain is fetched early. Such
perf_events are marked with __PERF_SAMPLE_CALLCHAIN_EARLY.

Similarly, calling bpf_get_[stack|stackid] on perf_events from PEBS may
also cause unwinder errors. To fix this, add separate version of these
two helpers, bpf_get_[stack|stackid]_pe. These two hepers use callchain in
bpf_perf_event_data_kern->data->callchain.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723180648.1429892-2-songliubraving@fb.com
2020-07-25 20:16:34 -07:00
Yonghong Song d3cc2ab546 bpf: Implement bpf iterator for array maps
The bpf iterators for array and percpu array
are implemented. Similar to hash maps, for percpu
array map, bpf program will receive values
from all cpus.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184115.590532-1-yhs@fb.com
2020-07-25 20:16:33 -07:00
Yonghong Song d6c4503cc2 bpf: Implement bpf iterator for hash maps
The bpf iterators for hash, percpu hash, lru hash
and lru percpu hash are implemented. During link time,
bpf_iter_reg->check_target() will check map type
and ensure the program access key/value region is
within the map defined key/value size limit.

For percpu hash and lru hash maps, the bpf program
will receive values for all cpus. The map element
bpf iterator infrastructure will prepare value
properly before passing the value pointer to the
bpf program.

This patch set supports readonly map keys and
read/write map values. It does not support deleting
map elements, e.g., from hash tables. If there is
a user case for this, the following mechanism can
be used to support map deletion for hashtab, etc.
  - permit a new bpf program return value, e.g., 2,
    to let bpf iterator know the map element should
    be removed.
  - since bucket lock is taken, the map element will be
    queued.
  - once bucket lock is released after all elements under
    this bucket are traversed, all to-be-deleted map
    elements can be deleted.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184114.590470-1-yhs@fb.com
2020-07-25 20:16:33 -07:00
Yonghong Song a5cbe05a66 bpf: Implement bpf iterator for map elements
The bpf iterator for map elements are implemented.
The bpf program will receive four parameters:
  bpf_iter_meta *meta: the meta data
  bpf_map *map:        the bpf_map whose elements are traversed
  void *key:           the key of one element
  void *value:         the value of the same element

Here, meta and map pointers are always valid, and
key has register type PTR_TO_RDONLY_BUF_OR_NULL and
value has register type PTR_TO_RDWR_BUF_OR_NULL.
The kernel will track the access range of key and value
during verification time. Later, these values will be compared
against the values in the actual map to ensure all accesses
are within range.

A new field iter_seq_info is added to bpf_map_ops which
is used to add map type specific information, i.e., seq_ops,
init/fini seq_file func and seq_file private data size.
Subsequent patches will have actual implementation
for bpf_map_ops->iter_seq_info.

In user space, BPF_ITER_LINK_MAP_FD needs to be
specified in prog attr->link_create.flags, which indicates
that attr->link_create.target_fd is a map_fd.
The reason for such an explicit flag is for possible
future cases where one bpf iterator may allow more than
one possible customization, e.g., pid and cgroup id for
task_file.

Current kernel internal implementation only allows
the target to register at most one required bpf_iter_link_info.
To support the above case, optional bpf_iter_link_info's
are needed, the target can be extended to register such link
infos, and user provided link_info needs to match one of
target supported ones.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184112.590360-1-yhs@fb.com
2020-07-25 20:16:32 -07:00
Yonghong Song afbf21dce6 bpf: Support readonly/readwrite buffers in verifier
Readonly and readwrite buffer register states
are introduced. Totally four states,
PTR_TO_RDONLY_BUF[_OR_NULL] and PTR_TO_RDWR_BUF[_OR_NULL]
are supported. As suggested by their respective
names, PTR_TO_RDONLY_BUF[_OR_NULL] are for
readonly buffers and PTR_TO_RDWR_BUF[_OR_NULL]
for read/write buffers.

These new register states will be used
by later bpf map element iterator.

New register states share some similarity to
PTR_TO_TP_BUFFER as it will calculate accessed buffer
size during verification time. The accessed buffer
size will be later compared to other metrics during
later attach/link_create time.

Similar to reg_state PTR_TO_BTF_ID_OR_NULL in bpf
iterator programs, PTR_TO_RDONLY_BUF_OR_NULL or
PTR_TO_RDWR_BUF_OR_NULL reg_types can be set at
prog->aux->bpf_ctx_arg_aux, and bpf verifier will
retrieve the values during btf_ctx_access().
Later bpf map element iterator implementation
will show how such information will be assigned
during target registeration time.

The verifier is also enhanced such that PTR_TO_RDONLY_BUF
can be passed to ARG_PTR_TO_MEM[_OR_NULL] helper argument, and
PTR_TO_RDWR_BUF can be passed to ARG_PTR_TO_MEM[_OR_NULL] or
ARG_PTR_TO_UNINIT_MEM.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184111.590274-1-yhs@fb.com
2020-07-25 20:16:32 -07:00
Yonghong Song f9c7927295 bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_t
This patch refactored target bpf_iter_init_seq_priv_t callback
function to accept additional information. This will be needed
in later patches for map element targets since a particular
map should be passed to traverse elements for that particular
map. In the future, other information may be passed to target
as well, e.g., pid, cgroup id, etc. to customize the iterator.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184110.590156-1-yhs@fb.com
2020-07-25 20:16:32 -07:00
Yonghong Song 14fc6bd6b7 bpf: Refactor bpf_iter_reg to have separate seq_info member
There is no functionality change for this patch.
Struct bpf_iter_reg is used to register a bpf_iter target,
which includes information for both prog_load, link_create
and seq_file creation.

This patch puts fields related seq_file creation into
a different structure. This will be useful for map
elements iterator where one iterator covers different
map types and different map types may have different
seq_ops, init/fini private_data function and
private_data size.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com
2020-07-25 20:16:32 -07:00
Alexei Starovoitov a228a64fc1 bpf: Add bpf_prog iterator
It's mostly a copy paste of commit 6086d29def ("bpf: Add bpf_map iterator")
that is use to implement bpf_seq_file opreations to traverse all bpf programs.

v1->v2: Tweak to use build time btf_id

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
2020-07-25 20:16:32 -07:00
Yonghong Song 3f9969f2c0 bpf: Fix pos computation for bpf_iter seq_ops->start()
Currently, the pos pointer in bpf iterator map/task/task_file
seq_ops->start() is always incremented.
This is incorrect. It should be increased only if
*pos is 0 (for SEQ_START_TOKEN) since these start()
function actually returns the first real object.
If *pos is not 0, it merely found the object
based on the state in seq->private, and not really
advancing the *pos. This patch fixed this issue
by only incrementing *pos if it is 0.

Note that the old *pos calculation, although not
correct, does not affect correctness of bpf_iter
as bpf_iter seq_file->read() does not support llseek.

This patch also renamed "mid" in bpf_map iterator
seq_file private data to "map_id" for better clarity.

Fixes: 6086d29def ("bpf: Add bpf_map iterator")
Fixes: eaaacd2391 ("bpf: Add task and task/file iterator targets")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200722195156.4029817-1-yhs@fb.com
2020-07-25 20:16:32 -07:00
David S. Miller a57066b1a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The UDP reuseport conflict was a little bit tricky.

The net-next code, via bpf-next, extracted the reuseport handling
into a helper so that the BPF sk lookup code could invoke it.

At the same time, the logic for reuseport handling of unconnected
sockets changed via commit efc6b6f6c3
which changed the logic to carry on the reuseport result into the
rest of the lookup loop if we do not return immediately.

This requires moving the reuseport_has_conns() logic into the callers.

While we are here, get rid of inline directives as they do not belong
in foo.c files.

The other changes were cases of more straightforward overlapping
modifications.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-25 17:49:04 -07:00
Linus Torvalds 78b1afe22d Fix a interaction/regression between uprobes based shared library tracing & GDB.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull uprobe fix from Ingo Molnar:
 "Fix an interaction/regression between uprobes based shared library
  tracing & GDB"

* tag 'perf-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression
2020-07-25 13:55:38 -07:00
Ingo Molnar c84d53051f Linux 5.8-rc6
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Merge tag 'v5.8-rc6' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-25 21:49:36 +02:00
Chris Wilson a7ef9b28aa locking/lockdep: Fix overflow in presentation of average lock-time
Though the number of lock-acquisitions is tracked as unsigned long, this
is passed as the divisor to div_s64() which interprets it as a s32,
giving nonsense values with more than 2 billion acquisitons. E.g.

  acquisitions   holdtime-min   holdtime-max holdtime-total   holdtime-avg
  -------------------------------------------------------------------------
    2350439395           0.07         353.38   649647067.36          0.-32

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200725185110.11588-1-chris@chris-wilson.co.uk
2020-07-25 21:47:42 +02:00
Qinglang Miao 13efa61612 sched/uclamp: Remove unnecessary mutex_init()
The uclamp_mutex lock is initialized statically via DEFINE_MUTEX(),
it is unnecessary to initialize it runtime via mutex_init().

Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20200725085629.98292-1-miaoqinglang@huawei.com
2020-07-25 12:10:36 +02:00
Jim Cromie e5ebffe18e dyndbg: rename __verbose section to __dyndbg
dyndbg populates its callsite info into __verbose section, change that
to a more specific and descriptive name, __dyndbg.

Also, per checkpatch:
  simplify __attribute(..) to __section(__dyndbg) declaration.

and 1 spelling fix, decriptor

Acked-by: <jbaron@akamai.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200719231058.1586423-6-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-24 17:00:08 +02:00
Oleg Nesterov fe5ed7ab99 uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression
If a tracee is uprobed and it hits int3 inserted by debugger, handle_swbp()
does send_sig(SIGTRAP, current, 0) which means si_code == SI_USER. This used
to work when this code was written, but then GDB started to validate si_code
and now it simply can't use breakpoints if the tracee has an active uprobe:

	# cat test.c
	void unused_func(void)
	{
	}
	int main(void)
	{
		return 0;
	}

	# gcc -g test.c -o test
	# perf probe -x ./test -a unused_func
	# perf record -e probe_test:unused_func gdb ./test -ex run
	GNU gdb (GDB) 10.0.50.20200714-git
	...
	Program received signal SIGTRAP, Trace/breakpoint trap.
	0x00007ffff7ddf909 in dl_main () from /lib64/ld-linux-x86-64.so.2
	(gdb)

The tracee hits the internal breakpoint inserted by GDB to monitor shared
library events but GDB misinterprets this SIGTRAP and reports a signal.

Change handle_swbp() to use force_sig(SIGTRAP), this matches do_int3_user()
and fixes the problem.

This is the minimal fix for -stable, arch/x86/kernel/uprobes.c is equally
wrong; it should use send_sigtrap(TRAP_TRACE) instead of send_sig(SIGTRAP),
but this doesn't confuse GDB and needs another x86-specific patch.

Reported-by: Aaron Merey <amerey@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200723154420.GA32043@redhat.com
2020-07-24 15:38:37 +02:00
Thomas Gleixner 935ace2fb5 entry: Provide infrastructure for work before transitioning to guest mode
Entering a guest is similar to exiting to user space. Pending work like
handling signals, rescheduling, task work etc. needs to be handled before
that.

Provide generic infrastructure to avoid duplication of the same handling
code all over the place.

The transfer to guest mode handling is different from the exit to usermode
handling, e.g. vs. rseq and live patching, so a separate function is used.

The initial list of work items handled is:

    TIF_SIGPENDING, TIF_NEED_RESCHED, TIF_NOTIFY_RESUME

Architecture specific TIF flags can be added via defines in the
architecture specific include files.

The calling convention is also different from the syscall/interrupt entry
functions as KVM invokes this from the outer vcpu_run() loop with
interrupts and preemption enabled. To prevent missing a pending work item
it invokes a check for pending TIF work from interrupt disabled code right
before transitioning to guest mode. The lockdep, RCU and tracing state
handling is also done directly around the switch to and from guest mode.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200722220519.833296398@linutronix.de
2020-07-24 15:03:42 +02:00
Thomas Gleixner a5497bab5f entry: Provide generic interrupt entry/exit code
Like the syscall entry/exit code interrupt/exception entry after the real
low level ASM bits should not be different accross architectures.

Provide a generic version based on the x86 code.

irqentry_enter() is called after the low level entry code and
irqentry_exit() must be invoked right before returning to the low level
code which just contains the actual return logic. The code before
irqentry_enter() and irqentry_exit() must not be instrumented. Code after
irqentry_enter() and before irqentry_exit() can be instrumented.

irqentry_enter() invokes irqentry_enter_from_user_mode() if the
interrupt/exception came from user mode. If if entered from kernel mode it
handles the kernel mode variant of establishing state for lockdep, RCU and
tracing depending on the kernel context it interrupted (idle, non-idle).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200722220519.723703209@linutronix.de
2020-07-24 14:59:04 +02:00
Thomas Gleixner a9f3a74a29 entry: Provide generic syscall exit function
Like syscall entry all architectures have similar and pointlessly different
code to handle pending work before returning from a syscall to user space.

  1) One-time syscall exit work:
      - rseq syscall exit
      - audit
      - syscall tracing
      - tracehook (single stepping)

  2) Preparatory work
      - Exit to user mode loop (common TIF handling).
      - Architecture specific one time work arch_exit_to_user_mode_prepare()
      - Address limit and lockdep checks
     
  3) Final transition (lockdep, tracing, context tracking, RCU). Invokes
     arch_exit_to_user_mode() to handle e.g. speculation mitigations

Provide a generic version based on the x86 code which has all the RCU and
instrumentation protections right.

Provide a variant for interrupt return to user mode as well which shares
the above #2 and #3 work items.

After syscall_exit_to_user_mode() and irqentry_exit_to_user_mode() the
architecture code just has to return to user space. The code after
returning from these functions must not be instrumented.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200722220519.613977173@linutronix.de
2020-07-24 14:59:03 +02:00
Thomas Gleixner 142781e108 entry: Provide generic syscall entry functionality
On syscall entry certain work needs to be done:

   - Establish state (lockdep, context tracking, tracing)
   - Conditional work (ptrace, seccomp, audit...)

This code is needlessly duplicated and  different in all
architectures.

Provide a generic version based on the x86 implementation which has all the
RCU and instrumentation bits right.

As interrupt/exception entry from user space needs parts of the same
functionality, provide a function for this as well.

syscall_enter_from_user_mode() and irqentry_enter_from_user_mode() must be
called right after the low level ASM entry. The calling code must be
non-instrumentable. After the functions returns state is correct and the
subsequent functions can be instrumented.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200722220519.513463269@linutronix.de
2020-07-24 14:59:03 +02:00
Chris Wilson 062d3f95b6 sched: Warn if garbage is passed to default_wake_function()
Since the default_wake_function() passes its flags onto
try_to_wake_up(), warn if those flags collide with internal values.

Given that the supplied flags are garbage, no repair can be done but at
least alert the user to the damage they are causing.

In the belief that these errors should be picked up during testing, the
warning is only compiled in under CONFIG_SCHED_DEBUG.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20200723201042.18861-1-chris@chris-wilson.co.uk
2020-07-24 14:40:25 +02:00
Frederic Weisbecker 31cd0e119d timers: Recalculate next timer interrupt only when necessary
The nohz tick code recalculates the timer wheel's next expiry on each idle
loop iteration.

On the other hand, the base next expiry is now always cached and updated
upon timer enqueue and execution. Only timer dequeue may leave
base->next_expiry out of date (but then its stale value won't ever go past
the actual next expiry to be recalculated).

Since recalculating the next_expiry isn't a free operation, especially when
the last wheel level is reached to find out that no timer has been enqueued
at all, reuse the next expiry cache when it is known to be reliable, which
it is most of the time.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200723151641.12236-1-frederic@kernel.org
2020-07-24 12:49:40 +02:00
Peter Enderborg 072e133d55 tracefs: Remove unnecessary debug_fs checks.
This is a preparation for debugfs restricted mode.
We don't need debugfs to trace, the removed check stop tracefs to work
if debugfs is not initialised. We instead tries to automount within
debugfs and relay on it's handling. The code path is to create a
backward compatibility from when tracefs was part of debugfs, it is now
standalone and does not need debugfs. When debugfs is in restricted
it is compiled in but not active and return EPERM to clients and
tracefs wont work if it assumes it is active it is compiled in
kernel.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200716071511.26864-2-peter.enderborg@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23 17:10:25 +02:00
Daniel Jordan f601c725a6 padata: remove padata_parallel_queue
Only its reorder field is actually used now, so remove the struct and
embed @reorder directly in parallel_data.

No functional change, just a cleanup.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-23 17:34:18 +10:00
Daniel Jordan 3f257191d3 padata: fold padata_alloc_possible() into padata_alloc()
There's no reason to have two interfaces when there's only one caller.
Removing _possible saves text and simplifies future changes.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-23 17:34:18 +10:00
Daniel Jordan d69e037bcc padata: remove effective cpumasks from the instance
A padata instance has effective cpumasks that store the user-supplied
masks ANDed with the online mask, but this middleman is unnecessary.
parallel_data keeps the same information around.  Removing this saves
text and code churn in future changes.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-23 17:34:18 +10:00
Daniel Jordan cec00e6e12 padata: inline single call of pd_setup_cpumasks()
pd_setup_cpumasks() has only one caller.  Move its contents inline to
prepare for the next cleanup.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-23 17:34:18 +10:00
Daniel Jordan 350ef051d4 padata: remove stop function
padata_stop() has two callers and is unnecessary in both cases.  When
pcrypt calls it before padata_free(), it's being unloaded so there are
no outstanding padata jobs[0].  When __padata_free() calls it, it's
either along the same path or else pcrypt initialization failed, which
of course means there are also no outstanding jobs.

Removing it simplifies padata and saves text.

[0] https://lore.kernel.org/linux-crypto/20191119225017.mjrak2fwa5vccazl@gondor.apana.org.au/

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-23 17:34:18 +10:00
Daniel Jordan bd25b4886d padata: remove start function
padata_start() is only used right after pcrypt allocates an instance
with all possible CPUs, when PADATA_INVALID can't happen, so there's no
need for a separate "start" step.  It can be done during allocation to
save text, make using padata easier, and avoid unneeded calls in the
future.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-23 17:34:17 +10:00
Valentin Schneider 25980c7a79 arch_topology, sched/core: Cleanup thermal pressure definition
The following commit:

  14533a16c4 ("thermal/cpu-cooling, sched/core: Move the arch_set_thermal_pressure() API to generic scheduler code")

moved the definition of arch_set_thermal_pressure() to sched/core.c, but
kept its declaration in linux/arch_topology.h. When building e.g. an x86
kernel with CONFIG_SCHED_THERMAL_PRESSURE=y, cpufreq_cooling.c ends up
getting the declaration of arch_set_thermal_pressure() from
include/linux/arch_topology.h, which is somewhat awkward.

On top of this, sched/core.c unconditionally defines
o The thermal_pressure percpu variable
o arch_set_thermal_pressure()

while arch_scale_thermal_pressure() does nothing unless redefined by the
architecture.

arch_*() functions are meant to be defined by architectures, so revert the
aforementioned commit and re-implement it in a way that keeps
arch_set_thermal_pressure() architecture-definable, and doesn't define the
thermal pressure percpu variable for kernels that don't need
it (CONFIG_SCHED_THERMAL_PRESSURE=n).

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200712165917.9168-2-valentin.schneider@arm.com
2020-07-22 10:22:05 +02:00
Muchun Song 589343569d smp: Fix a potential usage of stale nr_cpus
The get_option() maybe return 0, it means that the nr_cpus is
not initialized. Then we will use the stale nr_cpus to initialize
the nr_cpu_ids. So fix it.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200716070457.53255-1-songmuchun@bytedance.com
2020-07-22 10:22:04 +02:00
Peter Puhov 3edecfef02 sched/fair: update_pick_idlest() Select group with lowest group_util when idle_cpus are equal
In slow path, when selecting idlest group, if both groups have type
group_has_spare, only idle_cpus count gets compared.
As a result, if multiple tasks are created in a tight loop,
and go back to sleep immediately
(while waiting for all tasks to be created),
they may be scheduled on the same core, because CPU is back to idle
when the new fork happen.

For example:
sudo perf record -e sched:sched_wakeup_new -- \
                                  sysbench threads --threads=4 run
...
    total number of events:              61582
...
sudo perf script
sysbench 129378 [006] 74586.633466: sched:sched_wakeup_new:
                            sysbench:129380 [120] success=1 CPU:007
sysbench 129378 [006] 74586.634718: sched:sched_wakeup_new:
                            sysbench:129381 [120] success=1 CPU:007
sysbench 129378 [006] 74586.635957: sched:sched_wakeup_new:
                            sysbench:129382 [120] success=1 CPU:007
sysbench 129378 [006] 74586.637183: sched:sched_wakeup_new:
                            sysbench:129383 [120] success=1 CPU:007

This may have negative impact on performance for workloads with frequent
creation of multiple threads.

In this patch we are using group_util to select idlest group if both groups
have equal number of idle_cpus. Comparing the number of idle cpu is
not enough in this case, because the newly forked thread sleeps
immediately and before we select the cpu for the next one.
This is shown in the trace where the same CPU7 is selected for
all wakeup_new events.
That's why, looking at utilization when there is the same number of
CPU is a good way to see where the previous task was placed. Using
nr_running doesn't solve the problem because the newly forked task is not
running and the cpu would not have been idle in this case and an idle
CPU would have been selected instead.

With this patch newly created tasks would be better distributed.

With this patch:
sudo perf record -e sched:sched_wakeup_new -- \
                                    sysbench threads --threads=4 run
...
    total number of events:              74401
...
sudo perf script
sysbench 129455 [006] 75232.853257: sched:sched_wakeup_new:
                            sysbench:129457 [120] success=1 CPU:008
sysbench 129455 [006] 75232.854489: sched:sched_wakeup_new:
                            sysbench:129458 [120] success=1 CPU:009
sysbench 129455 [006] 75232.855732: sched:sched_wakeup_new:
                            sysbench:129459 [120] success=1 CPU:010
sysbench 129455 [006] 75232.856980: sched:sched_wakeup_new:
                            sysbench:129460 [120] success=1 CPU:011

We tested this patch with following benchmarks:
master: 'commit b3a9e3b962 ("Linux 5.8-rc1")'

100 iterations of: perf bench -f simple futex wake -s -t 128 -w 1
Lower result is better
|         |   BASELINE |   +PATCH |   DELTA (%) |
|---------|------------|----------|-------------|
| mean    |      0.33  |    0.313 |      +5.152 |
| std (%) |     10.433 |    7.563 |             |

100 iterations of: sysbench threads --threads=8 run
Higher result is better
|         |   BASELINE |   +PATCH |   DELTA (%) |
|---------|------------|----------|-------------|
| mean    |   5235.02  | 5863.73  |      +12.01 |
| std (%) |      8.166 |   10.265 |             |

100 iterations of: sysbench mutex --mutex-num=1 --threads=8 run
Lower result is better
|         |   BASELINE |   +PATCH |   DELTA (%) |
|---------|------------|----------|-------------|
| mean    |      0.413 |    0.404 |      +2.179 |
| std (%) |      3.791 |    1.816 |             |

Signed-off-by: Peter Puhov <peter.puhov@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200714125941.4174-1-peter.puhov@linaro.org
2020-07-22 10:22:04 +02:00
Paul Gortmaker 46132e3ac5 sched: nohz: stop passing around unused "ticks" parameter.
The "ticks" parameter was added in commit 0f004f5a69 ("sched: Cure more
NO_HZ load average woes") since calc_global_nohz() was called and needed
the "ticks" argument.

But in commit c308b56b53 ("sched: Fix nohz load accounting -- again!")
it became unused as the function calc_global_nohz() dropped using "ticks".

Fixes: c308b56b53 ("sched: Fix nohz load accounting -- again!")
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1593628458-32290-1-git-send-email-paul.gortmaker@windriver.com
2020-07-22 10:22:04 +02:00
Peter Zijlstra 58877d347b sched: Better document ttwu()
Dave hit the problem fixed by commit:

  b6e13e8582 ("sched/core: Fix ttwu() race")

and failed to understand much of the code involved. Per his request a
few comments to (hopefully) clarify things.

Requested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200702125211.GQ4800@hirez.programming.kicks-ass.net
2020-07-22 10:22:03 +02:00
Peter Zijlstra 015dc08918 Merge branch 'sched/urgent' 2020-07-22 10:22:02 +02:00
Peter Zijlstra d136122f58 sched: Fix race against ptrace_freeze_trace()
There is apparently one site that violates the rule that only current
and ttwu() will modify task->state, namely ptrace_{,un}freeze_traced()
will change task->state for a remote task.

Oleg explains:

  "TASK_TRACED/TASK_STOPPED was always protected by siglock. In
particular, ttwu(__TASK_TRACED) must be always called with siglock
held. That is why ptrace_freeze_traced() assumes it can safely do
s/TASK_TRACED/__TASK_TRACED/ under spin_lock(siglock)."

This breaks the ordering scheme introduced by commit:

  dbfb089d36 ("sched: Fix loadavg accounting race")

Specifically, the reload not matching no longer implies we don't have
to block.

Simply things by noting that what we need is a LOAD->STORE ordering
and this can be provided by a control dependency.

So replace:

	prev_state = prev->state;
	raw_spin_lock(&rq->lock);
	smp_mb__after_spinlock(); /* SMP-MB */
	if (... && prev_state && prev_state == prev->state)
		deactivate_task();

with:

	prev_state = prev->state;
	if (... && prev_state) /* CTRL-DEP */
		deactivate_task();

Since that already implies the 'prev->state' load must be complete
before allowing the 'prev->on_rq = 0' store to become visible.

Fixes: dbfb089d36 ("sched: Fix loadavg accounting race")
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Tested-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-22 10:22:00 +02:00
Yonghong Song 951cf368bc bpf: net: Use precomputed btf_id for bpf iterators
One additional field btf_id is added to struct
bpf_ctx_arg_aux to store the precomputed btf_ids.
The btf_id is computed at build time with
BTF_ID_LIST or BTF_ID_LIST_GLOBAL macro definitions.
All existing bpf iterators are changed to used
pre-compute btf_ids.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200720163403.1393551-1-yhs@fb.com
2020-07-21 13:26:26 -07:00
Yonghong Song bc4f0548f6 bpf: Compute bpf_skc_to_*() helper socket btf ids at build time
Currently, socket types (struct tcp_sock, udp_sock, etc.)
used by bpf_skc_to_*() helpers are computed when vmlinux_btf
is first built in the kernel.

Commit 5a2798ab32
("bpf: Add BTF_ID_LIST/BTF_ID/BTF_ID_UNUSED macros")
implemented a mechanism to compute btf_ids at kernel build
time which can simplify kernel implementation and reduce
runtime overhead by removing in-kernel btf_id calculation.
This patch did exactly this, removing in-kernel btf_id
computation and utilizing build-time btf_id computation.

If CONFIG_DEBUG_INFO_BTF is not defined, BTF_ID_LIST will
define an array with size of 5, which is not enough for
btf_sock_ids. So define its own static array if
CONFIG_DEBUG_INFO_BTF is not defined.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200720163358.1393023-1-yhs@fb.com
2020-07-21 13:26:26 -07:00
Lorenzo Bianconi c576b9c77b bpf: cpumap: Fix possible rcpu kthread hung
Fix the following cpumap kthread hung. The issue is currently occurring
when __cpu_map_load_bpf_program fails (e.g if the bpf prog has not
BPF_XDP_CPUMAP as expected_attach_type)

$./test_progs -n 101
101/1 cpumap_with_progs:OK
101 xdp_cpumap_attach:OK
Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
[  369.996478] INFO: task cpumap/0/map:7:205 blocked for more than 122 seconds.
[  369.998463]       Not tainted 5.8.0-rc4-01472-ge57892f50a07 #212
[  370.000102] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  370.001918] cpumap/0/map:7  D    0   205      2 0x00004000
[  370.003228] Call Trace:
[  370.003930]  __schedule+0x5c7/0xf50
[  370.004901]  ? io_schedule_timeout+0xb0/0xb0
[  370.005934]  ? static_obj+0x31/0x80
[  370.006788]  ? mark_held_locks+0x24/0x90
[  370.007752]  ? cpu_map_bpf_prog_run_xdp+0x6c0/0x6c0
[  370.008930]  schedule+0x6f/0x160
[  370.009728]  schedule_preempt_disabled+0x14/0x20
[  370.010829]  kthread+0x17b/0x240
[  370.011433]  ? kthread_create_worker_on_cpu+0xd0/0xd0
[  370.011944]  ret_from_fork+0x1f/0x30
[  370.012348]
               Showing all locks held in the system:
[  370.013025] 1 lock held by khungtaskd/33:
[  370.013432]  #0: ffffffff82b24720 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x28/0x1c3

[  370.014461] =============================================

Fixes: 9216477449 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap")
Reported-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/e54f2aabf959f298939e5507b09c48f8c2e380be.1595170625.git.lorenzo@kernel.org
2020-07-21 09:15:28 -07:00
Jakub Sitnicki 343ead287d bpf, netns: Fix build without CONFIG_INET
When CONFIG_NET is set but CONFIG_INET isn't, build fails with:

  ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_unneed':
  kernel/bpf/net_namespace.c:32: undefined reference to `bpf_sk_lookup_enabled'
  ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_need':
  kernel/bpf/net_namespace.c:43: undefined reference to `bpf_sk_lookup_enabled'

This is because without CONFIG_INET bpf_sk_lookup_enabled symbol is not
available. Wrap references to bpf_sk_lookup_enabled with preprocessor
conditionals.

Fixes: 1559b4aa1d ("inet: Run SK_LOOKUP BPF program on socket lookup")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/bpf/20200721100716.720477-1-jakub@cloudflare.com
2020-07-21 09:12:34 -07:00
Max Englander b43870c74f audit: report audit wait metric in audit status reply
In environments where the preservation of audit events and predictable
usage of system memory are prioritized, admins may use a combination of
--backlog_wait_time and -b options at the risk of degraded performance
resulting from backlog waiting. In some cases, this risk may be
preferred to lost events or unbounded memory usage. Ideally, this risk
can be mitigated by making adjustments when backlog waiting is detected.

However, detection can be difficult using the currently available
metrics. For example, an admin attempting to debug degraded performance
may falsely believe a full backlog indicates backlog waiting. It may
turn out the backlog frequently fills up but drains quickly.

To make it easier to reliably track degraded performance to backlog
waiting, this patch makes the following changes:

Add a new field backlog_wait_time_total to the audit status reply.
Initialize this field to zero. Add to this field the total time spent
by the current task on scheduled timeouts while the backlog limit is
exceeded. Reset field to zero upon request via AUDIT_SET.

Tested on Ubuntu 18.04 using complementary changes to the
audit-userspace and audit-testsuite:
- https://github.com/linux-audit/audit-userspace/pull/134
- https://github.com/linux-audit/audit-testsuite/pull/97

Signed-off-by: Max Englander <max.englander@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-21 11:21:44 -04:00
Richard Guy Briggs f1d9b23cab audit: purge audit_log_string from the intra-kernel audit API
audit_log_string() was inteded to be an internal audit function and
since there are only two internal uses, remove them.  Purge all external
uses of it by restructuring code to use an existing audit_log_format()
or using audit_log_format().

Please see the upstream issue
https://github.com/linux-audit/audit-kernel/issues/84

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-21 11:12:31 -04:00
Eric W. Biederman be619f7f06 exec: Implement kernel_execve
To allow the kernel not to play games with set_fs to call exec
implement kernel_execve.  The function kernel_execve takes pointers
into kernel memory and copies the values pointed to onto the new
userspace stack.

The calls with arguments from kernel space of do_execve are replaced
with calls to kernel_execve.

The calls do_execve and do_execveat are made static as there are now
no callers outside of exec.

The comments that mention do_execve are updated to refer to
kernel_execve or execve depending on the circumstances.  In addition
to correcting the comments, this makes it easy to grep for do_execve
and verify it is not used.

Inspired-by: https://lkml.kernel.org/r/20200627072704.2447163-1-hch@lst.de
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87wo365ikj.fsf@x220.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-21 08:24:52 -05:00
Tyler Hicks 4834177e63 ima: Support additional conditionals in the KEXEC_CMDLINE hook function
Take the properties of the kexec kernel's inode and the current task
ownership into consideration when matching a KEXEC_CMDLINE operation to
the rules in the IMA policy. This allows for some uniformity when
writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK,
and KEXEC_CMDLINE operations.

Prior to this patch, it was not possible to write a set of rules like
this:

 dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t
 dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t
 dont_measure func=KEXEC_CMDLINE obj_type=foo_t
 measure func=KEXEC_KERNEL_CHECK
 measure func=KEXEC_INITRAMFS_CHECK
 measure func=KEXEC_CMDLINE

The inode information associated with the kernel being loaded by a
kexec_kernel_load(2) syscall can now be included in the decision to
measure or not

Additonally, the uid, euid, and subj_* conditionals can also now be
used in KEXEC_CMDLINE rules. There was no technical reason as to why
those conditionals weren't being considered previously other than
ima_match_rules() didn't have a valid inode to use so it immediately
bailed out for KEXEC_CMDLINE operations rather than going through the
full list of conditional comparisons.

Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: kexec@lists.infradead.org
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20 13:28:16 -04:00
Ahmed S. Darwish aadd6e5caa time/sched_clock: Use raw_read_seqcount_latch()
sched_clock uses seqcount_t latching to switch between two storage
places protected by the sequence counter. This allows it to have
interruptible, NMI-safe, seqcount_t write side critical sections.

Since 7fc26327b7 ("seqlock: Introduce raw_read_seqcount_latch()"),
raw_read_seqcount_latch() became the standardized way for seqcount_t
latch read paths. Due to the dependent load, it also has one read
memory barrier less than the currently used raw_read_seqcount() API.

Use raw_read_seqcount_latch() for the seqcount_t latch read path.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Link: https://lkml.kernel.org/r/20200625085745.GD117543@hirez.programming.kicks-ass.net
Link: https://lkml.kernel.org/r/20200715092345.GA231464@debian-buster-darwi.lab.linutronix.de
Link: https://lore.kernel.org/r/20200716051130.4359-3-leo.yan@linaro.org
References: 1809bfa44e ("timers, sched/clock: Avoid deadlock during read from NMI")
Signed-off-by: Will Deacon <will@kernel.org>
2020-07-20 11:50:47 +01:00
Peter Zijlstra 1b86abc1c6 sched_clock: Expose struct clock_read_data
In order to support perf_event_mmap_page::cap_time features, an
architecture needs, aside from a userspace readable counter register,
to expose the exact clock data so that userspace can convert the
counter register into a correct timestamp.

Provide struct clock_read_data and two (seqcount) helpers so that
architectures (arm64 in specific) can expose the numbers to userspace.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20200716051130.4359-2-leo.yan@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-07-20 11:50:47 +01:00
Linus Torvalds 66e4b63624 Two fixes for the timer wheel:
- A timer which is already expired at enqueue time can set the
    base->next_expiry value backwards. As a consequence base->clk can be set
    back as well. This can lead to timers expiring early. Add a sanity check
    to prevent this.
 
  - When a timer is queued with an expiry time beyond the wheel capacity
    then it should be queued in the bucket of the last wheel level which is
    expiring last. The code adjusts expiry time to the maximum wheel
    capacity, which is only correct when the wheel clock is 0. Aside of that
    the check whether the delta is larger than wheel capacity does not check
    the delta, it checks the expiry value itself. As a result timers can
    expire at random.
 
    Fix this by checking the right variable and adjust expiry time so it
    becomes base->clock plus capacity which places it into the outmost
    bucket in the last wheel level.
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Merge tag 'timers-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull timer fixes from Thomas Gleixner:
 "Two fixes for the timer wheel:

   - A timer which is already expired at enqueue time can set the
     base->next_expiry value backwards. As a consequence base->clk can
     be set back as well. This can lead to timers expiring early. Add a
     sanity check to prevent this.

   - When a timer is queued with an expiry time beyond the wheel
     capacity then it should be queued in the bucket of the last wheel
     level which is expiring last.

     The code adjusted the expiry time to the maximum wheel capacity,
     which is only correct when the wheel clock is 0. Aside of that the
     check whether the delta is larger than wheel capacity does not
     check the delta, it checks the expiry value itself. As a result
     timers can expire at random.

     Fix this by checking the right variable and adjust expiry time so
     it becomes base->clock plus capacity which places it into the
     outmost bucket in the last wheel level"

* tag 'timers-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timer: Fix wheel index calculation on last level
  timer: Prevent base->clk from moving backward
2020-07-19 12:06:08 -07:00
Linus Torvalds 43768f7ce0 A set of scheduler fixes:
- Plug a load average accounting race which was introduced with a recent
    optimization casing load average to show bogus numbers.
 
  - Fix the rseq CPU id initialization for new tasks. sched_fork() does not
    update the rseq CPU id so the id is the stale id of the parent task,
    which can cause user space data corruption.
 
  - Handle a 0 return value of task_h_load() correctly in the load balancer,
    which does not decrease imbalance and therefore pulls until the maximum
    number of loops is reached, which might be all tasks just created by a
    fork bomb.
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Merge tag 'sched-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler fixes:

   - Plug a load average accounting race which was introduced with a
     recent optimization casing load average to show bogus numbers.

   - Fix the rseq CPU id initialization for new tasks. sched_fork() does
     not update the rseq CPU id so the id is the stale id of the parent
     task, which can cause user space data corruption.

   - Handle a 0 return value of task_h_load() correctly in the load
     balancer, which does not decrease imbalance and therefore pulls
     until the maximum number of loops is reached, which might be all
     tasks just created by a fork bomb"

* tag 'sched-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: handle case of task_h_load() returning 0
  sched: Fix unreliable rseq cpu_id for new tasks
  sched: Fix loadavg accounting race
2020-07-19 11:55:24 -07:00
Linus Torvalds 9413cd7792 Two fixes for the interrupt subsystem:
- Make the handling of the firmware node consistent and do not free the
    node after the domain has been created successfully. The core code
    stores a pointer to it which can lead to a use after free or double
    free.
 
    This used to "work" because the pointer was not stored when the initial
    code was written, but at some point later it was required to store
    it. Of course nobody noticed that the existing users break that way.
 
  - Handle affinity setting on inactive interrupts correctly when
    hierarchical irq domains are enabled. When interrupts are inactive with
    the modern hierarchical irqdomain design, the interrupt chips are not
    necessarily in a state where affinity changes can be handled. The legacy
    irq chip design allowed this because interrupts are immediately fully
    initialized at allocation time. X86 has a hacky workaround for this, but
    other implementations do not. This cased malfunction on GIC-V3. Instead
    of playing whack a mole to find all affected drivers, change the core
    code to store the requested affinity setting and then establish it when
    the interrupt is allocated, which makes the X86 hack go away.
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Merge tag 'irq-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull irq fixes from Thomas Gleixner:
 "Two fixes for the interrupt subsystem:

   - Make the handling of the firmware node consistent and do not free
     the node after the domain has been created successfully. The core
     code stores a pointer to it which can lead to a use after free or
     double free.

     This used to "work" because the pointer was not stored when the
     initial code was written, but at some point later it was required
     to store it. Of course nobody noticed that the existing users break
     that way.

   - Handle affinity setting on inactive interrupts correctly when
     hierarchical irq domains are enabled.

     When interrupts are inactive with the modern hierarchical irqdomain
     design, the interrupt chips are not necessarily in a state where
     affinity changes can be handled. The legacy irq chip design allowed
     this because interrupts are immediately fully initialized at
     allocation time. X86 has a hacky workaround for this, but other
     implementations do not.

     This cased malfunction on GIC-V3. Instead of playing whack a mole
     to find all affected drivers, change the core code to store the
     requested affinity setting and then establish it when the interrupt
     is allocated, which makes the X86 hack go away"

* tag 'irq-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/affinity: Handle affinity setting on inactive interrupts correctly
  irqdomain/treewide: Keep firmware node unconditionally allocated
2020-07-19 11:53:08 -07:00
Nicolas Viennot 227175b2c9 prctl: exe link permission error changed from -EINVAL to -EPERM
This brings consistency with the rest of the prctl() syscall where
-EPERM is returned when failing a capability check.

Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
Signed-off-by: Adrian Reber <areber@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Link: https://lore.kernel.org/r/20200719100418.2112740-7-areber@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19 20:14:42 +02:00
Nicolas Viennot ebd6de6812 prctl: Allow local CAP_CHECKPOINT_RESTORE to change /proc/self/exe
Originally, only a local CAP_SYS_ADMIN could change the exe link,
making it difficult for doing checkpoint/restore without CAP_SYS_ADMIN.
This commit adds CAP_CHECKPOINT_RESTORE in addition to CAP_SYS_ADMIN
for permitting changing the exe link.

The following describes the history of the /proc/self/exe permission
checks as it may be difficult to understand what decisions lead to this
point.

* [1] May 2012: This commit introduces the ability of changing
  /proc/self/exe if the user is CAP_SYS_RESOURCE capable.
  In the related discussion [2], no clear thread model is presented for
  what could happen if the /proc/self/exe changes multiple times, or why
  would the admin be at the mercy of userspace.

* [3] Oct 2014: This commit introduces a new API to change
  /proc/self/exe. The permission no longer checks for CAP_SYS_RESOURCE,
  but instead checks if the current user is root (uid=0) in its local
  namespace. In the related discussion [4] it is said that "Controlling
  exe_fd without privileges may turn out to be dangerous. At least
  things like tomoyo examine it for making policy decisions (see
  tomoyo_manager())."

* [5] Dec 2016: This commit removes the restriction to change
  /proc/self/exe at most once. The related discussion [6] informs that
  the audit subsystem relies on the exe symlink, presumably
  audit_log_d_path_exe() in kernel/audit.c.

* [7] May 2017: This commit changed the check from uid==0 to local
  CAP_SYS_ADMIN. No discussion.

* [8] July 2020: A PoC to spoof any program's /proc/self/exe via ptrace
  is demonstrated

Overall, the concrete points that were made to retain capability checks
around changing the exe symlink is that tomoyo_manager() and
audit_log_d_path_exe() uses the exe_file path.

Christian Brauner said that relying on /proc/<pid>/exe being immutable (or
guarded by caps) in a sake of security is a bit misleading. It can only
be used as a hint without any guarantees of what code is being executed
once execve() returns to userspace. Christian suggested that in the
future, we could call audit_log() or similar to inform the admin of all
exe link changes, instead of attempting to provide security guarantees
via permission checks. However, this proposed change requires the
understanding of the security implications in the tomoyo/audit subsystems.

[1] b32dfe3771 ("c/r: prctl: add ability to set new mm_struct::exe_file")
[2] https://lore.kernel.org/patchwork/patch/292515/
[3] f606b77f1a ("prctl: PR_SET_MM -- introduce PR_SET_MM_MAP operation")
[4] https://lore.kernel.org/patchwork/patch/479359/
[5] 3fb4afd9a5 ("prctl: remove one-shot limitation for changing exe link")
[6] https://lore.kernel.org/patchwork/patch/697304/
[7] 4d28df6152 ("prctl: Allow local CAP_SYS_ADMIN changing exe_file")
[8] https://github.com/nviennot/run_as_exe

Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
Signed-off-by: Adrian Reber <areber@redhat.com>
Link: https://lore.kernel.org/r/20200719100418.2112740-6-areber@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19 20:14:42 +02:00
Adrian Reber b9a3db92e1 pid_namespace: use checkpoint_restore_ns_capable() for ns_last_pid
Use the newly introduced capability CAP_CHECKPOINT_RESTORE to allow
writing to ns_last_pid.

Signed-off-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200719100418.2112740-4-areber@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19 20:14:42 +02:00
Adrian Reber 1caef81da0 pid: use checkpoint_restore_ns_capable() for set_tid
Use the newly introduced capability CAP_CHECKPOINT_RESTORE to allow
using clone3() with set_tid set.

Signed-off-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200719100418.2112740-3-areber@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-19 20:14:42 +02:00
Christoph Hellwig 23efed6fa7 dma-debug: use named initializers for dir2name
Make dir2name a little more readable and maintainable by using
named initializers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-07-19 09:31:13 +02:00
Christoph Hellwig d35834c648 dma-mapping: add a dma_ops_bypass flag to struct device
Several IOMMU drivers have a bypass mode where they can use a direct
mapping if the devices DMA mask is large enough.  Add generic support
to the core dma-mapping code to do that to switch those drivers to
a common solution.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-19 09:29:29 +02:00
Christoph Hellwig 2f9237d4f6 dma-mapping: make support for dma ops optional
Avoid the overhead of the dma ops support for tiny builds that only
use the direct mapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-19 09:29:23 +02:00
Jakub Sitnicki 1559b4aa1d inet: Run SK_LOOKUP BPF program on socket lookup
Run a BPF program before looking up a listening socket on the receive path.
Program selects a listening socket to yield as result of socket lookup by
calling bpf_sk_assign() helper and returning SK_PASS code. Program can
revert its decision by assigning a NULL socket with bpf_sk_assign().

Alternatively, BPF program can also fail the lookup by returning with
SK_DROP, or let the lookup continue as usual with SK_PASS on return, when
no socket has been selected with bpf_sk_assign().

This lets the user match packets with listening sockets freely at the last
possible point on the receive path, where we know that packets are destined
for local delivery after undergoing policing, filtering, and routing.

With BPF code selecting the socket, directing packets destined to an IP
range or to a port range to a single socket becomes possible.

In case multiple programs are attached, they are run in series in the order
in which they were attached. The end result is determined from return codes
of all the programs according to following rules:

 1. If any program returned SK_PASS and selected a valid socket, the socket
    is used as result of socket lookup.
 2. If more than one program returned SK_PASS and selected a socket,
    last selection takes effect.
 3. If any program returned SK_DROP, and no program returned SK_PASS and
    selected a socket, socket lookup fails with -ECONNREFUSED.
 4. If all programs returned SK_PASS and none of them selected a socket,
    socket lookup continues to htable-based lookup.

Suggested-by: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200717103536.397595-5-jakub@cloudflare.com
2020-07-17 20:18:16 -07:00
Jakub Sitnicki e9ddbb7707 bpf: Introduce SK_LOOKUP program type with a dedicated attach point
Add a new program type BPF_PROG_TYPE_SK_LOOKUP with a dedicated attach type
BPF_SK_LOOKUP. The new program kind is to be invoked by the transport layer
when looking up a listening socket for a new connection request for
connection oriented protocols, or when looking up an unconnected socket for
a packet for connection-less protocols.

When called, SK_LOOKUP BPF program can select a socket that will receive
the packet. This serves as a mechanism to overcome the limits of what
bind() API allows to express. Two use-cases driving this work are:

 (1) steer packets destined to an IP range, on fixed port to a socket

     192.0.2.0/24, port 80 -> NGINX socket

 (2) steer packets destined to an IP address, on any port to a socket

     198.51.100.1, any port -> L7 proxy socket

In its run-time context program receives information about the packet that
triggered the socket lookup. Namely IP version, L4 protocol identifier, and
address 4-tuple. Context can be further extended to include ingress
interface identifier.

To select a socket BPF program fetches it from a map holding socket
references, like SOCKMAP or SOCKHASH, and calls bpf_sk_assign(ctx, sk, ...)
helper to record the selection. Transport layer then uses the selected
socket as a result of socket lookup.

In its basic form, SK_LOOKUP acts as a filter and hence must return either
SK_PASS or SK_DROP. If the program returns with SK_PASS, transport should
look for a socket to receive the packet, or use the one selected by the
program if available, while SK_DROP informs the transport layer that the
lookup should fail.

This patch only enables the user to attach an SK_LOOKUP program to a
network namespace. Subsequent patches hook it up to run on local delivery
path in ipv4 and ipv6 stacks.

Suggested-by: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200717103536.397595-3-jakub@cloudflare.com
2020-07-17 20:18:16 -07:00
Jakub Sitnicki ce3aa9cc51 bpf, netns: Handle multiple link attachments
Extend the BPF netns link callbacks to rebuild (grow/shrink) or update the
prog_array at given position when link gets attached/updated/released.

This let's us lift the limit of having just one link attached for the new
attach type introduced by subsequent patch.

No functional changes intended.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200717103536.397595-2-jakub@cloudflare.com
2020-07-17 20:18:16 -07:00
André Almeida 9a71df495c futex: Remove unused or redundant includes
Since 82af7aca ("Removal of FUTEX_FD"), some includes related to file
operations aren't needed anymore. More investigation around the includes
showed that a lot of includes aren't required for compilation, possible
due to redundant includes. Simplify the code by removing unused
includes.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200702202843.520764-4-andrealmeid@collabora.com
2020-07-18 01:56:09 +02:00
André Almeida 9261308598 futex: Consistently use fshared as boolean
Since fshared is only conveying true/false values, declare it as bool.

In get_futex_key() the usage of fshared can be restricted to the first part
of the function. If fshared is false the function is terminated early and
the subsequent code can use a constant 'true' instead of the variable.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200702202843.520764-5-andrealmeid@collabora.com
2020-07-18 01:56:08 +02:00
André Almeida d7c5ed73b1 futex: Remove needless goto's
As stated in the coding style documentation, "if there is no cleanup
needed then just return directly", instead of jumping to a label and
then returning.

Remove such goto's and replace with a return statement.  When there's a
ternary operator on the return value, replace it with the result of the
operation when it is logically possible to determine it by the control
flow.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200702202843.520764-3-andrealmeid@collabora.com
2020-07-17 23:58:49 +02:00
André Almeida 9180bd467f futex: Remove put_futex_key()
Since 4b39f99c ("futex: Remove {get,drop}_futex_key_refs()"),
put_futex_key() is empty.

Remove all references for this function and the then redundant labels.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200702202843.520764-2-andrealmeid@collabora.com
2020-07-17 23:58:49 +02:00
Thomas Gleixner baedb87d1b genirq/affinity: Handle affinity setting on inactive interrupts correctly
Setting interrupt affinity on inactive interrupts is inconsistent when
hierarchical irq domains are enabled. The core code should just store the
affinity and not call into the irq chip driver for inactive interrupts
because the chip drivers may not be in a state to handle such requests.

X86 has a hacky workaround for that but all other irq chips have not which
causes problems e.g. on GIC V3 ITS.

Instead of adding more ugly hacks all over the place, solve the problem in
the core code. If the affinity is set on an inactive interrupt then:

    - Store it in the irq descriptors affinity mask
    - Update the effective affinity to reflect that so user space has
      a consistent view
    - Don't call into the irq chip driver

This is the core equivalent of the X86 workaround and works correctly
because the affinity setting is established in the irq chip when the
interrupt is activated later on.

Note, that this is only effective when hierarchical irq domains are enabled
by the architecture. Doing it unconditionally would break legacy irq chip
implementations.

For hierarchial irq domains this works correctly as none of the drivers can
have a dependency on affinity setting in inactive state by design.

Remove the X86 workaround as it is not longer required.

Fixes: 02edee152d ("x86/apic/vector: Ignore set_affinity call for inactive interrupts")
Reported-by: Ali Saidi <alisaidi@amazon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ali Saidi <alisaidi@amazon.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200529015501.15771-1-alisaidi@amazon.com
Link: https://lkml.kernel.org/r/877dv2rv25.fsf@nanos.tec.linutronix.de
2020-07-17 23:30:43 +02:00
Frederic Weisbecker 36cd28a4cd timers: Lower base clock forwarding threshold
There is nothing that prevents from forwarding the base clock if it's one
jiffy off. The reason for this arbitrary limit of two jiffies is historical
and does not longer exist.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-13-frederic@kernel.org
2020-07-17 21:55:25 +02:00
Frederic Weisbecker 0975fb565b timers: Remove must_forward_clk
There is no reason to keep this guard around. The code makes sure that
base->clk remains sane and won't be forwarded beyond jiffies nor set
backward.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-12-frederic@kernel.org
2020-07-17 21:55:25 +02:00
Frederic Weisbecker d4f7dae870 timers: Spare timer softirq until next expiry
Now that the core timer infrastructure doesn't depend anymore on
periodic base->clk increments, even when the CPU is not in NO_HZ mode,
timer softirqs can be skipped until there are timers to expire.

Some spurious softirqs can still remain since base->next_expiry doesn't
keep track of canceled timers but this still reduces the number of softirqs
significantly: ~15 times less for HZ=1000 and ~5 times less for HZ=100.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-11-frederic@kernel.org
2020-07-17 21:55:24 +02:00
Frederic Weisbecker 1f8a4212dc timers: Expand clk forward logic beyond nohz
As for next_expiry, the base->clk catch up logic will be expanded beyond
NOHZ in order to avoid triggering useless softirqs.

If softirqs should only fire to expire pending timers, periodic base->clk
increments must be skippable for random amounts of time.  Therefore prepare
to catch-up with missing updates whenever an up-to-date base clock is
needed.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-10-frederic@kernel.org
2020-07-17 21:55:24 +02:00
Frederic Weisbecker 90d52f65f3 timers: Reuse next expiry cache after nohz exit
Now that the next expiry it tracked unconditionally when a timer is added,
this information can be reused on a tick firing after exiting nohz.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-9-frederic@kernel.org
2020-07-17 21:55:23 +02:00
Frederic Weisbecker dc2a0f1fb2 timers: Always keep track of next expiry
So far next expiry was only tracked while the CPU was in nohz_idle mode
in order to cope with missing ticks that can't increment the base->clk
periodically anymore.

This logic is going to be expanded beyond nohz in order to spare timer
softirqs so do it unconditionally.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-8-frederic@kernel.org
2020-07-17 21:55:23 +02:00
Frederic Weisbecker 001ec1b392 timers: Optimize _next_timer_interrupt() level iteration
If a level has a timer that expires before reaching the next level, there
is no need to iterate further.

The next level is reached when the 3 lower bits of the current level are
cleared. If the next event happens before/during that, the next levels
won't provide an earlier expiration.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-7-frederic@kernel.org
2020-07-17 21:55:22 +02:00
Frederic Weisbecker 4468897211 timers: Add comments about calc_index() ceiling work
calc_index() adds 1 unit of the level granularity to the expiry passed
in parameter to ensure that the timer doesn't expire too early. Add a
comment to explain that and the resulting layout in the wheel.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-6-frederic@kernel.org
2020-07-17 21:55:22 +02:00
Frederic Weisbecker 9a2b764b06 timers: Move trigger_dyntick_cpu() to enqueue_timer()
Consolidate the code by calling trigger_dyntick_cpu() from
enqueue_timer() instead of calling it from all its callers.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-5-frederic@kernel.org
2020-07-17 21:55:22 +02:00
Anna-Maria Behnsen 1f32cab0db timers: Use only bucket expiry for base->next_expiry value
The bucket expiry time is the effective expriy time of timers and is
greater than or equal to the requested timer expiry time. This is due
to the guarantee that timers never expire early and the reduced expiry
granularity in the secondary wheel levels.

When a timer is enqueued, trigger_dyntick_cpu() checks whether the
timer is the new first timer. This check compares next_expiry with
the requested timer expiry value and not with the effective expiry
value of the bucket into which the timer was queued.

Storing the requested timer expiry value in base->next_expiry can lead
to base->clk going backwards if the requested timer expiry value is
smaller than base->clk. Commit 30c66fc30e ("timer: Prevent base->clk
from moving backward") worked around this by preventing the store when
timer->expiry is before base->clk, but did not fix the underlying
problem.

Use the expiry value of the bucket into which the timer is queued to
do the new first timer check. This fixes the base->clk going backward
problem.

The workaround of commit 30c66fc30e ("timer: Prevent base->clk from
moving backward") in trigger_dyntick_cpu() is not longer necessary as the
timers bucket expiry is guaranteed to be greater than or equal base->clk.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200717140551.29076-4-frederic@kernel.org
2020-07-17 21:55:21 +02:00
Frederic Weisbecker 3d2e83a2a6 timers: Preserve higher bits of expiration on index calculation
The higher bits of the timer expiration are cropped while calling
calc_index() due to the implicit cast from unsigned long to unsigned int.

This loss shouldn't have consequences on the current code since all the
computation to calculate the index is done on the lower 32 bits.

However to prepare for returning the actual bucket expiration from
calc_index() in order to properly fix base->next_expiry updates, the higher
bits need to be preserved.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200717140551.29076-3-frederic@kernel.org
2020-07-17 21:55:21 +02:00
Frederic Weisbecker e2a71bdea8 timer: Fix wheel index calculation on last level
When an expiration delta falls into the last level of the wheel, that delta
has be compared against the maximum possible delay and reduced to fit in if
necessary.

However instead of comparing the delta against the maximum, the code
compares the actual expiry against the maximum. Then instead of fixing the
delta to fit in, it sets the maximum delta as the expiry value.

This can result in various undesired outcomes, the worst possible one
being a timer expiring 15 days ahead to fire immediately.

Fixes: 500462a9de ("timers: Switch to a non-cascading wheel")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200717140551.29076-2-frederic@kernel.org
2020-07-17 21:44:05 +02:00
Vincent Guittot 01cfcde9c2 sched/fair: handle case of task_h_load() returning 0
task_h_load() can return 0 in some situations like running stress-ng
mmapfork, which forks thousands of threads, in a sched group on a 224 cores
system. The load balance doesn't handle this correctly because
env->imbalance never decreases and it will stop pulling tasks only after
reaching loop_max, which can be equal to the number of running tasks of
the cfs. Make sure that imbalance will be decreased by at least 1.

misfit task is the other feature that doesn't handle correctly such
situation although it's probably more difficult to face the problem
because of the smaller number of CPUs and running tasks on heterogenous
system.

We can't simply ensure that task_h_load() returns at least one because it
would imply to handle underflow in other places.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: <stable@vger.kernel.org> # v4.4+
Link: https://lkml.kernel.org/r/20200710152426.16981-1-vincent.guittot@linaro.org
2020-07-16 23:19:48 +02:00
Kees Cook 3f649ab728 treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16 12:35:15 -07:00
Lorenzo Bianconi 28b1520ebf bpf: cpumap: Implement XDP_REDIRECT for eBPF programs attached to map entries
Introduce XDP_REDIRECT support for eBPF programs attached to cpumap
entries.
This patch has been tested on Marvell ESPRESSObin using a modified
version of xdp_redirect_cpu sample in order to attach a XDP program
to CPUMAP entries to perform a redirect on the mvneta interface.
In particular the following scenario has been tested:

rq (cpu0) --> mvneta - XDP_REDIRECT (cpu0) --> CPUMAP - XDP_REDIRECT (cpu1) --> mvneta

$./xdp_redirect_cpu -p xdp_cpu_map0 -d eth0 -c 1 -e xdp_redirect \
	-f xdp_redirect_kern.o -m tx_port -r eth0

tx: 285.2 Kpps rx: 285.2 Kpps

Attaching a simple XDP program on eth0 to perform XDP_TX gives
comparable results:

tx: 288.4 Kpps rx: 288.4 Kpps

Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/2cf8373a731867af302b00c4ff16c122630c4980.1594734381.git.lorenzo@kernel.org
2020-07-16 17:00:32 +02:00
Lorenzo Bianconi 9216477449 bpf: cpumap: Add the possibility to attach an eBPF program to cpumap
Introduce the capability to attach an eBPF program to cpumap entries.
The idea behind this feature is to add the possibility to define on
which CPU run the eBPF program if the underlying hw does not support
RSS. Current supported verdicts are XDP_DROP and XDP_PASS.

This patch has been tested on Marvell ESPRESSObin using xdp_redirect_cpu
sample available in the kernel tree to identify possible performance
regressions. Results show there are no observable differences in
packet-per-second:

$./xdp_redirect_cpu --progname xdp_cpu_map0 --dev eth0 --cpu 1
rx: 354.8 Kpps
rx: 356.0 Kpps
rx: 356.8 Kpps
rx: 356.3 Kpps
rx: 356.6 Kpps
rx: 356.6 Kpps
rx: 356.7 Kpps
rx: 355.8 Kpps
rx: 356.8 Kpps
rx: 356.8 Kpps

Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/5c9febdf903d810b3415732e5cd98491d7d9067a.1594734381.git.lorenzo@kernel.org
2020-07-16 17:00:32 +02:00
Lorenzo Bianconi 644bfe51fa cpumap: Formalize map value as a named struct
As it has been already done for devmap, introduce 'struct bpf_cpumap_val'
to formalize the expected values that can be passed in for a CPUMAP.
Update cpumap code to use the struct.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/754f950674665dae6139c061d28c1d982aaf4170.1594734381.git.lorenzo@kernel.org
2020-07-16 17:00:32 +02:00
Jesper Dangaard Brouer 9b74ebb2b0 cpumap: Use non-locked version __ptr_ring_consume_batched
Commit 77361825bb ("bpf: cpumap use ptr_ring_consume_batched") changed
away from using single frame ptr_ring dequeue (__ptr_ring_consume) to
consume a batched, but it uses a locked version, which as the comment
explain isn't needed.

Change to use the non-locked version __ptr_ring_consume_batched.

Fixes: 77361825bb ("bpf: cpumap use ptr_ring_consume_batched")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/a9c7d06f9a009e282209f0c8c7b2c5d9b9ad60b9.1594734381.git.lorenzo@kernel.org
2020-07-16 17:00:31 +02:00
Christoph Hellwig b417417300 dma-mapping: inline the fast path dma-direct calls
Inline the single page map/unmap/sync dma-direct calls into the now
out of line generic wrappers.  This restores the behavior of a single
function call that we had before moving the generic calls out of line.
Besides the dma-mapping callers there are just a few callers in IOMMU
drivers that have a bypass mode, and more of those are going to be
switched to the generic bypass soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-16 16:58:37 +02:00
Christoph Hellwig d3fa60d7bf dma-mapping: move the remaining DMA API calls out of line
For a long time the DMA API has been implemented inline in dma-mapping.h,
but the function bodies can be quite large.  Move them all out of line.

This also removes all the dma_direct_* exports as those are just
implementation details and should never be used by drivers directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-16 16:58:33 +02:00
Peilin Ye 5b801dfb7f bpf: Fix NULL pointer dereference in __btf_resolve_helper_id()
Prevent __btf_resolve_helper_id() from dereferencing `btf_vmlinux`
as NULL. This patch fixes the following syzbot bug:

    https://syzkaller.appspot.com/bug?id=f823224ada908fa5c207902a5a62065e53ca0fcc

Reported-by: syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200714180904.277512-1-yepeilin.cs@gmail.com
2020-07-15 22:53:39 +02:00
Sargun Dhillon 7cf97b1254 seccomp: Introduce addfd ioctl to seccomp user notifier
The current SECCOMP_RET_USER_NOTIF API allows for syscall supervision over
an fd. It is often used in settings where a supervising task emulates
syscalls on behalf of a supervised task in userspace, either to further
restrict the supervisee's syscall abilities or to circumvent kernel
enforced restrictions the supervisor deems safe to lift (e.g. actually
performing a mount(2) for an unprivileged container).

While SECCOMP_RET_USER_NOTIF allows for the interception of any syscall,
only a certain subset of syscalls could be correctly emulated. Over the
last few development cycles, the set of syscalls which can't be emulated
has been reduced due to the addition of pidfd_getfd(2). With this we are
now able to, for example, intercept syscalls that require the supervisor
to operate on file descriptors of the supervisee such as connect(2).

However, syscalls that cause new file descriptors to be installed can not
currently be correctly emulated since there is no way for the supervisor
to inject file descriptors into the supervisee. This patch adds a
new addfd ioctl to remove this restriction by allowing the supervisor to
install file descriptors into the intercepted task. By implementing this
feature via seccomp the supervisor effectively instructs the supervisee
to install a set of file descriptors into its own file descriptor table
during the intercepted syscall. This way it is possible to intercept
syscalls such as open() or accept(), and install (or replace, like
dup2(2)) the supervisor's resulting fd into the supervisee. One
replacement use-case would be to redirect the stdout and stderr of a
supervisee into log file descriptors opened by the supervisor.

The ioctl handling is based on the discussions[1] of how Extensible
Arguments should interact with ioctls. Instead of building size into
the addfd structure, make it a function of the ioctl command (which
is how sizes are normally passed to ioctls). To support forward and
backward compatibility, just mask out the direction and size, and match
everything. The size (and any future direction) checks are done along
with copy_struct_from_user() logic.

As a note, the seccomp_notif_addfd structure is laid out based on 8-byte
alignment without requiring packing as there have been packing issues
with uapi highlighted before[2][3]. Although we could overload the
newfd field and use -1 to indicate that it is not to be used, doing
so requires changing the size of the fd field, and introduces struct
packing complexity.

[1]: https://lore.kernel.org/lkml/87o8w9bcaf.fsf@mid.deneb.enyo.de/
[2]: https://lore.kernel.org/lkml/a328b91d-fd8f-4f27-b3c2-91a9c45f18c0@rasmusvillemoes.dk/
[3]: https://lore.kernel.org/lkml/20200612104629.GA15814@ircssh-2.c.rugged-nimbus-611.internal

Cc: Christoph Hellwig <hch@lst.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Jann Horn <jannh@google.com>
Cc: Robert Sesek <rsesek@google.com>
Cc: Chris Palmer <palmer@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-api@vger.kernel.org
Suggested-by: Matt Denton <mpdenton@google.com>
Link: https://lore.kernel.org/r/20200603011044.7972-4-sargun@sargun.me
Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Reviewed-by: Will Drewry <wad@chromium.org>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-14 16:29:42 -07:00
Alexei Starovoitov ec2ffdf65f Merge branch 'usermode-driver-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace into bpf-next 2020-07-14 12:18:01 -07:00
Alexey Dobriyan 02d7f4005e PM: sleep: spread "const char *" correctness
Fixed string literals can be referred to as "const char *".

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
[ rjw: Minor subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-14 19:25:41 +02:00
Xiang Chen 6ada7ba2fa PM: hibernate: fix white space in a few places
In hibernate.c, some places lack of spaces while some places have
redundant spaces. So fix them.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-14 19:25:41 +02:00
Nicolas Saenz Julienne d9765e41d8 dma-pool: do not allocate pool memory from CMA
There is no guarantee to CMA's placement, so allocating a zone specific
atomic pool from CMA might return memory from a completely different
memory zone. So stop using it.

Fixes: c84dc6e68a ("dma-pool: add additional coherent pools to map to gfp mask")
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14 15:46:32 +02:00
Nicolas Saenz Julienne 81e9d894e0 dma-pool: make sure atomic pool suits device
When allocating DMA memory from a pool, the core can only guess which
atomic pool will fit a device's constraints. If it doesn't, get a safer
atomic pool and try again.

Fixes: c84dc6e68a ("dma-pool: add additional coherent pools to map to gfp mask")
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14 15:42:33 +02:00
Nicolas Saenz Julienne 48b6703858 dma-pool: introduce dma_guess_pool()
dma-pool's dev_to_pool() creates the false impression that there is a
way to grantee a mapping between a device's DMA constraints and an
atomic pool. It tuns out it's just a guess, and the device might need to
use an atomic pool containing memory from a 'safer' (or lower) memory
zone.

To help mitigate this, introduce dma_guess_pool() which can be fed a
device's DMA constraints and atomic pools already known to be faulty, in
order for it to provide an better guess on which pool to use.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14 15:42:30 +02:00
Nicolas Saenz Julienne 23e469be62 dma-pool: get rid of dma_in_atomic_pool()
The function is only used once and can be simplified to a one-liner.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14 15:42:27 +02:00
Nicolas Saenz Julienne 567f6a6eba dma-direct: provide function to check physical memory area validity
dma_coherent_ok() checks if a physical memory area fits a device's DMA
constraints.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-14 15:42:24 +02:00
David S. Miller 07dd1b7e68 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-07-13

The following pull-request contains BPF updates for your *net-next* tree.

We've added 36 non-merge commits during the last 7 day(s) which contain
a total of 62 files changed, 2242 insertions(+), 468 deletions(-).

The main changes are:

1) Avoid trace_printk warning banner by switching bpf_trace_printk to use
   its own tracing event, from Alan.

2) Better libbpf support on older kernels, from Andrii.

3) Additional AF_XDP stats, from Ciara.

4) build time resolution of BTF IDs, from Jiri.

5) BPF_CGROUP_INET_SOCK_RELEASE hook, from Stanislav.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-13 18:04:05 -07:00
Alan Maguire ac5a72ea5c bpf: Use dedicated bpf_trace_printk event instead of trace_printk()
The bpf helper bpf_trace_printk() uses trace_printk() under the hood.
This leads to an alarming warning message originating from trace
buffer allocation which occurs the first time a program using
bpf_trace_printk() is loaded.

We can instead create a trace event for bpf_trace_printk() and enable
it in-kernel when/if we encounter a program using the
bpf_trace_printk() helper.  With this approach, trace_printk()
is not used directly and no warning message appears.

This work was started by Steven (see Link) and finished by Alan; added
Steven's Signed-off-by with his permission.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/r/20200628194334.6238b933@oasis.local.home
Link: https://lore.kernel.org/bpf/1594641154-18897-2-git-send-email-alan.maguire@oracle.com
2020-07-13 16:55:49 -07:00
Kees Cook 910d2f16ac pidfd: Replace open-coded receive_fd()
Replace the open-coded version of receive_fd() with a call to the
new helper.

Thanks to Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> for
catching a missed fput() in an earlier version of this patch.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sargun Dhillon <sargun@sargun.me>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-13 11:03:45 -07:00
Kees Cook 4969f8a073 pidfd: Add missing sock updates for pidfd_getfd()
The sock counting (sock_update_netprioidx() and sock_update_classid())
was missing from pidfd's implementation of received fd installation. Add
a call to the new __receive_sock() helper.

Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 8649c322f7 ("pid: Implement pidfd_getfd syscall")
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-13 11:03:44 -07:00
Jiri Olsa 49f4e67207 bpf: Use BTF_ID to resolve bpf_ctx_convert struct
This way the ID is resolved during compile time,
and we can remove the runtime name search.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200711215329.41165-7-jolsa@kernel.org
2020-07-13 10:42:03 -07:00
Jiri Olsa 138b9a0511 bpf: Remove btf_id helpers resolving
Now when we moved the helpers btf_id arrays into .BTF_ids section,
we can remove the code that resolve those IDs in runtime.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200711215329.41165-6-jolsa@kernel.org
2020-07-13 10:42:02 -07:00
Jiri Olsa c9a0f3b85e bpf: Resolve BTF IDs in vmlinux image
Using BTF_ID_LIST macro to define lists for several helpers
using BTF arguments.

And running resolve_btfids on vmlinux elf object during linking,
so the .BTF_ids section gets the IDs resolved.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200711215329.41165-5-jolsa@kernel.org
2020-07-13 10:42:02 -07:00
Bruno Meneguele bc885f1ab6 doc:kmsg: explicitly state the return value in case of SEEK_CUR
The commit 625d344978 ("Revert "kernel/printk: add kmsg SEEK_CUR
handling"") reverted a change done to the return value in case a SEEK_CUR
operation was performed for kmsg buffer based on the fact that different
userspace apps were handling the new return value (-ESPIPE) in different
ways, breaking them.

At the same time -ESPIPE was the wrong decision because kmsg /does support/
seek() but doesn't follow the "normal" behavior userspace is used to.
Because of that and also considering the time -EINVAL has been used, it was
decided to keep this way to avoid more userspace breakage.

This patch adds an official statement to the kmsg documentation pointing to
the current return value for SEEK_CUR, -EINVAL, thus userspace libraries
and apps can refer to it for a definitive guide on what to expect.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200710174423.10480-1-bmeneg@redhat.com
2020-07-13 15:07:45 +02:00
Linus Torvalds 9901a6bd15 RISC-V Fixes for 5.8-rc5 (ideally)
I have a few KGDB-related fixes that I'd like to target for 5.8-rc5.  They're
 mostly fixes for build warnings, but there's also:
 
 * Support for the qSupported and qXfer packets, which are necessary to pass
   around GDB XML information which we need for the RISC-V GDB port to fully
   function.
 * Users can now select STRICT_KERNEL_RWX instead of forcing it on.
 
 I know it's a bit late for rc5, as these are not critical it's not a big deal
 if they don't make it in.
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Merge tag 'riscv-for-linus-5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:
 "I have a few KGDB-related fixes. They're mostly fixes for build
  warnings, but there's also:

   - Support for the qSupported and qXfer packets, which are necessary
     to pass around GDB XML information which we need for the RISC-V GDB
     port to fully function.

   - Users can now select STRICT_KERNEL_RWX instead of forcing it on"

* tag 'riscv-for-linus-5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Avoid kgdb.h including gdb_xml.h to solve unused-const-variable warning
  kgdb: Move the extern declaration kgdb_has_hit_break() to generic kgdb.h
  riscv: Fix "no previous prototype" compile warning in kgdb.c file
  riscv: enable the Kconfig prompt of STRICT_KERNEL_RWX
  kgdb: enable arch to support XML packet.
2020-07-11 19:22:46 -07:00
David S. Miller 71930d6102 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
All conflicts seemed rather trivial, with some guidance from
Saeed Mameed on the tc_ct.c one.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-11 00:46:00 -07:00
Linus Torvalds 5a764898af Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Restore previous behavior of CAP_SYS_ADMIN wrt loading networking
    BPF programs, from Maciej Żenczykowski.

 2) Fix dropped broadcasts in mac80211 code, from Seevalamuthu
    Mariappan.

 3) Slay memory leak in nl80211 bss color attribute parsing code, from
    Luca Coelho.

 4) Get route from skb properly in ip_route_use_hint(), from Miaohe Lin.

 5) Don't allow anything other than ARPHRD_ETHER in llc code, from Eric
    Dumazet.

 6) xsk code dips too deeply into DMA mapping implementation internals.
    Add dma_need_sync and use it. From Christoph Hellwig

 7) Enforce power-of-2 for BPF ringbuf sizes. From Andrii Nakryiko.

 8) Check for disallowed attributes when loading flow dissector BPF
    programs. From Lorenz Bauer.

 9) Correct packet injection to L3 tunnel devices via AF_PACKET, from
    Jason A. Donenfeld.

10) Don't advertise checksum offload on ipa devices that don't support
    it. From Alex Elder.

11) Resolve several issues in TCP MD5 signature support. Missing memory
    barriers, bogus options emitted when using syncookies, and failure
    to allow md5 key changes in established states. All from Eric
    Dumazet.

12) Fix interface leak in hsr code, from Taehee Yoo.

13) VF reset fixes in hns3 driver, from Huazhong Tan.

14) Make loopback work again with ipv6 anycast, from David Ahern.

15) Fix TX starvation under high load in fec driver, from Tobias
    Waldekranz.

16) MLD2 payload lengths not checked properly in bridge multicast code,
    from Linus Lüssing.

17) Packet scheduler code that wants to find the inner protocol
    currently only works for one level of VLAN encapsulation. Allow
    Q-in-Q situations to work properly here, from Toke
    Høiland-Jørgensen.

18) Fix route leak in l2tp, from Xin Long.

19) Resolve conflict between the sk->sk_user_data usage of bpf reuseport
    support and various protocols. From Martin KaFai Lau.

20) Fix socket cgroup v2 reference counting in some situations, from
    Cong Wang.

21) Cure memory leak in mlx5 connection tracking offload support, from
    Eli Britstein.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (146 commits)
  mlxsw: pci: Fix use-after-free in case of failed devlink reload
  mlxsw: spectrum_router: Remove inappropriate usage of WARN_ON()
  net: macb: fix call to pm_runtime in the suspend/resume functions
  net: macb: fix macb_suspend() by removing call to netif_carrier_off()
  net: macb: fix macb_get/set_wol() when moving to phylink
  net: macb: mark device wake capable when "magic-packet" property present
  net: macb: fix wakeup test in runtime suspend/resume routines
  bnxt_en: fix NULL dereference in case SR-IOV configuration fails
  libbpf: Fix libbpf hashmap on (I)LP32 architectures
  net/mlx5e: CT: Fix memory leak in cleanup
  net/mlx5e: Fix port buffers cell size value
  net/mlx5e: Fix 50G per lane indication
  net/mlx5e: Fix CPU mapping after function reload to avoid aRFS RX crash
  net/mlx5e: Fix VXLAN configuration restore after function reload
  net/mlx5e: Fix usage of rcu-protected pointer
  net/mxl5e: Verify that rpriv is not NULL
  net/mlx5: E-Switch, Fix vlan or qos setting in legacy mode
  net/mlx5: Fix eeprom support for SFP module
  cgroup: Fix sock_cgroup_data on big-endian.
  selftests: bpf: Fix detach from sockmap tests
  ...
2020-07-10 18:16:22 -07:00
Kees Cook fe4bfff86e seccomp: Use -1 marker for end of mode 1 syscall list
The terminator for the mode 1 syscalls list was a 0, but that could be
a valid syscall number (e.g. x86_64 __NR_read). By luck, __NR_read was
listed first and the loop construct would not test it, so there was no
bug. However, this is fragile. Replace the terminator with -1 instead,
and make the variable name for mode 1 syscall lists more descriptive.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:52 -07:00
Kees Cook 47e33c05f9 seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID
When SECCOMP_IOCTL_NOTIF_ID_VALID was first introduced it had the wrong
direction flag set. While this isn't a big deal as nothing currently
enforces these bits in the kernel, it should be defined correctly. Fix
the define and provide support for the old command until it is no longer
needed for backward compatibility.

Fixes: 6a21cc50f0 ("seccomp: add a return code to trap to userspace")
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:52 -07:00
Kees Cook e68f9d49dd seccomp: Use pr_fmt
Avoid open-coding "seccomp: " prefixes for pr_*() calls.

Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:52 -07:00
Christian Brauner 99cdb8b9a5 seccomp: notify about unused filter
We've been making heavy use of the seccomp notifier to intercept and
handle certain syscalls for containers. This patch allows a syscall
supervisor listening on a given notifier to be notified when a seccomp
filter has become unused.

A container is often managed by a singleton supervisor process the
so-called "monitor". This monitor process has an event loop which has
various event handlers registered. If the user specified a seccomp
profile that included a notifier for various syscalls then we also
register a seccomp notify even handler. For any container using a
separate pid namespace the lifecycle of the seccomp notifier is bound to
the init process of the pid namespace, i.e. when the init process exits
the filter must be unused.

If a new process attaches to a container we force it to assume a seccomp
profile. This can either be the same seccomp profile as the container
was started with or a modified one. If the attaching process makes use
of the seccomp notifier we will register a new seccomp notifier handler
in the monitor's event loop. However, when the attaching process exits
we can't simply delete the handler since other child processes could've
been created (daemons spawned etc.) that have inherited the seccomp
filter and so we need to keep the seccomp notifier fd alive in the event
loop. But this is problematic since we don't get a notification when the
seccomp filter has become unused and so we currently never remove the
seccomp notifier fd from the event loop and just keep accumulating fds
in the event loop. We've had this issue for a while but it has recently
become more pressing as more and larger users make use of this.

To fix this, we introduce a new "users" reference counter that tracks any
tasks and dependent filters making use of a filter. When a notifier is
registered waiting tasks will be notified that the filter is now empty
by receiving a (E)POLLHUP event.

The concept in this patch introduces is the same as for signal_struct,
i.e. reference counting for life-cycle management is decoupled from
reference counting taks using the object. There's probably some trickery
possible but the second counter is just the correct way of doing this
IMHO and has precedence.

Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matt Denton <mpdenton@google.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Jann Horn <jannh@google.com>
Cc: Chris Palmer <palmer@google.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Robert Sesek <rsesek@google.com>
Cc: Jeffrey Vander Stoep <jeffv@google.com>
Cc: Linux Containers <containers@lists.linux-foundation.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200531115031.391515-3-christian.brauner@ubuntu.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:51 -07:00
Christian Brauner 76194c4e83 seccomp: Lift wait_queue into struct seccomp_filter
Lift the wait_queue from struct notification into struct seccomp_filter.
This is cleaner overall and lets us avoid having to take the notifier
mutex in the future for EPOLLHUP notifications since we need to neither
read nor modify the notifier specific aspects of the seccomp filter. In
the exit path I'd very much like to avoid having to take the notifier mutex
for each filter in the task's filter hierarchy.

Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matt Denton <mpdenton@google.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Jann Horn <jannh@google.com>
Cc: Chris Palmer <palmer@google.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Robert Sesek <rsesek@google.com>
Cc: Jeffrey Vander Stoep <jeffv@google.com>
Cc: Linux Containers <containers@lists.linux-foundation.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:51 -07:00
Christian Brauner 3a15fb6ed9 seccomp: release filter after task is fully dead
The seccomp filter used to be released in free_task() which is called
asynchronously via call_rcu() and assorted mechanisms. Since we need
to inform tasks waiting on the seccomp notifier when a filter goes empty
we will notify them as soon as a task has been marked fully dead in
release_task(). To not split seccomp cleanup into two parts, move
filter release out of free_task() and into release_task() after we've
unhashed struct task from struct pid, exited signals, and unlinked it
from the threadgroups' thread list. We'll put the empty filter
notification infrastructure into it in a follow up patch.

This also renames put_seccomp_filter() to seccomp_filter_release() which
is a more descriptive name of what we're doing here especially once
we've added the empty filter notification mechanism in there.

We're also NULL-ing the task's filter tree entrypoint which seems
cleaner than leaving a dangling pointer in there. Note that this shouldn't
need any memory barriers since we're calling this when the task is in
release_task() which means it's EXIT_DEAD. So it can't modify its seccomp
filters anymore. You can also see this from the point where we're calling
seccomp_filter_release(). It's after __exit_signal() and at this point,
tsk->sighand will already have been NULLed which is required for
thread-sync and filter installation alike.

Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matt Denton <mpdenton@google.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Jann Horn <jannh@google.com>
Cc: Chris Palmer <palmer@google.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Robert Sesek <rsesek@google.com>
Cc: Jeffrey Vander Stoep <jeffv@google.com>
Cc: Linux Containers <containers@lists.linux-foundation.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200531115031.391515-2-christian.brauner@ubuntu.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:51 -07:00
Christian Brauner b707ddee11 seccomp: rename "usage" to "refs" and document
Naming the lifetime counter of a seccomp filter "usage" suggests a
little too strongly that its about tasks that are using this filter
while it also tracks other references such as the user notifier or
ptrace. This also updates the documentation to note this fact.

We'll be introducing an actual usage counter in a follow-up patch.

Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matt Denton <mpdenton@google.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Jann Horn <jannh@google.com>
Cc: Chris Palmer <palmer@google.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Robert Sesek <rsesek@google.com>
Cc: Jeffrey Vander Stoep <jeffv@google.com>
Cc: Linux Containers <containers@lists.linux-foundation.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200531115031.391515-1-christian.brauner@ubuntu.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:51 -07:00
Sargun Dhillon 9f87dcf14b seccomp: Add find_notification helper
This adds a helper which can iterate through a seccomp_filter to
find a notification matching an ID. It removes several replicated
chunks of code.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Tycho Andersen <tycho@tycho.ws>
Cc: Matt Denton <mpdenton@google.com>
Cc: Kees Cook <keescook@google.com>,
Cc: Jann Horn <jannh@google.com>,
Cc: Robert Sesek <rsesek@google.com>,
Cc: Chris Palmer <palmer@google.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Tycho Andersen <tycho@tycho.ws>
Link: https://lore.kernel.org/r/20200601112532.150158-1-sargun@sargun.me
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:51 -07:00
Kees Cook c818c03b66 seccomp: Report number of loaded filters in /proc/$pid/status
A common question asked when debugging seccomp filters is "how many
filters are attached to your process?" Provide a way to easily answer
this question through /proc/$pid/status with a "Seccomp_filters" line.

Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-10 16:01:51 -07:00
Linus Torvalds 1bfde03742 dma-mapping fixes for 5.8
- add a warning when the atomic pool is depleted (David Rientjes)
  - protect the parameters of the new scatterlist helper macros
    (Marek Szyprowski )
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Merge tag 'dma-mapping-5.8-5' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - add a warning when the atomic pool is depleted (David Rientjes)

 - protect the parameters of the new scatterlist helper macros (Marek
   Szyprowski )

* tag 'dma-mapping-5.8-5' of git://git.infradead.org/users/hch/dma-mapping:
  scatterlist: protect parameters of the sg_table related macros
  dma-mapping: warn when coherent pool is depleted
2020-07-10 09:36:03 -07:00
Peter Zijlstra f9ad4a5f3f lockdep: Remove lockdep_hardirq{s_enabled,_context}() argument
Now that the macros use per-cpu data, we no longer need the argument.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200623083721.571835311@infradead.org
2020-07-10 12:00:02 +02:00
Peter Zijlstra a21ee6055c lockdep: Change hardirq{s_enabled,_context} to per-cpu variables
Currently all IRQ-tracking state is in task_struct, this means that
task_struct needs to be defined before we use it.

Especially for lockdep_assert_irq*() this can lead to header-hell.

Move the hardirq state into per-cpu variables to avoid the task_struct
dependency.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200623083721.512673481@infradead.org
2020-07-10 12:00:02 +02:00
Peter Zijlstra 859d069ee1 lockdep: Prepare for NMI IRQ state tracking
There is no reason not to always, accurately, track IRQ state.

This change also makes IRQ state tracking ignore lockdep_off().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200623083721.155449112@infradead.org
2020-07-10 12:00:01 +02:00
Marco Elver 248591f5d2 kcsan: Make KCSAN compatible with new IRQ state tracking
The new IRQ state tracking code does not honor lockdep_off(), and as
such we should again permit tracing by using non-raw functions in
core.c. Update the lockdep_off() comment in report.c, to reflect the
fact there is still a potential risk of deadlock due to using printk()
from scheduler code.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200624113246.GA170324@elver.google.com
2020-07-10 12:00:00 +02:00
Vincent Chen 8c080d3a97
kgdb: enable arch to support XML packet.
The XML packet could be supported by required architecture if the
architecture defines CONFIG_HAVE_ARCH_KGDB_QXFER_PKT and implement its own
kgdb_arch_handle_qxfer_pkt(). Except for the kgdb_arch_handle_qxfer_pkt(),
the architecture also needs to record the feature supported by gdb stub
into the kgdb_arch_gdb_stub_feature, and these features will be reported
to host gdb when gdb stub receives the qSupported packet.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-07-09 20:09:28 -07:00
Wei Yang 36b8aacf2a tracing: Save one trace_event->type by using __TRACE_LAST_TYPE
Static defined trace_event->type stops at (__TRACE_LAST_TYPE - 1) and
dynamic trace_event->type starts from (__TRACE_LAST_TYPE + 1).

To save one trace_event->type index, let's use __TRACE_LAST_TYPE.

Link: https://lkml.kernel.org/r/20200703020612.12930-3-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-09 18:14:58 -04:00
Wei Yang 746cf3459f tracing: Simplify defining of the next event id
The value to be used and compared in trace_search_list() is "last + 1".
Let's just define next to be "last + 1" instead of doing the addition
each time.

Link: https://lkml.kernel.org/r/20200703020612.12930-2-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-09 18:00:47 -04:00
Linus Torvalds ce69fb3b39 Refactor kallsyms_show_value() users for correct cred
Several users of kallsyms_show_value() were performing checks not
 during "open". Refactor everything needed to gain proper checks against
 file->f_cred for modules, kprobes, and bpf.
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Merge tag 'kallsyms_show_value-v5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kallsyms fix from Kees Cook:
 "Refactor kallsyms_show_value() users for correct cred.

  I'm not delighted by the timing of getting these changes to you, but
  it does fix a handful of kernel address exposures, and no one has
  screamed yet at the patches.

  Several users of kallsyms_show_value() were performing checks not
  during "open". Refactor everything needed to gain proper checks
  against file->f_cred for modules, kprobes, and bpf"

* tag 'kallsyms_show_value-v5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  selftests: kmod: Add module address visibility test
  bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok()
  kprobes: Do not expose probe addresses to non-CAP_SYSLOG
  module: Do not expose section addresses to non-CAP_SYSLOG
  module: Refactor section attr into bin attribute
  kallsyms: Refactor kallsyms_show_value() to take cred
2020-07-09 13:09:30 -07:00
Martin KaFai Lau c9a368f1c0 bpf: net: Avoid incorrect bpf_sk_reuseport_detach call
bpf_sk_reuseport_detach is currently called when sk->sk_user_data
is not NULL.  It is incorrect because sk->sk_user_data may not be
managed by the bpf's reuseport_array.  It has been reported in [1] that,
the bpf_sk_reuseport_detach() which is called from udp_lib_unhash() has
corrupted the sk_user_data managed by l2tp.

This patch solves it by using another bit (defined as SK_USER_DATA_BPF)
of the sk_user_data pointer value.  It marks that a sk_user_data is
managed/owned by BPF.

The patch depends on a PTRMASK introduced in
commit f1ff5ce2cd ("net, sk_msg: Clear sk_user_data pointer on clone if tagged").

[ Note: sk->sk_user_data is used by bpf's reuseport_array only when a sk is
  added to the bpf's reuseport_array.
  i.e. doing setsockopt(SO_REUSEPORT) and having "sk->sk_reuseport == 1"
  alone will not stop sk->sk_user_data being used by other means. ]

[1]: https://lore.kernel.org/netdev/20200706121259.GA20199@katalix.com/

Fixes: 5dc4c4b7d4 ("bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY")
Reported-by: James Chapman <jchapman@katalix.com>
Reported-by: syzbot+9f092552ba9a5efca5df@syzkaller.appspotmail.com
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: James Chapman <jchapman@katalix.com>
Acked-by: James Chapman <jchapman@katalix.com>
Link: https://lore.kernel.org/bpf/20200709061110.4019316-1-kafai@fb.com
2020-07-09 22:03:31 +02:00
Martin KaFai Lau f3dda7a679 bpf: net: Avoid copying sk_user_data of reuseport_array during sk_clone
It makes little sense for copying sk_user_data of reuseport_array during
sk_clone_lock().  This patch reuses the SK_USER_DATA_NOCOPY bit introduced in
commit f1ff5ce2cd ("net, sk_msg: Clear sk_user_data pointer on clone if tagged").
It is used to mark the sk_user_data is not supposed to be copied to its clone.

Although the cloned sk's sk_user_data will not be used/freed in
bpf_sk_reuseport_detach(), this change can still allow the cloned
sk's sk_user_data to be used by some other means.

Freeing the reuseport_array's sk_user_data does not require a rcu grace
period.  Thus, the existing rcu_assign_sk_user_data_nocopy() is not
used.

Fixes: 5dc4c4b7d4 ("bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20200709061104.4018798-1-kafai@fb.com
2020-07-09 22:03:31 +02:00
Frederic Weisbecker 30c66fc30e timer: Prevent base->clk from moving backward
When a timer is enqueued with a negative delta (ie: expiry is below
base->clk), it gets added to the wheel as expiring now (base->clk).

Yet the value that gets stored in base->next_expiry, while calling
trigger_dyntick_cpu(), is the initial timer->expires value. The
resulting state becomes:

	base->next_expiry < base->clk

On the next timer enqueue, forward_timer_base() may accidentally
rewind base->clk. As a possible outcome, timers may expire way too
early, the worst case being that the highest wheel levels get spuriously
processed again.

To prevent from that, make sure that base->next_expiry doesn't get below
base->clk.

Fixes: a683f390b9 ("timers: Forward the wheel clock whenever possible")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200703010657.2302-1-frederic@kernel.org
2020-07-09 11:56:57 +02:00
Richard Guy Briggs d7481b24b8 audit: issue CWD record to accompany LSM_AUDIT_DATA_* records
The LSM_AUDIT_DATA_* records for PATH, FILE, IOCTL_OP, DENTRY and INODE
are incomplete without the task context of the AUDIT Current Working
Directory record.  Add it.

This record addition can't use audit_dummy_context to determine whether
or not to store the record information since the LSM_AUDIT_DATA_*
records are initiated by various LSMs independent of any audit rules.
context->in_syscall is used to determine if it was called in user
context like audit_getname.

Please see the upstream issue
https://github.com/linux-audit/audit-kernel/issues/96

Adapted from Vladis Dronov's v2 patch.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-08 19:02:11 -04:00
Kees Cook 6396026045 bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok()
When evaluating access control over kallsyms visibility, credentials at
open() time need to be used, not the "current" creds (though in BPF's
case, this has likely always been the same). Plumb access to associated
file->f_cred down through bpf_dump_raw_ok() and its callers now that
kallsysm_show_value() has been refactored to take struct cred.

Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 7105e828c0 ("bpf: allow for correlation of maps and helpers in dump")
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-08 16:01:21 -07:00
Kees Cook 60f7bb66b8 kprobes: Do not expose probe addresses to non-CAP_SYSLOG
The kprobe show() functions were using "current"'s creds instead
of the file opener's creds for kallsyms visibility. Fix to use
seq_file->file->f_cred.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 81365a947d ("kprobes: Show address of kprobes if kallsyms does")
Fixes: ffb9bd68eb ("kprobes: Show blacklist addresses as same as kallsyms does")
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-08 16:00:22 -07:00
Kees Cook b25a7c5af9 module: Do not expose section addresses to non-CAP_SYSLOG
The printing of section addresses in /sys/module/*/sections/* was not
using the correct credentials to evaluate visibility.

Before:

 # cat /sys/module/*/sections/.*text
 0xffffffffc0458000
 ...
 # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text"
 0xffffffffc0458000
 ...

After:

 # cat /sys/module/*/sections/*.text
 0xffffffffc0458000
 ...
 # capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text"
 0x0000000000000000
 ...

Additionally replaces the existing (safe) /proc/modules check with
file->f_cred for consistency.

Reported-by: Dominik Czarnota <dominik.czarnota@trailofbits.com>
Fixes: be71eda538 ("module: Fix display of wrong module .text address")
Cc: stable@vger.kernel.org
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-08 16:00:19 -07:00
Kees Cook ed66f991bb module: Refactor section attr into bin attribute
In order to gain access to the open file's f_cred for kallsym visibility
permission checks, refactor the module section attributes to use the
bin_attribute instead of attribute interface. Additionally removes the
redundant "name" struct member.

Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-08 16:00:17 -07:00
Kees Cook 160251842c kallsyms: Refactor kallsyms_show_value() to take cred
In order to perform future tests against the cred saved during open(),
switch kallsyms_show_value() to operate on a cred, and have all current
callers pass current_cred(). This makes it very obvious where callers
are checking the wrong credential in their "read" contexts. These will
be fixed in the coming patches.

Additionally switch return value to bool, since it is always used as a
direct permission check, not a 0-on-success, negative-on-error style
function return.

Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-08 15:59:57 -07:00
Zhenzhong Duan 05eee619ed x86/kvm: Add "nopvspin" parameter to disable PV spinlocks
There are cases where a guest tries to switch spinlocks to bare metal
behavior (e.g. by setting "xen_nopvspin" on XEN platform and
"hv_nopvspin" on HYPER_V).

That feature is missed on KVM, add a new parameter "nopvspin" to disable
PV spinlocks for KVM guest.

The new 'nopvspin' parameter will also replace Xen and Hyper-V specific
parameters in future patches.

Define variable nopvsin as global because it will be used in future
patches as above.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:57 -04:00
Phil Auld 9d246053a6 sched: Add a tracepoint to track rq->nr_running
Add a bare tracepoint trace_sched_update_nr_running_tp which tracks
->nr_running CPU's rq. This is used to accurately trace this data and
provide a visualization of scheduler imbalances in, for example, the
form of a heat map.  The tracepoint is accessed by loading an external
kernel module. An example module (forked from Qais' module and including
the pelt related tracepoints) can be found at:

  https://github.com/auldp/tracepoints-helpers.git

A script to turn the trace-cmd report output into a heatmap plot can be
found at:

  https://github.com/jirvoz/plot-nr-running

The tracepoints are added to add_nr_running() and sub_nr_running() which
are in kernel/sched/sched.h. In order to avoid CREATE_TRACE_POINTS in
the header a wrapper call is used and the trace/events/sched.h include
is moved before sched.h in kernel/sched/core.

Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200629192303.GC120228@lorien.usersys.redhat.com
2020-07-08 11:39:02 +02:00
Qais Yousef 46609ce227 sched/uclamp: Protect uclamp fast path code with static key
There is a report that when uclamp is enabled, a netperf UDP test
regresses compared to a kernel compiled without uclamp.

https://lore.kernel.org/lkml/20200529100806.GA3070@suse.de/

While investigating the root cause, there were no sign that the uclamp
code is doing anything particularly expensive but could suffer from bad
cache behavior under certain circumstances that are yet to be
understood.

https://lore.kernel.org/lkml/20200616110824.dgkkbyapn3io6wik@e107158-lin/

To reduce the pressure on the fast path anyway, add a static key that is
by default will skip executing uclamp logic in the
enqueue/dequeue_task() fast path until it's needed.

As soon as the user start using util clamp by:

	1. Changing uclamp value of a task with sched_setattr()
	2. Modifying the default sysctl_sched_util_clamp_{min, max}
	3. Modifying the default cpu.uclamp.{min, max} value in cgroup

We flip the static key now that the user has opted to use util clamp.
Effectively re-introducing uclamp logic in the enqueue/dequeue_task()
fast path. It stays on from that point forward until the next reboot.

This should help minimize the effect of util clamp on workloads that
don't need it but still allow distros to ship their kernels with uclamp
compiled in by default.

SCHED_WARN_ON() in uclamp_rq_dec_id() was removed since now we can end
up with unbalanced call to uclamp_rq_dec_id() if we flip the key while
a task is running in the rq. Since we know it is harmless we just
quietly return if we attempt a uclamp_rq_dec_id() when
rq->uclamp[].bucket[].tasks is 0.

In schedutil, we introduce a new uclamp_is_enabled() helper which takes
the static key into account to ensure RT boosting behavior is retained.

The following results demonstrates how this helps on 2 Sockets Xeon E5
2x10-Cores system.

                                   nouclamp                 uclamp      uclamp-static-key
Hmean     send-64         162.43 (   0.00%)      157.84 *  -2.82%*      163.39 *   0.59%*
Hmean     send-128        324.71 (   0.00%)      314.78 *  -3.06%*      326.18 *   0.45%*
Hmean     send-256        641.55 (   0.00%)      628.67 *  -2.01%*      648.12 *   1.02%*
Hmean     send-1024      2525.28 (   0.00%)     2448.26 *  -3.05%*     2543.73 *   0.73%*
Hmean     send-2048      4836.14 (   0.00%)     4712.08 *  -2.57%*     4867.69 *   0.65%*
Hmean     send-3312      7540.83 (   0.00%)     7425.45 *  -1.53%*     7621.06 *   1.06%*
Hmean     send-4096      9124.53 (   0.00%)     8948.82 *  -1.93%*     9276.25 *   1.66%*
Hmean     send-8192     15589.67 (   0.00%)    15486.35 *  -0.66%*    15819.98 *   1.48%*
Hmean     send-16384    26386.47 (   0.00%)    25752.25 *  -2.40%*    26773.74 *   1.47%*

The perf diff between nouclamp and uclamp-static-key when uclamp is
disabled in the fast path:

     8.73%     -1.55%  [kernel.kallsyms]        [k] try_to_wake_up
     0.07%     +0.04%  [kernel.kallsyms]        [k] deactivate_task
     0.13%     -0.02%  [kernel.kallsyms]        [k] activate_task

The diff between nouclamp and uclamp-static-key when uclamp is enabled
in the fast path:

     8.73%     -0.72%  [kernel.kallsyms]        [k] try_to_wake_up
     0.13%     +0.39%  [kernel.kallsyms]        [k] activate_task
     0.07%     +0.38%  [kernel.kallsyms]        [k] deactivate_task

Fixes: 69842cba9a ("sched/uclamp: Add CPU's clamp buckets refcounting")
Reported-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lkml.kernel.org/r/20200630112123.12076-3-qais.yousef@arm.com
2020-07-08 11:39:01 +02:00
Qais Yousef d81ae8aac8 sched/uclamp: Fix initialization of struct uclamp_rq
struct uclamp_rq was zeroed out entirely in assumption that in the first
call to uclamp_rq_inc() they'd be initialized correctly in accordance to
default settings.

But when next patch introduces a static key to skip
uclamp_rq_{inc,dec}() until userspace opts in to use uclamp, schedutil
will fail to perform any frequency changes because the
rq->uclamp[UCLAMP_MAX].value is zeroed at init and stays as such. Which
means all rqs are capped to 0 by default.

Fix it by making sure we do proper initialization at init without
relying on uclamp_rq_inc() doing it later.

Fixes: 69842cba9a ("sched/uclamp: Add CPU's clamp buckets refcounting")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lkml.kernel.org/r/20200630112123.12076-2-qais.yousef@arm.com
2020-07-08 11:39:01 +02:00
Peter Zijlstra 85c2ce9104 sched, vmlinux.lds: Increase STRUCT_ALIGNMENT to 64 bytes for GCC-4.9
For some mysterious reason GCC-4.9 has a 64 byte section alignment for
structures, all other GCC versions (and Clang) tested (including 4.8
and 5.0) are fine with the 32 bytes alignment.

Getting this right is important for the new SCHED_DATA macro that
creates an explicitly ordered array of 'struct sched_class' in the
linker script and expect pointer arithmetic to work.

Fixes: c3a340f7e7 ("sched: Have sched_class_highest define by vmlinux.lds.h")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200630144905.GX4817@hirez.programming.kicks-ass.net
2020-07-08 11:39:00 +02:00
Peter Zijlstra faa2fd7cba Merge branch 'sched/urgent' 2020-07-08 11:38:59 +02:00
Kan Liang 5a09928d33 perf/x86: Remove task_ctx_size
A new kmem_cache method has replaced the kzalloc() to allocate the PMU
specific data. The task_ctx_size is not required anymore.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1593780569-62993-19-git-send-email-kan.liang@linux.intel.com
2020-07-08 11:38:55 +02:00
Kan Liang 217c2a633e perf/core: Use kmem_cache to allocate the PMU specific data
Currently, the PMU specific data task_ctx_data is allocated by the
function kzalloc() in the perf generic code. When there is no specific
alignment requirement for the task_ctx_data, the method works well for
now. However, there will be a problem once a specific alignment
requirement is introduced in future features, e.g., the Architecture LBR
XSAVE feature requires 64-byte alignment. If the specific alignment
requirement is not fulfilled, the XSAVE family of instructions will fail
to save/restore the xstate to/from the task_ctx_data.

The function kzalloc() itself only guarantees a natural alignment. A
new method to allocate the task_ctx_data has to be introduced, which
has to meet the requirements as below:
- must be a generic method can be used by different architectures,
  because the allocation of the task_ctx_data is implemented in the
  perf generic code;
- must be an alignment-guarantee method (The alignment requirement is
  not changed after the boot);
- must be able to allocate/free a buffer (smaller than a page size)
  dynamically;
- should not cause extra CPU overhead or space overhead.

Several options were considered as below:
- One option is to allocate a larger buffer for task_ctx_data. E.g.,
    ptr = kmalloc(size + alignment, GFP_KERNEL);
    ptr &= ~(alignment - 1);
  This option causes space overhead.
- Another option is to allocate the task_ctx_data in the PMU specific
  code. To do so, several function pointers have to be added. As a
  result, both the generic structure and the PMU specific structure
  will become bigger. Besides, extra function calls are added when
  allocating/freeing the buffer. This option will increase both the
  space overhead and CPU overhead.
- The third option is to use a kmem_cache to allocate a buffer for the
  task_ctx_data. The kmem_cache can be created with a specific alignment
  requirement by the PMU at boot time. A new pointer for kmem_cache has
  to be added in the generic struct pmu, which would be used to
  dynamically allocate a buffer for the task_ctx_data at run time.
  Although the new pointer is added to the struct pmu, the existing
  variable task_ctx_size is not required anymore. The size of the
  generic structure is kept the same.

The third option which meets all the aforementioned requirements is used
to replace kzalloc() for the PMU specific data allocation. A later patch
will remove the kzalloc() method and the related variables.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1593780569-62993-17-git-send-email-kan.liang@linux.intel.com
2020-07-08 11:38:55 +02:00
Kan Liang ff9ff92688 perf/core: Factor out functions to allocate/free the task_ctx_data
The method to allocate/free the task_ctx_data is going to be changed in
the following patch. Currently, the task_ctx_data is allocated/freed in
several different places. To avoid repeatedly modifying the same codes
in several different places, alloc_task_ctx_data() and
free_task_ctx_data() are factored out to allocate/free the
task_ctx_data. The modification only needs to be applied once.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1593780569-62993-16-git-send-email-kan.liang@linux.intel.com
2020-07-08 11:38:54 +02:00
Mathieu Desnoyers ce3614daab sched: Fix unreliable rseq cpu_id for new tasks
While integrating rseq into glibc and replacing glibc's sched_getcpu
implementation with rseq, glibc's tests discovered an issue with
incorrect __rseq_abi.cpu_id field value right after the first time
a newly created process issues sched_setaffinity.

For the records, it triggers after building glibc and running tests, and
then issuing:

  for x in {1..2000} ; do posix/tst-affinity-static  & done

and shows up as:

error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0

This is caused by the scheduler invoking __set_task_cpu() directly from
sched_fork() and wake_up_new_task(), thus bypassing rseq_migrate() which
is done by set_task_cpu().

Add the missing rseq_migrate() to both functions. The only other direct
use of __set_task_cpu() is done by init_idle(), which does not involve a
user-space task.

Based on my testing with the glibc test-case, just adding rseq_migrate()
to wake_up_new_task() is sufficient to fix the observed issue. Also add
it to sched_fork() to keep things consistent.

The reason why this never triggered so far with the rseq/basic_test
selftest is unclear.

The current use of sched_getcpu(3) does not typically require it to be
always accurate. However, use of the __rseq_abi.cpu_id field within rseq
critical sections requires it to be accurate. If it is not accurate, it
can cause corruption in the per-cpu data targeted by rseq critical
sections in user-space.

Reported-By: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-By: Florian Weimer <fweimer@redhat.com>
Cc: stable@vger.kernel.org # v4.18+
Link: https://lkml.kernel.org/r/20200707201505.2632-1-mathieu.desnoyers@efficios.com
2020-07-08 11:38:50 +02:00
Peter Zijlstra dbfb089d36 sched: Fix loadavg accounting race
The recent commit:

  c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")

moved these lines in ttwu():

	p->sched_contributes_to_load = !!task_contributes_to_load(p);
	p->state = TASK_WAKING;

up before:

	smp_cond_load_acquire(&p->on_cpu, !VAL);

into the 'p->on_rq == 0' block, with the thinking that once we hit
schedule() the current task cannot change it's ->state anymore. And
while this is true, it is both incorrect and flawed.

It is incorrect in that we need at least an ACQUIRE on 'p->on_rq == 0'
to avoid weak hardware from re-ordering things for us. This can fairly
easily be achieved by relying on the control-dependency already in
place.

The second problem, which makes the flaw in the original argument, is
that while schedule() will not change prev->state, it will read it a
number of times (arguably too many times since it's marked volatile).
The previous condition 'p->on_cpu == 0' was sufficient because that
indicates schedule() has completed, and will no longer read
prev->state. So now the trick is to make this same true for the (much)
earlier 'prev->on_rq == 0' case.

Furthermore, in order to make the ordering stick, the 'prev->on_rq = 0'
assignment needs to he a RELEASE, but adding additional ordering to
schedule() is an unwelcome proposition at the best of times, doubly so
for mere accounting.

Luckily we can push the prev->state load up before rq->lock, with the
only caveat that we then have to re-read the state after. However, we
know that if it changed, we no longer have to worry about the blocking
path. This gives us the required ordering, if we block, we did the
prev->state load before an (effective) smp_mb() and the p->on_rq store
needs not change.

With this we end up with the effective ordering:

	LOAD p->state           LOAD-ACQUIRE p->on_rq == 0
	MB
	STORE p->on_rq, 0       STORE p->state, TASK_WAKING

which ensures the TASK_WAKING store happens after the prev->state
load, and all is well again.

Fixes: c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Dave Jones <davej@codemonkey.org.uk>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: https://lkml.kernel.org/r/20200707102957.GN117543@hirez.programming.kicks-ass.net
2020-07-08 11:38:49 +02:00
Christian Brauner 76c12881a3
nsproxy: support CLONE_NEWTIME with setns()
So far setns() was missing time namespace support. This was partially due
to it simply not being implemented but also because vdso_join_timens()
could still fail which made switching to multiple namespaces atomically
problematic. This is now fixed so support CLONE_NEWTIME with setns()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20200706154912.3248030-4-christian.brauner@ubuntu.com
2020-07-08 11:14:22 +02:00
Christian Brauner 5cfea9a106
timens: add timens_commit() helper
Wrap the calls to timens_set_vvar_page() and vdso_join_timens() in
timens_on_fork() and timens_install() in a new timens_commit() helper.
We'll use this helper in a follow-up patch in nsproxy too.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20200706154912.3248030-3-christian.brauner@ubuntu.com
2020-07-08 11:14:21 +02:00
Christian Brauner 42815808f1
timens: make vdso_join_timens() always succeed
As discussed on-list (cf. [1]), in order to make setns() support time
namespaces when attaching to multiple namespaces at once properly we
need to tweak vdso_join_timens() to always succeed. So switch
vdso_join_timens() to using a read lock and replacing
mmap_write_lock_killable() to mmap_read_lock() as we discussed.

Last cycle setns() was changed to support attaching to multiple namespaces
atomically. This requires all namespaces to have a point of no return where
they can't fail anymore. Specifically, <namespace-type>_install() is
allowed to perform permission checks and install the namespace into the new
struct nsset that it has been given but it is not allowed to make visible
changes to the affected task. Once <namespace-type>_install() returns
anything that the given namespace type requires to be setup in addition
needs to ideally be done in a function that can't fail or if it fails the
failure is not fatal. For time namespaces the relevant functions that fall
into this category are timens_set_vvar_page() and vdso_join_timens().
Currently the latter can fail but doesn't need to. With this we can go on
to implement a timens_commit() helper in a follow up patch to be used by
setns().

[1]: https://lore.kernel.org/lkml/20200611110221.pgd3r5qkjrjmfqa2@wittgenstein

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20200706154912.3248030-2-christian.brauner@ubuntu.com
2020-07-08 11:14:21 +02:00
Stanislav Fomichev f5836749c9 bpf: Add BPF_CGROUP_INET_SOCK_RELEASE hook
Sometimes it's handy to know when the socket gets freed. In
particular, we'd like to try to use a smarter allocation of
ports for bpf_bind and explore the possibility of limiting
the number of SOCK_DGRAM sockets the process can have.

Implement BPF_CGROUP_INET_SOCK_RELEASE hook that triggers on
inet socket release. It triggers only for userspace sockets
(not in-kernel ones) and therefore has the same semantics as
the existing BPF_CGROUP_INET_SOCK_CREATE.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200706230128.4073544-2-sdf@google.com
2020-07-08 01:03:31 +02:00
Cong Wang ad0f75e5f5 cgroup: fix cgroup_sk_alloc() for sk_clone_lock()
When we clone a socket in sk_clone_lock(), its sk_cgrp_data is
copied, so the cgroup refcnt must be taken too. And, unlike the
sk_alloc() path, sock_update_netprioidx() is not called here.
Therefore, it is safe and necessary to grab the cgroup refcnt
even when cgroup_sk_alloc is disabled.

sk_clone_lock() is in BH context anyway, the in_interrupt()
would terminate this function if called there. And for sk_alloc()
skcd->val is always zero. So it's safe to factor out the code
to make it more readable.

The global variable 'cgroup_sk_alloc_disabled' is used to determine
whether to take these reference counts. It is impossible to make
the reference counting correct unless we save this bit of information
in skcd->val. So, add a new bit there to record whether the socket
has already taken the reference counts. This obviously relies on
kmalloc() to align cgroup pointers to at least 4 bytes,
ARCH_KMALLOC_MINALIGN is certainly larger than that.

This bug seems to be introduced since the beginning, commit
d979a39d72 ("cgroup: duplicate cgroup reference when cloning sockets")
tried to fix it but not compeletely. It seems not easy to trigger until
the recent commit 090e28b229
("netprio_cgroup: Fix unlimited memory leak of v2 cgroups") was merged.

Fixes: bd1060a1d6 ("sock, cgroup: add sock->sk_cgroup")
Reported-by: Cameron Berkenpas <cam@neo-zeon.de>
Reported-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reported-by: Daniël Sonck <dsonck92@gmail.com>
Reported-by: Zhang Qiang <qiang.zhang@windriver.com>
Tested-by: Cameron Berkenpas <cam@neo-zeon.de>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-07 13:34:11 -07:00
Eric W. Biederman 33c326014f umd: Stop using split_argv
There is exactly one argument so there is nothing to split.  All
split_argv does now is cause confusion and avoid the need for a cast
when passing a "const char *" string to call_usermodehelper_setup.

So avoid confusion and the possibility of an odd driver name causing
problems by just using a fixed argv array with a cast in the call to
call_usermodehelper_setup.

v1: https://lkml.kernel.org/r/87sged3a9n.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-16-ebiederm@xmission.com
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-07 11:58:59 -05:00
Eric W. Biederman 8c2f526639 umd: Remove exit_umh
The bpfilter code no longer uses the umd_info.cleanup callback.  This
callback is what exit_umh exists to call.  So remove exit_umh and all
of it's associated booking.

v1: https://lkml.kernel.org/r/87bll6dlte.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87y2o53abg.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-15-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-07 11:58:59 -05:00
Eric W. Biederman 38fd525a4c exit: Factor thread_group_exited out of pidfd_poll
Create an independent helper thread_group_exited which returns true
when all threads have passed exit_notify in do_exit.  AKA all of the
threads are at least zombies and might be dead or completely gone.

Create this helper by taking the logic out of pidfd_poll where it is
already tested, and adding a READ_ONCE on the read of
task->exit_state.

I will be changing the user mode driver code to use this same logic
to know when a user mode driver needs to be restarted.

Place the new helper thread_group_exited in kernel/exit.c and
EXPORT it so it can be used by modules.

Link: https://lkml.kernel.org/r/20200702164140.4468-13-ebiederm@xmission.com
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-07 11:58:17 -05:00
Linus Torvalds 5465a324af A single fix for a printk format warning in RCU.
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Merge tag 'core-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull rcu fixlet from Thomas Gleixner:
 "A single fix for a printk format warning in RCU"

* tag 'core-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcuperf: Fix printk format warning
2020-07-05 12:21:28 -07:00
David S. Miller f91c031e65 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-07-04

The following pull-request contains BPF updates for your *net-next* tree.

We've added 73 non-merge commits during the last 17 day(s) which contain
a total of 106 files changed, 5233 insertions(+), 1283 deletions(-).

The main changes are:

1) bpftool ability to show PIDs of processes having open file descriptors
   for BPF map/program/link/BTF objects, relying on BPF iterator progs
   to extract this info efficiently, from Andrii Nakryiko.

2) Addition of BPF iterator progs for dumping TCP and UDP sockets to
   seq_files, from Yonghong Song.

3) Support access to BPF map fields in struct bpf_map from programs
   through BTF struct access, from Andrey Ignatov.

4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack
   via seq_file from BPF iterator progs, from Song Liu.

5) Make SO_KEEPALIVE and related options available to bpf_setsockopt()
   helper, from Dmitry Yakunin.

6) Optimize BPF sk_storage selection of its caching index, from Martin
   KaFai Lau.

7) Removal of redundant synchronize_rcu()s from BPF map destruction which
   has been a historic leftover, from Alexei Starovoitov.

8) Several improvements to test_progs to make it easier to create a shell
   loop that invokes each test individually which is useful for some CIs,
   from Jesper Dangaard Brouer.

9) Fix bpftool prog dump segfault when compiled without skeleton code on
   older clang versions, from John Fastabend.

10) Bunch of cleanups and minor improvements, from various others.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-04 17:48:34 -07:00
Christian Brauner 714acdbd1c
arch: rename copy_thread_tls() back to copy_thread()
Now that HAVE_COPY_THREAD_TLS has been removed, rename copy_thread_tls()
back simply copy_thread(). It's a simpler name, and doesn't imply that only
tls is copied here. This finishes an outstanding chunk of internal process
creation work since we've added clone3().

Cc: linux-arch@vger.kernel.org
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>A
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Greentime Hu <green.hu@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>A
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-04 23:41:37 +02:00
Christian Brauner 140c8180eb
arch: remove HAVE_COPY_THREAD_TLS
All architectures support copy_thread_tls() now, so remove the legacy
copy_thread() function and the HAVE_COPY_THREAD_TLS config option. Everyone
uses the same process creation calling convention based on
copy_thread_tls() and struct kernel_clone_args. This will make it easier to
maintain the core process creation code under kernel/, simplifies the
callpaths and makes the identical for all architectures.

Cc: linux-arch@vger.kernel.org
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Greentime Hu <green.hu@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-04 23:41:37 +02:00
Christian Brauner ff2a91127b
fork: remove do_fork()
Now that all architectures have been switched to use _do_fork() and the new
struct kernel_clone_args calling convention we can remove the legacy
do_fork() helper completely. The calling convention used to be brittle and
do_fork() didn't buy us anything. The only calling convention accepted
should be based on struct kernel_clone_args going forward. It's cleaner and
uniform.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-04 23:41:36 +02:00
Eric W. Biederman 1c340ead18 umd: Track user space drivers with struct pid
Use struct pid instead of user space pid values that are prone to wrap
araound.

In addition track the entire thread group instead of just the first
thread that is started by exec.  There are no multi-threaded user mode
drivers today but there is nothing preclucing user drivers from being
multi-threaded, so it is just a good idea to track the entire process.

Take a reference count on the tgid's in question to make it possible
to remove exit_umh in a future change.

As a struct pid is available directly use kill_pid_info.

The prior process signalling code was iffy in using a userspace pid
known to be in the initial pid namespace and then looking up it's task
in whatever the current pid namespace is.  It worked only because
kernel threads always run in the initial pid namespace.

As the tgid is now refcounted verify the tgid is NULL at the start of
fork_usermode_driver to avoid the possibility of silent pid leaks.

v1: https://lkml.kernel.org/r/87mu4qdlv2.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/a70l4oy8.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-12-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:35:56 -05:00
Eric W. Biederman 55e6074e3f umh: Stop calling do_execve_file
With the user mode driver code changed to not set subprocess_info.file
there are no more users of subproces_info.file.  Remove this field
from struct subprocess_info and remove the only user in
call_usermodehelper_exec_async that would call do_execve_file instead
of do_execve if file was set.

v1: https://lkml.kernel.org/r/877dvuf0i7.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87r1tx4p2a.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-9-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:35:36 -05:00
Eric W. Biederman e2dc9bf3f5 umd: Transform fork_usermode_blob into fork_usermode_driver
Instead of loading a binary blob into a temporary file with
shmem_kernel_file_setup load a binary blob into a temporary tmpfs
filesystem.  This means that the blob can be stored in an init section
and discared, and it means the binary blob will have a filename so can
be executed normally.

The only tricky thing about this code is that in the helper function
blob_to_mnt __fput_sync is used.  That is because a file can not be
executed if it is still open for write, and the ordinary delayed close
for kernel threads does not happen soon enough, which causes the
following exec to fail.  The function umd_load_blob is not called with
any locks so this should be safe.

Executing the blob normally winds up correcting several problems with
the user mode driver code discovered by Tetsuo Handa[1].  By passing
an ordinary filename into the exec, it is no longer necessary to
figure out how to turn a O_RDWR file descriptor into a properly
referende counted O_EXEC file descriptor that forbids all writes.  For
path based LSMs there are no new special cases.

[1] https://lore.kernel.org/linux-fsdevel/2a8775b4-1dd5-9d5c-aa42-9872445e0942@i-love.sakura.ne.jp/
v1: https://lkml.kernel.org/r/87d05mf0j9.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87wo3p4p35.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-8-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:35:29 -05:00
Eric W. Biederman 1199c6c3da umd: Rename umd_info.cmdline umd_info.driver_name
The only thing supplied in the cmdline today is the driver name so
rename the field to clarify the code.

As this value is always supplied stop trying to handle the case of
a NULL cmdline.

Additionally since we now have a name we can count on use the
driver_name any place where the code is looking for a name
of the binary.

v1: https://lkml.kernel.org/r/87imfef0k3.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87366d63os.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-7-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:35:13 -05:00
Eric W. Biederman 74be2d3b80 umd: For clarity rename umh_info umd_info
This structure is only used for user mode drivers so change
the prefix from umh to umd to make that clear.

v1: https://lkml.kernel.org/r/87o8p6f0kw.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/878sg563po.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-6-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:34:39 -05:00
Eric W. Biederman 884c5e683b umh: Separate the user mode driver and the user mode helper support
This makes it clear which code is part of the core user mode
helper support and which code is needed to implement user mode
drivers.

This makes the kernel smaller for everyone who does not use a usermode
driver.

v1: https://lkml.kernel.org/r/87tuyyf0ln.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87imf963s6.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-5-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:34:32 -05:00
Eric W. Biederman 21d5982806 umh: Remove call_usermodehelper_setup_file.
The only caller of call_usermodehelper_setup_file is fork_usermode_blob.
In fork_usermode_blob replace call_usermodehelper_setup_file with
call_usermodehelper_setup and delete fork_usermodehelper_setup_file.

For this to work the argv_free is moved from umh_clean_and_save_pid
to fork_usermode_blob.

v1: https://lkml.kernel.org/r/87zh8qf0mp.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87o8p163u1.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-4-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:34:26 -05:00
Eric W. Biederman 3a171042ae umh: Rename the user mode driver helpers for clarity
Now that the functionality of umh_setup_pipe and
umh_clean_and_save_pid has changed their names are too specific and
don't make much sense.  Instead name them  umd_setup and umd_cleanup
for the functional role in setting up user mode drivers.

v1: https://lkml.kernel.org/r/875zbegf82.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87tuyt63x3.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-3-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:34:18 -05:00
Eric W. Biederman b044fa2ae5 umh: Move setting PF_UMH into umh_pipe_setup
I am separating the code specific to user mode drivers from the code
for ordinary user space helpers.  Move setting of PF_UMH from
call_usermodehelper_exec_async which is core user mode helper code
into umh_pipe_setup which is user mode driver code.

The code is equally as easy to write in one location as the other and
the movement minimizes the impact of the user mode driver code on the
core of the user mode helper code.

Setting PF_UMH unconditionally is harmless as an action will only
happen if it is paired with an entry on umh_list.

v1: https://lkml.kernel.org/r/87bll6gf8t.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87zh8l63xs.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-2-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:34:06 -05:00
Eric W. Biederman 5fec25f2cb umh: Capture the pid in umh_pipe_setup
The pid in struct subprocess_info is only used by umh_clean_and_save_pid to
write the pid into umh_info.

Instead always capture the pid on struct umh_info in umh_pipe_setup, removing
code that is specific to user mode drivers from the common user path of
user mode helpers.

v1: https://lkml.kernel.org/r/87h7uygf9i.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/875zb97iix.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-1-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-04 09:33:40 -05:00
Valentin Schneider 8fa88a88d5 genirq: Remove preflow handler support
That was put in place for sparc64, and blackfin also used it for some time;
sparc64 no longer uses those, and blackfin is dead.

As there are no more users, remove preflow handlers.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200703155645.29703-3-valentin.schneider@arm.com
2020-07-04 10:02:06 +02:00
Christoph Hellwig a3a66c3822 vmalloc: fix the owner argument for the new __vmalloc_node_range callers
Fix the recently added new __vmalloc_node_range callers to pass the
correct values as the owner for display in /proc/vmallocinfo.

Fixes: 800e26b813 ("x86/hyperv: allocate the hypercall page with only read and execute bits")
Fixes: 10d5e97c1b ("arm64: use PAGE_KERNEL_ROX directly in alloc_insn_page")
Fixes: 7a0e27b2a0 ("mm: remove vmalloc_exec")
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200627075649.2455097-1-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-03 16:15:25 -07:00
Linus Torvalds 45564bcd57 for-linus-2020-07-02
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Merge tag 'for-linus-2020-07-02' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull data race annotation from Christian Brauner:
 "This contains an annotation patch for a data race in copy_process()
  reported by KCSAN when reading and writing nr_threads.

  The data race is intentional and benign. This is obvious from the
  comment above the relevant code and based on general consensus when
  discussing this issue. So simply using data_race() to annotate this as
  an intentional race seems the best option"

* tag 'for-linus-2020-07-02' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  fork: annotate data race in copy_process()
2020-07-02 22:40:06 -07:00
Song Liu 046cc3dd9a bpf: Fix build without CONFIG_STACKTRACE
Without CONFIG_STACKTRACE stack_trace_save_tsk() is not defined. Let
get_callchain_entry_for_task() to always return NULL in such cases.

Fixes: fa28dcb82a ("bpf: Introduce helper bpf_get_task_stack()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200703024537.79971-1-songliubraving@fb.com
2020-07-02 20:21:56 -07:00
Linus Torvalds c93493b7cd io_uring-5.8-2020-07-01
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Merge tag 'io_uring-5.8-2020-07-01' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "One fix in here, for a regression in 5.7 where a task is waiting in
  the kernel for a condition, but that condition won't become true until
  task_work is run. And the task_work can't be run exactly because the
  task is waiting in the kernel, so we'll never make any progress.

  One example of that is registering an eventfd and queueing io_uring
  work, and then the task goes and waits in eventfd read with the
  expectation that it'll get woken (and read an event) when the io_uring
  request completes. The io_uring request is finished through task_work,
  which won't get run while the task is looping in eventfd read"

* tag 'io_uring-5.8-2020-07-01' of git://git.kernel.dk/linux-block:
  io_uring: use signal based task_work running
  task_work: teach task_work_add() to do signal_wake_up()
2020-07-02 14:56:22 -07:00
Bhupesh Sharma 1d50e5d0c5 crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo
Right now user-space tools like 'makedumpfile' and 'crash' need to rely
on a best-guess method of determining value of 'MAX_PHYSMEM_BITS'
supported by underlying kernel.

This value is used in user-space code to calculate the bit-space
required to store a section for SPARESMEM (similar to the existing
calculation method used in the kernel implementation):

  #define SECTIONS_SHIFT    (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)

Now, regressions have been reported in user-space utilities
like 'makedumpfile' and 'crash' on arm64, with the recently added
kernel support for 52-bit physical address space, as there is
no clear method of determining this value in user-space
(other than reading kernel CONFIG flags).

As per suggestion from makedumpfile maintainer (Kazu), it makes more
sense to append 'MAX_PHYSMEM_BITS' to vmcoreinfo in the core code itself
rather than in arch-specific code, so that the user-space code for other
archs can also benefit from this addition to the vmcoreinfo and use it
as a standard way of determining 'SECTIONS_SHIFT' value in user-land.

A reference 'makedumpfile' implementation which reads the
'MAX_PHYSMEM_BITS' value from vmcoreinfo in a arch-independent fashion
is available here:

While at it also update vmcoreinfo documentation for 'MAX_PHYSMEM_BITS'
variable being added to vmcoreinfo.

'MAX_PHYSMEM_BITS' defines the maximum supported physical address
space memory.

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Tested-by: John Donnelly <john.p.donnelly@oracle.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Boris Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: kexec@lists.infradead.org
Link: https://lore.kernel.org/r/1589395957-24628-2-git-send-email-bhsharma@redhat.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-02 17:56:11 +01:00
Peter Zijlstra 78c2141b65 Merge branch 'perf/vlbr' 2020-07-02 15:51:48 +02:00
Quentin Perret 10dd8573b0 cpufreq: Register governors at core_initcall
Currently, most CPUFreq governors are registered at the core_initcall
time when the given governor is the default one, and the module_init
time otherwise.

In preparation for letting users specify the default governor on the
kernel command line, change all of them to be registered at the
core_initcall unconditionally, as it is already the case for the
schedutil and performance governors. This will allow us to assume
that builtin governors have been registered before the built-in
CPUFreq drivers probe.

And since all governors have similar init/exit patterns now, introduce
two new macros, cpufreq_governor_{init,exit}(), to factorize the code.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02 13:03:30 +02:00
Steven Rostedt (VMware) 29ce24519c ring-buffer: Do not trigger a WARN if clock going backwards is detected
After tweaking the ring buffer to be a bit faster, a warning is triggering
on one of my machines, and causing my tests to fail. This warning is caused
when the delta (current time stamp minus previous time stamp), is larger
than the max time held by the ring buffer (59 bits).

If the clock were to go backwards slightly, this would then easily trigger
this warning. The machine that it triggered on, the clock did go backwards
by around 450 nanoseconds, and this happened after a recalibration of the
TSC clock. Now that the ring buffer is faster, it detects this, and the
delta that is used larger than the max, the warning is triggered and my test
fails.

To handle the clock going backwards, look at the saved before and after time
stamps. If they are the same, it means that the current event did not
interrupt another event, and that those timestamp are of a previous event
that was recorded. If the max delta is triggered, look at those time stamps,
make sure they are the same, then use them to compare with the current
timestamp. If the current timestamp is less than the before/after time
stamps, then that means the clock being used went backward.

Print out a message that this has happened, but do not warn about it (and
only print the message once).

Still do the warning if the delta is indeed larger than what can be used.

Also remove the unneeded KERN_WARNING from the WARN_ONCE() print.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:12:07 -04:00
Steven Rostedt (VMware) bbeba3e58f ring-buffer: Call trace_clock_local() directly for RETPOLINE kernels
After doing some benchmarks and examining the code, I found that the ring
buffer clock calls were quite expensive, and noticed that it uses
retpolines. This is because the ring buffer clock is programmable, and can
be set. But in most cases it simply uses the fastest ns unit clock which is
the trace_clock_local(). For RETPOLINE builds, checking if the ring buffer
clock is set to trace_clock_local() and then calling it directly has brought
the time of an event on my i7 box from an average of 93 nanoseconds an event
down to 83 nanoseconds an event, and the minimum time from 81 nanoseconds to
68 nanoseconds!

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:12:07 -04:00
Steven Rostedt (VMware) 74e879373b ring-buffer: Move the add_timestamp into its own function
Make a helper function rb_add_timestamp() that moves the adding of the
extended time stamps into its own function. Also, remove the noinline and
inline for the functions it calls, as recent benchmarks appear they do not
make a difference (just let gcc decide).

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:12:06 -04:00