Use force_fatal_sig instead of calling do_exit directly. This ensures
the ordinary signal handling path gets invoked, core dumps as
appropriate get created, and for multi-threaded processes all of the
threads are terminated not just a single thread.
When asked Gabriel Krisman Bertazi <krisman@collabora.com> said [1]:
> ebiederm@xmission.com (Eric W. Biederman) asked:
>
> > Why does do_syscal_user_dispatch call do_exit(SIGSEGV) and
> > do_exit(SIGSYS) instead of force_sig(SIGSEGV) and force_sig(SIGSYS)?
> >
> > Looking at the code these cases are not expected to happen, so I would
> > be surprised if userspace depends on any particular behaviour on the
> > failure path so I think we can change this.
>
> Hi Eric,
>
> There is not really a good reason, and the use case that originated the
> feature doesn't rely on it.
>
> Unless I'm missing yet another problem and others correct me, I think
> it makes sense to change it as you described.
>
> > Is using do_exit in this way something you copied from seccomp?
>
> I'm not sure, its been a while, but I think it might be just that. The
> first prototype of SUD was implemented as a seccomp mode.
If at some point it becomes interesting we could relax
"force_fatal_sig(SIGSEGV)" to instead say
"force_sig_fault(SIGSEGV, SEGV_MAPERR, sd->selector)".
I avoid doing that in this patch to avoid making it possible
to catch currently uncatchable signals.
Cc: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
[1] https://lkml.kernel.org/r/87mtr6gdvi.fsf@collabora.com
Link: https://lkml.kernel.org/r/20211020174406.17889-14-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Add a simple helper force_fatal_sig that causes a signal to be
delivered to a process as if the signal handler was set to SIG_DFL.
Reimplement force_sigsegv based upon this new helper. This fixes
force_sigsegv so that when it forces the default signal handler
to be used the code now forces the signal to be unblocked as well.
Reusing the tested logic in force_sig_info_to_task that was built for
force_sig_seccomp this makes the implementation trivial.
This is interesting both because it makes force_sigsegv simpler and
because there are a couple of buggy places in the kernel that call
do_exit(SIGILL) or do_exit(SIGSYS) because there is no straight
forward way today for those places to simply force the exit of a
process with the chosen signal. Creating force_fatal_sig allows
those places to be implemented with normal signal exits.
Link: https://lkml.kernel.org/r/20211020174406.17889-13-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
In 2009 Oleg reworked[1] the kernel threads so that it is not
necessary to call do_exit if you are not using kthread_stop(). Remove
the explicit calls of do_exit and complete_and_exit (with a NULL
completion) that were previously necessary.
[1] 63706172f3 ("kthreads: rework kthread_stop()")
Link: https://lkml.kernel.org/r/20211020174406.17889-12-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
- Some bots have informed me that some of the ftrace functions kernel-doc
has formatting issues.
- Also, fix my snake instinct.
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Merge tag 'trace-v5.15-rc6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing comment fixes from Steven Rostedt:
- Some bots have informed me that some of the ftrace functions
kernel-doc has formatting issues.
- Also, fix my snake instinct.
* tag 'trace-v5.15-rc6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix misspelling of "missing"
ftrace: Fix kernel-doc formatting issues
Some functions had kernel-doc that used a comma instead of a hash to
separate the function name from the one line description.
Also, the "ftrace_is_dead()" had an incomplete description.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- A large cross-arch rework to move irq_enter()/irq_exit() into
the arch code, and removing it from the generic irq code.
Thanks to Mark Rutland for the huge effort!
- A few irqchip drivers are made modular (broadcom, meson), because
that's apparently a thing...
- A new driver for the Microchip External Interrupt Controller
- The irq_cpu_offline()/irq_cpu_online() API is now deprecated and
can only be selected on the Cavium Octeon platform. Once this
platform is removed, the API will be removed at the same time.
- A sprinkle of devm_* helper, as people seem to love that.
- The usual spattering of small fixes and minor improvements.
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Merge tag 'irqchip-5.16' into irq/core
Merge irqchip updates for Linux 5.16 from Marc Zyngier:
- A large cross-arch rework to move irq_enter()/irq_exit() into
the arch code, and removing it from the generic irq code.
Thanks to Mark Rutland for the huge effort!
- A few irqchip drivers are made modular (broadcom, meson), because
that's apparently a thing...
- A new driver for the Microchip External Interrupt Controller
- The irq_cpu_offline()/irq_cpu_online() API is now deprecated and
can only be selected on the Cavium Octeon platform. Once this
platform is removed, the API will be removed at the same time.
- A sprinkle of devm_* helper, as people seem to love that.
- The usual spattering of small fixes and minor improvements.
* tag 'irqchip-5.16': (912 commits)
h8300: Fix linux/irqchip.h include mess
dt-bindings: irqchip: renesas-irqc: Document r8a774e1 bindings
MIPS: irq: Avoid an unused-variable error
genirq: Hide irq_cpu_{on,off}line() behind a deprecated option
irqchip/mips-gic: Get rid of the reliance on irq_cpu_online()
MIPS: loongson64: Drop call to irq_cpu_offline()
irq: remove handle_domain_{irq,nmi}()
irq: remove CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
irq: riscv: perform irqentry in entry code
irq: openrisc: perform irqentry in entry code
irq: csky: perform irqentry in entry code
irq: arm64: perform irqentry in entry code
irq: arm: perform irqentry in entry code
irq: add a (temporary) CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
irq: nds32: avoid CONFIG_HANDLE_DOMAIN_IRQ
irq: arc: avoid CONFIG_HANDLE_DOMAIN_IRQ
irq: add generic_handle_arch_irq()
irq: unexport handle_irq_desc()
irq: simplify handle_domain_{irq,nmi}()
irq: mips: simplify do_domain_IRQ()
...
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211029083332.3680101-1-maz@kernel.org
This helper allows us to get the address of a kernel symbol from inside
a BPF_PROG_TYPE_SYSCALL prog (used by gen_loader), so that we can
relocate typeless ksym vars.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-2-memxor@gmail.com
This patch adds the kernel-side changes for the implementation of
a bpf bloom filter map.
The bloom filter map supports peek (determining whether an element
is present in the map) and push (adding an element to the map)
operations.These operations are exposed to userspace applications
through the already existing syscalls in the following way:
BPF_MAP_LOOKUP_ELEM -> peek
BPF_MAP_UPDATE_ELEM -> push
The bloom filter map does not have keys, only values. In light of
this, the bloom filter map's API matches that of queue stack maps:
user applications use BPF_MAP_LOOKUP_ELEM/BPF_MAP_UPDATE_ELEM
which correspond internally to bpf_map_peek_elem/bpf_map_push_elem,
and bpf programs must use the bpf_map_peek_elem and bpf_map_push_elem
APIs to query or add an element to the bloom filter map. When the
bloom filter map is created, it must be created with a key_size of 0.
For updates, the user will pass in the element to add to the map
as the value, with a NULL key. For lookups, the user will pass in the
element to query in the map as the value, with a NULL key. In the
verifier layer, this requires us to modify the argument type of
a bloom filter's BPF_FUNC_map_peek_elem call to ARG_PTR_TO_MAP_VALUE;
as well, in the syscall layer, we need to copy over the user value
so that in bpf_map_peek_elem, we know which specific value to query.
A few things to please take note of:
* If there are any concurrent lookups + updates, the user is
responsible for synchronizing this to ensure no false negative lookups
occur.
* The number of hashes to use for the bloom filter is configurable from
userspace. If no number is specified, the default used will be 5 hash
functions. The benchmarks later in this patchset can help compare the
performance of using different number of hashes on different entry
sizes. In general, using more hashes decreases both the false positive
rate and the speed of a lookup.
* Deleting an element in the bloom filter map is not supported.
* The bloom filter map may be used as an inner map.
* The "max_entries" size that is specified at map creation time is used
to approximate a reasonable bitmap size for the bloom filter, and is not
otherwise strictly enforced. If the user wishes to insert more entries
into the bloom filter than "max_entries", they may do so but they should
be aware that this may lead to a higher false positive rate.
Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-2-joannekoong@fb.com
(mac80211), and BPF.
Current release - regressions:
- skb_expand_head: adjust skb->truesize to fix socket memory
accounting
- mptcp: fix corrupt receiver key in MPC + data + checksum
Previous releases - regressions:
- multicast: calculate csum of looped-back and forwarded packets
- cgroup: fix memory leak caused by missing cgroup_bpf_offline
- cfg80211: fix management registrations locking, prevent list
corruption
- cfg80211: correct false positive in bridge/4addr mode check
- tcp_bpf: fix race in the tcp_bpf_send_verdict resulting in reusing
previous verdict
Previous releases - always broken:
- sctp: enhancements for the verification tag, prevent attackers
from killing SCTP sessions
- tipc: fix size validations for the MSG_CRYPTO type
- mac80211: mesh: fix HE operation element length check, prevent
out of bound access
- tls: fix sign of socket errors, prevent positive error codes
being reported from read()/write()
- cfg80211: scan: extend RCU protection in cfg80211_add_nontrans_list()
- implement ->sock_is_readable() for UDP and AF_UNIX, fix poll()
for sockets in a BPF sockmap
- bpf: fix potential race in tail call compatibility check resulting
in two operations which would make the map incompatible succeeding
- bpf: prevent increasing bpf_jit_limit above max
- bpf: fix error usage of map_fd and fdget() in generic batch update
- phy: ethtool: lock the phy for consistency of results
- prevent infinite while loop in skb_tx_hash() when Tx races with
driver reconfiguring the queue <> traffic class mapping
- usbnet: fixes for bad HW conjured by syzbot
- xen: stop tx queues during live migration, prevent UAF
- net-sysfs: initialize uid and gid before calling net_ns_get_ownership
- mlxsw: prevent Rx stalls under memory pressure
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from WiFi (mac80211), and BPF.
Current release - regressions:
- skb_expand_head: adjust skb->truesize to fix socket memory
accounting
- mptcp: fix corrupt receiver key in MPC + data + checksum
Previous releases - regressions:
- multicast: calculate csum of looped-back and forwarded packets
- cgroup: fix memory leak caused by missing cgroup_bpf_offline
- cfg80211: fix management registrations locking, prevent list
corruption
- cfg80211: correct false positive in bridge/4addr mode check
- tcp_bpf: fix race in the tcp_bpf_send_verdict resulting in reusing
previous verdict
Previous releases - always broken:
- sctp: enhancements for the verification tag, prevent attackers from
killing SCTP sessions
- tipc: fix size validations for the MSG_CRYPTO type
- mac80211: mesh: fix HE operation element length check, prevent out
of bound access
- tls: fix sign of socket errors, prevent positive error codes being
reported from read()/write()
- cfg80211: scan: extend RCU protection in
cfg80211_add_nontrans_list()
- implement ->sock_is_readable() for UDP and AF_UNIX, fix poll() for
sockets in a BPF sockmap
- bpf: fix potential race in tail call compatibility check resulting
in two operations which would make the map incompatible succeeding
- bpf: prevent increasing bpf_jit_limit above max
- bpf: fix error usage of map_fd and fdget() in generic batch update
- phy: ethtool: lock the phy for consistency of results
- prevent infinite while loop in skb_tx_hash() when Tx races with
driver reconfiguring the queue <> traffic class mapping
- usbnet: fixes for bad HW conjured by syzbot
- xen: stop tx queues during live migration, prevent UAF
- net-sysfs: initialize uid and gid before calling
net_ns_get_ownership
- mlxsw: prevent Rx stalls under memory pressure"
* tag 'net-5.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (67 commits)
Revert "net: hns3: fix pause config problem after autoneg disabled"
mptcp: fix corrupt receiver key in MPC + data + checksum
riscv, bpf: Fix potential NULL dereference
octeontx2-af: Fix possible null pointer dereference.
octeontx2-af: Display all enabled PF VF rsrc_alloc entries.
octeontx2-af: Check whether ipolicers exists
net: ethernet: microchip: lan743x: Fix skb allocation failure
net/tls: Fix flipped sign in async_wait.err assignment
net/tls: Fix flipped sign in tls_err_abort() calls
net/smc: Correct spelling mistake to TCPF_SYN_RECV
net/smc: Fix smc_link->llc_testlink_time overflow
nfp: bpf: relax prog rejection for mtu check through max_pkt_offset
vmxnet3: do not stop tx queues after netif_device_detach()
r8169: Add device 10ec:8162 to driver r8169
ptp: Document the PTP_CLK_MAGIC ioctl number
usbnet: fix error return code in usbnet_probe()
net: hns3: adjust string spaces of some parameters of tx bd info in debugfs
net: hns3: expand buffer len for some debugfs command
net: hns3: add more string spaces for dumping packets number of queue info in debugfs
net: hns3: fix data endian problem of some functions of debugfs
...
If the user tries to attach an event probe (eprobe) to an event that does
not exist, it will trigger a warning. There's an error check that only
expects memory issues otherwise it is considered a bug. But changes in the
code to move around the locking made it that it can error out if the user
attempts to attach to an event that does not exist, returning an -ENODEV.
As this path can be caused by user space putting in a bad value, do not
trigger a WARN.
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Merge tag 'trace-v5.15-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Do not WARN when attaching event probe to non-existent event
If the user tries to attach an event probe (eprobe) to an event that
does not exist, it will trigger a warning. There's an error check that
only expects memory issues otherwise it is considered a bug. But
changes in the code to move around the locking made it that it can
error out if the user attempts to attach to an event that does not
exist, returning an -ENODEV. As this path can be caused by user space
putting in a bad value, do not trigger a WARN"
* tag 'trace-v5.15-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Do not warn when connecting eprobe to non existing event
* irq/irq_cpu_offline:
: .
: Make irq_cpu_{on,off}line() deprecated kernel API, and only
: enable it for some obscure Cavium platform after having
: moved all the other users away from it.
:
: Next step, drop the platform itself.
: .
genirq: Hide irq_cpu_{on,off}line() behind a deprecated option
irqchip/mips-gic: Get rid of the reliance on irq_cpu_online()
MIPS: loongson64: Drop call to irq_cpu_offline()
Signed-off-by: Marc Zyngier <maz@kernel.org>
* irq/remove-handle-domain-irq-20211026:
: Large rework of the architecture entry code from Mark Rutland.
: From the cover letter:
:
: <quote>
: The handle_domain_{irq,nmi}() functions were oringally intended as a
: convenience, but recent rework to entry code across the kernel tree has
: demonstrated that they cause more pain than they're worth and prevent
: architectures from being able to write robust entry code.
:
: This series reworks the irq code to remove them, handling the necessary
: entry work consistently in entry code (be it architectural or generic).
: </quote>
MIPS: irq: Avoid an unused-variable error
irq: remove handle_domain_{irq,nmi}()
irq: remove CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
irq: riscv: perform irqentry in entry code
irq: openrisc: perform irqentry in entry code
irq: csky: perform irqentry in entry code
irq: arm64: perform irqentry in entry code
irq: arm: perform irqentry in entry code
irq: add a (temporary) CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
irq: nds32: avoid CONFIG_HANDLE_DOMAIN_IRQ
irq: arc: avoid CONFIG_HANDLE_DOMAIN_IRQ
irq: add generic_handle_arch_irq()
irq: unexport handle_irq_desc()
irq: simplify handle_domain_{irq,nmi}()
irq: mips: simplify do_domain_IRQ()
irq: mips: stop (ab)using handle_domain_irq()
irq: mips: simplify bcm6345_l1_irq_handle()
irq: mips: avoid nested irq_enter()
Signed-off-by: Marc Zyngier <maz@kernel.org>
When the syscall trace points are not configured in, the kselftests for
ftrace will try to attach an event probe (eprobe) to one of the system
call trace points. This triggered a WARNING, because the failure only
expects to see memory issues. But this is not the only failure. The user
may attempt to attach to a non existent event, and the kernel must not
warn about it.
Link: https://lkml.kernel.org/r/20211027120854.0680aa0f@gandalf.local.home
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Commit 316580b69d ("u64_stats: provide u64_stats_t type")
fixed possible load/store tearing on 64bit arches.
For instance the following C code
stats->nsecs += sched_clock() - start;
Could be rightfully implemented like this by a compiler,
confusing concurrent readers a lot:
stats->nsecs += sched_clock();
// arbitrary delay
stats->nsecs -= start;
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026214133.3114279-4-eric.dumazet@gmail.com
It seems update_prog_stats() suffers from same issue fixed
in the prior patch:
As it can run while interrupts are enabled, it could
be re-entered and the u64_stats syncp could be mangled.
Fixes: fec56f5890 ("bpf: Introduce BPF trampoline")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026214133.3114279-3-eric.dumazet@gmail.com
If the perf buffer isn't large enough, provide a hint about how large it
needs to be for whatever is running.
Link: https://lkml.kernel.org/r/20210831043723.13481-1-robbat2@gentoo.org
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
With CONFIG_DEBUG_PREEMPT we observed reports like:
BUG: using smp_processor_id() in preemptible
caller is perf_ftrace_function_call+0x6f/0x2e0
CPU: 1 PID: 680 Comm: a.out Not tainted
Call Trace:
<TASK>
dump_stack_lvl+0x8d/0xcf
check_preemption_disabled+0x104/0x110
? optimize_nops.isra.7+0x230/0x230
? text_poke_bp_batch+0x9f/0x310
perf_ftrace_function_call+0x6f/0x2e0
...
__text_poke+0x5/0x620
text_poke_bp_batch+0x9f/0x310
This telling us the CPU could be changed after task is preempted, and
the checking on CPU before preemption will be invalid.
Since now ftrace_test_recursion_trylock() will help to disable the
preemption, this patch just do the checking after trylock() to address
the issue.
Link: https://lkml.kernel.org/r/54880691-5fe2-33e7-d12f-1fa6136f5183@linux.alibaba.com
CC: Steven Rostedt <rostedt@goodmis.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Jisheng Zhang <jszhang@kernel.org>
Reported-by: Abaci <abaci@linux.alibaba.com>
Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As the documentation explained, ftrace_test_recursion_trylock()
and ftrace_test_recursion_unlock() were supposed to disable and
enable preemption properly, however currently this work is done
outside of the function, which could be missing by mistake.
And since the internal using of trace_test_and_set_recursion()
and trace_clear_recursion() also require preemption disabled, we
can just merge the logical.
This patch will make sure the preemption has been disabled when
trace_test_and_set_recursion() return bit >= 0, and
trace_clear_recursion() will enable the preemption if previously
enabled.
Link: https://lkml.kernel.org/r/13bde807-779c-aa4c-0672-20515ae365ea@linux.alibaba.com
CC: Petr Mladek <pmladek@suse.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Jisheng Zhang <jszhang@kernel.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Miroslav Benes <mbenes@suse.cz>
Reported-by: Abaci <abaci@linux.alibaba.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com>
[ Removed extra line in comment - SDR ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Clarify argument names and contract for fsnotify_create() and
fsnotify_mkdir() to reflect the anomaly of kernfs, which leaves dentries
negavite after mkdir/create.
Remove the WARN_ON(!inode) in audit code that were added by the Fixes
commit under the wrong assumption that dentries cannot be negative after
mkdir/create.
Fixes: aa93bdc550 ("fsnotify: use helpers to access data by data_type")
Link: https://lore.kernel.org/linux-fsdevel/87mtp5yz0q.fsf@collabora.com/
Link: https://lore.kernel.org/r/20211025192746.66445-4-krisman@collabora.com
Reviewed-by: Jan Kara <jack@suse.cz>
Reported-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Jan Kara <jack@suse.cz>
'dma_mem->bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code,
improve the semantic and avoid some open-coded arithmetic in allocator
arguments.
Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The division is a slow operation. If the divisor is a power of 2, use a
shift instead.
Results were obtained using Android's version of perf (simpleperf[1]) as
described below:
1. hist_field_div() is modified to call 2 test functions:
test_hist_field_div_[not]_optimized(); passing them the
same args. Use noinline and volatile to ensure these are
not optimized out by the compiler.
2. Create a hist event trigger that uses division:
events/kmem/rss_stat$ echo 'hist:keys=common_pid:x=size/<divisor>'
>> trigger
events/kmem/rss_stat$ echo 'hist:keys=common_pid:vals=$x'
>> trigger
3. Run Android's lmkd_test[2] to generate rss_stat events, and
record CPU samples with Android's simpleperf:
simpleperf record -a --exclude-perf --post-unwind=yes -m 16384 -g
-f 2000 -o perf.data
== Results ==
Divisor is a power of 2 (divisor == 32):
test_hist_field_div_not_optimized | 8,717,091 cpu-cycles
test_hist_field_div_optimized | 1,643,137 cpu-cycles
If the divisor is a power of 2, the optimized version is ~5.3x faster.
Divisor is not a power of 2 (divisor == 33):
test_hist_field_div_not_optimized | 4,444,324 cpu-cycles
test_hist_field_div_optimized | 5,497,958 cpu-cycles
If the divisor is not a power of 2, as expected, the optimized version is
slightly slower (~24% slower).
[1] https://android.googlesource.com/platform/system/extras/+/master/simpleperf/doc/README.md
[2] https://cs.android.com/android/platform/superproject/+/master:system/memory/lmkd/tests/lmkd_test.cpp
Link: https://lkml.kernel.org/r/20211025200852.3002369-7-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If both operands of a hist trigger expression are constants, convert the
expression to a constant. This optimization avoids having to perform the
same calculation multiple times and also saves on memory since the
merged constants are represented by a single struct hist_field instead
or multiple.
Link: https://lkml.kernel.org/r/20211025200852.3002369-6-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The '-' in .sym-offset can confuse the hist trigger arithmetic
expression parsing. Simplify the handling of this by replacing the
'sym-offset' with 'symXoffset'. This allows us to correctly evaluate
expressions where the user may have inadvertently added a .sym-offset
modifier to one of the operands in an expression, instead of bailing
out. In this case the .sym-offset has no effect on the evaluation of the
expression. The only valid use of the .sym-offset is as a hist key
modifier.
Link: https://lkml.kernel.org/r/20211025200852.3002369-5-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The current histogram expression evaluation logic evaluates the
expression from right to left. This can lead to incorrect results
if the operations are not associative (as is the case for subtraction
and, the now added, division operators).
e.g. 16-8-4-2 should be 2 not 10 --> 16-8-4-2 = ((16-8)-4)-2
64/8/4/2 should be 1 not 16 --> 64/8/4/2 = ((64/8)/4)/2
Division and multiplication are currently limited to single operation
expression due to operator precedence support not yet implemented.
Rework the expression parsing to support the correct evaluation of
expressions containing operators of different precedences; and fix
the associativity error by evaluating expressions with operators of
the same precedence from left to right.
Examples:
(1) echo 'hist:keys=common_pid:a=8,b=4,c=2,d=1,w=$a-$b-$c-$d' \
>> event/trigger
(2) echo 'hist:keys=common_pid:x=$a/$b/3/2' >> event/trigger
(3) echo 'hist:keys=common_pid:y=$a+10/$c*1024' >> event/trigger
(4) echo 'hist:keys=common_pid:z=$a/$b+$c*$d' >> event/trigger
Link: https://lkml.kernel.org/r/20211025200852.3002369-4-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Adds basic support for division and multiplication operations for
hist trigger variable expressions.
For simplicity this patch only supports, division and multiplication
for a single operation expression (e.g. x=$a/$b), as currently
expressions are always evaluated right to left. This can lead to some
incorrect results:
e.g. echo 'hist:keys=common_pid:x=8-4-2' >> event/trigger
8-4-2 should evaluate to 2 i.e. (8-4)-2
but currently x evaluate to 6 i.e. 8-(4-2)
Multiplication and division in sub-expressions will work correctly, once
correct operator precedence support is added (See next patch in this
series).
For the undefined case of division by 0, the histogram expression
evaluates to (u64)(-1). Since this cannot be detected when the
expression is created, it is the responsibility of the user to be
aware and account for this possibility.
Examples:
echo 'hist:keys=common_pid:a=8,b=4,x=$a/$b' \
>> event/trigger
echo 'hist:keys=common_pid:y=5*$b' \
>> event/trigger
Link: https://lkml.kernel.org/r/20211025200852.3002369-3-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently hist trigger expressions don't support the use of numeric
literals:
e.g. echo 'hist:keys=common_pid:x=$y-1234'
--> is not valid expression syntax
Having the ability to use numeric constants in hist triggers supports
a wider range of expressions for creating variables.
Add support for creating trace event histogram variables from numeric
literals.
e.g. echo 'hist:keys=common_pid:x=1234,y=size-1024' >> event/trigger
A negative numeric constant is created, using unary minus operator
(parentheses are required).
e.g. echo 'hist:keys=common_pid:z=-(2)' >> event/trigger
Constants can be used with division/multiplication (added in the
next patch in this series) to implement granularity filters for frequent
trace events. For instance we can limit emitting the rss_stat
trace event to when there is a 512KB cross over in the rss size:
# Create a synthetic event to monitor instead of the high frequency
# rss_stat event
echo 'rss_stat_throttled unsigned int mm_id; unsigned int curr;
int member; long size' >> tracing/synthetic_events
# Create a hist trigger that emits the synthetic rss_stat_throttled
# event only when the rss size crosses a 512KB boundary.
echo 'hist:keys=keys=mm_id,member:bucket=size/0x80000:onchange($bucket)
.rss_stat_throttled(mm_id,curr,member,size)'
>> events/kmem/rss_stat/trigger
A use case for using constants with addition/subtraction is not yet
known, but for completeness the use of constants are supported for all
operators.
Link: https://lkml.kernel.org/r/20211025200852.3002369-2-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Daniel Borkmann says:
====================
pull-request: bpf 2021-10-26
We've added 12 non-merge commits during the last 7 day(s) which contain
a total of 23 files changed, 118 insertions(+), 98 deletions(-).
The main changes are:
1) Fix potential race window in BPF tail call compatibility check, from Toke Høiland-Jørgensen.
2) Fix memory leak in cgroup fs due to missing cgroup_bpf_offline(), from Quanyang Wang.
3) Fix file descriptor reference counting in generic_map_update_batch(), from Xu Kuohai.
4) Fix bpf_jit_limit knob to the max supported limit by the arch's JIT, from Lorenz Bauer.
5) Fix BPF sockmap ->poll callbacks for UDP and AF_UNIX sockets, from Cong Wang and Yucong Sun.
6) Fix BPF sockmap concurrency issue in TCP on non-blocking sendmsg calls, from Liu Jian.
7) Fix build failure of INODE_STORAGE and TASK_STORAGE maps on !CONFIG_NET, from Tejun Heo.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Fix potential race in tail call compatibility check
bpf: Move BPF_MAP_TYPE for INODE_STORAGE and TASK_STORAGE outside of CONFIG_NET
selftests/bpf: Use recv_timeout() instead of retries
net: Implement ->sock_is_readable() for UDP and AF_UNIX
skmsg: Extract and reuse sk_msg_is_readable()
net: Rename ->stream_memory_read to ->sock_is_readable
tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function
cgroup: Fix memory leak caused by missing cgroup_bpf_offline
bpf: Fix error usage of map_fd and fdget() in generic_map_update_batch()
bpf: Prevent increasing bpf_jit_limit above max
bpf: Define bpf_jit_alloc_exec_limit for arm64 JIT
bpf: Define bpf_jit_alloc_exec_limit for riscv JIT
====================
Link: https://lore.kernel.org/r/20211026201920.11296-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since config KPROBES_SANITY_TEST is in lib/Kconfig.debug, it is better to
let test_kprobes.c in lib/, just like other similar tests found in lib/.
Link: https://lkml.kernel.org/r/1635213091-24387-4-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a test case for stacktrace from kretprobe handler and
nested kretprobe handlers.
This test checks both of stack trace inside kretprobe handler
and stack trace from pt_regs. Those stack trace must include
actual function return address instead of kretprobe trampoline.
The nested kretprobe stacktrace test checks whether the unwinder
can correctly unwind the call frame on the stack which has been
modified by the kretprobe.
Since the stacktrace on kretprobe is correctly fixed only on x86,
this introduces a meta kconfig ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
which tells user that the stacktrace on kretprobe is correct or not.
The test results will be shown like below;
TAP version 14
1..1
# Subtest: kprobes_test
1..6
ok 1 - test_kprobe
ok 2 - test_kprobes
ok 3 - test_kretprobe
ok 4 - test_kretprobes
ok 5 - test_stacktrace_on_kretprobe
ok 6 - test_stacktrace_on_nested_kretprobe
# kprobes_test: pass:6 fail:0 skip:0 total:6
# Totals: pass:6 fail:0 skip:0 total:6
ok 1 - kprobes_test
Link: https://lkml.kernel.org/r/163516211244.604541.18350507860972214415.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Lorenzo noticed that the code testing for program type compatibility of
tail call maps is potentially racy in that two threads could encounter a
map with an unset type simultaneously and both return true even though they
are inserting incompatible programs.
The race window is quite small, but artificially enlarging it by adding a
usleep_range() inside the check in bpf_prog_array_compatible() makes it
trivial to trigger from userspace with a program that does, essentially:
map_fd = bpf_create_map(BPF_MAP_TYPE_PROG_ARRAY, 4, 4, 2, 0);
pid = fork();
if (pid) {
key = 0;
value = xdp_fd;
} else {
key = 1;
value = tc_fd;
}
err = bpf_map_update_elem(map_fd, &key, &value, 0);
While the race window is small, it has potentially serious ramifications in
that triggering it would allow a BPF program to tail call to a program of a
different type. So let's get rid of it by protecting the update with a
spinlock. The commit in the Fixes tag is the last commit that touches the
code in question.
v2:
- Use a spinlock instead of an atomic variable and cmpxchg() (Alexei)
v3:
- Put lock and the members it protects into an embedded 'owner' struct (Daniel)
Fixes: 3324b584b6 ("ebpf: misc core cleanup")
Reported-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211026110019.363464-1-toke@redhat.com
Make valid_state() check if the ->enter callback is present in
suspend_ops (only PM_SUSPEND_TO_IDLE can be valid otherwise) and
make sleep_state_supported() call valid_state() consistently to
validate the states other than PM_SUSPEND_TO_IDLE.
While at it, clean up the comment in valid_state().
No expected functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 8651f97bd9 ("PM / cpuidle: System resume hang fix with
cpuidle") that introduced cpuidle pausing during system suspend
did that to work around a platform firmware issue causing systems
to hang during resume if CPUs were allowed to enter idle states
in the system suspend and resume code paths.
However, pausing cpuidle before the last phase of suspending
devices is the source of an otherwise arbitrary difference between
the suspend-to-idle path and other system suspend variants, so it is
cleaner to do that later, before taking secondary CPUs offline (it
is still safer to take secondary CPUs offline with cpuidle paused,
though).
Modify the code accordingly, but in order to avoid code duplication,
introduce new wrapper functions, pm_sleep_disable_secondary_cpus()
and pm_sleep_enable_secondary_cpus(), to combine cpuidle_pause()
and cpuidle_resume(), respectively, with the handling of secondary
CPUs during system-wide transitions to sleep states.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
It is pointless to pause cpuidle in the suspend-to-idle path,
because it is going to be resumed in the same path later and
pausing it does not serve any particular purpose in that case.
Rework the code to avoid doing that.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
The sparse tool complains as follows:
kernel/trace/trace_hwlat.c:82:27: warning: symbol 'hwlat_single_cpu_data' was not declared. Should it be static?
kernel/trace/trace_hwlat.c:83:1: warning: symbol '__pcpu_scope_hwlat_per_cpu_data' was not declared. Should it be static?
This symbol is not used outside of trace_hwlat.c, so this commit
marks it static.
Link: https://lkml.kernel.org/r/20211021035225.1050685-1-bobo.shaobowang@huawei.com
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
irq_cpu_{on,off}line() are now only used by the Octeon platform.
Make their use conditional on this plaform being enabled, and
otherwise hidden away.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20211021170414.3341522-4-maz@kernel.org
Now that entry code handles IRQ entry (including setting the IRQ regs)
before calling irqchip code, irqchip code can safely call
generic_handle_domain_irq(), and there's no functional reason for it to
call handle_domain_irq().
Let's cement this split of responsibility and remove handle_domain_irq()
entirely, updating irqchip drivers to call generic_handle_domain_irq().
For consistency, handle_domain_nmi() is similarly removed and replaced
with a generic_handle_domain_nmi() function which also does not perform
any entry logic.
Previously handle_domain_{irq,nmi}() had a WARN_ON() which would fire
when they were called in an inappropriate context. So that we can
identify similar issues going forward, similar WARN_ON_ONCE() logic is
added to the generic_handle_*() functions, and comments are updated for
clarity and consistency.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Now that all users of CONFIG_HANDLE_DOMAIN_IRQ perform the irq entry
work themselves, we can remove the legacy
CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY behaviour.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
New x86 FPU features will be very large, requiring ~10k of stack in
signal handlers. These new features require a new approach called
"dynamic features".
The kernel currently tries to ensure that altstacks are reasonably
sized. Right now, on x86, sys_sigaltstack() requires a size of >=2k.
However, that 2k is a constant. Simply raising that 2k requirement
to >10k for the new features would break existing apps which have a
compiled-in size of 2k.
Instead of universally enforcing a larger stack, prohibit a process from
using dynamic features without properly-sized altstacks. This must be
enforced in two places:
* A dynamic feature can not be enabled without an large-enough altstack
for each process thread.
* Once a dynamic feature is enabled, any request to install a too-small
altstack will be rejected
The dynamic feature enabling code must examine each thread in a
process to ensure that the altstacks are large enough. Add a new lock
(sigaltstack_lock()) to ensure that threads can not race and change
their altstack after being examined.
Add the infrastructure in form of a config option and provide empty
stubs for architectures which do not need dynamic altstack size checks.
This implementation will be fleshed out for x86 in a future patch called
x86/arch_prctl: Add controls for dynamic XSTATE components
[dhansen: commit message. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211021225527.10184-2-chang.seok.bae@intel.com
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing
output," the migrate disabled field is also printed in the !PREEMPR_RT
kernel config. While this information was added to the vast majority of
tracers, osnoise and timerlat were not updated (because they are new
tracers).
Fix timerlat header by adding the information about migrate disabled.
Link: https://lkml.kernel.org/r/bc0c234ab49946cdd63effa6584e1d5e8662cb44.1634308385.git.bristot@kernel.org
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
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: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Fixes: 54357f0c91 ("tracing: Add migrate-disabled counter to tracing output.")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing
output," the migrate disabled field is also printed in the !PREEMPR_RT
kernel config. While this information was added to the vast majority of
tracers, osnoise and timerlat were not updated (because they are new
tracers).
Fix osnoise header by adding the information about migrate disabled.
Link: https://lkml.kernel.org/r/9cb3d54e29e0588dbba12e81486bd8a09adcd8ca.1634308385.git.bristot@kernel.org
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
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: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Fixes: 54357f0c91 ("tracing: Add migrate-disabled counter to tracing output.")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It is useful to trace functions in kernel/event/core.c. Allow ftrace for
them by removing $(CC_FLAGS_FTRACE) from Makefile.
Link: https://lkml.kernel.org/r/20211006210732.2826289-1-songliubraving@fb.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This symbol is not used outside of ftrace.c, so marks it static.
Fixes the following sparse warning:
kernel/trace/ftrace.c:579:5: warning: symbol 'ftrace_profile_pages_init'
was not declared. Should it be static?
Link: https://lkml.kernel.org/r/1634640534-18280-1-git-send-email-jiapeng.chong@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Fixes: cafb168a1c ("tracing: make the function profiler per cpu")
Signed-off-by: chongjiapeng <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
On the real systems, the cgroups hierarchies are setup early and just
once by the node controller, so, other than number of cgroups, all
information in /proc/cgroups remain same for the system uptime. Let's
remove the cgroup_mutex usage on reading /proc/cgroups. There is a
chance of inconsistent number of cgroups for co-mounted cgroups while
printing the information from /proc/cgroups but that is not a big
issue. In addition /proc/cgroups is a v1 specific interface, so the
dependency on it should reduce over time.
The main motivation for removing the cgroup_mutex from /proc/cgroups is
to reduce the avenues of its contention. On our fleet, we have observed
buggy application hammering on /proc/cgroups and drastically slowing
down the node controller on the system which have many negative
consequences on other workloads running on the system.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The function cgroupstats_build extracts cgroup from the kernfs_node's
priv pointer which is a RCU pointer. So, there is no need to grab
cgroup_mutex. Just get the reference on the cgroup before using and
remove the cgroup_mutex altogether.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently cgroup_get_from_path() and cgroup_get_from_id() grab
cgroup_mutex before traversing the default hierarchy to find the
kernfs_node corresponding to the path/id and then extract the linked
cgroup. Since cgroup_mutex is still held, it is guaranteed that the
cgroup will be alive and the reference can be taken on it.
However similar guarantee can be provided without depending on the
cgroup_mutex and potentially reducing avenues of cgroup_mutex contentions.
The kernfs_node's priv pointer is RCU protected pointer and with just
rcu read lock we can grab the reference on the cgroup without
cgroup_mutex. So, remove cgroup_mutex from them.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Going forward we want architecture/entry code to perform all the
necessary work to enter/exit IRQ context, with irqchip code merely
handling the mapping of the interrupt to any handler(s). Among other
reasons, this is necessary to consistently fix some longstanding issues
with the ordering of lockdep/RCU/tracing instrumentation which many
architectures get wrong today in their entry code.
Importantly, rcu_irq_{enter,exit}() must be called precisely once per
IRQ exception, so that rcu_is_cpu_rrupt_from_idle() can correctly
identify when an interrupt was taken from an idle context which must be
explicitly preempted. Currently handle_domain_irq() calls
rcu_irq_{enter,exit}() via irq_{enter,exit}(), but entry code needs to
be able to call rcu_irq_{enter,exit}() earlier for correct ordering
across lockdep/RCU/tracing updates for sequences such as:
lockdep_hardirqs_off(CALLER_ADDR0);
rcu_irq_enter();
trace_hardirqs_off_finish();
To permit each architecture to be converted to the new style in turn,
this patch adds a new CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY selected by all
current users of HANDLE_DOMAIN_IRQ, which gates the existing behaviour.
When CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY is not selected,
handle_domain_irq() requires entry code to perform the
irq_{enter,exit}() work, with an explicit check for this matching the
style of handle_domain_nmi().
Subsequent patches will:
1) Add the necessary IRQ entry accounting to each architecture in turn,
dropping CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY from that architecture's
Kconfig.
2) Remove CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY once it is no longer
selected.
3) Convert irqchip drivers to consistently use
generic_handle_domain_irq() rather than handle_domain_irq().
4) Remove handle_domain_irq() and CONFIG_HANDLE_DOMAIN_IRQ.
... which should leave us with a clear split of responsiblity across the
entry and irqchip code, making it possible to perform additional
cleanups and fixes for the aforementioned longstanding issues with entry
code.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Several architectures select GENERIC_IRQ_MULTI_HANDLER and branch to
handle_arch_irq() without performing any entry accounting.
Add a generic wrapper to handle the common irqentry work when invoking
handle_arch_irq(). Where an architecture needs to perform some entry
accounting itself, it will need to invoke handle_arch_irq() itself.
In subsequent patches it will become the responsibilty of the entry code
to set the irq regs when entering an IRQ (rather than deferring this to
an irqchip handler), so generic_handle_arch_irq() is made to set the irq
regs now. This can be redundant in some cases, but is never harmful as
saving/restoring the old regs nests safely.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
There are no modular users of handle_irq_desc(). Remove the export
before we gain any.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
There's no need for handle_domain_{irq,nmi}() to open-code the NULL
check performed by handle_irq_desc(), nor the resolution of the desc
performed by generic_handle_domain_irq().
Use generic_handle_domain_irq() directly, as this is functioanlly
equivalent and clearer. At the same time, delete the stale comments,
which are no longer helpful.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
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Merge tag 'sched_urgent_for_v5.15_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Borislav Petkov:
"Reset clang's Shadow Call Stack on hotplug to prevent it from
overflowing"
* tag 'sched_urgent_for_v5.15_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/scs: Reset the shadow stack when idle_task_exit
When enabling CONFIG_CGROUP_BPF, kmemleak can be observed by running
the command as below:
$mount -t cgroup -o none,name=foo cgroup cgroup/
$umount cgroup/
unreferenced object 0xc3585c40 (size 64):
comm "mount", pid 425, jiffies 4294959825 (age 31.990s)
hex dump (first 32 bytes):
01 00 00 80 84 8c 28 c0 00 00 00 00 00 00 00 00 ......(.........
00 00 00 00 00 00 00 00 6c 43 a0 c3 00 00 00 00 ........lC......
backtrace:
[<e95a2f9e>] cgroup_bpf_inherit+0x44/0x24c
[<1f03679c>] cgroup_setup_root+0x174/0x37c
[<ed4b0ac5>] cgroup1_get_tree+0x2c0/0x4a0
[<f85b12fd>] vfs_get_tree+0x24/0x108
[<f55aec5c>] path_mount+0x384/0x988
[<e2d5e9cd>] do_mount+0x64/0x9c
[<208c9cfe>] sys_mount+0xfc/0x1f4
[<06dd06e0>] ret_fast_syscall+0x0/0x48
[<a8308cb3>] 0xbeb4daa8
This is because that since the commit 2b0d3d3e4f ("percpu_ref: reduce
memory footprint of percpu_ref in fast path") root_cgrp->bpf.refcnt.data
is allocated by the function percpu_ref_init in cgroup_bpf_inherit which
is called by cgroup_setup_root when mounting, but not freed along with
root_cgrp when umounting. Adding cgroup_bpf_offline which calls
percpu_ref_kill to cgroup_kill_sb can free root_cgrp->bpf.refcnt.data in
umount path.
This patch also fixes the commit 4bfc0bb2c6 ("bpf: decouple the lifetime
of cgroup_bpf from cgroup itself"). A cgroup_bpf_offline is needed to do a
cleanup that frees the resources which are allocated by cgroup_bpf_inherit
in cgroup_setup_root.
And inside cgroup_bpf_offline, cgroup_get() is at the beginning and
cgroup_put is at the end of cgroup_bpf_release which is called by
cgroup_bpf_offline. So cgroup_bpf_offline can keep the balance of
cgroup's refcount.
Fixes: 2b0d3d3e4f ("percpu_ref: reduce memory footprint of percpu_ref in fast path")
Fixes: 4bfc0bb2c6 ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211018075623.26884-1-quanyang.wang@windriver.com
1. The ufd in generic_map_update_batch() should be read from batch.map_fd;
2. A call to fdget() should be followed by a symmetric call to fdput().
Fixes: aa2e93b8e5 ("bpf: Add generic support for update and delete batch ops")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211019032934.1210517-1-xukuohai@huawei.com
As reported by syzbot and experienced by Pavel, using cpus_read_lock()
in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem
and possibly others).
Instead, shrink the preempt disable region by iterating all CPUs and
checking the online status for each individual CPU while having
preemption disabled.
Fixes: 8850cb663b ("sched: Simplify wake_up_*idle*()")
Reported-by: syzbot+d5b23b18d2f4feae8a67@syzkaller.appspotmail.com
Reported-by: Pavel Machek <pavel@ucw.cz>
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Qian Cai <quic_qiancai@quicinc.com>
Pull ucounts fixes from Eric Biederman:
"There has been one very hard to track down bug in the ucount code that
we have been tracking since roughly v5.14 was released. Alex managed
to find a reliable reproducer a few days ago and then I was able to
instrument the code and figure out what the issue was.
It turns out the sigqueue_alloc single atomic operation optimization
did not play nicely with ucounts multiple level rlimits. It turned out
that either sigqueue_alloc or sigqueue_free could be operating on
multiple levels and trigger the conditions for the optimization on
more than one level at the same time.
To deal with that situation I have introduced inc_rlimit_get_ucounts
and dec_rlimit_put_ucounts that just focuses on the optimization and
the rlimit and ucount changes.
While looking into the big bug I found I couple of other little issues
so I am including those fixes here as well.
When I have time I would very much like to dig into process ownership
of the shared signal queue and see if we could pick a single owner for
the entire queue so that all of the rlimits can count to that owner.
That should entirely remove the need to call get_ucounts and
put_ucounts in sigqueue_alloc and sigqueue_free. It is difficult
because Linux unlike POSIX supports setuid that works on a single
thread"
* 'ucount-fixes-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ucounts: Move get_ucounts from cred_alloc_blank to key_change_session_keyring
ucounts: Proper error handling in set_cred_ucounts
ucounts: Pair inc_rlimit_ucounts with dec_rlimit_ucoutns in commit_creds
ucounts: Fix signal ucount refcounting
This stat is currently printed in the verifier log and not stored
anywhere. To ease consumption of this data, add a field to bpf_prog_aux
so it can be exposed via BPF_OBJ_GET_INFO_BY_FD and fdinfo.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211020074818.1017682-2-davemarchevsky@fb.com
The helper is used in tracing programs to cast a socket
pointer to a unix_sock pointer.
The return value could be NULL if the casting is illegal.
Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021134752.1223426-2-hengqi.chen@gmail.com
This converts the kprobes testcases to use the kunit framework.
It adds a dependency on CONFIG_KUNIT, and the output will change
to TAP:
TAP version 14
1..1
# Subtest: kprobes_test
1..4
random: crng init done
ok 1 - test_kprobe
ok 2 - test_kprobes
ok 3 - test_kretprobe
ok 4 - test_kretprobes
ok 1 - kprobes_test
Note that the kprobes testcases are no longer run immediately after
kprobes initialization, but as a late initcall when kunit is
initialized. kprobes itself is initialized with an early initcall,
so the order is still correct.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
clang started warning about excessive stack usage in
hist_trigger_print_key()
kernel/trace/trace_events_hist.c:4723:13: error: stack frame size (1336) exceeds limit (1024) in function 'hist_trigger_print_key' [-Werror,-Wframe-larger-than]
The problem is that there are two 512-byte arrays on the stack if
hist_trigger_stacktrace_print() gets inlined. I don't think this has
changed in the past five years, but something probably changed the
inlining decisions made by the compiler, so the problem is now made
more obvious.
Rather than printing the symbol names into separate buffers, it
seems we can simply use the special %ps format string modifier
to print the pointers symbolically and get rid of both buffers.
Marking hist_trigger_stacktrace_print() would be a simpler
way of avoiding the warning, but that would not address the
excessive stack usage.
Link: https://lkml.kernel.org/r/20211019153337.294790-1-arnd@kernel.org
Fixes: 69a0200c2e ("tracing: Add hist trigger support for stacktraces as keys")
Link: https://lore.kernel.org/all/20211015095704.49a99859@gandalf.local.home/
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently to switch a set of "multi" direct trampolines from one
trampoline to another, a full shutdown of the current set needs to be
done, followed by an update to what trampoline the direct callers would
call, and then re-enabling the callers. This leaves a time when the
functions will not be calling anything, and events may be missed.
Instead, use a trick to allow all the functions with direct trampolines
attached will always call either the new or old trampoline while the
switch is happening. To do this, first attach a "dummy" callback via
ftrace to all the functions that the current direct trampoline is attached
to. This will cause the functions to call the "list func" instead of the
direct trampoline. The list function will call the direct trampoline
"helper" that will set the function it should call as it returns back to
the ftrace trampoline.
At this moment, the direct caller descriptor can safely update the direct
call trampoline. The list function will pick either the new or old
function (depending on the memory coherency model of the architecture).
Now removing the dummy function from each of the locations of the direct
trampoline caller, will put back the direct call, but now to the new
trampoline.
A better visual is:
[ Changing direct call from my_direct_1 to my_direct_2 ]
<traced_func>:
call my_direct_1
||||||||||||||||||||
vvvvvvvvvvvvvvvvvvvv
<traced_func>:
call ftrace_caller
<ftrace_caller>:
[..]
call ftrace_ops_list_func
ftrace_ops_list_func()
{
ops->func() -> direct_helper -> set rax to my_direct_1 or my_direct_2
}
call rax (to either my_direct_1 or my_direct_2
||||||||||||||||||||
vvvvvvvvvvvvvvvvvvvv
<traced_func>:
call my_direct_2
Link: https://lore.kernel.org/all/20211014162819.5c85618b@gandalf.local.home/
Acked-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Adding interface to modify registered direct function
for ftrace_ops. Adding following function:
modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
The function changes the currently registered direct
function for all attached functions.
Link: https://lkml.kernel.org/r/20211008091336.33616-8-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Adding interface to register multiple direct functions
within single call. Adding following functions:
register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
The register_ftrace_direct_multi registers direct function (addr)
with all functions in ops filter. The ops filter can be updated
before with ftrace_set_filter_ip calls.
All requested functions must not have direct function currently
registered, otherwise register_ftrace_direct_multi will fail.
The unregister_ftrace_direct_multi unregisters ops related direct
functions.
Link: https://lkml.kernel.org/r/20211008091336.33616-7-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Factor out the code that adds (ip, addr) tuple to direct_functions
hash in new ftrace_add_rec_direct function. It will be used in
following patches.
Link: https://lkml.kernel.org/r/20211008091336.33616-6-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There's a new test in trace_selftest_startup_function_graph() that
requires the use of ftrace args being supported as well does some tricks
with dynamic tracing. Although this code checks HAVE_DYNAMIC_FTRACE_WITH_ARGS
it fails to check DYNAMIC_FTRACE, and the kernel fails to build due to
that dependency.
Also only define the prototype of trace_direct_tramp() if it is used.
Link: https://lkml.kernel.org/r/20211021134357.7f48e173@gandalf.local.home
Acked-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Replace vmalloc()/memset() with vzalloc() and kmalloc()/memset() with
kzalloc() to simplify the code.
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When building the kernel with sparse enabled 'C=1' the following
warnings shows up:
kernel/power/swap.c:390:29: warning: incorrect type in assignment (different base types)
kernel/power/swap.c:390:29: expected int ret
kernel/power/swap.c:390:29: got restricted blk_status_t
This is due to function hib_wait_io() returns a 'blk_status_t' which is
a bitwise u8. Commit 5416da01ff ("PM: hibernate: Remove
blk_status_to_errno in hib_wait_io") seemed to have mixed up the return
type. However, the 4e4cbee93d ("block: switch bios to blk_status_t")
actually broke the behaviour by returning the wrong type.
Rework so function hib_wait_io() returns a 'int' instead of
'blk_status_t' and make sure to call function
blk_status_to_errno(hb->error)' when returning from function
hib_wait_io() a int gets returned.
Fixes: 4e4cbee93d ("block: switch bios to blk_status_t")
Fixes: 5416da01ff ("PM: hibernate: Remove blk_status_to_errno in hib_wait_io")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Adding selftest for checking that direct trampoline can
co-exist together with graph tracer on same function.
This is supported for CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
config option, which is defined only for x86_64 for now.
Link: https://lkml.kernel.org/r/20211008091336.33616-5-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We don't need special hook for graph tracer entry point,
but instead we can use graph_ops::func function to install
the return_hooker.
This moves the graph tracing setup _before_ the direct
trampoline prepares the stack, so the return_hooker will
be called when the direct trampoline is finished.
This simplifies the code, because we don't need to take into
account the direct trampoline setup when preparing the graph
tracer hooker and we can allow function graph tracer on entries
registered with direct trampoline.
Link: https://lkml.kernel.org/r/20211008091336.33616-4-jolsa@kernel.org
[fixed compile error reported by kernel test robot <lkp@intel.com>]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In order to build drivers/irqchip/irq-bcm7120-l2.c as a module which
references irq_gc_noop(), we need to export it towards modules.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211020184859.2705451-10-f.fainelli@gmail.com
In order to allow drivers/irqchip/irq-brcmstb-l2.c to be built as a
module we need to export: irq_gc_unmask_enable_reg() and
irq_gc_mask_disable_reg().
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211020184859.2705451-8-f.fainelli@gmail.com
kernel/bpf/preload/Makefile was recently updated to have it install
libbpf's headers locally instead of pulling them from tools/lib/bpf. But
two items still need to be addressed.
First, the local .gitignore file was not adjusted to ignore the files
generated in the new kernel/bpf/preload/libbpf output directory.
Second, the "clean-files" target is now incorrect. The old artefacts
names were not removed from the target, while the new ones were added
incorrectly. This is because "clean-files" expects names relative to
$(obj), but we passed the absolute path instead. This results in the
output and header-destination directories for libbpf (and their
contents) not being removed from kernel/bpf/preload on "make clean" from
the root of the repository.
This commit fixes both issues. Note that $(userprogs) needs not be added
to "clean-files", because the cleaning infrastructure already accounts
for it.
Cleaning the files properly also prevents make from printing the
following message, for builds coming after a "make clean":
"make[4]: Nothing to be done for 'install_headers'."
v2: Simplify the "clean-files" target.
Fixes: bf60791741 ("bpf: preload: Install libbpf headers when building")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211020094647.15564-1-quentin@isovalent.com
Currently show_workqueue_state shows the state of all workqueues and of
all worker pools. In certain cases we may need to dump state of only a
specific workqueue or worker pool. For example in destroy_workqueue we
only need to show state of the workqueue which is getting destroyed.
So rename show_workqueue_state to show_all_workqueues(to signify it
dumps state of all busy workqueues) and divide it into more granular
functions (show_one_workqueue and show_one_worker_pool), that would show
states of individual workqueues and worker pools and can be used in
cases such as the one mentioned above.
Also, as mentioned earlier, make destroy_workqueue dump data pertaining
to only the workqueue that is being destroyed and make user(s) of
earlier interface(show_workqueue_state), use new interface
(show_all_workqueues).
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Merge tag 'audit-pr-20211019' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit fix from Paul Moore:
"One small audit patch to add a pointer NULL check"
* tag 'audit-pr-20211019' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: fix possible null-pointer dereference in audit_filter_rules
- While cleaning up some of the tracing recursion protection logic,
I discovered a scenario that the current design would miss, and
would allow an infinite recursion. Removing an optimization trick
that opened the hole, fixes the issue and cleans up the code as well.
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Merge tag 'trace-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Recursion fix for tracing.
While cleaning up some of the tracing recursion protection logic, I
discovered a scenario that the current design would miss, and would
allow an infinite recursion. Removing an optimization trick that
opened the hole fixes the issue and cleans up the code as well"
* tag 'trace-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Have all levels of checks prevent recursion
Consolidate the various helpers into a single blk_flush_plug helper that
takes a plk_plug and the from_scheduler bool and switch all callsites to
call it directly. Checks that the plug is non-NULL must be performed by
the caller, something that most already do anyway.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211020144119.142582-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Decrement ucounts using atomic_long_sub_return to make it
clear the point is for the ucount to decrease.
Not a big deal but it should make it easier to catch bugs.
Suggested-by: Yu Zhao <yuzhao@google.com>
Link: https://lkml.kernel.org/r/87k0iaqkqj.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Add a helper function get_ucounts_or_wrap that is a trivial
wrapper around atomic_add_negative, that makes it clear
how atomic_add_negative is used in the context of ucounts.
Link: https://lkml.kernel.org/r/87pms2qkr9.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
All of the callers of get_ucounts are passeds a non-NULL value so stop
handling a NULL ucounts pointer in get_ucounts.
It is guaranteed that ever valid fully formed cred that is passed to
commit_cred contains a non-NULL ucounts pointer. This in turn
gurantees that current_ucounts() never returns NULL.
The call of get_ucounts in user_shm_lock is always passed
current_ucounts().
The call of get_ucounts in mqueue_get_inode is always passed
current_ucounts().
The call of get_ucounts in inc_rlmit_get_ucounts is always
passed iter, after iter has been verified to be non-NULL.
The call of get_ucounts in key_change_session_keyring is always passed
current_ucounts().
The call of get_ucounts in prepare_cred is always passed
current_ucounts().
The call of get_ucounts in prepare_kernel_cred is always
passed task->cred->ucounts or init_cred->ucounts which
being on tasks are guaranteed to have a non-NULL ucounts
field.
Link: https://lkml.kernel.org/r/87v91uqksg.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Any cred that is destined for use by commit_creds must have a non-NULL
cred->ucounts field. Only curing credential construction is a NULL
cred->ucounts valid. Only abort_creds, put_cred, and put_cred_rcu
needs to deal with a cred with a NULL ucount. As set_cred_ucounts is
non of those case don't confuse people by handling something that can
not happen.
Link: https://lkml.kernel.org/r/871r4irzds.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Setting cred->ucounts in cred_alloc_blank does not make sense. The
uid and user_ns are deliberately not set in cred_alloc_blank but
instead the setting is delayed until key_change_session_keyring.
So move dealing with ucounts into key_change_session_keyring as well.
Unfortunately that movement of get_ucounts adds a new failure mode to
key_change_session_keyring. I do not see anything stopping the parent
process from calling setuid and changing the relevant part of it's
cred while keyctl_session_to_parent is running making it fundamentally
necessary to call get_ucounts in key_change_session_keyring. Which
means that the new failure mode cannot be avoided.
A failure of key_change_session_keyring results in a single threaded
parent keeping it's existing credentials. Which results in the parent
process not being able to access the session keyring and whichever
keys are in the new keyring.
Further get_ucounts is only expected to fail if the number of bits in
the refernece count for the structure is too few.
Since the code has no other way to report the failure of get_ucounts
and because such failures are not expected to be common add a WARN_ONCE
to report this problem to userspace.
Between the WARN_ONCE and the parent process not having access to
the keys in the new session keyring I expect any failure of get_ucounts
will be noticed and reported and we can find another way to handle this
condition. (Possibly by just making ucounts->count an atomic_long_t).
Cc: stable@vger.kernel.org
Fixes: 905ae01c4a ("Add a reference to ucounts for each cred")
Link: https://lkml.kernel.org/r/7k0ias0uf.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that there are three different instances of doing the addition trick
to the preempt_count() and NMI_MASK, HARDIRQ_MASK and SOFTIRQ_OFFSET
macros, it deserves a helper function defined in the preempt.h header.
Add the interrupt_context_level() helper and replace the three instances
that do that logic with it.
Link: https://lore.kernel.org/all/20211015142541.4badd8a9@gandalf.local.home/
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of having branches that adds noise to the branch prediction, use
the addition logic to set the bit for the level of interrupt context that
the state is currently in. This copies the logic from perf's
get_recursion_context() function.
Link: https://lore.kernel.org/all/20211015161702.GF174703@worktop.programming.kicks-ass.net/
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If CONFIG_CFI_CLANG=y, attempting to read an event histogram will cause
the kernel to panic due to failed CFI check.
1. echo 'hist:keys=common_pid' >> events/sched/sched_switch/trigger
2. cat events/sched/sched_switch/hist
3. kernel panics on attempting to read hist
This happens because the sort() function expects a generic
int (*)(const void *, const void *) pointer for the compare function.
To prevent this CFI failure, change tracing map cmp_entries_* function
signatures to match this.
Also, fix the build error reported by the kernel test robot [1].
[1] https://lore.kernel.org/r/202110141140.zzi4dRh4-lkp@intel.com/
Link: https://lkml.kernel.org/r/20211014045217.3265162-1-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In an effort to enable -Wcast-function-type in the top-level Makefile to
support Control Flow Integrity builds, all function casts need to be
removed.
This means that ftrace_ops_list_func() can no longer be defined as
ftrace_ops_no_ops(). The reason for ftrace_ops_no_ops() is to use that when
an architecture calls ftrace_ops_list_func() with only two parameters
(called from assembly). And to make sure there's no C side-effects, those
archs call ftrace_ops_no_ops() which only has two parameters, as
ftrace_ops_list_func() has four parameters.
Instead of a typecast, use vmlinux.lds.h to define ftrace_ops_list_func() to
arch_ftrace_ops_list_func() that will define the proper set of parameters.
Link: https://lore.kernel.org/r/20200614070154.6039-1-oscar.carter@gmx.com
Link: https://lkml.kernel.org/r/20200617165616.52241bde@oasis.local.home
Link: https://lore.kernel.org/all/20211005053922.GA702049@embeddedor/
Requested-by: Oscar Carter <oscar.carter@gmx.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The helper function returns a pointer that in the failure case encodes
an error in the struct btf pointer. The current code lead to Coverity
warning about the use of the invalid pointer:
*** CID 1507963: Memory - illegal accesses (USE_AFTER_FREE)
/kernel/bpf/verifier.c: 1788 in find_kfunc_desc_btf()
1782 return ERR_PTR(-EINVAL);
1783 }
1784
1785 kfunc_btf = __find_kfunc_desc_btf(env, offset, btf_modp);
1786 if (IS_ERR_OR_NULL(kfunc_btf)) {
1787 verbose(env, "cannot find module BTF for func_id %u\n", func_id);
>>> CID 1507963: Memory - illegal accesses (USE_AFTER_FREE)
>>> Using freed pointer "kfunc_btf".
1788 return kfunc_btf ?: ERR_PTR(-ENOENT);
1789 }
1790 return kfunc_btf;
1791 }
1792 return btf_vmlinux ?: ERR_PTR(-ENOENT);
1793 }
Daniel suggested the use of ERR_CAST so that the intended use is clear
to Coverity, but on closer look it seems that we never return NULL from
the helper. Andrii noted that since __find_kfunc_desc_btf already logs
errors for all cases except btf_get_by_fd, it is much easier to add
logging for that and remove the IS_ERR check altogether, returning
directly from it.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211009040900.803436-1-memxor@gmail.com
Revert commit bfcc1e67ff ("PM: sleep: Do not assume that "mem" is
always present"), because it breaks compatibility with user space
utilities assuming that "mem" will always be present in
/sys/power/state.
Fixes: bfcc1e67ff ("PM: sleep: Do not assume that "mem" is always present")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some unfriendly component, such as dpdk, write the same mask to
unbound kworker cpumask again and again. Every time it write to
this interface some work is queue to cpu, even though the mask
is same with the original mask.
So, fix it by return success and do nothing if the cpumask is
equal with the old one.
Signed-off-by: Mengen Sun <mengensun@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Instead of leaking the ucounts in new if alloc_ucounts fails, store
the result of alloc_ucounts into a temporary variable, which is later
assigned to new->ucounts.
Cc: stable@vger.kernel.org
Fixes: 905ae01c4a ("Add a reference to ucounts for each cred")
Link: https://lkml.kernel.org/r/87pms2s0v8.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The purpose of inc_rlimit_ucounts and dec_rlimit_ucounts in commit_creds
is to change which rlimit counter is used to track a process when the
credentials changes.
Use the same test for both to guarantee the tracking is correct.
Cc: stable@vger.kernel.org
Fixes: 21d1c5e386 ("Reimplement RLIMIT_NPROC on top of ucounts")
Link: https://lkml.kernel.org/r/87v91us0w4.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Commit f1a0a376ca ("sched/core: Initialize the idle task with
preemption disabled") removed the init_idle() call from
idle_thread_get(). This was the sole call-path on hotplug that resets
the Shadow Call Stack (scs) Stack Pointer (sp).
Not resetting the scs-sp leads to scs overflow after enough hotplug
cycles. Therefore add an explicit scs_task_reset() to the hotplug code
to make sure the scs-sp does get reset on hotplug.
Fixes: f1a0a376ca ("sched/core: Initialize the idle task with preemption disabled")
Signed-off-by: Woody Lin <woodylin@google.com>
[peterz: Changelog]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20211012083521.973587-1-woodylin@google.com
After the commit 617f3ef951 ("locking/rwsem: Remove reader
optimistic spinning"), reader doesn't support optimistic spinning
anymore, there is no need meet the condition which OSQ is empty.
BTW, add an unlikely() for the max reader wakeup check in the loop.
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20211013134154.1085649-4-yanfei.xu@windriver.com
preempt_disable/enable() is equal to RCU read-side crital section, and
the spinning codes in mutex and rwsem could ensure that the preemption
is disabled. So let's remove the unnecessary rcu_read_lock/unlock for
saving some cycles in hot codes.
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20211013134154.1085649-2-yanfei.xu@windriver.com
The spinning region rwsem_spin_on_owner() should not be preempted,
however the rwsem_down_write_slowpath() invokes it and don't disable
preemption. Fix it by adding a pair of preempt_disable/enable().
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
[peterz: Fix CONFIG_RWSEM_SPIN_ON_OWNER=n build]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20211013134154.1085649-3-yanfei.xu@windriver.com
Mike reported that rcuwait went walk-about and is causing failures on
the PREEMPT_RT builds, restore it.
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
We only need to call it to resolve the blk_status_t -> errno mapping for
tracing, so move the conversion into the tracepoints that are not called
at all when tracing isn't enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Patch set [1] introduced BTF_KIND_TAG to allow tagging
declarations for struct/union, struct/union field, var, func
and func arguments and these tags will be encoded into
dwarf. They are also encoded to btf by llvm for the bpf target.
After BTF_KIND_TAG is introduced, we intended to use it
for kernel __user attributes. But kernel __user is actually
a type attribute. Upstream and internal discussion showed
it is not a good idea to mix declaration attribute and
type attribute. So we proposed to introduce btf_type_tag
as a type attribute and existing btf_tag renamed to
btf_decl_tag ([2]).
This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some
other declarations with *_tag to *_decl_tag to make it clear
the tag is for declaration. In the future, BTF_KIND_TYPE_TAG
might be introduced per [3].
[1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/
[2] https://reviews.llvm.org/D111588
[3] https://reviews.llvm.org/D111199
Fixes: b5ea834dde ("bpf: Support for new btf kind BTF_KIND_TAG")
Fixes: 5b84bd1036 ("libbpf: Add support for BTF_KIND_TAG")
Fixes: 5c07f2fec0 ("bpftool: Add support for BTF_KIND_TAG")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
It is not necessary for audit_filter_rules() functions to check
audit fileds of the rule with a lower priority, and if we did,
there might be some unintended effects, such as the ctx->ppid
may be changed unexpectedly, so return early if the rule has
a lower priority.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
[PM: slight tweak to the subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Fix possible null-pointer dereference in audit_filter_rules.
audit_filter_rules() error: we previously assumed 'ctx' could be null
Cc: stable@vger.kernel.org
Fixes: bf361231c2 ("audit: add saddr_fam filter field")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
While writing an email explaining the "bit = 0" logic for a discussion on
making ftrace_test_recursion_trylock() disable preemption, I discovered a
path that makes the "not do the logic if bit is zero" unsafe.
The recursion logic is done in hot paths like the function tracer. Thus,
any code executed causes noticeable overhead. Thus, tricks are done to try
to limit the amount of code executed. This included the recursion testing
logic.
Having recursion testing is important, as there are many paths that can
end up in an infinite recursion cycle when tracing every function in the
kernel. Thus protection is needed to prevent that from happening.
Because it is OK to recurse due to different running context levels (e.g.
an interrupt preempts a trace, and then a trace occurs in the interrupt
handler), a set of bits are used to know which context one is in (normal,
softirq, irq and NMI). If a recursion occurs in the same level, it is
prevented*.
Then there are infrastructure levels of recursion as well. When more than
one callback is attached to the same function to trace, it calls a loop
function to iterate over all the callbacks. Both the callbacks and the
loop function have recursion protection. The callbacks use the
"ftrace_test_recursion_trylock()" which has a "function" set of context
bits to test, and the loop function calls the internal
trace_test_and_set_recursion() directly, with an "internal" set of bits.
If an architecture does not implement all the features supported by ftrace
then the callbacks are never called directly, and the loop function is
called instead, which will implement the features of ftrace.
Since both the loop function and the callbacks do recursion protection, it
was seemed unnecessary to do it in both locations. Thus, a trick was made
to have the internal set of recursion bits at a more significant bit
location than the function bits. Then, if any of the higher bits were set,
the logic of the function bits could be skipped, as any new recursion
would first have to go through the loop function.
This is true for architectures that do not support all the ftrace
features, because all functions being traced must first go through the
loop function before going to the callbacks. But this is not true for
architectures that support all the ftrace features. That's because the
loop function could be called due to two callbacks attached to the same
function, but then a recursion function inside the callback could be
called that does not share any other callback, and it will be called
directly.
i.e.
traced_function_1: [ more than one callback tracing it ]
call loop_func
loop_func:
trace_recursion set internal bit
call callback
callback:
trace_recursion [ skipped because internal bit is set, return 0 ]
call traced_function_2
traced_function_2: [ only traced by above callback ]
call callback
callback:
trace_recursion [ skipped because internal bit is set, return 0 ]
call traced_function_2
[ wash, rinse, repeat, BOOM! out of shampoo! ]
Thus, the "bit == 0 skip" trick is not safe, unless the loop function is
call for all functions.
Since we want to encourage architectures to implement all ftrace features,
having them slow down due to this extra logic may encourage the
maintainers to update to the latest ftrace features. And because this
logic is only safe for them, remove it completely.
[*] There is on layer of recursion that is allowed, and that is to allow
for the transition between interrupt context (normal -> softirq ->
irq -> NMI), because a trace may occur before the context update is
visible to the trace recursion logic.
Link: https://lore.kernel.org/all/609b565a-ed6e-a1da-f025-166691b5d994@linux.alibaba.com/
Link: https://lkml.kernel.org/r/20211018154412.09fcad3c@gandalf.local.home
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Jisheng Zhang <jszhang@kernel.org>
Cc: =?utf-8?b?546L6LSH?= <yun.wang@linux.alibaba.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: stable@vger.kernel.org
Fixes: edc15cafcb ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In commit fda31c5029 ("signal: avoid double atomic counter
increments for user accounting") Linus made a clever optimization to
how rlimits and the struct user_struct. Unfortunately that
optimization does not work in the obvious way when moved to nested
rlimits. The problem is that the last decrement of the per user
namespace per user sigpending counter might also be the last decrement
of the sigpending counter in the parent user namespace as well. Which
means that simply freeing the leaf ucount in __free_sigqueue is not
enough.
Maintain the optimization and handle the tricky cases by introducing
inc_rlimit_get_ucounts and dec_rlimit_put_ucounts.
By moving the entire optimization into functions that perform all of
the work it becomes possible to ensure that every level is handled
properly.
The new function inc_rlimit_get_ucounts returns 0 on failure to
increment the ucount. This is different than inc_rlimit_ucounts which
increments the ucounts and returns LONG_MAX if the ucount counter has
exceeded it's maximum or it wrapped (to indicate the counter needs to
decremented).
I wish we had a single user to account all pending signals to across
all of the threads of a process so this complexity was not necessary
Cc: stable@vger.kernel.org
Fixes: d646969055 ("Reimplement RLIMIT_SIGPENDING on top of ucounts")
v1: https://lkml.kernel.org/r/87mtnavszx.fsf_-_@disp2133
Link: https://lkml.kernel.org/r/87fssytizw.fsf_-_@disp2133
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Tested-by: Rune Kleveland <rune.kleveland@infomedia.dk>
Tested-by: Yu Zhao <yuzhao@google.com>
Tested-by: Jordan Glover <Golden_Miller83@protonmail.ch>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Only core.c needs blkdev.h, so move the #include statement there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Various files have acquired spurious includes of <linux/blkdev.h> over
time. Remove them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Convert __add_to_page_cache_locked() into __filemap_add_folio().
Add an assertion to it that (for !hugetlbfs), the folio is naturally
aligned within the file. Move the prototype from mm.h to pagemap.h.
Convert add_to_page_cache_lru() into filemap_add_folio(). Add a
compatibility wrapper for unconverted callers.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Mapping something twice should be possible as long as,
DMA_ATTR_SKIP_CPU_SYNC is passed to the strictly speaking second relevant
mapping operation (that attempts to map the same thing). So, don't issue a
warning if the specified condition is met in add_dma_entry().
Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Some drivers like Qualcomm pm8941-pwrkey need to access 'reboot_mode'
for triggering reboot between cold and warm mode. Export the symbol, so
that drivers built as module can still access the symbol.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20210714095850.27185-2-shawn.guo@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
- Fix defined but not use warning/error for osnoise function
- Fix memory leak in event probe
- Fix memblock leak in bootconfig
- Fix the API of event probes to be like kprobes
- Added test to check removal of event probe API
- Fix recordmcount.pl for nds32 failed build
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Merge tag 'trace-v5.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Tracing fixes for 5.15:
- Fix defined but not use warning/error for osnoise function
- Fix memory leak in event probe
- Fix memblock leak in bootconfig
- Fix the API of event probes to be like kprobes
- Added test to check removal of event probe API
- Fix recordmcount.pl for nds32 failed build
* tag 'trace-v5.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
nds32/ftrace: Fix Error: invalid operands (*UND* and *UND* sections) for `^'
selftests/ftrace: Update test for more eprobe removal process
tracing: Fix event probe removal from dynamic events
tracing: Fix missing * in comment block
bootconfig: init: Fix memblock leak in xbc_make_cmdline()
tracing: Fix memory leak in eprobe_register()
tracing: Fix missing osnoise tracer on max_latency
It is useful to trace functions in kernel/event/core.c. Allow ftrace for
them by removing $(CC_FLAGS_FTRACE) from Makefile.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211006210732.2826289-1-songliubraving@fb.com
PEBS-via-PT records contain a mask of applicable counters. To identify
which event belongs to which counter, a side-band event is needed. Until
now, there has been no side-band event, and consequently users were limited
to using a single event.
Add such a side-band event. Note the event is optimised to output only
when the counter index changes for an event. That works only so long as
all PEBS-via-PT events are scheduled together, which they are for a
recording session because they are in a single group.
Also no attribute bit is used to select the new event, so a new
kernel is not compatible with older perf tools. The assumption
being that PEBS-via-PT is sufficiently esoteric that users will not
be troubled by this.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210907163903.11820-2-adrian.hunter@intel.com
On PREEMPT_RT most items are processed as LAZY via softirq context.
Avoid to spin-wait for them because irq_work_sync() could have higher
priority and not allow the irq-work to be completed.
Wait additionally for !IRQ_WORK_HARD_IRQ irq_work items on PREEMPT_RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211006111852.1514359-5-bigeasy@linutronix.de
The irq_work callback is invoked in hard IRQ context. By default all
callbacks are scheduled for invocation right away (given supported by
the architecture) except for the ones marked IRQ_WORK_LAZY which are
delayed until the next timer-tick.
While looking over the callbacks, some of them may acquire locks
(spinlock_t, rwlock_t) which are transformed into sleeping locks on
PREEMPT_RT and must not be acquired in hard IRQ context.
Changing the locks into locks which could be acquired in this context
will lead to other problems such as increased latencies if everything
in the chain has IRQ-off locks. This will not solve all the issues as
one callback has been noticed which invoked kref_put() and its callback
invokes kfree() and this can not be invoked in hardirq context.
Some callbacks are required to be invoked in hardirq context even on
PREEMPT_RT to work properly. This includes for instance the NO_HZ
callback which needs to be able to observe the idle context.
The callbacks which require to be run in hardirq have already been
marked. Use this information to split the callbacks onto the two lists
on PREEMPT_RT:
- lazy_list
Work items which are not marked with IRQ_WORK_HARD_IRQ will be added
to this list. Callbacks on this list will be invoked from a per-CPU
thread.
The handler here may acquire sleeping locks such as spinlock_t and
invoke kfree().
- raised_list
Work items which are marked with IRQ_WORK_HARD_IRQ will be added to
this list. They will be invoked in hardirq context and must not
acquire any sleeping locks.
The wake up of the per-CPU thread occurs from irq_work handler/
hardirq context. The thread runs with lowest RT priority to ensure it
runs before any SCHED_OTHER tasks do.
[bigeasy: melt tglx's irq_work_tick_soft() which splits irq_work_tick() into a
hard and soft variant. Collected fixes over time from Steven
Rostedt and Mike Galbraith. Move to per-CPU threads instead of
softirq as suggested by PeterZ.]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211007092646.uhshe3ut2wkrcfzv@linutronix.de
irq_work() triggers instantly an interrupt if supported by the
architecture. Otherwise the work will be processed on the next timer
tick. In worst case irq_work_sync() could spin up to a jiffy.
irq_work_sync() is usually used in tear down context which is fully
preemptible. Based on review irq_work_sync() is invoked from preemptible
context and there is one waiter at a time. This qualifies it to use
rcuwait for synchronisation.
Let irq_work_sync() synchronize with rcuwait if the architecture
processes irqwork via the timer tick.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211006111852.1514359-3-bigeasy@linutronix.de
The push-IPI logic for RT tasks expects to be invoked from hardirq
context. One reason is that a RT task on the remote CPU would block the
softirq processing on PREEMPT_RT and so avoid pulling / balancing the RT
tasks as intended.
Annotate root_domain::rto_push_work as IRQ_WORK_HARD_IRQ.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211006111852.1514359-2-bigeasy@linutronix.de
The compilers can't deal with obvious DCE vs that warning, resulting
in code like:
if (0) {
sched sched_statistics *stats;
stats = __schedstats_from_se(se);
...
}
triggering the warning. Kill the warning to make the robots stop
reporting this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lkml.kernel.org/r/YWWPLnaZGybHsTkv@hirez.programming.kicks-ass.net
Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm]
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
tools/testing/selftests/net/ioam6.sh
7b1700e009 ("selftests: net: modify IOAM tests for undef bits")
bf77b1400a ("selftests: net: Test for the IOAM encapsulation with IPv6")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The number of system calls making use of pidfds is constantly
increasing. Some of those new system calls duplicate the code to turn a
pidfd into task_struct it refers to. Give them a simple helper for this.
Link: https://lore.kernel.org/r/20211004125050.1153693-2-christian.brauner@ubuntu.com
Link: https://lore.kernel.org/r/20211011133245.1703103-2-brauner@kernel.org
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Matthew Bobrowski <repnop@google.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Reviewed-by: Matthew Bobrowski <repnop@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
There is a small race between copy_process() and sched_fork()
where child->sched_task_group point to an already freed pointer.
parent doing fork() | someone moving the parent
| to another cgroup
-------------------------------+-------------------------------
copy_process()
+ dup_task_struct()<1>
parent move to another cgroup,
and free the old cgroup. <2>
+ sched_fork()
+ __set_task_cpu()<3>
+ task_fork_fair()
+ sched_slice()<4>
In the worst case, this bug can lead to "use-after-free" and
cause panic as shown above:
(1) parent copy its sched_task_group to child at <1>;
(2) someone move the parent to another cgroup and free the old
cgroup at <2>;
(3) the sched_task_group and cfs_rq that belong to the old cgroup
will be accessed at <3> and <4>, which cause a panic:
[] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[] PGD 8000001fa0a86067 P4D 8000001fa0a86067 PUD 2029955067 PMD 0
[] Oops: 0000 [#1] SMP PTI
[] CPU: 7 PID: 648398 Comm: ebizzy Kdump: loaded Tainted: G OE --------- - - 4.18.0.x86_64+ #1
[] RIP: 0010:sched_slice+0x84/0xc0
[] Call Trace:
[] task_fork_fair+0x81/0x120
[] sched_fork+0x132/0x240
[] copy_process.part.5+0x675/0x20e0
[] ? __handle_mm_fault+0x63f/0x690
[] _do_fork+0xcd/0x3b0
[] do_syscall_64+0x5d/0x1d0
[] entry_SYSCALL_64_after_hwframe+0x65/0xca
[] RIP: 0033:0x7f04418cd7e1
Between cgroup_can_fork() and cgroup_post_fork(), the cgroup
membership and thus sched_task_group can't change. So update child's
sched_task_group at sched_post_fork() and move task_fork() and
__set_task_cpu() (where accees the sched_task_group) from sched_fork()
to sched_post_fork().
Fixes: 8323f26ce3 ("sched: Fix race in task_group")
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lkml.kernel.org/r/20210915064030.2231-1-zhangqiao22@huawei.com
numa_distance in cpu_attach_domain() is introduced in
commit b5b217346d ("sched/topology: Warn when NUMA diameter > 2")
to warn user when NUMA diameter > 2 as we'll misrepresent
the scheduler topology structures at that time. This is
fixed by Barry in commit 585b6d2723 ("sched/topology: fix the issue
groups don't span domain->span for NUMA diameter > 2") and
numa_distance is unused now. So remove it.
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20210915063158.80639-1-yangyicong@hisilicon.com
Fix a few comments to help understand them better.
Signed-off-by: Bharata B Rao <bharata@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20211004105706.3669-4-bharata@amd.com
numa_group::fault_cpus is actually a pointer to the region
in numa_group::faults[] where NUMA_CPU stats are located.
Remove this redundant member and use numa_group::faults[NUMA_CPU]
directly like it is done for similar per-process numa fault stats.
There is no functionality change due to this commit.
Signed-off-by: Bharata B Rao <bharata@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20211004105706.3669-3-bharata@amd.com
While allocating group fault stats, task_numa_group()
is using a hard coded number 4. Replace this by
NR_NUMA_HINT_FAULT_STATS.
No functionality change in this commit.
Signed-off-by: Bharata B Rao <bharata@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20211004105706.3669-2-bharata@amd.com
Make sure to prod idle CPUs so they call klp_update_patch_state().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com> # on s390
Link: https://lkml.kernel.org/r/20210929151723.162004989@infradead.org
When an event probe is to be removed via the API that created it via the
dynamic events, an -ENOENT error is returned.
This is because the removal of the event probe does not expect to see the
event system and name that the event probe is attached to, even though
that's part of the API to create it. As the removal of probes is to use
the same API as they are created.
In fact, the removal is not consistent with the kprobes and uprobes
removal. Fix that by allowing various ways to remove the eprobe.
The eprobe is created with:
e:[GROUP/]NAME SYSTEM/EVENT [OPTIONS]
Have it get removed by echoing in the following into dynamic_events:
# Remove all eprobes with NAME
echo '-:NAME' >> dynamic_events
# Remove a specific eprobe
echo '-:GROUP/NAME' >> dynamic_events
echo '-:GROUP/NAME SYSTEM/EVENT' >> dynamic_events
echo '-:NAME SYSTEM/EVENT' >> dynamic_events
echo '-:GROUP/NAME SYSTEM/EVENT OPTIONS' >> dynamic_events
echo '-:NAME SYSTEM/EVENT OPTIONS' >> dynamic_events
Link: https://lkml.kernel.org/r/20211012081925.0e19cc4f@gandalf.local.home
Link: https://lkml.kernel.org/r/20211013205533.630722129@goodmis.org
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Replace the obsolete and ambiguos macro in_irq() with new
macro in_hardirq().
Link: https://lkml.kernel.org/r/20210930000342.6016-1-changbin.du@gmail.com
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull cgroup fixes from Tejun Heo:
"All documentation / comment updates"
* 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroupv2, docs: fix misinformation in "device controller" section
cgroup/cpuset: Change references of cpuset_mutex to cpuset_rwsem
docs/cgroup: remove some duplicate words
Pull workqueue fixes from Tejun Heo:
"One patch to add a missing __printf annotation and the other to enable
deferred printing for debug dumps to avoid deadlocks when triggered
from some contexts (e.g. console drivers)"
* 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix state-dump console deadlock
workqueue: annotate alloc_workqueue() as printf
Console drivers often queue work while holding locks also taken in their
console write paths, something which can lead to deadlocks on SMP when
dumping workqueue state (e.g. sysrq-t or on suspend failures).
For serial console drivers this could look like:
CPU0 CPU1
---- ----
show_workqueue_state();
lock(&pool->lock); <IRQ>
lock(&port->lock);
schedule_work();
lock(&pool->lock);
printk();
lock(console_owner);
lock(&port->lock);
where workqueues are, for example, used to push data to the line
discipline, process break signals and handle modem-status changes. Line
disciplines and serdev drivers can also queue work on write-wakeup
notifications, etc.
Reworking every console driver to avoid queuing work while holding locks
also taken in their write paths would complicate drivers and is neither
desirable or feasible.
Instead use the deferred-printk mechanism to avoid printing while
holding pool locks when dumping workqueue state.
Note that there are a few WARN_ON() assertions in the workqueue code
which could potentially also trigger a deadlock. Hopefully the ongoing
printk rework will provide a general solution for this eventually.
This was originally reported after a lockdep splat when executing
sysrq-t with the imx serial driver.
Fixes: 3494fc3084 ("workqueue: dump workqueues on sysrq-t")
Cc: stable@vger.kernel.org # 4.0
Reported-by: Fabio Estevam <festevam@denx.de>
Tested-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
The following warning occurred sporadically on s390:
DMA-API: nvme 0006:00:00.0: device driver maps memory from kernel text or rodata [addr=0000000048cc5e2f] [len=131072]
WARNING: CPU: 4 PID: 825 at kernel/dma/debug.c:1083 check_for_illegal_area+0xa8/0x138
It is a false-positive warning, due to broken logic in debug_dma_map_sg().
check_for_illegal_area() checks for overlay of sg elements with kernel text
or rodata. It is called with sg_dma_len(s) instead of s->length as
parameter. After the call to ->map_sg(), sg_dma_len() will contain the
length of possibly combined sg elements in the DMA address space, and not
the individual sg element length, which would be s->length.
The check will then use the physical start address of an sg element, and
add the DMA length for the overlap check, which could result in the false
warning, because the DMA length can be larger than the actual single sg
element length.
In addition, the call to check_for_illegal_area() happens in the iteration
over mapped_ents, which will not include all individual sg elements if
any of them were combined in ->map_sg().
Fix this by using s->length instead of sg_dma_len(s). Also put the call to
check_for_illegal_area() in a separate loop, iterating over all the
individual sg elements ("nents" instead of "mapped_ents").
While at it, as suggested by Robin Murphy, also move check_for_stack()
inside the new loop, as it is similarly concerned with validating the
individual sg elements.
Link: https://lore.kernel.org/lkml/20210705185252.4074653-1-gerald.schaefer@linux.ibm.com
Fixes: 884d05970b ("dma-debug: use sg_dma_len accessor")
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
htmldocs began producing the following warnings:
kernel/dma/mapping.c:256: WARNING: Definition list ends without a
blank line; unexpected unindent.
kernel/dma/mapping.c:257: WARNING: Bullet list ends without a blank
line; unexpected unindent.
Reformatting the list without hyphens fixes the warnings and produces
both a readable text and HTML output.
Fixes: fffe3cc8c2 ("dma-mapping: allow map_sg() ops to return negative error code")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Most of ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common
ftrace_dyn_arch_init() to cleanup them.
Link: https://lkml.kernel.org/r/20210909090216.1955240-1-o451686892@gmail.com
Acked-by: Heiko Carstens <hca@linux.ibm.com> (s390)
Acked-by: Helge Deller <deller@gmx.de> (parisc)
Signed-off-by: Weizhao Ouyang <o451686892@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When building the files in the tracefs file system, do not by default set
any permissions for OTH (other). This will make it easier for admins who
want to define a group for accessing tracefs and not having to first
disable all the permission bits for "other" in the file system.
As tracing can leak sensitive information, it should never by default
allowing all users access. An admin can still set the permission bits for
others to have access, which may be useful for creating a honeypot and
seeing who takes advantage of it and roots the machine.
Link: https://lkml.kernel.org/r/20210818153038.864149276@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
With "make install", bpftool installs its binary and its bash completion
file. Usually, this is what we want. But a few components in the kernel
repository (namely, BPF iterators and selftests) also install bpftool
locally before using it. In such a case, bash completion is not
necessary and is just a useless build artifact.
Let's add an "install-bin" target to bpftool, to offer a way to install
the binary only.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-13-quentin@isovalent.com
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that bpf/preload/iterators/Makefile
installs the headers properly when building.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-8-quentin@isovalent.com
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that bpf/preload/Makefile installs the
headers properly when building.
Note that we declare an additional dependency for iterators/iterators.o:
having $(LIBBPF_A) as a dependency to "$(obj)/bpf_preload_umd" is not
sufficient, as it makes it required only at the linking step. But we
need libbpf to be compiled, and in particular its headers to be
exported, before we attempt to compile iterators.o. The issue would not
occur before this commit, because libbpf's headers were not exported and
were always available under tools/lib/bpf.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-7-quentin@isovalent.com
Today when a signal is delivered with a handler of SIG_DFL whose
default behavior is to generate a core dump not only that process but
every process that shares the mm is killed.
In the case of vfork this looks like a real world problem. Consider
the following well defined sequence.
if (vfork() == 0) {
execve(...);
_exit(EXIT_FAILURE);
}
If a signal that generates a core dump is received after vfork but
before the execve changes the mm the process that called vfork will
also be killed (as the mm is shared).
Similarly if the execve fails after the point of no return the kernel
delivers SIGSEGV which will kill both the exec'ing process and because
the mm is shared the process that called vfork as well.
As far as I can tell this behavior is a violation of people's
reasonable expectations, POSIX, and is unnecessarily fragile when the
system is low on memory.
Solve this by making a userspace visible change to only kill a single
process/thread group. This is possible because Jann Horn recently
modified[1] the coredump code so that the mm can safely be modified
while the coredump is happening. With LinuxThreads long gone I don't
expect anyone to have a notice this behavior change in practice.
To accomplish this move the core_state pointer from mm_struct to
signal_struct, which allows different thread groups to coredump
simultatenously.
In zap_threads remove the work to kill anything except for the current
thread group.
v2: Remove core_state from the VM_BUG_ON_MM print to fix
compile failure when CONFIG_DEBUG_VM is enabled.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
[1] a07279c9a8 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3")
History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133
Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
vmlinux.o: warning: objtool: rcu_nmi_enter()+0x36: call to __kasan_check_read() leaves .noinstr.text section
noinstr cannot have atomic_*() functions in because they're explicitly
annotated, use arch_atomic_*().
Fixes: 2be57f7328 ("rcu: Weaken ->dynticks accesses and updates")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
RCU managed to grow a few noinstr violations:
vmlinux.o: warning: objtool: rcu_dynticks_eqs_enter()+0x0: call to rcu_dynticks_task_trace_enter() leaves .noinstr.text section
vmlinux.o: warning: objtool: rcu_dynticks_eqs_exit()+0xe: call to rcu_dynticks_task_trace_exit() leaves .noinstr.text section
Fix them by adding __always_inline to the relevant trivial functions.
Also replace the noinstr with __always_inline for the existing
rcu_dynticks_task_*() functions since noinstr would force noinline
them, even when empty, which seems silly.
Fixes: 7d0c9c50c5 ("rcu-tasks: Avoid IPIing userspace/idle tasks if kernel is so built")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
netfilter, and wireless.
Current release - regressions:
- xfrm: fix XFRM_MSG_MAPPING ABI breakage caused by inserting
a new value in the middle of an enum
- unix: fix an issue in unix_shutdown causing the other end
read/write failures
- phy: mdio: fix memory leak
Current release - new code bugs:
- mlx5e: improve MQPRIO resiliency against bad configs
Previous releases - regressions:
- bpf: fix integer overflow leading to OOB access in map element
pre-allocation
- stmmac: dwmac-rk: fix ethernet on rk3399 based devices
- netfilter: conntrack: fix boot failure with nf_conntrack.enable_hooks=1
- brcmfmac: revert using ISO3166 country code and 0 rev as fallback
- i40e: fix freeing of uninitialized misc IRQ vector
- iavf: fix double unlock of crit_lock
Previous releases - always broken:
- bpf, arm: fix register clobbering in div/mod implementation
- netfilter: nf_tables: correct issues in netlink rule change
event notifications
- dsa: tag_dsa: fix mask for trunked packets
- usb: r8152: don't resubmit rx immediately to avoid soft lockup
on device unplug
- i40e: fix endless loop under rtnl if FW fails to correctly
respond to capability query
- mlx5e: fix rx checksum offload coexistence with ipsec offload
- mlx5: force round second at 1PPS out start time and allow it
only in supported clock modes
- phy: pcs: xpcs: fix incorrect CL37 AN sequence, EEE disable
sequence
Misc:
- xfrm: slightly rejig the new policy uAPI to make it less cryptic
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from xfrm, bpf, netfilter, and wireless.
Current release - regressions:
- xfrm: fix XFRM_MSG_MAPPING ABI breakage caused by inserting a new
value in the middle of an enum
- unix: fix an issue in unix_shutdown causing the other end
read/write failures
- phy: mdio: fix memory leak
Current release - new code bugs:
- mlx5e: improve MQPRIO resiliency against bad configs
Previous releases - regressions:
- bpf: fix integer overflow leading to OOB access in map element
pre-allocation
- stmmac: dwmac-rk: fix ethernet on rk3399 based devices
- netfilter: conntrack: fix boot failure with
nf_conntrack.enable_hooks=1
- brcmfmac: revert using ISO3166 country code and 0 rev as fallback
- i40e: fix freeing of uninitialized misc IRQ vector
- iavf: fix double unlock of crit_lock
Previous releases - always broken:
- bpf, arm: fix register clobbering in div/mod implementation
- netfilter: nf_tables: correct issues in netlink rule change event
notifications
- dsa: tag_dsa: fix mask for trunked packets
- usb: r8152: don't resubmit rx immediately to avoid soft lockup on
device unplug
- i40e: fix endless loop under rtnl if FW fails to correctly respond
to capability query
- mlx5e: fix rx checksum offload coexistence with ipsec offload
- mlx5: force round second at 1PPS out start time and allow it only
in supported clock modes
- phy: pcs: xpcs: fix incorrect CL37 AN sequence, EEE disable
sequence
Misc:
- xfrm: slightly rejig the new policy uAPI to make it less cryptic"
* tag 'net-5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (66 commits)
net: prefer socket bound to interface when not in VRF
iavf: fix double unlock of crit_lock
i40e: Fix freeing of uninitialized misc IRQ vector
i40e: fix endless loop under rtnl
dt-bindings: net: dsa: marvell: fix compatible in example
ionic: move filter sync_needed bit set
gve: report 64bit tx_bytes counter from gve_handle_report_stats()
gve: fix gve_get_stats()
rtnetlink: fix if_nlmsg_stats_size() under estimation
gve: Properly handle errors in gve_assign_qpl
gve: Avoid freeing NULL pointer
gve: Correct available tx qpl check
unix: Fix an issue in unix_shutdown causing the other end read/write failures
net: stmmac: trigger PCS EEE to turn off on link down
net: pcs: xpcs: fix incorrect steps on disable EEE
netlink: annotate data races around nlk->bound
net: pcs: xpcs: fix incorrect CL37 AN sequence
net: sfp: Fix typo in state machine debug string
net/sched: sch_taprio: properly cancel timer from taprio_destroy()
net: bridge: fix under estimation in br_get_linkxstats_size()
...
Daniel Borkmann says:
====================
pull-request: bpf 2021-10-07
We've added 7 non-merge commits during the last 8 day(s) which contain
a total of 8 files changed, 38 insertions(+), 21 deletions(-).
The main changes are:
1) Fix ARM BPF JIT to preserve caller-saved regs for DIV/MOD JIT-internal
helper call, from Johan Almbladh.
2) Fix integer overflow in BPF stack map element size calculation when
used with preallocation, from Tatsuhiko Yasumatsu.
3) Fix an AF_UNIX regression due to added BPF sockmap support related
to shutdown handling, from Jiang Wang.
4) Fix a segfault in libbpf when generating light skeletons from objects
without BTF, from Kumar Kartikeya Dwivedi.
5) Fix a libbpf memory leak in strset to free the actual struct strset
itself, from Andrii Nakryiko.
6) Dual-license bpf_insn.h similarly as we did for libbpf and bpftool,
with ACKs from all contributors, from Luca Boccassi.
====================
Link: https://lore.kernel.org/r/20211007135010.21143-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The upper and lower variables are set as link lists to add into the sparse
array. If they are NULL, after the needed allocations are done, then there
is nothing to add. But they need to be initialized to NULL for this to
work.
Link: https://lore.kernel.org/all/221bc7ba-a475-1cb9-1bbe-730bb9c2d448@canonical.com/
Fixes: 8d6e90983a ("tracing: Create a sparse bitmask for pid filtering")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The compiler warns when the data are actually unused:
kernel/trace/trace.c:1712:13: error: ‘trace_create_maxlat_file’ defined but not used [-Werror=unused-function]
1712 | static void trace_create_maxlat_file(struct trace_array *tr,
| ^~~~~~~~~~~~~~~~~~~~~~~~
[Why]
CONFIG_HWLAT_TRACER=n, CONFIG_TRACER_MAX_TRACE=n, CONFIG_OSNOISE_TRACER=y
gcc report warns.
[How]
Now trace_create_maxlat_file will only take effect when
CONFIG_HWLAT_TRACER=y or CONFIG_TRACER_MAX_TRACE=y. In fact, after
adding osnoise trace, it also needs to take effect.
Link: https://lore.kernel.org/all/c1d9e328-ad7c-920b-6c24-9e1598a6421c@infradead.org/
Link: https://lkml.kernel.org/r/20210922025122.3268022-1-liu.yun@linux.dev
Fixes: bce29ac9ce ("trace: Add osnoise tracer")
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Simplify and make wake_up_if_idle() more robust, also don't iterate
the whole machine with preempt_disable() in it's caller:
wake_up_all_idle_cpus().
This prepares for another wake_up_if_idle() user that needs a full
do_idle() cycle.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com> # on s390
Link: https://lkml.kernel.org/r/20210929152428.769328779@infradead.org
Instead of frobbing around with scheduler internals, use the shiny new
task_call_func() interface.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com> # on s390
Link: https://lkml.kernel.org/r/20210929152428.709906138@infradead.org
Give try_invoke_on_locked_down_task() a saner name and have it return
an int so that the caller might distinguish between different reasons
of failure.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com> # on s390
Link: https://lkml.kernel.org/r/20210929152428.649944917@infradead.org
Clarify and tighten try_invoke_on_locked_down_task().
Basically the function calls @func under task_rq_lock(), except it
avoids taking rq->lock when possible.
This makes calling @func unconditional (the function will get renamed
in a later patch to remove the try).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com> # on s390
Link: https://lkml.kernel.org/r/20210929152428.589323576@infradead.org
Add support to wait on multiple futexes. This is the interface
implemented by this syscall:
futex_waitv(struct futex_waitv *waiters, unsigned int nr_futexes,
unsigned int flags, struct timespec *timeout, clockid_t clockid)
struct futex_waitv {
__u64 val;
__u64 uaddr;
__u32 flags;
__u32 __reserved;
};
Given an array of struct futex_waitv, wait on each uaddr. The thread
wakes if a futex_wake() is performed at any uaddr. The syscall returns
immediately if any waiter has *uaddr != val. *timeout is an optional
absolute timeout value for the operation. This syscall supports only
64bit sized timeout structs. The flags argument of the syscall should be
empty, but it can be used for future extensions. Flags for shared
futexes, sizes, etc. should be used on the individual flags of each
waiter.
__reserved is used for explicit padding and should be 0, but it might be
used for future extensions. If the userspace uses 32-bit pointers, it
should make sure to explicitly cast it when assigning to waitv::uaddr.
Returns the array index of one of the woken futexes. There’s no given
information of how many were woken, or any particular attribute of it
(if it’s the first woken, if it is of the smaller index...).
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210923171111.300673-17-andrealmeid@collabora.com
We need to make sure that all requeue operations take the hash bucket
locks in the same order to avoid deadlock. Simplify the current
double_lock_hb implementation by making sure hb1 is always the
"smallest" bucket to avoid extra checks.
[André: Add commit description]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-16-andrealmeid@collabora.com
Move the wait/wake bits into their own file.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-15-andrealmeid@collabora.com
Move all the requeue bits into their own file.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-14-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename:
s/mark_wake_futex/futex_wake_mark/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-13-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename:
s/match_futex/futex_match/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-12-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename them:
s/hb_waiters_/futex_&/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-11-andrealmeid@collabora.com
Move the PI futex implementation into it's own file.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-10-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename them:
s/\<\([^_ ]*\)_futex_value_locked/futex_\1_value_locked/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-9-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename:
s/hash_futex/futex_hash/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-8-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename:
s/__unqueue_futex/__futex_unqueue/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-7-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename them:
s/queue_\(un\)*lock/futex_q_\1lock/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-6-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename them:
s/futex_wait_queue_me/futex_wait_queue/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-5-andrealmeid@collabora.com
In order to prepare introducing these symbols into the global
namespace; rename them:
s/\<\(__\)*\(un\)*queue_me/\1futex_\2queue/g
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-4-andrealmeid@collabora.com
Put the syscalls in their own little file.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-3-andrealmeid@collabora.com
In preparation for splitup..
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@collabora.com>
Link: https://lore.kernel.org/r/20210923171111.300673-2-andrealmeid@collabora.com
Instead of a full barrier around the Rmw insn, micro-optimize
for weakly ordered archs such that we only provide the required
ACQUIRE semantics when taking the read lock.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20210920052031.54220-2-dave@stgolabs.net
Rename coredump_exit_mm to coredump_task_exit and call it from do_exit
before PTRACE_EVENT_EXIT, and before any cleanup work for a task
happens. This ensures that an accurate copy of the process can be
captured in the coredump as no cleanup for the process happens before
the coredump completes. This also ensures that PTRACE_EVENT_EXIT
will not be visited by any thread until the coredump is complete.
Add a new flag PF_POSTCOREDUMP so that tasks that have passed through
coredump_task_exit can be recognized and ignored in zap_process.
Now that all of the coredumping happens before exit_mm remove code to
test for a coredump in progress from mm_release.
Replace "may_ptrace_stop()" with a simple test of "current->ptrace".
The other tests in may_ptrace_stop all concern avoiding stopping
during a coredump. These tests are no longer necessary as it is now
guaranteed that fatal_signal_pending will be set if the code enters
ptrace_stop during a coredump. The code in ptrace_stop is guaranteed
not to stop if fatal_signal_pending returns true.
Until this change "ptrace_event(PTRACE_EVENT_EXIT)" could call
ptrace_stop without fatal_signal_pending being true, as signals are
dequeued in get_signal before calling do_exit. This is no longer
an issue as "ptrace_event(PTRACE_EVENT_EXIT)" is no longer reached
until after the coredump completes.
Link: https://lkml.kernel.org/r/874kaax26c.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Separate the coredump logic from the ordinary exit_mm logic
by moving the coredump logic out of exit_mm into it's own
function coredump_exit_mm.
Link: https://lkml.kernel.org/r/87a6k2x277.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Both arch_ptrace_stop_needed and arch_ptrace_stop are called with an
exit_code and a siginfo structure. Neither argument is used by any of
the implementations so just remove the unneeded arguments.
The two arechitectures that implement arch_ptrace_stop are ia64 and
sparc. Both architectures flush their register stacks before a
ptrace_stack so that all of the register information can be accessed
by debuggers.
As the question of if a register stack needs to be flushed is
independent of why ptrace is stopping not needing arguments make sense.
Cc: David Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Link: https://lkml.kernel.org/r/87lf3mx290.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The existence of sigkill_pending is a little silly as it is
functionally a duplicate of fatal_signal_pending that is used in
exactly one place.
Checking for pending fatal signals and returning early in ptrace_stop
is actively harmful. It casues the ptrace_stop called by
ptrace_signal to return early before setting current->exit_code.
Later when ptrace_signal reads the signal number from
current->exit_code is undefined, making it unpredictable what will
happen.
Instead rely on the fact that schedule will not sleep if there is a
pending signal that can awaken a task.
Removing the explict sigkill_pending test fixes fixes ptrace_signal
when ptrace_stop does not stop because current->exit_code is always
set to to signr.
Cc: stable@vger.kernel.org
Fixes: 3d749b9e67 ("ptrace: simplify ptrace_stop()->sigkill_pending() path")
Fixes: 1a669c2f16 ("Add arch_ptrace_stop")
Link: https://lkml.kernel.org/r/87pmsyx29t.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
When !SCHEDSTATS schedstat_enabled() is an unconditional 0 and the
whole block doesn't exist, however GCC figures the scoped variable
'stats' is unused and complains about it.
Upgrade the warning from -Wunused-variable to -Wunused-but-set-variable
by writing it in two statements. This fixes the build because the new
warning is in W=1.
Given that whole if(0) {} thing, I don't feel motivated to change
things overly much and quite strongly feel this is the compiler being
daft.
Fixes: cb3e971c435d ("sched: Make struct sched_statistics independent of fair sched class")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This adds selftests that tests the success and failure path for modules
kfuncs (in presence of invalid kfunc calls) for both libbpf and
gen_loader. It also adds a prog_test kfunc_btf_id_list so that we can
add module BTF ID set from bpf_testmod.
This also introduces a couple of test cases to verifier selftests for
validating whether we get an error or not depending on if invalid kfunc
call remains after elimination of unreachable instructions.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-10-memxor@gmail.com
This commit moves BTF ID lookup into the newly added registration
helper, in a way that the bbr, cubic, and dctcp implementation set up
their sets in the bpf_tcp_ca kfunc_btf_set list, while the ones not
dependent on modules are looked up from the wrapper function.
This lifts the restriction for them to be compiled as built in objects,
and can be loaded as modules if required. Also modify Makefile.modfinal
to call resolve_btfids for each module.
Note that since kernel kfunc_ids never overlap with module kfunc_ids, we
only match the owner for module btf id sets.
See following commits for background on use of:
CONFIG_X86 ifdef:
569c484f99 (bpf: Limit static tcp-cc functions in the .BTF_ids list to x86)
CONFIG_DYNAMIC_FTRACE ifdef:
7aae231ac9 (bpf: tcp: Limit calling some tcp cc functions to CONFIG_DYNAMIC_FTRACE)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-6-memxor@gmail.com
This adds helpers for registering btf_id_set from modules and the
bpf_check_mod_kfunc_call callback that can be used to look them up.
With in kernel sets, the way this is supposed to work is, in kernel
callback looks up within the in-kernel kfunc whitelist, and then defers
to the dynamic BTF set lookup if it doesn't find the BTF id. If there is
no in-kernel BTF id set, this callback can be used directly.
Also fix includes for btf.h and bpfptr.h so that they can included in
isolation. This is in preparation for their usage in tcp_bbr, tcp_cubic
and tcp_dctcp modules in the next patch.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-4-memxor@gmail.com
This patch also modifies the BPF verifier to only return error for
invalid kfunc calls specially marked by userspace (with insn->imm == 0,
insn->off == 0) after the verifier has eliminated dead instructions.
This can be handled in the fixup stage, and skip processing during add
and check stages.
If such an invalid call is dropped, the fixup stage will not encounter
insn->imm as 0, otherwise it bails out and returns an error.
This will be exposed as weak ksym support in libbpf in later patches.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-3-memxor@gmail.com
This change adds support on the kernel side to allow for BPF programs to
call kernel module functions. Userspace will prepare an array of module
BTF fds that is passed in during BPF_PROG_LOAD using fd_array parameter.
In the kernel, the module BTFs are placed in the auxilliary struct for
bpf_prog, and loaded as needed.
The verifier then uses insn->off to index into the fd_array. insn->off
0 is reserved for vmlinux BTF (for backwards compat), so userspace must
use an fd_array index > 0 for module kfunc support. kfunc_btf_tab is
sorted based on offset in an array, and each offset corresponds to one
descriptor, with a max limit up to 256 such module BTFs.
We also change existing kfunc_tab to distinguish each element based on
imm, off pair as each such call will now be distinct.
Another change is to check_kfunc_call callback, which now include a
struct module * pointer, this is to be used in later patch such that the
kfunc_id and module pointer are matched for dynamically registered BTF
sets from loadable modules, so that same kfunc_id in two modules doesn't
lead to check_kfunc_call succeeding. For the duration of the
check_kfunc_call, the reference to struct module exists, as it returns
the pointer stored in kfunc_btf_tab.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-2-memxor@gmail.com
When the trace_pid_list was created, the default pid max was 32768.
Creating a bitmask that can hold one bit for all 32768 took up 4096 (one
page). Having a one page bitmask was not much of a problem, and that was
used for mapping pids. But today, systems are bigger and can run more
tasks, and now the default pid_max is usually set to 4194304. Which means
to handle that many pids requires 524288 bytes. Worse yet, the pid_max can
be set to 2^30 (1073741824 or 1G) which would take 134217728 (128M) of
memory to store this array.
Since the pid_list array is very sparsely populated, it is a huge waste of
memory to store all possible bits for each pid when most will not be set.
Instead, use a page table scheme to store the array, and allow this to
handle up to 30 bit pids.
The pid_mask will start out with 256 entries for the first 8 MSB bits.
This will cost 1K for 32 bit architectures and 2K for 64 bit. Each of
these will have a 256 array to store the next 8 bits of the pid (another
1 or 2K). These will hold an 2K byte bitmask (which will cover the LSB
14 bits or 16384 pids).
When the trace_pid_list is allocated, it will have the 1/2K upper bits
allocated, and then it will allocate a cache for the next upper chunks and
the lower chunks (default 6 of each). Then when a bit is "set", these
chunks will be pulled from the free list and added to the array. If the
free list gets down to a lever (default 2), it will trigger an irqwork
that will refill the cache back up.
On clearing a bit, if the clear causes the bitmask to be zero, that chunk
will then be placed back into the free cache for later use, keeping the
need to allocate more down to a minimum.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of having the logic that does trace_pid_list open coded, wrap it in
abstract functions. This will allow a rewrite of the logic that implements
the trace_pid_list without affecting the users.
Note, this causes a change in behavior. Every time a pid is written into
the set_*_pid file, it creates a new list and uses RCU to update it. If
pid_max is lowered, but there was a pid currently in the list that was
higher than pid_max, those pids will now be removed on updating the list.
The old behavior kept that from happening.
The rewrite of the pid_list logic will no longer depend on pid_max,
and will return the old behavior.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Found an issue within cgroup_attach_task_all() fn which seem
to exclude cgrp_dfl_root (cgroupv2) while attaching tasks to
the given cgroup. This was noticed when the system was running
qemu/kvm with kernel vhost helper threads. It appears that the
vhost layer which uses cgroup_attach_task_all() fn to assign the
vhost kthread to the right qemu cgroup works fine with cgroupv1
based configuration but not in cgroupv2. With cgroupv2, the vhost
helper thread ends up just belonging to the root cgroup as is
shown below:
$ stat -fc %T /sys/fs/cgroup/
cgroup2fs
$ sudo pgrep qemu
1916421
$ ps -eL | grep 1916421
1916421 1916421 ? 00:00:01 qemu-system-x86
1916421 1916431 ? 00:00:00 call_rcu
1916421 1916435 ? 00:00:00 IO mon_iothread
1916421 1916436 ? 00:00:34 CPU 0/KVM
1916421 1916439 ? 00:00:00 SPICE Worker
1916421 1916440 ? 00:00:00 vnc_worker
1916433 1916433 ? 00:00:00 vhost-1916421
1916437 1916437 ? 00:00:00 kvm-pit/1916421
$ cat /proc/1916421/cgroup
0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator
$ cat /proc/1916439/cgroup
0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator
$ cat /proc/1916433/cgroup
0::/
From above, it can be seen that the vhost kthread (PID: 1916433)
doesn't seem to belong the qemu cgroup like other qemu PIDs.
After applying this patch:
$ pgrep qemu
1643
$ ps -eL | grep 1643
1643 1643 ? 00:00:00 qemu-system-x86
1643 1645 ? 00:00:00 call_rcu
1643 1648 ? 00:00:00 IO mon_iothread
1643 1649 ? 00:00:00 CPU 0/KVM
1643 1652 ? 00:00:00 SPICE Worker
1643 1653 ? 00:00:00 vnc_worker
1647 1647 ? 00:00:00 vhost-1643
1651 1651 ? 00:00:00 kvm-pit/1643
$ cat /proc/1647/cgroup
0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Vishal Verma <vverma@digitalocean.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The Energy Model has a 1:1 mapping between OPPs and performance states
(em_perf_state). If a CPUFreq driver registers an Energy Model,
inefficiencies found by the latter can be applied to CPUFreq.
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The new performance domain flag EM_PERF_DOMAIN_SKIP_INEFFICIENCIES allows
to not take into account inefficient states when estimating energy
consumption. This intends to let the Energy Model know that CPUFreq itself
will skip inefficiencies and such states don't need to be part of the
estimation anymore.
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge the current "milliwatts" option into a "flag" field. This intends to
prepare the extension of this structure for inefficient states support in
the Energy Model.
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some SoCs, such as the sd855 have OPPs within the same performance domain,
whose cost is higher than others with a higher frequency. Even though
those OPPs are interesting from a cooling perspective, it makes no sense
to use them when the device can run at full capacity. Those OPPs handicap
the performance domain, when choosing the most energy-efficient CPU and
are wasting energy. They are inefficient.
Hence, add support for such OPPs to the Energy Model. The table can now
be read skipping inefficient performance states (and by extension,
inefficient OPPs).
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently, a debug message is printed if an inefficient state is detected
in the Energy Model. Unfortunately, it won't detect if the first state is
inefficient or if two successive states are. Fix this behavior.
Fixes: 27871f7a8a (PM: Introduce an Energy Model management framework)
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Eric W. Biederman