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Merge tag 'for-5.15/drivers-2021-08-30' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
"Sitting on top of the core block changes, here are the driver changes
for the 5.15 merge window:
- NVMe updates via Christoph:
- suspend improvements for devices with an HMB (Keith Busch)
- handle double completions more gacefull (Sagi Grimberg)
- cleanup the selects for the nvme core code a bit (Sagi Grimberg)
- don't update queue count when failing to set io queues (Ruozhu Li)
- various nvmet connect fixes (Amit Engel)
- cleanup lightnvm leftovers (Keith Busch, me)
- small cleanups (Colin Ian King, Hou Pu)
- add tracing for the Set Features command (Hou Pu)
- CMB sysfs cleanups (Keith Busch)
- add a mutex_destroy call (Keith Busch)
- remove lightnvm subsystem. It's served its purpose and ultimately
led to zoned nvme support, we no longer need it (Christoph)
- revert floppy O_NDELAY fix (Denis)
- nbd fixes (Hou, Pavel, Baokun)
- nbd locking fixes (Tetsuo)
- nbd device removal fixes (Christoph)
- raid10 rcu warning fix (Xiao)
- raid1 write behind fix (Guoqing)
- rnbd fixes (Gioh, Md Haris)
- misc fixes (Colin)"
* tag 'for-5.15/drivers-2021-08-30' of git://git.kernel.dk/linux-block: (42 commits)
Revert "floppy: reintroduce O_NDELAY fix"
raid1: ensure write behind bio has less than BIO_MAX_VECS sectors
md/raid10: Remove unnecessary rcu_dereference in raid10_handle_discard
nbd: remove nbd->destroy_complete
nbd: only return usable devices from nbd_find_unused
nbd: set nbd->index before releasing nbd_index_mutex
nbd: prevent IDR lookups from finding partially initialized devices
nbd: reset NBD to NULL when restarting in nbd_genl_connect
nbd: add missing locking to the nbd_dev_add error path
nvme: remove the unused NVME_NS_* enum
nvme: remove nvm_ndev from ns
nvme: Have NVME_FABRICS select NVME_CORE instead of transport drivers
block: nbd: add sanity check for first_minor
nvmet: check that host sqsize does not exceed ctrl MQES
nvmet: avoid duplicate qid in connect cmd
nvmet: pass back cntlid on successful completion
nvme-rdma: don't update queue count when failing to set io queues
nvme-tcp: don't update queue count when failing to set io queues
nvme-tcp: pair send_mutex init with destroy
nvme: allow user toggling hmb usage
...
Daniel Borkmann says:
====================
bpf-next 2021-08-31
We've added 116 non-merge commits during the last 17 day(s) which contain
a total of 126 files changed, 6813 insertions(+), 4027 deletions(-).
The main changes are:
1) Add opaque bpf_cookie to perf link which the program can read out again,
to be used in libbpf-based USDT library, from Andrii Nakryiko.
2) Add bpf_task_pt_regs() helper to access userspace pt_regs, from Daniel Xu.
3) Add support for UNIX stream type sockets for BPF sockmap, from Jiang Wang.
4) Allow BPF TCP congestion control progs to call bpf_setsockopt() e.g. to switch
to another congestion control algorithm during init, from Martin KaFai Lau.
5) Extend BPF iterator support for UNIX domain sockets, from Kuniyuki Iwashima.
6) Allow bpf_{set,get}sockopt() calls from setsockopt progs, from Prankur Gupta.
7) Add bpf_get_netns_cookie() helper for BPF_PROG_TYPE_{SOCK_OPS,CGROUP_SOCKOPT}
progs, from Xu Liu and Stanislav Fomichev.
8) Support for __weak typed ksyms in libbpf, from Hao Luo.
9) Shrink struct cgroup_bpf by 504 bytes through refactoring, from Dave Marchevsky.
10) Fix a smatch complaint in verifier's narrow load handling, from Andrey Ignatov.
11) Fix BPF interpreter's tail call count limit, from Daniel Borkmann.
12) Big batch of improvements to BPF selftests, from Magnus Karlsson, Li Zhijian,
Yucong Sun, Yonghong Song, Ilya Leoshkevich, Jussi Maki, Ilya Leoshkevich, others.
13) Another big batch to revamp XDP samples in order to give them consistent look
and feel, from Kumar Kartikeya Dwivedi.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (116 commits)
MAINTAINERS: Remove self from powerpc BPF JIT
selftests/bpf: Fix potential unreleased lock
samples: bpf: Fix uninitialized variable in xdp_redirect_cpu
selftests/bpf: Reduce more flakyness in sockmap_listen
bpf: Fix bpf-next builds without CONFIG_BPF_EVENTS
bpf: selftests: Add dctcp fallback test
bpf: selftests: Add connect_to_fd_opts to network_helpers
bpf: selftests: Add sk_state to bpf_tcp_helpers.h
bpf: tcp: Allow bpf-tcp-cc to call bpf_(get|set)sockopt
selftests: xsk: Preface options with opt
selftests: xsk: Make enums lower case
selftests: xsk: Generate packets from specification
selftests: xsk: Generate packet directly in umem
selftests: xsk: Simplify cleanup of ifobjects
selftests: xsk: Decrease sending speed
selftests: xsk: Validate tx stats on tx thread
selftests: xsk: Simplify packet validation in xsk tests
selftests: xsk: Rename worker_* functions that are not thread entry points
selftests: xsk: Disassociate umem size with packets sent
selftests: xsk: Remove end-of-test packet
...
====================
Link: https://lore.kernel.org/r/20210830225618.11634-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Core code:
- Cure a couple of incorrectness issues in the posix CPU timer code to
prevent that the tick dependency for NOHZ full is kept alive for no
reason.
- Avoid expensive double reprogramming of the clockevent device in
hrtimer_start_range_ns().
- Avoid pointless SMP function calls when the clock was set to avoid
disturbing CPUs which do not have any affected timers queued.
- Make the clocksource watchdog test work correctly when CONFIG_HZ is
less than 100.
Drivers:
- Prefer the ARM architected timer over the Exynos timer which is way
more expensive to access.
- Add device tree bindings for new Ingenic SoCs
- The usual improvements and cleanups all over the place
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Merge tag 'timers-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"Updates for timekeeping, timers and related drivers:
Core code:
- Cure a couple of correctness issues in the posix CPU timer code to
prevent that the tick dependency for NOHZ full is kept alive for no
reason.
- Avoid expensive double reprogramming of the clockevent device in
hrtimer_start_range_ns().
- Avoid pointless SMP function calls when the clock was set to avoid
disturbing CPUs which do not have any affected timers queued.
- Make the clocksource watchdog test work correctly when CONFIG_HZ is
less than 100.
Drivers:
- Prefer the ARM architected timer over the Exynos timer which is way
more expensive to access.
- Add device tree bindings for new Ingenic SoCs
- The usual improvements and cleanups all over the place"
* tag 'timers-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
clocksource: Make clocksource watchdog test safe for slow-HZ systems
dt-bindings: timer: Add ABIs for new Ingenic SoCs
clocksource/drivers/fttmr010: Pass around less pointers
clocksource/drivers/mediatek: Optimize systimer irq clear flow on shutdown
clocksource/drivers/ingenic: Use bitfield macro helpers
clocksource/drivers/sh_cmt: Fix wrong setting if don't request IRQ for clock source channel
dt-bindings: timer: convert rockchip,rk-timer.txt to YAML
clocksource/drivers/exynos_mct: Mark MCT device as CLOCK_EVT_FEAT_PERCPU
clocksource/drivers/exynos_mct: Prioritise Arm arch timer on arm64
hrtimer: Unbreak hrtimer_force_reprogram()
hrtimer: Use raw_cpu_ptr() in clock_was_set()
hrtimer: Avoid more SMP function calls in clock_was_set()
hrtimer: Avoid unnecessary SMP function calls in clock_was_set()
hrtimer: Add bases argument to clock_was_set()
time/timekeeping: Avoid invoking clock_was_set() twice
timekeeping: Distangle resume and clock-was-set events
timerfd: Provide timerfd_resume()
hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y case
hrtimer: Ensure timerfd notification for HIGHRES=n
hrtimer: Consolidate reprogramming code
...
Core changes:
- The usual set of small fixes and improvements all over the place, but nothing
outstanding
MSI changes:
- Further consolidation of the PCI/MSI interrupt chip code
- Make MSI sysfs code independent of PCI/MSI and expose the MSI interrupts
of platform devices in the same way as PCI exposes them.
Driver changes:
- Support for ARM GICv3 EPPI partitions
- Treewide conversion to generic_handle_domain_irq() for all chained
interrupt controllers
- Conversion to bitmap_zalloc() throughout the irq chip drivers
- The usual set of small fixes and improvements
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Merge tag 'irq-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
"Updates to the interrupt core and driver subsystems:
Core changes:
- The usual set of small fixes and improvements all over the place,
but nothing stands out
MSI changes:
- Further consolidation of the PCI/MSI interrupt chip code
- Make MSI sysfs code independent of PCI/MSI and expose the MSI
interrupts of platform devices in the same way as PCI exposes them.
Driver changes:
- Support for ARM GICv3 EPPI partitions
- Treewide conversion to generic_handle_domain_irq() for all chained
interrupt controllers
- Conversion to bitmap_zalloc() throughout the irq chip drivers
- The usual set of small fixes and improvements"
* tag 'irq-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
platform-msi: Add ABI to show msi_irqs of platform devices
genirq/msi: Move MSI sysfs handling from PCI to MSI core
genirq/cpuhotplug: Demote debug printk to KERN_DEBUG
irqchip/qcom-pdc: Trim unused levels of the interrupt hierarchy
irqdomain: Export irq_domain_disconnect_hierarchy()
irqchip/gic-v3: Fix priority comparison when non-secure priorities are used
irqchip/apple-aic: Fix irq_disable from within irq handlers
pinctrl/rockchip: drop the gpio related codes
gpio/rockchip: drop irq_gc_lock/irq_gc_unlock for irq set type
gpio/rockchip: support next version gpio controller
gpio/rockchip: use struct rockchip_gpio_regs for gpio controller
gpio/rockchip: add driver for rockchip gpio
dt-bindings: gpio: change items restriction of clock for rockchip,gpio-bank
pinctrl/rockchip: add pinctrl device to gpio bank struct
pinctrl/rockchip: separate struct rockchip_pin_bank to a head file
pinctrl/rockchip: always enable clock for gpio controller
genirq: Fix kernel doc indentation
EDAC/altera: Convert to generic_handle_domain_irq()
powerpc: Bulk conversion to generic_handle_domain_irq()
nios2: Bulk conversion to generic_handle_domain_irq()
...
The regular pile:
- A few improvements to the mutex code
- Documentation updates for atomics to clarify the difference between
cmpxchg() and try_cmpxchg() and to explain the forward progress
expectations.
- Simplification of the atomics fallback generator
- The addition of arch_atomic_long*() variants and generic arch_*()
bitops based on them.
- Add the missing might_sleep() invocations to the down*() operations of
semaphores.
The PREEMPT_RT locking core:
- Scheduler updates to support the state preserving mechanism for
'sleeping' spin- and rwlocks on RT. This mechanism is carefully
preserving the state of the task when blocking on a 'sleeping' spin- or
rwlock and takes regular wake-ups targeted at the same task into
account. The preserved or updated (via a regular wakeup) state is
restored when the lock has been acquired.
- Restructuring of the rtmutex code so it can be utilized and extended
for the RT specific lock variants.
- Restructuring of the ww_mutex code to allow sharing of the ww_mutex
specific functionality for rtmutex based ww_mutexes.
- Header file disentangling to allow substitution of the regular lock
implementations with the PREEMPT_RT variants without creating an
unmaintainable #ifdef mess.
- Shared base code for the PREEMPT_RT specific rw_semaphore and rwlock
implementations. Contrary to the regular rw_semaphores and rwlocks the
PREEMPT_RT implementation is writer unfair because it is infeasible to
do priority inheritance on multiple readers. Experience over the years
has shown that real-time workloads are not the typical workloads which
are sensitive to writer starvation. The alternative solution would be
to allow only a single reader which has been tried and discarded as it
is a major bottleneck especially for mmap_sem. Aside of that many of
the writer starvation critical usage sites have been converted to a
writer side mutex/spinlock and RCU read side protections in the past
decade so that the issue is less prominent than it used to be.
- The actual rtmutex based lock substitutions for PREEMPT_RT enabled
kernels which affect mutex, ww_mutex, rw_semaphore, spinlock_t and
rwlock_t. The spin/rw_lock*() functions disable migration across the
critical section to preserve the existing semantics vs. per CPU
variables.
- Rework of the futex REQUEUE_PI mechanism to handle the case of early
wake-ups which interleave with a re-queue operation to prevent the
situation that a task would be blocked on both the rtmutex associated
to the outer futex and the rtmutex based hash bucket spinlock.
While this situation cannot happen on !RT enabled kernels the changes
make the underlying concurrency problems easier to understand in
general. As a result the difference between !RT and RT kernels is
reduced to the handling of waiting for the critical section. !RT
kernels simply spin-wait as before and RT kernels utilize rcu_wait().
- The substitution of local_lock for PREEMPT_RT with a spinlock which
protects the critical section while staying preemptible. The CPU
locality is established by disabling migration.
The underlying concepts of this code have been in use in PREEMPT_RT for
way more than a decade. The code has been refactored several times over
the years and this final incarnation has been optimized once again to be
as non-intrusive as possible, i.e. the RT specific parts are mostly
isolated.
It has been extensively tested in the 5.14-rt patch series and it has
been verified that !RT kernels are not affected by these changes.
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Merge tag 'locking-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and atomics updates from Thomas Gleixner:
"The regular pile:
- A few improvements to the mutex code
- Documentation updates for atomics to clarify the difference between
cmpxchg() and try_cmpxchg() and to explain the forward progress
expectations.
- Simplification of the atomics fallback generator
- The addition of arch_atomic_long*() variants and generic arch_*()
bitops based on them.
- Add the missing might_sleep() invocations to the down*() operations
of semaphores.
The PREEMPT_RT locking core:
- Scheduler updates to support the state preserving mechanism for
'sleeping' spin- and rwlocks on RT.
This mechanism is carefully preserving the state of the task when
blocking on a 'sleeping' spin- or rwlock and takes regular wake-ups
targeted at the same task into account. The preserved or updated
(via a regular wakeup) state is restored when the lock has been
acquired.
- Restructuring of the rtmutex code so it can be utilized and
extended for the RT specific lock variants.
- Restructuring of the ww_mutex code to allow sharing of the ww_mutex
specific functionality for rtmutex based ww_mutexes.
- Header file disentangling to allow substitution of the regular lock
implementations with the PREEMPT_RT variants without creating an
unmaintainable #ifdef mess.
- Shared base code for the PREEMPT_RT specific rw_semaphore and
rwlock implementations.
Contrary to the regular rw_semaphores and rwlocks the PREEMPT_RT
implementation is writer unfair because it is infeasible to do
priority inheritance on multiple readers. Experience over the years
has shown that real-time workloads are not the typical workloads
which are sensitive to writer starvation.
The alternative solution would be to allow only a single reader
which has been tried and discarded as it is a major bottleneck
especially for mmap_sem. Aside of that many of the writer
starvation critical usage sites have been converted to a writer
side mutex/spinlock and RCU read side protections in the past
decade so that the issue is less prominent than it used to be.
- The actual rtmutex based lock substitutions for PREEMPT_RT enabled
kernels which affect mutex, ww_mutex, rw_semaphore, spinlock_t and
rwlock_t. The spin/rw_lock*() functions disable migration across
the critical section to preserve the existing semantics vs per-CPU
variables.
- Rework of the futex REQUEUE_PI mechanism to handle the case of
early wake-ups which interleave with a re-queue operation to
prevent the situation that a task would be blocked on both the
rtmutex associated to the outer futex and the rtmutex based hash
bucket spinlock.
While this situation cannot happen on !RT enabled kernels the
changes make the underlying concurrency problems easier to
understand in general. As a result the difference between !RT and
RT kernels is reduced to the handling of waiting for the critical
section. !RT kernels simply spin-wait as before and RT kernels
utilize rcu_wait().
- The substitution of local_lock for PREEMPT_RT with a spinlock which
protects the critical section while staying preemptible. The CPU
locality is established by disabling migration.
The underlying concepts of this code have been in use in PREEMPT_RT for
way more than a decade. The code has been refactored several times over
the years and this final incarnation has been optimized once again to be
as non-intrusive as possible, i.e. the RT specific parts are mostly
isolated.
It has been extensively tested in the 5.14-rt patch series and it has
been verified that !RT kernels are not affected by these changes"
* tag 'locking-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (92 commits)
locking/rtmutex: Return success on deadlock for ww_mutex waiters
locking/rtmutex: Prevent spurious EDEADLK return caused by ww_mutexes
locking/rtmutex: Dequeue waiter on ww_mutex deadlock
locking/rtmutex: Dont dereference waiter lockless
locking/semaphore: Add might_sleep() to down_*() family
locking/ww_mutex: Initialize waiter.ww_ctx properly
static_call: Update API documentation
locking/local_lock: Add PREEMPT_RT support
locking/spinlock/rt: Prepare for RT local_lock
locking/rtmutex: Add adaptive spinwait mechanism
locking/rtmutex: Implement equal priority lock stealing
preempt: Adjust PREEMPT_LOCK_OFFSET for RT
locking/rtmutex: Prevent lockdep false positive with PI futexes
futex: Prevent requeue_pi() lock nesting issue on RT
futex: Simplify handle_early_requeue_pi_wakeup()
futex: Reorder sanity checks in futex_requeue()
futex: Clarify comment in futex_requeue()
futex: Restructure futex_requeue()
futex: Correct the number of requeued waiters for PI
futex: Remove bogus condition for requeue PI
...
- Replace get/put_online_cpus() in various places. The final removal will
happen shortly before v5.15-rc1 when the rest of the patches have been
merged.
- Add debug code to help the analysis of CPU hotplug failures
- A set of kernel doc updates
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Merge tag 'smp-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP core updates from Thomas Gleixner:
- Replace get/put_online_cpus() in various places. The final removal
will happen shortly before v5.15-rc1 when the rest of the patches
have been merged.
- Add debug code to help the analysis of CPU hotplug failures
- A set of kernel doc updates
* tag 'smp-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mm: Replace deprecated CPU-hotplug functions.
md/raid5: Replace deprecated CPU-hotplug functions.
Documentation: Replace deprecated CPU-hotplug functions.
smp: Fix all kernel-doc warnings
cpu/hotplug: Add debug printks for hotplug callback failures
cpu/hotplug: Use DEVICE_ATTR_*() macro
cpu/hotplug: Eliminate all kernel-doc warnings
cpu/hotplug: Fix kernel doc warnings for __cpuhp_setup_state_cpuslocked()
cpu/hotplug: Fix comment typo
smpboot: Replace deprecated CPU-hotplug functions.
- Add support for Intel Sapphire Rapids server CPU uncore events
- Allow the AMD uncore driver to be built as a module
- Misc cleanups and fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf event updates from Ingo Molnar:
- Add support for Intel Sapphire Rapids server CPU uncore events
- Allow the AMD uncore driver to be built as a module
- Misc cleanups and fixes
* tag 'perf-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
perf/x86/amd/ibs: Add bitfield definitions in new <asm/amd-ibs.h> header
perf/amd/uncore: Allow the driver to be built as a module
x86/cpu: Add get_llc_id() helper function
perf/amd/uncore: Clean up header use, use <linux/ include paths instead of <asm/
perf/amd/uncore: Simplify code, use free_percpu()'s built-in check for NULL
perf/hw_breakpoint: Replace deprecated CPU-hotplug functions
perf/x86/intel: Replace deprecated CPU-hotplug functions
perf/x86: Remove unused assignment to pointer 'e'
perf/x86/intel/uncore: Fix IIO cleanup mapping procedure for SNR/ICX
perf/x86/intel/uncore: Support IMC free-running counters on Sapphire Rapids server
perf/x86/intel/uncore: Support IIO free-running counters on Sapphire Rapids server
perf/x86/intel/uncore: Factor out snr_uncore_mmio_map()
perf/x86/intel/uncore: Add alias PMU name
perf/x86/intel/uncore: Add Sapphire Rapids server MDF support
perf/x86/intel/uncore: Add Sapphire Rapids server M3UPI support
perf/x86/intel/uncore: Add Sapphire Rapids server UPI support
perf/x86/intel/uncore: Add Sapphire Rapids server M2M support
perf/x86/intel/uncore: Add Sapphire Rapids server IMC support
perf/x86/intel/uncore: Add Sapphire Rapids server PCU support
perf/x86/intel/uncore: Add Sapphire Rapids server M2PCIe support
...
- The biggest change in this cycle is scheduler support for asymmetric
scheduling affinity, to support the execution of legacy 32-bit tasks on
AArch32 systems that also have 64-bit-only CPUs.
Architectures can fill in this functionality by defining their
own task_cpu_possible_mask(p). When this is done, the scheduler will
make sure the task will only be scheduled on CPUs that support it.
(The actual arm64 specific changes are not part of this tree.)
For other architectures there will be no change in functionality.
- Add cgroup SCHED_IDLE support
- Increase node-distance flexibility & delay determining it until a CPU
is brought online. (This enables platforms where node distance isn't
final until the CPU is only.)
- Deadline scheduler enhancements & fixes
- Misc fixes & cleanups.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- The biggest change in this cycle is scheduler support for asymmetric
scheduling affinity, to support the execution of legacy 32-bit tasks
on AArch32 systems that also have 64-bit-only CPUs.
Architectures can fill in this functionality by defining their own
task_cpu_possible_mask(p). When this is done, the scheduler will make
sure the task will only be scheduled on CPUs that support it.
(The actual arm64 specific changes are not part of this tree.)
For other architectures there will be no change in functionality.
- Add cgroup SCHED_IDLE support
- Increase node-distance flexibility & delay determining it until a CPU
is brought online. (This enables platforms where node distance isn't
final until the CPU is only.)
- Deadline scheduler enhancements & fixes
- Misc fixes & cleanups.
* tag 'sched-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
eventfd: Make signal recursion protection a task bit
sched/fair: Mark tg_is_idle() an inline in the !CONFIG_FAIR_GROUP_SCHED case
sched: Introduce dl_task_check_affinity() to check proposed affinity
sched: Allow task CPU affinity to be restricted on asymmetric systems
sched: Split the guts of sched_setaffinity() into a helper function
sched: Introduce task_struct::user_cpus_ptr to track requested affinity
sched: Reject CPU affinity changes based on task_cpu_possible_mask()
cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq()
cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus()
cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1
sched: Introduce task_cpu_possible_mask() to limit fallback rq selection
sched: Cgroup SCHED_IDLE support
sched/topology: Skip updating masks for non-online nodes
sched: Replace deprecated CPU-hotplug functions.
sched: Skip priority checks with SCHED_FLAG_KEEP_PARAMS
sched: Fix UCLAMP_FLAG_IDLE setting
sched/deadline: Fix missing clock update in migrate_task_rq_dl()
sched/fair: Avoid a second scan of target in select_idle_cpu
sched/fair: Use prev instead of new target as recent_used_cpu
sched: Don't report SCHED_FLAG_SUGOV in sched_getattr()
...
- Improve ftrace code patching so that stop_machine is not required anymore.
This requires a small common code patch acked by Steven Rostedt:
https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/
- Enable KCSAN for s390. This comes with a small common code change to fix a
compile warning. Acked by Marco Elver:
https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com
- Add KFENCE support for s390. This also comes with a minimal x86 patch from
Marco Elver who said also this can be carried via the s390 tree:
https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/
- More changes to prepare the decompressor for relocation.
- Enable DAT also for CPU restart path.
- Final set of register asm removal patches; leaving only three locations where
needed and sane.
- Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO support to
hwcaps flags.
- Cleanup hwcaps implementation.
- Add new instructions to in-kernel disassembler.
- Various QDIO cleanups.
- Add SCLP debug feature.
- Various other cleanups and improvements all over the place.
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Merge tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Heiko Carstens:
- Improve ftrace code patching so that stop_machine is not required
anymore. This requires a small common code patch acked by Steven
Rostedt:
https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/
- Enable KCSAN for s390. This comes with a small common code change to
fix a compile warning. Acked by Marco Elver:
https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com
- Add KFENCE support for s390. This also comes with a minimal x86 patch
from Marco Elver who said also this can be carried via the s390 tree:
https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/
- More changes to prepare the decompressor for relocation.
- Enable DAT also for CPU restart path.
- Final set of register asm removal patches; leaving only three
locations where needed and sane.
- Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO
support to hwcaps flags.
- Cleanup hwcaps implementation.
- Add new instructions to in-kernel disassembler.
- Various QDIO cleanups.
- Add SCLP debug feature.
- Various other cleanups and improvements all over the place.
* tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (105 commits)
s390: remove SCHED_CORE from defconfigs
s390/smp: do not use nodat_stack for secondary CPU start
s390/smp: enable DAT before CPU restart callback is called
s390: update defconfigs
s390/ap: fix state machine hang after failure to enable irq
KVM: s390: generate kvm hypercall functions
s390/sclp: add tracing of SCLP interactions
s390/debug: add early tracing support
s390/debug: fix debug area life cycle
s390/debug: keep debug data on resize
s390/diag: make restart_part2 a local label
s390/mm,pageattr: fix walk_pte_level() early exit
s390: fix typo in linker script
s390: remove do_signal() prototype and do_notify_resume() function
s390/crypto: fix all kernel-doc warnings in vfio_ap_ops.c
s390/pci: improve DMA translation init and exit
s390/pci: simplify CLP List PCI handling
s390/pci: handle FH state mismatch only on disable
s390/pci: fix misleading rc in clp_set_pci_fn()
s390/boot: factor out offset_vmlinux_info() function
...
Pull crypto updates from Herbert Xu:
"Algorithms:
- Add AES-NI/AVX/x86_64 implementation of SM4.
Drivers:
- Add Arm SMCCC TRNG based driver"
[ And obviously a lot of random fixes and updates - Linus]
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (84 commits)
crypto: sha512 - remove imaginary and mystifying clearing of variables
crypto: aesni - xts_crypt() return if walk.nbytes is 0
padata: Remove repeated verbose license text
crypto: ccp - Add support for new CCP/PSP device ID
crypto: x86/sm4 - add AES-NI/AVX2/x86_64 implementation
crypto: x86/sm4 - export reusable AESNI/AVX functions
crypto: rmd320 - remove rmd320 in Makefile
crypto: skcipher - in_irq() cleanup
crypto: hisilicon - check _PS0 and _PR0 method
crypto: hisilicon - change parameter passing of debugfs function
crypto: hisilicon - support runtime PM for accelerator device
crypto: hisilicon - add runtime PM ops
crypto: hisilicon - using 'debugfs_create_file' instead of 'debugfs_create_regset32'
crypto: tcrypt - add GCM/CCM mode test for SM4 algorithm
crypto: testmgr - Add GCM/CCM mode test of SM4 algorithm
crypto: tcrypt - Fix missing return value check
crypto: hisilicon/sec - modify the hardware endian configuration
crypto: hisilicon/sec - fix the abnormal exiting process
crypto: qat - store vf.compatible flag
crypto: qat - do not export adf_iov_putmsg()
...
Pull RCU updates from Paul McKenney:
"RCU changes for this cycle were:
- Documentation updates
- Miscellaneous fixes
- Offloaded-callbacks updates
- Updates to the nolibc library
- Tasks-RCU updates
- In-kernel torture-test updates
- Torture-test scripting, perhaps most notably the pinning of
torture-test guest OSes so as to force differences in memory
latency. For example, in a two-socket system, a four-CPU guest OS
will have one pair of its CPUs pinned to threads in a single core
on one socket and the other pair pinned to threads in a single core
on the other socket. This approach proved able to force race
conditions that earlier testing missed. Some of these race
conditions are still being tracked down"
* 'core-rcu.2021.08.28a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (61 commits)
torture: Replace deprecated CPU-hotplug functions.
rcu: Replace deprecated CPU-hotplug functions
rcu: Print human-readable message for schedule() in RCU reader
rcu: Explain why rcu_all_qs() is a stub in preemptible TREE RCU
rcu: Use per_cpu_ptr to get the pointer of per_cpu variable
rcu: Remove useless "ret" update in rcu_gp_fqs_loop()
rcu: Mark accesses in tree_stall.h
rcu: Make rcu_gp_init() and rcu_gp_fqs_loop noinline to conserve stack
rcu: Mark lockless ->qsmask read in rcu_check_boost_fail()
srcutiny: Mark read-side data races
rcu: Start timing stall repetitions after warning complete
rcu: Do not disable GP stall detection in rcu_cpu_stall_reset()
rcu/tree: Handle VM stoppage in stall detection
rculist: Unify documentation about missing list_empty_rcu()
rcu: Mark accesses to ->rcu_read_lock_nesting
rcu: Weaken ->dynticks accesses and updates
rcu: Remove special bit at the bottom of the ->dynticks counter
rcu: Fix stall-warning deadlock due to non-release of rcu_node ->lock
rcu: Fix to include first blocked task in stall warning
torture: Make kvm-test-1-run-qemu.sh check for reboot loops
...
As done before in commit cb4a316752 ("cgroup: use bitmask to filter
for_each_subsys"), avoid compiler warnings for the pathological case of
having no subsystems (i.e. CGROUP_SUBSYS_COUNT == 0). This condition is
hit for the arm multi_v7_defconfig config under -Wzero-length-bounds:
In file included from ./arch/arm/include/generated/asm/rwonce.h:1,
from include/linux/compiler.h:264,
from include/uapi/linux/swab.h:6,
from include/linux/swab.h:5,
from arch/arm/include/asm/opcodes.h:86,
from arch/arm/include/asm/bug.h:7,
from include/linux/bug.h:5,
from include/linux/thread_info.h:13,
from include/asm-generic/current.h:5,
from ./arch/arm/include/generated/asm/current.h:1,
from include/linux/sched.h:12,
from include/linux/cgroup.h:12,
from kernel/cgroup/cgroup-internal.h:5,
from kernel/cgroup/cgroup.c:31:
kernel/cgroup/cgroup.c: In function 'of_css':
kernel/cgroup/cgroup.c:651:42: warning: array subscript '<unknown>' is outside the bounds of an
interior zero-length array 'struct cgroup_subsys_state *[0]' [-Wzero-length-bounds]
651 | return rcu_dereference_raw(cgrp->subsys[cft->ss->id]);
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
* pm-pci:
PCI: PM: Enable PME if it can be signaled from D3cold
PCI: PM: Avoid forcing PCI_D0 for wakeup reasons inconsistently
PCI: Use pci_update_current_state() in pci_enable_device_flags()
* pm-sleep:
PM: sleep: unmark 'state' functions as kernel-doc
PM: sleep: check RTC features instead of ops in suspend_test
PM: sleep: s2idle: Replace deprecated CPU-hotplug functions
* pm-domains:
PM: domains: Fix domain attach for CONFIG_PM_OPP=n
arm64: dts: sc7180: Add required-opps for i2c
PM: domains: Add support for 'required-opps' to set default perf state
opp: Don't print an error if required-opps is missing
* powercap:
powercap: Add Power Limit4 support for Alder Lake SoC
powercap: intel_rapl: Replace deprecated CPU-hotplug functions
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Merge tag 'fsnotify_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify updates from Jan Kara:
"fsnotify speedups when notification actually isn't used and support
for identifying processes which caused fanotify events through pidfd
instead of normal pid"
* tag 'fsnotify_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
fsnotify: optimize the case of no marks of any type
fsnotify: count all objects with attached connectors
fsnotify: count s_fsnotify_inode_refs for attached connectors
fsnotify: replace igrab() with ihold() on attach connector
fanotify: add pidfd support to the fanotify API
fanotify: introduce a generic info record copying helper
fanotify: minor cosmetic adjustments to fid labels
kernel/pid.c: implement additional checks upon pidfd_create() parameters
kernel/pid.c: remove static qualifier from pidfd_create()
API updates:
- Treewide conversion to generic_handle_domain_irq() for anything
that looks like a chained interrupt controller
- Update the irqdomain documentation
- Use of bitmap_zalloc() throughout the tree
New functionalities:
- Support for GICv3 EPPI partitions
Fixes:
- Qualcomm PDC hierarchy fixes
- Yet another priority decoding fix for the GICv3 pseudo-NMIs
- Fix the apple-aic driver irq_eoi() callback to always unmask
the interrupt
- Properly handle edge interrupts on loongson-pch-pic
- Let the mtk-sysirq driver advertise IRQCHIP_SKIP_SET_WAKE
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Merge tag 'irqchip-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Pull irqchip updates from Marc Zyngier:
- API updates:
- Treewide conversion to generic_handle_domain_irq() for anything
that looks like a chained interrupt controller
- Update the irqdomain documentation
- Use of bitmap_zalloc() throughout the tree
- New functionalities:
- Support for GICv3 EPPI partitions
- Fixes:
- Qualcomm PDC hierarchy fixes
- Yet another priority decoding fix for the GICv3 pseudo-NMIs
- Fix the apple-aic driver irq_eoi() callback to always unmask
the interrupt
- Properly handle edge interrupts on loongson-pch-pic
- Let the mtk-sysirq driver advertise IRQCHIP_SKIP_SET_WAKE
Link: https://lore.kernel.org/r/20210828121013.2647964-1-maz@kernel.org
thus avoid useless invocations of the migration thread
- Rework initialization flow so that all rq->core's are initialized,
even of CPUs which have not been onlined yet, so that iterating over
them all works as expected
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Merge tag 'sched_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Borislav Petkov:
- Have get_push_task() check whether current has migration disabled and
thus avoid useless invocations of the migration thread
- Rework initialization flow so that all rq->core's are initialized,
even of CPUs which have not been onlined yet, so that iterating over
them all works as expected
* tag 'sched_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix get_push_task() vs migrate_disable()
sched: Fix Core-wide rq->lock for uninitialized CPUs
The clocksource watchdog test sets a local JIFFIES_SHIFT macro and assumes
that HZ is >= 100. For smaller HZ values this shift value is too large and
causes undefined behaviour.
Move the HZ-based definitions of JIFFIES_SHIFT from kernel/time/jiffies.c
to kernel/time/tick-internal.h so the clocksource watchdog test can utilize
them, which makes it work correctly with all HZ values.
[ tglx: Resolved conflicts and massaged changelog ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20210812000133.GA402890@paulmck-ThinkPad-P17-Gen-1/
If CONFIG_MODULES is n, we got this:
kernel/printk/index.c:146:13: warning: ‘pi_remove_file’ defined but not used [-Wunused-function]
Move it inside #ifdef block to fix this warning.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210804130105.18732-1-yuehaibing@huawei.com
ww_mutexes can legitimately cause a deadlock situation in the lock graph
which is resolved afterwards by the wait/wound mechanics. The rtmutex chain
walk can detect such a deadlock and returns EDEADLK which in turn skips the
wait/wound mechanism and returns EDEADLK to the caller. That's wrong
because both lock chains might get EDEADLK or the wrong waiter would back
out.
Detect that situation and return 'success' in case that the waiter which
initiated the chain walk is a ww_mutex with context. This allows the
wait/wound mechanics to resolve the situation according to the rules.
[ tglx: Split it apart and added changelog ]
Reported-by: Sebastian Siewior <bigeasy@linutronix.de>
Fixes: add461325e ("locking/rtmutex: Extend the rtmutex core to support ww_mutex")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/YSeWjCHoK4v5OcOt@hirez.programming.kicks-ass.net
rtmutex based ww_mutexes can legitimately create a cycle in the lock graph
which can be observed by a blocker which didn't cause the problem:
P1: A, ww_A, ww_B
P2: ww_B, ww_A
P3: A
P3 might therefore be trapped in the ww_mutex induced cycle and run into
the lock depth limitation of rt_mutex_adjust_prio_chain() which returns
-EDEADLK to the caller.
Disable the deadlock detection walk when the chain walk observes a
ww_mutex to prevent this looping.
[ tglx: Split it apart and added changelog ]
Reported-by: Sebastian Siewior <bigeasy@linutronix.de>
Fixes: add461325e ("locking/rtmutex: Extend the rtmutex core to support ww_mutex")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/YSeWjCHoK4v5OcOt@hirez.programming.kicks-ass.net
remove it because SPDX-License-Identifier is already used
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Replace get_nr_threads with atomic_read(¤t->signal->live) as
that is a more accurate number that is decremented sooner.
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87lf6z6qbd.fsf_-_@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Current release - regressions:
- stmmac: revert "stmmac: align RX buffers"
- usb: asix: ax88772: move embedded PHY detection as early as possible
- usb: asix: do not call phy_disconnect() for ax88178
- Revert "net: really fix the build...", from Kalle to fix QCA6390
Current release - new code bugs:
- phy: mediatek: add the missing suspend/resume callbacks
Previous releases - regressions:
- qrtr: fix another OOB Read in qrtr_endpoint_post
- stmmac: dwmac-rk: fix unbalanced pm_runtime_enable warnings
Previous releases - always broken:
- inet: use siphash in exception handling
- ip_gre: add validation for csum_start
- bpf: fix ringbuf helper function compatibility
- rtnetlink: return correct error on changing device netns
- e1000e: do not try to recover the NVM checksum on Tiger Lake
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Networking fixes, including fixes from can and bpf.
Closing three hw-dependent regressions. Any fixes of note are in the
'old code' category. Nothing blocking release from our perspective.
Current release - regressions:
- stmmac: revert "stmmac: align RX buffers"
- usb: asix: ax88772: move embedded PHY detection as early as
possible
- usb: asix: do not call phy_disconnect() for ax88178
- Revert "net: really fix the build...", from Kalle to fix QCA6390
Current release - new code bugs:
- phy: mediatek: add the missing suspend/resume callbacks
Previous releases - regressions:
- qrtr: fix another OOB Read in qrtr_endpoint_post
- stmmac: dwmac-rk: fix unbalanced pm_runtime_enable warnings
Previous releases - always broken:
- inet: use siphash in exception handling
- ip_gre: add validation for csum_start
- bpf: fix ringbuf helper function compatibility
- rtnetlink: return correct error on changing device netns
- e1000e: do not try to recover the NVM checksum on Tiger Lake"
* tag 'net-5.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (43 commits)
Revert "net: really fix the build..."
net: hns3: fix get wrong pfc_en when query PFC configuration
net: hns3: fix GRO configuration error after reset
net: hns3: change the method of getting cmd index in debugfs
net: hns3: fix duplicate node in VLAN list
net: hns3: fix speed unknown issue in bond 4
net: hns3: add waiting time before cmdq memory is released
net: hns3: clear hardware resource when loading driver
net: fix NULL pointer reference in cipso_v4_doi_free
rtnetlink: Return correct error on changing device netns
net: dsa: hellcreek: Adjust schedule look ahead window
net: dsa: hellcreek: Fix incorrect setting of GCL
cxgb4: dont touch blocked freelist bitmap after free
ipv4: use siphash instead of Jenkins in fnhe_hashfun()
ipv6: use siphash in rt6_exception_hash()
can: usb: esd_usb2: esd_usb2_rx_event(): fix the interchange of the CAN RX and TX error counters
net: usb: asix: ax88772: fix boolconv.cocci warnings
net/sched: ets: fix crash when flipping from 'strict' to 'quantum'
qede: Fix memset corruption
net: stmmac: fix kernel panic due to NULL pointer dereference of buf->xdp
...
push_rt_task() attempts to move the currently running task away if the
next runnable task has migration disabled and therefore is pinned on the
current CPU.
The current task is retrieved via get_push_task() which only checks for
nr_cpus_allowed == 1, but does not check whether the task has migration
disabled and therefore cannot be moved either. The consequence is a
pointless invocation of the migration thread which correctly observes
that the task cannot be moved.
Return NULL if the task has migration disabled and cannot be moved to
another CPU.
Fixes: a7c81556ec ("sched: Fix migrate_disable() vs rt/dl balancing")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210826133738.yiotqbtdaxzjsnfj@linutronix.de
Factor out force_sig_seccomp from the seccomp signal generation and
place it in kernel/signal.c. The function force_sig_seccomp takes a
parameter force_coredump to indicate that the sigaction field should
be reset to SIGDFL so that a coredump will be generated when the
signal is delivered.
force_sig_seccomp is then used to replace both seccomp_send_sigsys
and seccomp_init_siginfo.
force_sig_info_to_task gains an extra parameter to force using
the default signal action.
With this change seccomp is no longer a special case and there
becomes exactly one place do_coredump is called from.
Further it no longer becomes necessary for __seccomp_filter
to call do_group_exit.
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87r1gr6qc4.fsf_-_@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
It's not actually used in the !CONFIG_FAIR_GROUP_SCHED case:
kernel/sched/fair.c:488:12: warning: ‘tg_is_idle’ defined but not used [-Wunused-function]
Keep around a placeholder nevertheless, for API completeness. Mark it inline,
so the compiler doesn't think it must be used.
Fixes: 304000390f88: ("sched: Cgroup SCHED_IDLE support")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Don <joshdon@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().
Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210803141621.780504-12-bigeasy@linutronix.de
This commit fixes linker errors along the lines of:
s390-linux-ld: task_iter.c:(.init.text+0xa4): undefined reference to `btf_task_struct_ids'`
Fix by defining btf_task_struct_ids unconditionally in kernel/bpf/btf.c
since there exists code that unconditionally uses btf_task_struct_ids.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/05d94748d9f4b3eecedc4fddd6875418a396e23c.1629942444.git.dxu@dxuuu.xyz
This patch allows the bpf-tcp-cc to call bpf_setsockopt. One use
case is to allow a bpf-tcp-cc switching to another cc during init().
For example, when the tcp flow is not ecn ready, the bpf_dctcp
can switch to another cc by calling setsockopt(TCP_CONGESTION).
During setsockopt(TCP_CONGESTION), the new tcp-cc's init() will be
called and this could cause a recursion but it is stopped by the
current trampoline's logic (in the prog->active counter).
While retiring a bpf-tcp-cc (e.g. in tcp_v[46]_destroy_sock()),
the tcp stack calls bpf-tcp-cc's release(). To avoid the retiring
bpf-tcp-cc making further changes to the sk, bpf_setsockopt is not
available to the bpf-tcp-cc's release(). This will avoid release()
making setsockopt() call that will potentially allocate new resources.
Although the bpf-tcp-cc already has a more powerful way to read tcp_sock
from the PTR_TO_BTF_ID, it is usually expected that bpf_getsockopt and
bpf_setsockopt are available together. Thus, bpf_getsockopt() is also
added to all tcp_congestion_ops except release().
When the old bpf-tcp-cc is calling setsockopt(TCP_CONGESTION)
to switch to a new cc, the old bpf-tcp-cc will be released by
bpf_struct_ops_put(). Thus, this patch also puts the bpf_struct_ops_map
after a rcu grace period because the trampoline's image cannot be freed
while the old bpf-tcp-cc is still running.
bpf-tcp-cc can only access icsk_ca_priv as SCALAR. All kernel's
tcp-cc is also accessing the icsk_ca_priv as SCALAR. The size
of icsk_ca_priv has already been raised a few times to avoid
extra kmalloc and memory referencing. The only exception is the
kernel's tcp_cdg.c that stores a kmalloc()-ed pointer in icsk_ca_priv.
To avoid the old bpf-tcp-cc accidentally overriding this tcp_cdg's pointer
value stored in icsk_ca_priv after switching and without over-complicating
the bpf's verifier for this one exception in tcp_cdg, this patch does not
allow switching to tcp_cdg. If there is a need, bpf_tcp_cdg can be
implemented and then use the bpf_sk_storage as the extended storage.
bpf_sk_setsockopt proto has only been recently added and used
in bpf-sockopt and bpf-iter-tcp, so impose the tcp_cdg limitation in the
same proto instead of adding a new proto specifically for bpf-tcp-cc.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210824173007.3976921-1-kafai@fb.com
The motivation behind this helper is to access userspace pt_regs in a
kprobe handler.
uprobe's ctx is the userspace pt_regs. kprobe's ctx is the kernelspace
pt_regs. bpf_task_pt_regs() allows accessing userspace pt_regs in a
kprobe handler. The final case (kernelspace pt_regs in uprobe) is
pretty rare (usermode helper) so I think that can be solved later if
necessary.
More concretely, this helper is useful in doing BPF-based DWARF stack
unwinding. Currently the kernel can only do framepointer based stack
unwinds for userspace code. This is because the DWARF state machines are
too fragile to be computed in kernelspace [0]. The idea behind
DWARF-based stack unwinds w/ BPF is to copy a chunk of the userspace
stack (while in prog context) and send it up to userspace for unwinding
(probably with libunwind) [1]. This would effectively enable profiling
applications with -fomit-frame-pointer using kprobes and uprobes.
[0]: https://lkml.org/lkml/2012/2/10/356
[1]: https://github.com/danobi/bpf-dwarf-walk
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/e2718ced2d51ef4268590ab8562962438ab82815.1629772842.git.dxu@dxuuu.xyz
bpf_get_current_task() is already supported so it's natural to also
include the _btf() variant for btf-powered helpers.
This is required for non-tracing progs to use bpf_task_pt_regs() in the
next commit.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/f99870ed5f834c9803d73b3476f8272b1bb987c0.1629772842.git.dxu@dxuuu.xyz
Pull ucount fixes from Eric Biederman:
"This branch fixes a regression that made it impossible to increase
rlimits that had been converted to the ucount infrastructure, and also
fixes a reference counting bug where the reference was not incremented
soon enough.
The fixes are trivial and the bugs have been encountered in the wild,
and the fixes have been tested"
* 'for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ucounts: Increase ucounts reference counter before the security hook
ucounts: Fix regression preventing increasing of rlimits in init_user_ns
With the introduction of ee9707e859 ("cgroup/cpuset: Enable memory
migration for cpuset v2") attaching a process to a different cgroup will
trigger a memory migration regardless of whether it's really needed.
Memory migration is an expensive operation, so bypass it if the
nodemasks passed to cpuset_migrate_mm() are equal.
Note that we're not only avoiding the migration work itself, but also a
call to lru_cache_disable(), which triggers and flushes an LRU drain
work on every online CPU.
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The rt_mutex based ww_mutex variant queues the new waiter first in the
lock's rbtree before evaluating the ww_mutex specific conditions which
might decide that the waiter should back out. This check and conditional
exit happens before the waiter is enqueued into the PI chain.
The failure handling at the call site assumes that the waiter, if it is the
top most waiter on the lock, is queued in the PI chain and then proceeds to
adjust the unmodified PI chain, which results in RB tree corruption.
Dequeue the waiter from the lock waiter list in the ww_mutex error exit
path to prevent this.
Fixes: add461325e ("locking/rtmutex: Extend the rtmutex core to support ww_mutex")
Reported-by: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210825102454.042280541@linutronix.de
The new rt_mutex_spin_on_onwer() loop checks whether the spinning waiter is
still the top waiter on the lock by utilizing rt_mutex_top_waiter(), which
is broken because that function contains a sanity check which dereferences
the top waiter pointer to check whether the waiter belongs to the
lock. That's wrong in the lockless spinwait case:
CPU 0 CPU 1
rt_mutex_lock(lock) rt_mutex_lock(lock);
queue(waiter0)
waiter0 == rt_mutex_top_waiter(lock)
rt_mutex_spin_on_onwer(lock, waiter0) { queue(waiter1)
waiter1 == rt_mutex_top_waiter(lock)
...
top_waiter = rt_mutex_top_waiter(lock)
leftmost = rb_first_cached(&lock->waiters);
-> signal
dequeue(waiter1)
destroy(waiter1)
w = rb_entry(leftmost, ....)
BUG_ON(w->lock != lock) <- UAF
The BUG_ON() is correct for the case where the caller holds lock->wait_lock
which guarantees that the leftmost waiter entry cannot vanish. For the
lockless spinwait case it's broken.
Create a new helper function which avoids the pointer dereference and just
compares the leftmost entry pointer with current's waiter pointer to
validate that currrent is still elegible for spinning.
Fixes: 992caf7f17 ("locking/rtmutex: Add adaptive spinwait mechanism")
Reported-by: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210825102453.981720644@linutronix.de
AUDIT_TRIM is expected to be idempotent, but multiple executions resulted
in a refcount underflow and use-after-free.
git bisect fingered commit fb041bb7c0 ("locking/refcount: Consolidate
implementations of refcount_t") but this patch with its more thorough
checking that wasn't in the x86 assembly code merely exposed a previously
existing tree refcount imbalance in the case of tree trimming code that
was refactored with prune_one() to remove a tree introduced in
commit 8432c70062 ("audit: Simplify locking around untag_chunk()")
Move the put_tree() to cover only the prune_one() case.
Passes audit-testsuite and 3 passes of "auditctl -t" with at least one
directory watch.
Cc: Jan Kara <jack@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Seiji Nishikawa <snishika@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 8432c70062 ("audit: Simplify locking around untag_chunk()")
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
[PM: reformatted/cleaned-up the commit description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Fix a verifier bug found by smatch static checker in [0].
This problem has never been seen in prod to my best knowledge. Fixing it
still seems to be a good idea since it's hard to say for sure whether
it's possible or not to have a scenario where a combination of
convert_ctx_access() and a narrow load would lead to an out of bound
write.
When narrow load is handled, one or two new instructions are added to
insn_buf array, but before it was only checked that
cnt >= ARRAY_SIZE(insn_buf)
And it's safe to add a new instruction to insn_buf[cnt++] only once. The
second try will lead to out of bound write. And this is what can happen
if `shift` is set.
Fix it by making sure that if the BPF_RSH instruction has to be added in
addition to BPF_AND then there is enough space for two more instructions
in insn_buf.
The full report [0] is below:
kernel/bpf/verifier.c:12304 convert_ctx_accesses() warn: offset 'cnt' incremented past end of array
kernel/bpf/verifier.c:12311 convert_ctx_accesses() warn: offset 'cnt' incremented past end of array
kernel/bpf/verifier.c
12282
12283 insn->off = off & ~(size_default - 1);
12284 insn->code = BPF_LDX | BPF_MEM | size_code;
12285 }
12286
12287 target_size = 0;
12288 cnt = convert_ctx_access(type, insn, insn_buf, env->prog,
12289 &target_size);
12290 if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf) ||
^^^^^^^^^^^^^^^^^^^^^^^^^^^
Bounds check.
12291 (ctx_field_size && !target_size)) {
12292 verbose(env, "bpf verifier is misconfigured\n");
12293 return -EINVAL;
12294 }
12295
12296 if (is_narrower_load && size < target_size) {
12297 u8 shift = bpf_ctx_narrow_access_offset(
12298 off, size, size_default) * 8;
12299 if (ctx_field_size <= 4) {
12300 if (shift)
12301 insn_buf[cnt++] = BPF_ALU32_IMM(BPF_RSH,
^^^^^
increment beyond end of array
12302 insn->dst_reg,
12303 shift);
--> 12304 insn_buf[cnt++] = BPF_ALU32_IMM(BPF_AND, insn->dst_reg,
^^^^^
out of bounds write
12305 (1 << size * 8) - 1);
12306 } else {
12307 if (shift)
12308 insn_buf[cnt++] = BPF_ALU64_IMM(BPF_RSH,
12309 insn->dst_reg,
12310 shift);
12311 insn_buf[cnt++] = BPF_ALU64_IMM(BPF_AND, insn->dst_reg,
^^^^^^^^^^^^^^^
Same.
12312 (1ULL << size * 8) - 1);
12313 }
12314 }
12315
12316 new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
12317 if (!new_prog)
12318 return -ENOMEM;
12319
12320 delta += cnt - 1;
12321
12322 /* keep walking new program and skip insns we just inserted */
12323 env->prog = new_prog;
12324 insn = new_prog->insnsi + i + delta;
12325 }
12326
12327 return 0;
12328 }
[0] https://lore.kernel.org/bpf/20210817050843.GA21456@kili/
v1->v2:
- clarify that problem was only seen by static checker but not in prod;
Fixes: 46f53a65d2 ("bpf: Allow narrow loads with offset > 0")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210820163935.1902398-1-rdna@fb.com
Move PCI's MSI sysfs code to the irq core so that other busses such as
platform can reuse it.
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210813035628.6844-2-21cnbao@gmail.com
This sort of information is only generally useful when debugging.
No need to have these sprinkled through the kernel log otherwise.
Real world problem:
During pre-release testing these have an affect on performance on
real products. To the point where so much logging builds up, that
it sets off the watchdog(s) on some high profile consumer devices.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210816134817.1503661-1-lee.jones@linaro.org
Add an enum (cgroup_bpf_attach_type) containing only valid cgroup_bpf
attach types and a function to map bpf_attach_type values to the new
enum. Inspired by netns_bpf_attach_type.
Then, migrate cgroup_bpf to use cgroup_bpf_attach_type wherever
possible. Functionality is unchanged as attach_type_to_prog_type
switches in bpf/syscall.c were preventing non-cgroup programs from
making use of the invalid cgroup_bpf array slots.
As a result struct cgroup_bpf uses 504 fewer bytes relative to when its
arrays were sized using MAX_BPF_ATTACH_TYPE.
bpf_cgroup_storage is notably not migrated as struct
bpf_cgroup_storage_key is part of uapi and contains a bpf_attach_type
member which is not meant to be opaque. Similarly, bpf_cgroup_link
continues to report its bpf_attach_type member to userspace via fdinfo
and bpf_link_info.
To ease disambiguation, bpf_attach_type variables are renamed from
'type' to 'atype' when changed to cgroup_bpf_attach_type.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210819092420.1984861-2-davemarchevsky@fb.com
"Ma, XinjianX" <xinjianx.ma@intel.com> reported:
> When lkp team run kernel selftests, we found after these series of patches, testcase mqueue: mq_perf_tests
> in kselftest failed with following message.
>
> # selftests: mqueue: mq_perf_tests
> #
> # Initial system state:
> # Using queue path: /mq_perf_tests
> # RLIMIT_MSGQUEUE(soft): 819200
> # RLIMIT_MSGQUEUE(hard): 819200
> # Maximum Message Size: 8192
> # Maximum Queue Size: 10
> # Nice value: 0
> #
> # Adjusted system state for testing:
> # RLIMIT_MSGQUEUE(soft): (unlimited)
> # RLIMIT_MSGQUEUE(hard): (unlimited)
> # Maximum Message Size: 16777216
> # Maximum Queue Size: 65530
> # Nice value: -20
> # Continuous mode: (disabled)
> # CPUs to pin: 3
> # ./mq_perf_tests: mq_open() at 296: Too many open files
> not ok 2 selftests: mqueue: mq_perf_tests # exit=1
> ```
>
> Test env:
> rootfs: debian-10
> gcc version: 9
After investigation the problem turned out to be that ucount_max for
the rlimits in init_user_ns was being set to the initial rlimit value.
The practical problem is that ucount_max provides a limit that
applications inside the user namespace can not exceed. Which means in
practice that rlimits that have been converted to use the ucount
infrastructure were not able to exceend their initial rlimits.
Solve this by setting the relevant values of ucount_max to
RLIM_INIFINITY. A limit in init_user_ns is pointless so the code
should allow the values to grow as large as possible without riscking
an underflow or an overflow.
As the ltp test case was a bit of a pain I have reproduced the rlimit failure
and tested the fix with the following little C program:
> #include <stdio.h>
> #include <fcntl.h>
> #include <sys/stat.h>
> #include <mqueue.h>
> #include <sys/time.h>
> #include <sys/resource.h>
> #include <errno.h>
> #include <string.h>
> #include <stdlib.h>
> #include <limits.h>
> #include <unistd.h>
>
> int main(int argc, char **argv)
> {
> struct mq_attr mq_attr;
> struct rlimit rlim;
> mqd_t mqd;
> int ret;
>
> ret = getrlimit(RLIMIT_MSGQUEUE, &rlim);
> if (ret != 0) {
> fprintf(stderr, "getrlimit(RLIMIT_MSGQUEUE) failed: %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
> printf("RLIMIT_MSGQUEUE %lu %lu\n",
> rlim.rlim_cur, rlim.rlim_max);
> rlim.rlim_cur = RLIM_INFINITY;
> rlim.rlim_max = RLIM_INFINITY;
> ret = setrlimit(RLIMIT_MSGQUEUE, &rlim);
> if (ret != 0) {
> fprintf(stderr, "setrlimit(RLIMIT_MSGQUEUE, RLIM_INFINITY) failed: %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
>
> memset(&mq_attr, 0, sizeof(struct mq_attr));
> mq_attr.mq_maxmsg = 65536 - 1;
> mq_attr.mq_msgsize = 16*1024*1024 - 1;
>
> mqd = mq_open("/mq_rlimit_test", O_RDONLY|O_CREAT, 0600, &mq_attr);
> if (mqd == (mqd_t)-1) {
> fprintf(stderr, "mq_open failed: %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
> ret = mq_close(mqd);
> if (ret) {
> fprintf(stderr, "mq_close failed; %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
>
> return EXIT_SUCCESS;
> }
Fixes: 6e52a9f053 ("Reimplement RLIMIT_MSGQUEUE on top of ucounts")
Fixes: d7c9e99aee ("Reimplement RLIMIT_MEMLOCK on top of ucounts")
Fixes: d646969055 ("Reimplement RLIMIT_SIGPENDING on top of ucounts")
Fixes: 21d1c5e386 ("Reimplement RLIMIT_NPROC on top of ucounts")
Reported-by: kernel test robot lkp@intel.com
Acked-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/87eeajswfc.fsf_-_@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Commit 457f44363a ("bpf: Implement BPF ring buffer and verifier support
for it") extended check_map_func_compatibility() by enforcing map -> helper
function match, but not helper -> map type match.
Due to this all of the bpf_ringbuf_*() helper functions could be used with
a wrong map type such as array or hash map, leading to invalid access due
to type confusion.
Also, both BPF_FUNC_ringbuf_{submit,discard} have ARG_PTR_TO_ALLOC_MEM as
argument and not a BPF map. Therefore, their check_map_func_compatibility()
presence is incorrect since it's only for map type checking.
Fixes: 457f44363a ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: Ryota Shiga (Flatt Security)
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
When doing cancellation, we use a parameter to indicate where it's from
do_exit or exec. So a boolean value is good enough for this, remove the
struct files* as it is not necessary.
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
[axboe: fixup io_uring_files_cancel for !CONFIG_IO_URING]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A new dynamic event is introduced: event probe. The event is attached
to an existing tracepoint and uses its fields as arguments. The user
can specify custom format string of the new event, select what tracepoint
arguments will be printed and how to print them.
An event probe is created by writing configuration string in
'dynamic_events' ftrace file:
e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe
-:SNAME/ENAME - Delete an event probe
Where:
SNAME - System name, if omitted 'eprobes' is used.
ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used.
SYSTEM - Name of the system, where the tracepoint is defined, mandatory.
EVENT - Name of the tracepoint event in SYSTEM, mandatory.
FETCHARGS - Arguments:
<name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print
it as given TYPE with given name. Supported
types are:
(u8/u16/u32/u64/s8/s16/s32/s64), basic type
(x8/x16/x32/x64), hexadecimal types
"string", "ustring" and bitfield.
Example, attach an event probe on openat system call and print name of the
file that will be opened:
echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events
A new dynamic event is created in events/esys/eopen/ directory. It
can be deleted with:
echo "-:esys/eopen" >> dynamic_events
Filters, triggers and histograms can be attached to the new event, it can
be matched in synthetic events. There is one limitation - an event probe
can not be attached to kprobe, uprobe or another event probe.
Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com
Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Semaphore is sleeping lock. Add might_sleep() to down*() family
(with exception of down_trylock()) to detect atomic context sleep.
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210809021215.19991-1-nixiaoming@huawei.com
In preparation for restricting the affinity of a task during execve()
on arm64, introduce a new dl_task_check_affinity() helper function to
give an indication as to whether the restricted mask is admissible for
a deadline task.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lore.kernel.org/r/20210730112443.23245-10-will@kernel.org
Asymmetric systems may not offer the same level of userspace ISA support
across all CPUs, meaning that some applications cannot be executed by
some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do
not feature support for 32-bit applications on both clusters.
Although userspace can carefully manage the affinity masks for such
tasks, one place where it is particularly problematic is execve()
because the CPU on which the execve() is occurring may be incompatible
with the new application image. In such a situation, it is desirable to
restrict the affinity mask of the task and ensure that the new image is
entered on a compatible CPU. From userspace's point of view, this looks
the same as if the incompatible CPUs have been hotplugged off in the
task's affinity mask. Similarly, if a subsequent execve() reverts to
a compatible image, then the old affinity is restored if it is still
valid.
In preparation for restricting the affinity mask for compat tasks on
arm64 systems without uniform support for 32-bit applications, introduce
{force,relax}_compatible_cpus_allowed_ptr(), which respectively restrict
and restore the affinity mask for a task based on the compatible CPUs.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210730112443.23245-9-will@kernel.org
In preparation for replaying user affinity requests using a saved mask,
split sched_setaffinity() up so that the initial task lookup and
security checks are only performed when the request is coming directly
from userspace.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-8-will@kernel.org
In preparation for saving and restoring the user-requested CPU affinity
mask of a task, add a new cpumask_t pointer to 'struct task_struct'.
If the pointer is non-NULL, then the mask is copied across fork() and
freed on task exit.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-7-will@kernel.org
Reject explicit requests to change the affinity mask of a task via
set_cpus_allowed_ptr() if the requested mask is not a subset of the
mask returned by task_cpu_possible_mask(). This ensures that the
'cpus_mask' for a given task cannot contain CPUs which are incapable of
executing it, except in cases where the affinity is forced.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210730112443.23245-6-will@kernel.org
select_fallback_rq() only needs to recheck for an allowed CPU if the
affinity mask of the task has changed since the last check.
Return a 'bool' from cpuset_cpus_allowed_fallback() to indicate whether
the affinity mask was updated, and use this to elide the allowed check
when the mask has been left alone.
No functional change.
Suggested-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-5-will@kernel.org
Asymmetric systems may not offer the same level of userspace ISA support
across all CPUs, meaning that some applications cannot be executed by
some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do
not feature support for 32-bit applications on both clusters.
Modify guarantee_online_cpus() to take task_cpu_possible_mask() into
account when trying to find a suitable set of online CPUs for a given
task. This will avoid passing an invalid mask to set_cpus_allowed_ptr()
during ->attach() and will subsequently allow the cpuset hierarchy to be
taken into account when forcefully overriding the affinity mask for a
task which requires migration to a compatible CPU.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lkml.kernel.org/r/20210730112443.23245-4-will@kernel.org
If the scheduler cannot find an allowed CPU for a task,
cpuset_cpus_allowed_fallback() will widen the affinity to cpu_possible_mask
if cgroup v1 is in use.
In preparation for allowing architectures to provide their own fallback
mask, just return early if we're either using cgroup v1 or we're using
cgroup v2 with a mask that contains invalid CPUs. This will allow
select_fallback_rq() to figure out the mask by itself.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lkml.kernel.org/r/20210730112443.23245-3-will@kernel.org
Asymmetric systems may not offer the same level of userspace ISA support
across all CPUs, meaning that some applications cannot be executed by
some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do
not feature support for 32-bit applications on both clusters.
On such a system, we must take care not to migrate a task to an
unsupported CPU when forcefully moving tasks in select_fallback_rq()
in response to a CPU hot-unplug operation.
Introduce a task_cpu_possible_mask() hook which, given a task argument,
allows an architecture to return a cpumask of CPUs that are capable of
executing that task. The default implementation returns the
cpu_possible_mask, since sane machines do not suffer from per-cpu ISA
limitations that affect scheduling. The new mask is used when selecting
the fallback runqueue as a last resort before forcing a migration to the
first active CPU.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210730112443.23245-2-will@kernel.org
This extends SCHED_IDLE to cgroups.
Interface: cgroup/cpu.idle.
0: default behavior
1: SCHED_IDLE
Extending SCHED_IDLE to cgroups means that we incorporate the existing
aspects of SCHED_IDLE; a SCHED_IDLE cgroup will count all of its
descendant threads towards the idle_h_nr_running count of all of its
ancestor cgroups. Thus, sched_idle_rq() will work properly.
Additionally, SCHED_IDLE cgroups are configured with minimum weight.
There are two key differences between the per-task and per-cgroup
SCHED_IDLE interface:
- The cgroup interface allows tasks within a SCHED_IDLE hierarchy to
maintain their relative weights. The entity that is "idle" is the
cgroup, not the tasks themselves.
- Since the idle entity is the cgroup, our SCHED_IDLE wakeup preemption
decision is not made by comparing the current task with the woken
task, but rather by comparing their matching sched_entity.
A typical use-case for this is a user that creates an idle and a
non-idle subtree. The non-idle subtree will dominate competition vs
the idle subtree, but the idle subtree will still be high priority vs
other users on the system. The latter is accomplished via comparing
matching sched_entity in the waken preemption path (this could also be
improved by making the sched_idle_rq() decision dependent on the
perspective of a specific task).
For now, we maintain the existing SCHED_IDLE semantics. Future patches
may make improvements that extend how we treat SCHED_IDLE entities.
The per-task_group idle field is an integer that currently only holds
either a 0 or a 1. This is explicitly typed as an integer to allow for
further extensions to this API. For example, a negative value may
indicate a highly latency-sensitive cgroup that should be preferred
for preemption/placement/etc.
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20210730020019.1487127-2-joshdon@google.com
The scheduler currently expects NUMA node distances to be stable from
init onwards, and as a consequence builds the related data structures
once-and-for-all at init (see sched_init_numa()).
Unfortunately, on some architectures node distance is unreliable for
offline nodes and may very well change upon onlining.
Skip over offline nodes during sched_init_numa(). Track nodes that have
been onlined at least once, and trigger a build of a node's NUMA masks
when it is first onlined post-init.
Reported-by: Geetika Moolchandani <Geetika.Moolchandani1@ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210818074333.48645-1-srikar@linux.vnet.ibm.com
Eugene tripped over the case where rq_lock(), as called in a
for_each_possible_cpu() loop came apart because rq->core hadn't been
setup yet.
This is a somewhat unusual, but valid case.
Rework things such that rq->core is initialized to point at itself. IOW
initialize each CPU as a single threaded Core. CPU online will then join
the new CPU (thread) to an existing Core where needed.
For completeness sake, have CPU offline fully undo the state so as to
not presume the topology will match the next time it comes online.
Fixes: 9edeaea1bc ("sched: Core-wide rq->lock")
Reported-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Don <joshdon@google.com>
Tested-by: Eugene Syromiatnikov <esyr@redhat.com>
Link: https://lkml.kernel.org/r/YR473ZGeKqMs6kw+@hirez.programming.kicks-ass.net
The consolidation of the debug code for mutex waiter intialization sets
waiter::ww_ctx to a poison value unconditionally. For regular mutexes this
is intended to catch the case where waiter_ww_ctx is dereferenced
accidentally.
For ww_mutex the poison value has to be overwritten either with a context
pointer or NULL for ww_mutexes without context.
The rework broke this as it made the store conditional on the context
pointer instead of the argument which signals whether ww_mutex code should
be compiled in or optiized out. As a result waiter::ww_ctx ends up with the
poison pointer for contextless ww_mutexes which causes a later dereference of
the poison pointer because it is != NULL.
Use the build argument instead so for ww_mutex the poison value is always
overwritten.
Fixes: c0afb0ffc0 ("locking/ww_mutex: Gather mutex_waiter initialization")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210819193030.zpwrpvvrmy7xxxiy@linutronix.de
Add logic to call bpf_setsockopt() and bpf_getsockopt() from setsockopt BPF
programs. An example use case is when the user sets the IPV6_TCLASS socket
option, we would also like to change the tcp-cc for that socket.
We don't have any use case for calling bpf_setsockopt() from supposedly read-
only sys_getsockopt(), so it is made available to BPF_CGROUP_SETSOCKOPT only
at this point.
Signed-off-by: Prankur Gupta <prankgup@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210817224221.3257826-2-prankgup@fb.com
Same as previous patch but for the keys. memdup_bpfptr is renamed
to kvmemdup_bpfptr (and converted to kvmalloc).
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818235216.1159202-2-sdf@google.com
Use kvmalloc/kvfree for temporary value when manipulating a map via
syscall. kmalloc might not be sufficient for percpu maps where the value
is big (and further multiplied by hundreds of CPUs).
Can be reproduced with netcnt test on qemu with "-smp 255".
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818235216.1159202-1-sdf@google.com
mac80211 trees.
Current release - regressions:
- tipc: call tipc_wait_for_connect only when dlen is not 0
- mac80211: fix locking in ieee80211_restart_work()
Current release - new code bugs:
- bpf: add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id()
- ethernet: ice: fix perout start time rounding
- wwan: iosm: prevent underflow in ipc_chnl_cfg_get()
Previous releases - regressions:
- bpf: clear zext_dst of dead insns
- sch_cake: fix srchost/dsthost hashing mode
- vrf: reset skb conntrack connection on VRF rcv
- net/rds: dma_map_sg is entitled to merge entries
Previous releases - always broken:
- ethernet: bnxt: fix Tx path locking and races, add Rx path barriers
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Networking fixes, including fixes from bpf, wireless and mac80211
trees.
Current release - regressions:
- tipc: call tipc_wait_for_connect only when dlen is not 0
- mac80211: fix locking in ieee80211_restart_work()
Current release - new code bugs:
- bpf: add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id()
- ethernet: ice: fix perout start time rounding
- wwan: iosm: prevent underflow in ipc_chnl_cfg_get()
Previous releases - regressions:
- bpf: clear zext_dst of dead insns
- sch_cake: fix srchost/dsthost hashing mode
- vrf: reset skb conntrack connection on VRF rcv
- net/rds: dma_map_sg is entitled to merge entries
Previous releases - always broken:
- ethernet: bnxt: fix Tx path locking and races, add Rx path
barriers"
* tag 'net-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (42 commits)
net: dpaa2-switch: disable the control interface on error path
Revert "flow_offload: action should not be NULL when it is referenced"
iavf: Fix ping is lost after untrusted VF had tried to change MAC
i40e: Fix ATR queue selection
r8152: fix the maximum number of PLA bp for RTL8153C
r8152: fix writing USB_BP2_EN
mptcp: full fully established support after ADD_ADDR
mptcp: fix memory leak on address flush
net/rds: dma_map_sg is entitled to merge entries
net: mscc: ocelot: allow forwarding from bridge ports to the tag_8021q CPU port
net: asix: fix uninit value bugs
ovs: clear skb->tstamp in forwarding path
net: mdio-mux: Handle -EPROBE_DEFER correctly
net: mdio-mux: Don't ignore memory allocation errors
net: mdio-mux: Delete unnecessary devm_kfree
net: dsa: sja1105: fix use-after-free after calling of_find_compatible_node, or worse
sch_cake: fix srchost/dsthost hashing mode
ixgbe, xsk: clean up the resources in ixgbe_xsk_pool_enable error path
net: qlcnic: add missed unlock in qlcnic_83xx_flash_read32
mac80211: fix locking in ieee80211_restart_work()
...
The BPF interpreter as well as x86-64 BPF JIT were both in line by allowing
up to 33 tail calls (however odd that number may be!). Recently, this was
changed for the interpreter to reduce it down to 32 with the assumption that
this should have been the actual limit "which is in line with the behavior of
the x86 JITs" according to b61a28cf11 ("bpf: Fix off-by-one in tail call
count limiting").
Paul recently reported:
I'm a bit surprised by this because I had previously tested the tail call
limit of several JIT compilers and found it to be 33 (i.e., allowing chains
of up to 34 programs). I've just extended a test program I had to validate
this again on the x86-64 JIT, and found a limit of 33 tail calls again [1].
Also note we had previously changed the RISC-V and MIPS JITs to allow up to
33 tail calls [2, 3], for consistency with other JITs and with the interpreter.
We had decided to increase these two to 33 rather than decrease the other
JITs to 32 for backward compatibility, though that probably doesn't matter
much as I'd expect few people to actually use 33 tail calls.
[1] ae78874829
[2] 96bc4432f5 ("bpf, riscv: Limit to 33 tail calls")
[3] e49e6f6db0 ("bpf, mips: Limit to 33 tail calls")
Therefore, revert b61a28cf11 to re-align interpreter to limit a maximum of
33 tail calls. While it is unlikely to hit the limit for the vast majority,
programs in the wild could one way or another depend on this, so lets rather
be a bit more conservative, and lets align the small remainder of JITs to 33.
If needed in future, this limit could be slightly increased, but not decreased.
Fixes: b61a28cf11 ("bpf: Fix off-by-one in tail call count limiting")
Reported-by: Paul Chaignon <paul@cilium.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/CAO5pjwTWrC0_dzTbTHFPSqDwA56aVH+4KFGVqdq8=ASs0MqZGQ@mail.gmail.com
Daniel Borkmann says:
====================
pull-request: bpf 2021-08-19
We've added 3 non-merge commits during the last 3 day(s) which contain
a total of 3 files changed, 29 insertions(+), 6 deletions(-).
The main changes are:
1) Fix to clear zext_dst for dead instructions which was causing invalid program
rejections on JITs with bpf_jit_needs_zext such as s390x, from Ilya Leoshkevich.
2) Fix RCU splat in bpf_get_current_{ancestor_,}cgroup_id() helpers when they are
invoked from sleepable programs, from Yonghong Song.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests, bpf: Test that dead ldx_w insns are accepted
bpf: Clear zext_dst of dead insns
bpf: Add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id() helpers
====================
Link: https://lore.kernel.org/r/20210819144904.20069-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since kprobe_events and uprobe_events only check whether the
other same-type probe event has the same name or not, if the
user gives the same name of the existing tracepoint event (or
the other type of probe events), it silently fails to create
the tracefs entry (but registered.) as below.
/sys/kernel/tracing # ls events/task/task_rename
enable filter format hist id trigger
/sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events
[ 113.048508] Could not create tracefs 'task_rename' directory
/sys/kernel/tracing # cat kprobe_events
p:task/task_rename vfs_read
To fix this issue, check whether the existing events have the
same name or not in trace_probe_register_event_call(). If exists,
it rejects to register the new event.
Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In preparation to allow event probes to use the process_fetch_insn()
callback in trace_probe_tmpl.h, change the data passed to it from a
pointer to pt_regs, as the event probe will not be using regs, and make it
a void pointer instead.
Update the process_fetch_insn() callers for kprobe and uprobe events to
have the regs defined in the function and just typecast the void pointer
parameter.
Link: https://lkml.kernel.org/r/20210819041842.291622924@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of a boolean "is_return" have traceprobe_set_print_fmt() take a
type (currently just PROBE_PRINT_NORMAL and PROBE_PRINT_RETURN). This will
simplify adding different types. For example, the development of the
event_probe, will need its own type as it prints an event, and not an IP.
Link: https://lkml.kernel.org/r/20210819041842.104626301@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().
Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.
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: live-patching@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Only build the code to support the global coherent pool if support for
it is enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
Delete/fixup few includes in anticipation of global -isystem compile
option removal.
Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefinition
of uintptr_t error (one definition comes from <stddef.h>, another from
<linux/types.h>).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Remove SIZEOF_TRACE_KPROBE() and SIZEOF_TRACE_UPROBE() and use
struct_size() as that's what it is made for. No need to have custom
macros. Especially since struct_size() has some extra memory checks for
correctness.
Link: https://lkml.kernel.org/r/20210817035027.795000217@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Kprobe and uprobe events can add a "system" to the events that are created
via the kprobe_events and uprobe_events files respectively. If they do not
include a "system" in the name, then the default "kprobes" or "uprobes" is
used. The current notation to specify a system for one of these probe
events is to add a '/' delimiter in the name, where the content before the
'/' will be the system to use, and the content after will be the event
name.
echo 'p:my_system/my_event' > kprobe_events
But this is inconsistent with the way histogram triggers separate their
system / event names. The histogram triggers use a '.' delimiter, which
can be confusing.
To allow this to be more consistent, as well as keep backward
compatibility, allow the kprobe and uprobe events to denote a system name
with either a '/' or a '.'.
That is:
echo 'p:my_system/my_event' > kprobe_events
is equivalent to:
echo 'p:my_system.my_event' > kprobe_events
Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.580493202@goodmis.org
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The two places that call traceprobe_parse_probe_arg() allocate a temporary
buffer to copy the argv[i] into, because argv[i] is constant and the
traceprobe_parse_probe_arg() will modify it to do the parsing. These two
places allocate this buffer and then free it right after calling this
function, leaving the onus of this allocation to the caller.
As there's about to be a third user of this function that will have to do
the same thing, instead of having the caller allocate the temporary
buffer, simply move that allocation into the traceprobe_parse_probe_arg()
itself, which will simplify the code of the callers.
Link: https://lkml.kernel.org/r/20210817035027.385422828@goodmis.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As dynamic events are not created by modules, if something is attached to
one, calling "try_module_get()" on its "mod" field, is not going to keep
the dynamic event from going away.
Since dynamic events do not need the "mod" pointer of the event structure,
make a union out of it in order to save memory (there's one structure for
each of the thousand+ events in the kernel), and have any event with the
DYNAMIC flag set to use a ref counter instead.
Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.174869074@goodmis.org
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
To differentiate between static and dynamic events, add a new flag
DYNAMIC to the event flags that all dynamic events have set. This will
allow to differentiate when attaching to a dynamic event from a static
event.
Static events have a mod pointer that references the module they were
created in (or NULL for core kernel). This can be incremented when the
event has something attached to it. But there exists no such mechanism for
dynamic events. This is dangerous as the dynamic events may now disappear
without the "attachment" knowing that it no longer exists.
To enforce the dynamic flag, change dyn_event_add() to pass the event that
is being created such that it can set the DYNAMIC flag of the event. This
helps make sure that no location that creates a dynamic event misses
setting this flag.
Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035026.936958254@goodmis.org
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a new helper to initialize the global coherent pool. This both
cleans up the existing initialization which indirects through the
reserved_mem_ops that are normally only used for struct device, and
also allows using the global pool for non-devicetree architectures.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
Return the allocated dma_coherent_mem structure, set the
use_dma_pfn_offset and print the failure warning inside of
dma_init_coherent_memory instead of leaving that to the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
Switch an ifdef so that the global coherent pool is initialized for
any architecture that selects the DMA_GLOBAL_POOL symbol insted of
hardcoding ARM.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
Add an option to allocate uncached memory for dma_alloc_coherent from
the global dma_coherent_default_memory. This will allow to move
arm-nommu (and eventually other platforms) to use generic code for
allocating uncached memory from a pre-populated pool.
Note that this is a different pool from the one that platforms that
can remap at runtime use for GFP_ATOMIC allocations for now, although
there might be opportunities to eventually end up with a common codebase
for the two use cases.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
Pull KCSAN updates from Paul E. McKenney:
- improve comments
- introduce CONFIG_KCSAN_STRICT (which RCU uses)
- optimize use of get_ctx() by kcsan_found_watchpoint()
- rework atomic.h into permissive.h
- add the ability to ignore writes that change only one bit of a given data-racy variable.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The variable allow is being initialized with a value that is never read, it
is being updated later on. The assignment is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817170842.495440-1-colin.king@canonical.com
The "tp_printk" option redirects the trace event output to printk at boot
up. This is useful when a machine crashes before boot where the trace events
can not be retrieved by the in kernel ring buffer. But it can be "dangerous"
because trace events can be located in high frequency locations such as
interrupts and the scheduler, where a printk can slow it down that it live
locks the machine (because by the time the printk finishes, the next event
is triggered). Thus tp_printk must be used with care.
It was discovered that the filter logic to trace events does not apply to
the tp_printk events. This can cause a surprise and live lock when the user
expects it to be filtered to limit the amount of events printed to the
console when in fact it still prints everything.
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Merge tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Limit the shooting in the foot of tp_printk
The "tp_printk" option redirects the trace event output to printk at
boot up. This is useful when a machine crashes before boot where the
trace events can not be retrieved by the in kernel ring buffer. But it
can be "dangerous" because trace events can be located in high
frequency locations such as interrupts and the scheduler, where a
printk can slow it down that it live locks the machine (because by the
time the printk finishes, the next event is triggered). Thus tp_printk
must be used with care.
It was discovered that the filter logic to trace events does not apply
to the tp_printk events. This can cause a surprise and live lock when
the user expects it to be filtered to limit the amount of events
printed to the console when in fact it still prints everything"
* tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Apply trace filters on all output channels
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().
Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.
Link: https://lkml.kernel.org/r/20210803141621.780504-37-bigeasy@linutronix.de
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There was no strong reason to or not to flush barrier work items in
flush_workqueue(). And we have to make barrier work items not participate
in nr_active so we had been using WORK_NO_COLOR for them which also makes
them can't be flushed by flush_workqueue().
And the users of flush_workqueue() often do not intend to wait barrier work
items issued by flush_work(). That made the choice sound perfect.
But barrier work items have reference to internal structure (pool_workqueue)
and the worker thread[s] is/are still busy for the workqueue user when the
barrrier work items are not done. So it is reasonable to make flush_workqueue()
also watch for flush_work() to make it more robust.
And a problem[1] reported by Li Zhe shows that we need such robustness.
The warning logs are listed below:
WARNING: CPU: 0 PID: 19336 at kernel/workqueue.c:4430 destroy_workqueue+0x11a/0x2f0
*****
destroy_workqueue: test_workqueue9 has the following busy pwq
pwq 4: cpus=2 node=0 flags=0x0 nice=0 active=0/1 refcnt=2
in-flight: 5658:wq_barrier_func
Showing busy workqueues and worker pools:
*****
It shows that even after drain_workqueue() returns, the barrier work item
is still in flight and the pwq (and a worker) is still busy on it.
The problem is caused by flush_workqueue() not watching flush_work():
Thread A Worker
/* normal work item with linked */
process_scheduled_works()
destroy_workqueue() process_one_work()
drain_workqueue() /* run normal work item */
/-- pwq_dec_nr_in_flight()
flush_workqueue() <---/
/* the last normal work item is done */
sanity_check process_one_work()
/-- raw_spin_unlock_irq(&pool->lock)
raw_spin_lock_irq(&pool->lock) <-/ /* maybe preempt */
*WARNING* wq_barrier_func()
/* maybe preempt by cond_resched() */
Thread A can get the pool lock after the Worker unlocks the pool lock before
running wq_barrier_func(). And if there is any preemption happen around
wq_barrier_func(), destroy_workqueue()'s sanity check is more likely to
get the lock and catch it. (Note: preemption is not necessary to cause the bug,
the unlocking is enough to possibly trigger the WARNING.)
A simple solution might be just executing all linked barrier work items
once without releasing pool lock after the head work item's
pwq_dec_nr_in_flight(). But this solution has two problems:
1) the head work item might also be barrier work item when the user-queued
work item is cancelled. For example:
thread 1: thread 2:
queue_work(wq, &my_work)
flush_work(&my_work)
cancel_work_sync(&my_work);
/* Neiter my_work nor the barrier work is scheduled. */
destroy_workqueue(wq);
/* This is an easier way to catch the WARNING. */
2) there might be too much linked barrier work items and running them
all once without releasing pool lock just causes trouble.
The only solution is to make flush_workqueue() aslo watch barrier work
items. So we have to assign a color to these barrier work items which
is the color of the head (user-queued) work item.
Assigning a color doesn't cause any problem in ative management, because
the prvious patch made barrier work items not participate in nr_active
via WORK_STRUCT_INACTIVE rather than reliance on the (old) WORK_NO_COLOR.
[1]: https://lore.kernel.org/lkml/20210812083814.32453-1-lizhe.67@bytedance.com/
Reported-by: Li Zhe <lizhe.67@bytedance.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, WORK_NO_COLOR has two meanings:
Not participate in flushing
Not participate in nr_active
And only non-barrier work items are marked with WORK_STRUCT_INACTIVE
when they are in inactive_works list. The barrier work items are not
marked INACTIVE even linked in inactive_works list since these tail
items are always moved together with the head work item.
These definitions are simple, clean and practical. (Except a small
blemish that only the first meaning of WORK_NO_COLOR is documented in
include/linux/workqueue.h while both meanings are in workqueue.c)
But dual-purpose WORK_NO_COLOR used for barrier work items has proven to
be problematical[1]. Only the second purpose is obligatory. So we plan
to make barrier work items participate in flushing but keep them still
not participating in nr_active.
So the plan is to mark barrier work items inactive without using
WORK_NO_COLOR in this patch so that we can assign a flushing color to
them in next patch.
The reasonable way is to add or reuse a bit in work data of the work
item. But adding a bit will double the size of pool_workqueue.
Currently, WORK_STRUCT_INACTIVE is only used in try_to_grab_pending()
for user-queued work items and try_to_grab_pending() can't work for
barrier work items. So we extend WORK_STRUCT_INACTIVE to also mark
barrier work items no matter which list they are in because we don't
need to determind which list a barrier work item is in.
So the meaning of WORK_STRUCT_INACTIVE becomes just "the work items don't
participate in nr_active" (no matter whether it is a barrier work item or
a user-queued work item). And WORK_STRUCT_INACTIVE for user-queued work
items means they are in inactive_works list.
This patch does it by setting WORK_STRUCT_INACTIVE for barrier work items
in insert_wq_barrier() and checking WORK_STRUCT_INACTIVE first in
pwq_dec_nr_in_flight(). And the meaning of WORK_NO_COLOR is reduced to
only "not participating in flushing".
There is no functionality change intended in this patch. Because
WORK_NO_COLOR+WORK_STRUCT_INACTIVE represents the previous WORK_NO_COLOR
in meaning and try_to_grab_pending() doesn't use for barrier work items
and avoids being confused by this extended WORK_STRUCT_INACTIVE.
A bunch of comment for nr_active & WORK_STRUCT_INACTIVE is also added for
documenting how WORK_STRUCT_INACTIVE works in nr_active management.
[1]: https://lore.kernel.org/lkml/20210812083814.32453-1-lizhe.67@bytedance.com/
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add a local var @work_flags to calculate work_flags step by step, so that
we don't need to squeeze several flags in only the last line of code.
Parepare for next patch to add a bit to barrier work item's flag. Not
squshing this to next patch makes it clear that what it will have changed.
No functional change intended.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Make pwq_dec_nr_in_flight() use work_data rather just work_color.
Prepare for later patch to get WORK_STRUCT_INACTIVE bit from work_data
in pwq_dec_nr_in_flight().
No functional change intended.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
There are two kinds of "delayed" work items in workqueue subsystem.
One is for timer-delayed work items which are visible to workqueue users.
The other kind is for work items delayed by active management which can
not be directly visible to workqueue users. We mixed the word "delayed"
for both kinds and caused somewhat ambiguity.
This patch renames the later one (delayed by active management) to
"inactive", because it is used for workqueue active management and
most of its related symbols are named with "active" or "activate".
All "delayed" and "DELAYED" are carefully checked and renamed one by
one to avoid accidentally changing the name of the other kind for
timer-delayed.
No functional change intended.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add the static and runtime initializer mechanics to support the RT variant
of local_lock, which requires the lock type in the lockdep map to be set
to LD_LOCK_PERCPU.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.967526724@linutronix.de
Going to sleep when locks are contended can be quite inefficient when the
contention time is short and the lock owner is running on a different CPU.
The MCS mechanism cannot be used because MCS is strictly FIFO ordered while
for rtmutex based locks the waiter ordering is priority based.
Provide a simple adaptive spinwait mechanism which currently restricts the
spinning to the top priority waiter.
[ tglx: Provide a contemporary changelog, extended it to all rtmutex based
locks and updated it to match the other spin on owner implementations ]
Originally-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.912050691@linutronix.de
The current logic only allows lock stealing to occur if the current task is
of higher priority than the pending owner.
Significant throughput improvements can be gained by allowing the lock
stealing to include tasks of equal priority when the contended lock is a
spin_lock or a rw_lock and the tasks are not in a RT scheduling task.
The assumption was that the system will make faster progress by allowing
the task already on the CPU to take the lock rather than waiting for the
system to wake up a different task.
This does add a degree of unfairness, but in reality no negative side
effects have been observed in the many years that this has been used in the
RT kernel.
[ tglx: Refactored and rewritten several times by Steve Rostedt, Sebastian
Siewior and myself ]
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.857240222@linutronix.de
On PREEMPT_RT the futex hashbucket spinlock becomes 'sleeping' and rtmutex
based. That causes a lockdep false positive because some of the futex
functions invoke spin_unlock(&hb->lock) with the wait_lock of the rtmutex
associated to the pi_futex held. spin_unlock() in turn takes wait_lock of
the rtmutex on which the spinlock is based which makes lockdep notice a
lock recursion.
Give the futex/rtmutex wait_lock a separate key.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.750701219@linutronix.de
The requeue_pi() operation on RT kernels creates a problem versus the
task::pi_blocked_on state when a waiter is woken early (signal, timeout)
and that early wake up interleaves with the requeue_pi() operation.
When the requeue manages to block the waiter on the rtmutex which is
associated to the second futex, then a concurrent early wakeup of that
waiter faces the problem that it has to acquire the hash bucket spinlock,
which is not an issue on non-RT kernels, but on RT kernels spinlocks are
substituted by 'sleeping' spinlocks based on rtmutex. If the hash bucket
lock is contended then blocking on that spinlock would result in a
impossible situation: blocking on two locks at the same time (the hash
bucket lock and the rtmutex representing the PI futex).
It was considered to make the hash bucket locks raw_spinlocks, but
especially requeue operations with a large amount of waiters can introduce
significant latencies, so that's not an option for RT.
The RT tree carried a solution which (ab)used task::pi_blocked_on to store
the information about an ongoing requeue and an early wakeup which worked,
but required to add checks for these special states all over the place.
The distangling of an early wakeup of a waiter for a requeue_pi() operation
is already looking at quite some different states and the task::pi_blocked_on
magic just expanded that to a hard to understand 'state machine'.
This can be avoided by keeping track of the waiter/requeue state in the
futex_q object itself.
Add a requeue_state field to struct futex_q with the following possible
states:
Q_REQUEUE_PI_NONE
Q_REQUEUE_PI_IGNORE
Q_REQUEUE_PI_IN_PROGRESS
Q_REQUEUE_PI_WAIT
Q_REQUEUE_PI_DONE
Q_REQUEUE_PI_LOCKED
The waiter starts with state = NONE and the following state transitions are
valid:
On the waiter side:
Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IGNORE
Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT
On the requeue side:
Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_INPROGRESS
Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_DONE/LOCKED
Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_NONE (requeue failed)
Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_DONE/LOCKED
Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_IGNORE (requeue failed)
The requeue side ignores a waiter with state Q_REQUEUE_PI_IGNORE as this
signals that the waiter is already on the way out. It also means that
the waiter is still on the 'wait' futex, i.e. uaddr1.
The waiter side signals early wakeup to the requeue side either through
setting state to Q_REQUEUE_PI_IGNORE or to Q_REQUEUE_PI_WAIT depending
on the current state. In case of Q_REQUEUE_PI_IGNORE it can immediately
proceed to take the hash bucket lock of uaddr1. If it set state to WAIT,
which means the wakeup is interleaving with a requeue in progress it has
to wait for the requeue side to change the state. Either to DONE/LOCKED
or to IGNORE. DONE/LOCKED means the waiter q is now on the uaddr2 futex
and either blocked (DONE) or has acquired it (LOCKED). IGNORE is set by
the requeue side when the requeue attempt failed via deadlock detection
and therefore the waiter's futex_q is still on the uaddr1 futex.
While this is not strictly required on !RT making this unconditional has
the benefit of common code and it also allows the waiter to avoid taking
the hash bucket lock on the way out in certain cases, which reduces
contention.
Add the required helpers required for the state transitions, invoke them at
the right places and restructure the futex_wait_requeue_pi() code to handle
the return from wait (early or not) based on the state machine values.
On !RT enabled kernels the waiter spin waits for the state going from
Q_REQUEUE_PI_WAIT to some other state, on RT enabled kernels this is
handled by rcuwait_wait_event() and the corresponding wake up on the
requeue side.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.693317658@linutronix.de
Move the futex key match out of handle_early_requeue_pi_wakeup() which
allows to simplify that function. The upcoming state machine for
requeue_pi() will make that go away.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.638938670@linutronix.de
No point in allocating memory when the input parameters are bogus.
Validate all parameters before proceeding.
Suggested-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.581789253@linutronix.de
The comment about the restriction of the number of waiters to wake for the
REQUEUE_PI case is confusing at best. Rewrite it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.524990421@linutronix.de
No point in taking two more 'requeue_pi' conditionals just to get to the
requeue. Same for the requeue_pi case just the other way round.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.468835790@linutronix.de
The accounting is wrong when either the PI sanity check or the
requeue PI operation fails. Adjust it in the failure path.
Will be simplified in the next step.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.416427548@linutronix.de
For requeue PI it's required to establish PI state for the PI futex to
which waiters are requeued. This either acquires the user space futex on
behalf of the top most waiter on the inner 'waitqueue' futex, or attaches to
the PI state of an existing waiter, or creates on attached to the owner of
the futex.
This code can retry in case of failure, but retry can never happen when the
pi state was successfully created. The condition to run this code is:
(task_count - nr_wake) < nr_requeue
which is always true because:
task_count = 0
nr_wake = 1
nr_requeue >= 0
Remove it completely.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.362730187@linutronix.de
When requeuing to a PI futex, then the requeue code tries to trylock the PI
futex on behalf of the topmost waiter on the inner 'waitqueue' futex. If
that succeeds, then PI state has to be allocated in order to requeue further
waiters to the PI futex.
The comment and the code are confusing, as the PI state allocation uses
lookup_pi_state(), which either attaches to an existing waiter or to the
owner. As the PI futex was just acquired, there cannot be a waiter on the
PI futex because the hash bucket lock is held.
Clarify the comment and use attach_to_pi_owner() directly. As the task on
which behalf the PI futex has been acquired is guaranteed to be alive and
not exiting, this call must succeed. Add a WARN_ON() in case that fails.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.305142462@linutronix.de
The futex key reference mechanism is long gone. Clean up the stale comments
which still mention it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.249178312@linutronix.de
The loop in futex_requeue() has a sanity check for the waiter, which is
missing in futex_proxy_trylock_atomic(). In theory the key2 check is
sufficient, but futexes are cursed so add it for completeness and paranoia
sake.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.193767519@linutronix.de
Add the necessary defines, helpers and API functions for replacing struct mutex on
a PREEMPT_RT enabled kernel with an rtmutex based variant.
No functional change when CONFIG_PREEMPT_RT=n
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.081517417@linutronix.de
Add the actual ww_mutex API functions which replace the mutex based variant
on RT enabled kernels.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.024057938@linutronix.de
Add a ww acquire context pointer to the waiter and various functions and
add the ww_mutex related invocations to the proper spots in the locking
code, similar to the mutex based variant.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.966139174@linutronix.de
Provide the defines for RT mutex based ww_mutexes and fix up the debug logic
so it's either enabled by DEBUG_MUTEXES or DEBUG_RT_MUTEXES on RT kernels.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.908012566@linutronix.de
RT mutex based ww_mutexes cannot order based on timestamps. They have to
order based on priority. Add the necessary decision logic.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.847536630@linutronix.de
Provide the type defines and the helper inlines for rtmutex based ww_mutexes.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.790760545@linutronix.de
Accessing the internal wait_lock of mutex and rtmutex is slightly
different. Provide helper functions for that.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.734635961@linutronix.de
Some ww_mutex helper functions use pointers for the underlying mutex and
mutex_waiter. The upcoming rtmutex based implementation needs to share
these functions. Add and use defines for the types and replace the direct
types in the affected functions.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.678720245@linutronix.de
Move the mutex related access from various ww_mutex functions into helper
functions so they can be substituted for rtmutex based ww_mutex later.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.622477030@linutronix.de
The upcoming rtmutex based ww_mutex needs a different handling for
enqueueing a waiter. Split it out into a helper function.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.566318143@linutronix.de
Split out the waiter iteration functions so they can be substituted for a
rtmutex based ww_mutex later.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.509186185@linutronix.de
None of these functions will be on the stack when blocking in
schedule(), hence __sched is not needed.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.453235952@linutronix.de
Split the W/W mutex helper functions out into a separate header file, so
they can be shared with a rtmutex based variant later.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.396893399@linutronix.de
Split the ww related part out into a helper function so it can be reused
for a rtmutex based ww_mutex implementation.
[ mingo: Fixed bisection failure. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.340166556@linutronix.de
The wait_lock of mutex is really a low level lock. Convert it to a
raw_spinlock like the wait_lock of rtmutex.
[ mingo: backmerged the test_lockup.c build fix by bigeasy. ]
Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.166863404@linutronix.de
Move the mutex waiter declaration from the public <linux/mutex.h> header
to the internal kernel/locking/mutex.h header.
There is no reason to expose it outside of the core code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.054325923@linutronix.de
Having two header files which contain just the non-debug and debug variants
is mostly waste of disc space and has no real value. Stick the debug
variants into the common mutex.h file as counterpart to the stubs for the
non-debug case.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.995350521@linutronix.de
Ensure all !RT tasks have the same prio such that they end up in FIFO
order and aren't split up according to nice level.
The reason why nice levels were taken into account so far is historical. In
the early days of the rtmutex code it was done to give the PI boosting and
deboosting a larger coverage.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.938676930@linutronix.de
Similar to rw_semaphores, on RT the rwlock substitution is not writer fair,
because it's not feasible to have a writer inherit its priority to
multiple readers. Readers blocked on a writer follow the normal rules of
priority inheritance. Like RT spinlocks, RT rwlocks are state preserving
across the slow lock operations (contended case).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.882793524@linutronix.de
Provide the actual locking functions which make use of the general and
spinlock specific rtmutex code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.826621464@linutronix.de
This is to let bool variable could be correctly displayed in
big/little endian sysctl procfs. sizeof(bool) is arch dependent,
proc_dobool should work in all arches.
Suggested-by: Pan Xinhui <xinhui@linux.vnet.ibm.com>
Signed-off-by: Jia He <hejianet@gmail.com>
[thuth: rebased the patch to the current kernel version]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
A simplified version of the rtmutex slowlock function, which neither handles
signals nor timeouts, and is careful about preserving the state of the
blocked task across the lock operation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.770228446@linutronix.de
Guard the regular sleeping lock specific functionality, which is used for
rtmutex on non-RT enabled kernels and for mutex, rtmutex and semaphores on
RT enabled kernels so the code can be reused for the RT specific
implementation of spinlocks and rwlocks in a different compilation unit.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.311535693@linutronix.de
Add an rtlock_task pointer to rt_mutex_wake_q, which allows to handle the RT
specific wakeup for spin/rwlock waiters. The pointer is just consuming 4/8
bytes on the stack so it is provided unconditionaly to avoid #ifdeffery all
over the place.
This cannot use a regular wake_q, because a task can have concurrent wakeups which
would make it miss either lock or the regular wakeups, depending on what gets
queued first, unless task struct gains a separate wake_q_node for this, which
would be overkill, because there can only be a single task which gets woken
up in the spin/rw_lock unlock path.
No functional change for non-RT enabled kernels.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.253614678@linutronix.de
Prepare for the required state aware handling of waiter wakeups via wake_q
and switch the rtmutex code over to the rtmutex specific wrapper.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.197113263@linutronix.de
To handle the difference between wakeups for regular sleeping locks (mutex,
rtmutex, rw_semaphore) and the wakeups for 'sleeping' spin/rwlocks on
PREEMPT_RT enabled kernels correctly, it is required to provide a
wake_q_head construct which allows to keep them separate.
Provide a wrapper around wake_q_head and the required helpers, which will be
extended with the state handling later.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.139337655@linutronix.de
Regular sleeping locks like mutexes, rtmutexes and rw_semaphores are always
entering and leaving a blocking section with task state == TASK_RUNNING.
On a non-RT kernel spinlocks and rwlocks never affect the task state, but
on RT kernels these locks are converted to rtmutex based 'sleeping' locks.
So in case of contention the task goes to block, which requires to carefully
preserve the task state, and restore it after acquiring the lock taking
regular wakeups for the task into account, which happened while the task was
blocked. This state preserving is achieved by having a separate task state
for blocking on a RT spin/rwlock and a saved_state field in task_struct
along with careful handling of these wakeup scenarios in try_to_wake_up().
To avoid conditionals in the rtmutex code, store the wake state which has
to be used for waking a lock waiter in rt_mutex_waiter which allows to
handle the regular and RT spin/rwlocks by handing it to wake_up_state().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.079800739@linutronix.de
The RT specific R/W semaphore implementation used to restrict the number of
readers to one, because a writer cannot block on multiple readers and
inherit its priority or budget.
The single reader restricting was painful in various ways:
- Performance bottleneck for multi-threaded applications in the page fault
path (mmap sem)
- Progress blocker for drivers which are carefully crafted to avoid the
potential reader/writer deadlock in mainline.
The analysis of the writer code paths shows that properly written RT tasks
should not take them. Syscalls like mmap(), file access which take mmap sem
write locked have unbound latencies, which are completely unrelated to mmap
sem. Other R/W sem users like graphics drivers are not suitable for RT tasks
either.
So there is little risk to hurt RT tasks when the RT rwsem implementation is
done in the following way:
- Allow concurrent readers
- Make writers block until the last reader left the critical section. This
blocking is not subject to priority/budget inheritance.
- Readers blocked on a writer inherit their priority/budget in the normal
way.
There is a drawback with this scheme: R/W semaphores become writer unfair
though the applications which have triggered writer starvation (mostly on
mmap_sem) in the past are not really the typical workloads running on a RT
system. So while it's unlikely to hit writer starvation, it's possible. If
there are unexpected workloads on RT systems triggering it, the problem
has to be revisited.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.016885947@linutronix.de
On PREEMPT_RT, rw_semaphores and rwlocks are substituted with an rtmutex and
a reader count. The implementation is writer unfair, as it is not feasible
to do priority inheritance on multiple readers, but experience has shown
that real-time workloads are not the typical workloads which are sensitive
to writer starvation.
The inner workings of rw_semaphores and rwlocks on RT are almost identical
except for the task state and signal handling. rw_semaphores are not state
preserving over a contention, they are expected to enter and leave with state
== TASK_RUNNING. rwlocks have a mechanism to preserve the state of the task
at entry and restore it after unblocking taking potential non-lock related
wakeups into account. rw_semaphores can also be subject to signal handling
interrupting a blocked state, while rwlocks ignore signals.
To avoid code duplication, provide a shared implementation which takes the
small difference vs. state and signals into account. The code is included
into the relevant rw_semaphore/rwlock base code and compiled for each use
case separately.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.957920571@linutronix.de
Split the inner workings of rt_mutex_slowlock() out into a separate
function, which can be reused by the upcoming RT lock substitutions,
e.g. for rw_semaphores.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.841971086@linutronix.de
RT builds substitutions for rwsem, mutex, spinlock and rwlock around
rtmutexes. Split the inner working out so each lock substitution can use
them with the appropriate lockdep annotations. This avoids having an extra
unused lockdep map in the wrapped rtmutex.
No functional change.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.784739994@linutronix.de
Prepare for reusing the inner functions of rtmutex for RT lock
substitutions: introduce kernel/locking/rtmutex_api.c and move
them there.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.726560996@linutronix.de
Allows the compiler to generate better code depending on the architecture.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.668958502@linutronix.de
Linus Torvalds