Commit graph

45160 commits

Author SHA1 Message Date
Linus Torvalds c89d780cc1 arm64 updates for 6.11:
* Virtual CPU hotplug support for arm64 ACPI systems
 
 * cpufeature infrastructure cleanups and making the FEAT_ECBHB ID bits
   visible to guests
 
 * CPU errata: expand the speculative SSBS workaround to more CPUs
 
 * arm64 ACPI:
 
   - acpi=nospcr option to disable SPCR as default console for arm64
 
   - Move some ACPI code (cpuidle, FFH) to drivers/acpi/arm64/
 
 * GICv3, use compile-time PMR values: optimise the way regular IRQs are
   masked/unmasked when GICv3 pseudo-NMIs are used, removing the need for
   a static key in fast paths by using a priority value chosen
   dynamically at boot time
 
 * arm64 perf updates:
 
   - Rework of the IMX PMU driver to enable support for I.MX95
 
   - Enable support for tertiary match groups in the CMN PMU driver
 
   - Initial refactoring of the CPU PMU code to prepare for the fixed
     instruction counter introduced by Arm v9.4
 
   - Add missing PMU driver MODULE_DESCRIPTION() strings
 
   - Hook up DT compatibles for recent CPU PMUs
 
 * arm64 kselftest updates:
 
   - Kernel mode NEON fp-stress
 
   - Cleanups, spelling mistakes
 
 * arm64 Documentation update with a minor clarification on TBI
 
 * Miscellaneous:
 
   - Fix missing IPI statistics
 
   - Implement raw_smp_processor_id() using thread_info rather than a
     per-CPU variable (better code generation)
 
   - Make MTE checking of in-kernel asynchronous tag faults conditional
     on KASAN being enabled
 
   - Minor cleanups, typos
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "The biggest part is the virtual CPU hotplug that touches ACPI,
  irqchip. We also have some GICv3 optimisation for pseudo-NMIs that has
  been queued via the arm64 tree. Otherwise the usual perf updates,
  kselftest, various small cleanups.

  Core:

   - Virtual CPU hotplug support for arm64 ACPI systems

   - cpufeature infrastructure cleanups and making the FEAT_ECBHB ID
     bits visible to guests

   - CPU errata: expand the speculative SSBS workaround to more CPUs

   - GICv3, use compile-time PMR values: optimise the way regular IRQs
     are masked/unmasked when GICv3 pseudo-NMIs are used, removing the
     need for a static key in fast paths by using a priority value
     chosen dynamically at boot time

  ACPI:

   - 'acpi=nospcr' option to disable SPCR as default console for arm64

   - Move some ACPI code (cpuidle, FFH) to drivers/acpi/arm64/

  Perf updates:

   - Rework of the IMX PMU driver to enable support for I.MX95

   - Enable support for tertiary match groups in the CMN PMU driver

   - Initial refactoring of the CPU PMU code to prepare for the fixed
     instruction counter introduced by Arm v9.4

   - Add missing PMU driver MODULE_DESCRIPTION() strings

   - Hook up DT compatibles for recent CPU PMUs

  Kselftest updates:

   - Kernel mode NEON fp-stress

   - Cleanups, spelling mistakes

  Miscellaneous:

   - arm64 Documentation update with a minor clarification on TBI

   - Fix missing IPI statistics

   - Implement raw_smp_processor_id() using thread_info rather than a
     per-CPU variable (better code generation)

   - Make MTE checking of in-kernel asynchronous tag faults conditional
     on KASAN being enabled

   - Minor cleanups, typos"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (69 commits)
  selftests: arm64: tags: remove the result script
  selftests: arm64: tags_test: conform test to TAP output
  perf: add missing MODULE_DESCRIPTION() macros
  arm64: smp: Fix missing IPI statistics
  irqchip/gic-v3: Fix 'broken_rdists' unused warning when !SMP and !ACPI
  ACPI: Add acpi=nospcr to disable ACPI SPCR as default console on ARM64
  Documentation: arm64: Update memory.rst for TBI
  arm64/cpufeature: Replace custom macros with fields from ID_AA64PFR0_EL1
  KVM: arm64: Replace custom macros with fields from ID_AA64PFR0_EL1
  perf: arm_pmuv3: Include asm/arm_pmuv3.h from linux/perf/arm_pmuv3.h
  perf: arm_v6/7_pmu: Drop non-DT probe support
  perf/arm: Move 32-bit PMU drivers to drivers/perf/
  perf: arm_pmuv3: Drop unnecessary IS_ENABLED(CONFIG_ARM64) check
  perf: arm_pmuv3: Avoid assigning fixed cycle counter with threshold
  arm64: Kconfig: Fix dependencies to enable ACPI_HOTPLUG_CPU
  perf: imx_perf: add support for i.MX95 platform
  perf: imx_perf: fix counter start and config sequence
  perf: imx_perf: refactor driver for imx93
  perf: imx_perf: let the driver manage the counter usage rather the user
  perf: imx_perf: add macro definitions for parsing config attr
  ...
2024-07-15 17:06:19 -07:00
Lai Jiangshan aa8684755a workqueue: Remove unneeded lockdep_assert_cpus_held()
The commit 19af457573 ("workqueue: Remove cpus_read_lock() from
apply_wqattrs_lock()") removes the unneed cpus_read_lock() after the pwq
creations and installations have been reworked based on wq_online_cpumask
rather than cpu_online_mask making cpus_read_lock() is unneeded during
wqattrs changes.

But it desn't remove the lockdep_assert_cpus_held() checks during wqattrs
changes, which leads to complaints from lockdep reported by kernel test
robot:

[   15.726567][  T131] ------------[ cut here ]------------
[ 15.728117][ T131] WARNING: CPU: 1 PID: 131 at kernel/cpu.c:525 lockdep_assert_cpus_held (kernel/cpu.c:525)
[   15.731191][  T131] Modules linked in: floppy(+) parport_pc(+) parport qemu_fw_cfg rtc_cmos
[   15.733423][  T131] CPU: 1 PID: 131 Comm: systemd-udevd Tainted: G                T  6.10.0-rc2-00254-g19af45757383 #1 df6f039f42e8818bf9a534449362ebad1aad32e2
[   15.737011][  T131] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 15.739760][ T131] EIP: lockdep_assert_cpus_held (kernel/cpu.c:525)
[ 15.741326][ T131] Code: 97 c2 03 72 20 83 3d f4 73 97 c2 00 74 17 55 89 e5 b8 fc bd 4d c2 ba ff ff ff ff e8 e4 57 d1 00 85 c0 74 06 5d 31 c0 31 d2 c3 <0f> 0b eb f6 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 e5 b8

Fix it by removing the unneeded lockdep_assert_cpus_held().
Also remove the unneed cpus_read_lock() from wq_affn_dfl_set().

tj: Dropped the removal of cpus_read_lock/unlock() in wq_affn_dfl_set() to
    keep this patch fix only.

Cc: kernel test robot <oliver.sang@intel.com>
Fixes: 19af45757383("workqueue: Remove cpus_read_lock() from apply_wqattrs_lock()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202407141846.665c0446-lkp@intel.com
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-15 14:01:14 -10:00
Linus Torvalds b02c520fee workqueue: Changes for v6.11
- Lai fixed a bug where CPU hotplug and workqueue attribute changes race
   leaving some workqueues not fully updated. This involved refactoring and
   changing how online CPUs are tracked. The resulting code is cleaner.
 
 - Workqueue watchdog touch operation was causing too much cacheline
   contention on very large machines. Nicholas improved scalabililty by
   avoiding unnecessary global updates.
 
 - Code cleanups and minor rescuer behavior improvement.
 
 - The last commit 58629d4871 ("workqueue: Always queue work items to the
   newest PWQ for order workqueues") is a cherry-picked straggler commit from
   for-6.10-fixes, a fix for a bug which may not actually trigger.
   Unfortunately, maybe because for-6.10-fixes was branched off at a
   different point from for-6.11, I couldn't persuade git request-pull to
   generate clean diffstat if pulled into for-6.11.
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Merge tag 'wq-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue updates from Tejun Heo:

 - Lai fixed a bug where CPU hotplug and workqueue attribute changes
   race leaving some workqueues not fully updated. This involved
   refactoring and changing how online CPUs are tracked. The resulting
   code is cleaner.

 - Workqueue watchdog touch operation was causing too much cacheline
   contention on very large machines. Nicholas improved scalabililty by
   avoiding unnecessary global updates.

 - Code cleanups and minor rescuer behavior improvement.

 - The last commit 58629d4871 ("workqueue: Always queue work items to
   the newest PWQ for order workqueues") is a cherry-picked straggler
   commit from for-6.10-fixes, a fix for a bug which may not actually
   trigger.

* tag 'wq-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (24 commits)
  workqueue: Always queue work items to the newest PWQ for order workqueues
  workqueue: Rename wq_update_pod() to unbound_wq_update_pwq()
  workqueue: Remove the arguments @hotplug_cpu and @online from wq_update_pod()
  workqueue: Remove the argument @cpu_going_down from wq_calc_pod_cpumask()
  workqueue: Remove the unneeded cpumask empty check in wq_calc_pod_cpumask()
  workqueue: Remove cpus_read_lock() from apply_wqattrs_lock()
  workqueue: Simplify wq_calc_pod_cpumask() with wq_online_cpumask
  workqueue: Add wq_online_cpumask
  workqueue: Init rescuer's affinities as the wq's effective cpumask
  workqueue: Put PWQ allocation and WQ enlistment in the same lock C.S.
  workqueue: Move kthread_flush_worker() out of alloc_and_link_pwqs()
  workqueue: Make rescuer initialization as the last step of the creation of a new wq
  workqueue: Register sysfs after the whole creation of the new wq
  workqueue: Simplify goto statement
  workqueue: Update cpumasks after only applying it successfully
  workqueue: Improve scalability of workqueue watchdog touch
  workqueue: wq_watchdog_touch is always called with valid CPU
  workqueue: Remove useless pool->dying_workers
  workqueue: Detach workers directly in idle_cull_fn()
  workqueue: Don't bind the rescuer in the last working cpu
  ...
2024-07-15 16:51:22 -07:00
Linus Torvalds 895b9b1207 cgroup: Changes for v6.11
- Added Michal Koutný as a maintainer.
 
 - Counters in pids.events were behaving inconsistently. pids.events made
   properly hierarchical and pids.events.local added.
 
 - misc.peak and misc.events.local added.
 
 - cpuset remote partition creation and cpuset.cpus.exclusive handling
   improved.
 
 - Code cleanups, non-critical fixes, doc updates.
 
 - for-6.10-fixes is merged in to receive two non-critical fixes that didn't
   trigger pull.
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Merge tag 'cgroup-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - Added Michal Koutný as a maintainer

 - Counters in pids.events were behaving inconsistently. pids.events
   made properly hierarchical and pids.events.local added

 - misc.peak and misc.events.local added

 - cpuset remote partition creation and cpuset.cpus.exclusive handling
   improved

 - Code cleanups, non-critical fixes, doc updates

 - for-6.10-fixes is merged in to receive two non-critical fixes that
   didn't trigger pull

* tag 'cgroup-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (23 commits)
  cgroup: Add Michal Koutný as a maintainer
  cgroup/misc: Introduce misc.events.local
  cgroup/rstat: add force idle show helper
  cgroup: Protect css->cgroup write under css_set_lock
  cgroup/misc: Introduce misc.peak
  cgroup_misc: add kernel-doc comments for enum misc_res_type
  cgroup/cpuset: Prevent UAF in proc_cpuset_show()
  selftest/cgroup: Update test_cpuset_prs.sh to match changes
  cgroup/cpuset: Make cpuset.cpus.exclusive independent of cpuset.cpus
  cgroup/cpuset: Delay setting of CS_CPU_EXCLUSIVE until valid partition
  selftest/cgroup: Fix test_cpuset_prs.sh problems reported by test robot
  cgroup/cpuset: Fix remote root partition creation problem
  cgroup: avoid the unnecessary list_add(dying_tasks) in cgroup_exit()
  cgroup/cpuset: Optimize isolated partition only generate_sched_domains() calls
  cgroup/cpuset: Reduce the lock protecting CS_SCHED_LOAD_BALANCE
  kernel/cgroup: cleanup cgroup_base_files when fail to add cgroup_psi_files
  selftests: cgroup: Add basic tests for pids controller
  selftests: cgroup: Lexicographic order in Makefile
  cgroup/pids: Add pids.events.local
  cgroup/pids: Make event counters hierarchical
  ...
2024-07-15 16:41:32 -07:00
Linus Torvalds e4b2b0b1e4 kcsan: Add __data_racy documentation and module description
This series contains on commit that improves the documentation for the
 new __data_racy type qualifier to the data_race() macro's kernel-doc
 header and to the LKMM's access-marking documentation.
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Merge tag 'kcsan.2024.07.12a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull KCSAN updates from Paul McKenney:

 - improve the documentation for the new __data_racy type qualifier
   to the data_race() macro's kernel-doc header and to the LKMM's
   access-marking documentation

 - add missing MODULE_DESCRIPTION

* tag 'kcsan.2024.07.12a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  kcsan: Add missing MODULE_DESCRIPTION() macro
  kcsan: Add example to data_race() kerneldoc header
2024-07-15 15:44:40 -07:00
Linus Torvalds b176e21d81 Torture-test updates for v6.11
This pull request adds MODULE_DESCRIPTION() to torture.c, locktorture.c,
 and scftorture.c, and also adds static to a global variable that is used
 only in scftorture.c.
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Merge tag 'torture.2024.07.12a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull torture-test updates from Paul McKenney:
 "This adds MODULE_DESCRIPTION() to torture.c, locktorture.c, and
  scftorture.c, and also adds 'static' to a global variable that is used
  only in scftorture.c"

* tag 'torture.2024.07.12a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  scftorture: Make torture_type static
  scftorture: Add MODULE_DESCRIPTION()
  locktorture: Add MODULE_DESCRIPTION()
  torture: Add MODULE_DESCRIPTION()
2024-07-15 15:39:25 -07:00
Linus Torvalds 9855e87328 RCU pull request for v6.11
doc.2024.06.06a: Update Tasks RCU and Tasks Rude RCU description in
 	Requirements.rst and clarify rcu_assign_pointer() and
 	rcu_dereference() ordering properties.
 
 fixes.2024.07.04a: Add lockdep assertions for RCU readers, limit inline
 	wakeups for callback-bypass synchronize_rcu(), add an
 	rcutree.nohz_full_patience_delay to reduce nohz_full OS jitter,
 	add Uladzislau Rezki as RCU maintainer, and fix a subtle
 	callback-migration memory-ordering issue.
 
 mb.2024.06.28a: Remove a number of redundant memory barriers.
 
 nocb.2024.06.03a: Remove unnecessary bypass-list lock-contention
 	mitigation, use parking API instead of open-coded ad-hoc
 	equivalent, and upgrade obsolete comments.
 
 rcu-tasks.2024.06.06a: Revert avoidance of a deadlock that can no
 	longer occur and properly synchronize Tasks Trace RCU checking
 	of runqueues.
 
 rcutorture.2024.06.06a: Add tests for handling of double-call_rcu()
 	bug, add missing MODULE_DESCRIPTION, and add a script that
 	histograms the number of calls to RCU updaters.
 
 srcu.2024.06.18a: Fill out SRCU polled-grace-period API.
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Merge tag 'rcu.2024.07.12a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

 - Update Tasks RCU and Tasks Rude RCU description in Requirements.rst
   and clarify rcu_assign_pointer() and rcu_dereference() ordering
   properties

 - Add lockdep assertions for RCU readers, limit inline wakeups for
   callback-bypass synchronize_rcu(), add an
   rcutree.nohz_full_patience_delay to reduce nohz_full OS jitter, add
   Uladzislau Rezki as RCU maintainer, and fix a subtle
   callback-migration memory-ordering issue

 - Remove a number of redundant memory barriers

 - Remove unnecessary bypass-list lock-contention mitigation, use
   parking API instead of open-coded ad-hoc equivalent, and upgrade
   obsolete comments

 - Revert avoidance of a deadlock that can no longer occur and properly
   synchronize Tasks Trace RCU checking of runqueues

 - Add tests for handling of double-call_rcu() bug, add missing
   MODULE_DESCRIPTION, and add a script that histograms the number of
   calls to RCU updaters

 - Fill out SRCU polled-grace-period API

* tag 'rcu.2024.07.12a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (29 commits)
  rcu: Fix rcu_barrier() VS post CPUHP_TEARDOWN_CPU invocation
  rcu: Eliminate lockless accesses to rcu_sync->gp_count
  MAINTAINERS: Add Uladzislau Rezki as RCU maintainer
  rcu: Add rcutree.nohz_full_patience_delay to reduce nohz_full OS jitter
  rcu/exp: Remove redundant full memory barrier at the end of GP
  rcu: Remove full memory barrier on RCU stall printout
  rcu: Remove full memory barrier on boot time eqs sanity check
  rcu/exp: Remove superfluous full memory barrier upon first EQS snapshot
  rcu: Remove superfluous full memory barrier upon first EQS snapshot
  rcu: Remove full ordering on second EQS snapshot
  srcu: Fill out polled grace-period APIs
  srcu: Update cleanup_srcu_struct() comment
  srcu: Add NUM_ACTIVE_SRCU_POLL_OLDSTATE
  srcu: Disable interrupts directly in srcu_gp_end()
  rcu: Disable interrupts directly in rcu_gp_init()
  rcu/tree: Reduce wake up for synchronize_rcu() common case
  rcu/tasks: Fix stale task snaphot for Tasks Trace
  tools/rcu: Add rcu-updaters.sh script
  rcutorture: Add missing MODULE_DESCRIPTION() macros
  rcutorture: Fix rcu_torture_fwd_cb_cr() data race
  ...
2024-07-15 15:25:27 -07:00
Linus Torvalds 4fd9435641 Updates for timers, timekeeping and related functionality:
- Core:
 
     - Make the takeover of a hrtimer based broadcast timer reliable during
       CPU hot-unplug. The current implementation suffers from a race which
       can lead to broadcast timer starvation in the worst case.
 
     - VDSO related cleanups and simplifications
 
     - Small cleanups and enhancements all over the place
 
   - PTP:
 
     - Replace the architecture specific base clock to clocksource, e.g. ART
       to TSC, conversion function with generic functionality to avoid
       exposing such internals to drivers and convert all existing drivers
       over. This also allows to provide functionality which converts the
       other way round in the core code based on the same parameter set.
 
     - Provide a function to convert CLOCK_REALTIME to the base clock to
       support the upcoming PPS output driver on Intel platforms.
 
   - Drivers:
 
     - A set of Device Tree bindings for new hardware
 
     - Cleanups and enhancements all over the place
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Merge tag 'timers-core-2024-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "Updates for timers, timekeeping and related functionality:

  Core:

   - Make the takeover of a hrtimer based broadcast timer reliable
     during CPU hot-unplug. The current implementation suffers from a
     race which can lead to broadcast timer starvation in the worst
     case.

   - VDSO related cleanups and simplifications

   - Small cleanups and enhancements all over the place

  PTP:

   - Replace the architecture specific base clock to clocksource, e.g.
     ART to TSC, conversion function with generic functionality to avoid
     exposing such internals to drivers and convert all existing drivers
     over. This also allows to provide functionality which converts the
     other way round in the core code based on the same parameter set.

   - Provide a function to convert CLOCK_REALTIME to the base clock to
     support the upcoming PPS output driver on Intel platforms.

  Drivers:

   - A set of Device Tree bindings for new hardware

   - Cleanups and enhancements all over the place"

* tag 'timers-core-2024-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  clocksource/drivers/realtek: Add timer driver for rtl-otto platforms
  dt-bindings: timer: Add schema for realtek,otto-timer
  dt-bindings: timer: Add SOPHGO SG2002 clint
  dt-bindings: timer: renesas,tmu: Add R-Car Gen2 support
  dt-bindings: timer: renesas,tmu: Add RZ/G1 support
  dt-bindings: timer: renesas,tmu: Add R-Mobile APE6 support
  clocksource/drivers/mips-gic-timer: Correct sched_clock width
  clocksource/drivers/mips-gic-timer: Refine rating computation
  clocksource/drivers/sh_cmt: Address race condition for clock events
  clocksource/driver/arm_global_timer: Remove unnecessary ‘0’ values from err
  clocksource/drivers/arm_arch_timer: Remove unnecessary ‘0’ values from irq
  tick/broadcast: Make takeover of broadcast hrtimer reliable
  tick/sched: Combine WARN_ON_ONCE and print_once
  x86/vdso: Remove unused include
  x86/vgtod: Remove unused typedef gtod_long_t
  x86/vdso: Fix function reference in comment
  vdso: Add comment about reason for vdso struct ordering
  vdso/gettimeofday: Clarify comment about open coded function
  timekeeping: Add missing kernel-doc function comments
  tick: Remove unnused tick_nohz_get_idle_calls()
  ...
2024-07-15 15:03:09 -07:00
Linus Torvalds 0eff0491e7 A small set of SMP/CPU hotplug updates:
- Reverse the order of iteration when freezing secondary CPUs for
     hibernation.
 
     This avoids that drivers like the Intel uncore performance counter have
     to transfer the assignement of handling the per package uncore events
     for every CPU in a package, which is a considerable speedup on larger
     systems.
 
   - Add a missing destroy_work_on_stack() invocation in smp_call_on_cpu()
     to prevent debug objects to emit a false positive warning when the
     stack is freed.
 
   - Small cleanups in comments and a str_plural() conversion
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Merge tag 'smp-core-2024-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull CPU hotplug updates from Thomas Gleixner:
 "A small set of SMP/CPU hotplug updates:

   - Reverse the order of iteration when freezing secondary CPUs for
     hibernation.

     This avoids that drivers like the Intel uncore performance counter
     have to transfer the assignement of handling the per package uncore
     events for every CPU in a package, which is a considerable speedup
     on larger systems.

   - Add a missing destroy_work_on_stack() invocation in
     smp_call_on_cpu() to prevent debug objects to emit a false positive
     warning when the stack is freed.

   - Small cleanups in comments and a str_plural() conversion"

* tag 'smp-core-2024-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()
  cpu/hotplug: Reverse order of iteration in freeze_secondary_cpus()
  smp: Use str_plural() to fix Coccinelle warnings
  cpu/hotplug: Fix typo in comment
2024-07-15 14:55:30 -07:00
Linus Torvalds 3a56e24173 for-6.11/io_uring-20240714
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Merge tag 'for-6.11/io_uring-20240714' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:
 "Here are the io_uring updates queued up for 6.11.

  Nothing major this time around, various minor improvements and
  cleanups/fixes. This contains:

   - Add bind/listen opcodes. Main motivation is to support direct
     descriptors, to avoid needing a regular fd just for doing these two
     operations (Gabriel)

   - Probe fixes (Gabriel)

   - Treat io-wq work flags as atomics. Not fixing a real issue, but may
     as well and it silences a KCSAN warning (me)

   - Cleanup of rsrc __set_current_state() usage (me)

   - Add 64-bit for {m,f}advise operations (me)

   - Improve performance of data ring messages (me)

   - Fix for ring message overflow posting (Pavel)

   - Fix for freezer interaction with TWA_NOTIFY_SIGNAL. Not strictly an
     io_uring thing, but since TWA_NOTIFY_SIGNAL was originally added
     for faster task_work signaling for io_uring, bundling it with this
     pull (Pavel)

   - Add Pavel as a co-maintainer

   - Various cleanups (me, Thorsten)"

* tag 'for-6.11/io_uring-20240714' of git://git.kernel.dk/linux: (28 commits)
  io_uring/net: check socket is valid in io_bind()/io_listen()
  kernel: rerun task_work while freezing in get_signal()
  io_uring/io-wq: limit retrying worker initialisation
  io_uring/napi: Remove unnecessary s64 cast
  io_uring/net: cleanup io_recv_finish() bundle handling
  io_uring/msg_ring: fix overflow posting
  MAINTAINERS: change Pavel Begunkov from io_uring reviewer to maintainer
  io_uring/msg_ring: use kmem_cache_free() to free request
  io_uring/msg_ring: check for dead submitter task
  io_uring/msg_ring: add an alloc cache for io_kiocb entries
  io_uring/msg_ring: improve handling of target CQE posting
  io_uring: add io_add_aux_cqe() helper
  io_uring: add remote task_work execution helper
  io_uring/msg_ring: tighten requirement for remote posting
  io_uring: Allocate only necessary memory in io_probe
  io_uring: Fix probe of disabled operations
  io_uring: Introduce IORING_OP_LISTEN
  io_uring: Introduce IORING_OP_BIND
  net: Split a __sys_listen helper for io_uring
  net: Split a __sys_bind helper for io_uring
  ...
2024-07-15 13:49:10 -07:00
levi.yun 7dc836187f trace/pid_list: Change gfp flags in pid_list_fill_irq()
pid_list_fill_irq() runs via irq_work.
When CONFIG_PREEMPT_RT is disabled, it would run in irq_context.
so it shouldn't sleep while memory allocation.

Change gfp flags from GFP_KERNEL to GFP_NOWAIT to prevent sleep in
irq_work.

This change wouldn't impact functionality in practice because the worst-size
is 2K.

Cc: stable@goodmis.org
Fixes: 8d6e90983a ("tracing: Create a sparse bitmask for pid filtering")
Link: https://lore.kernel.org/20240704150226.1359936-1-yeoreum.yun@arm.com
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: levi.yun <yeoreum.yun@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-15 15:07:14 -04:00
Linus Torvalds b051320d6a vfs-6.11.misc
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Merge tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Support passing NULL along AT_EMPTY_PATH for statx().

     NULL paths with any flag value other than AT_EMPTY_PATH go the
     usual route and end up with -EFAULT to retain compatibility (Rust
     is abusing calls of the sort to detect availability of statx)

     This avoids path lookup code, lockref management, memory allocation
     and in case of NULL path userspace memory access (which can be
     quite expensive with SMAP on x86_64)

   - Don't block i_writecount during exec. Remove the
     deny_write_access() mechanism for executables

   - Relax open_by_handle_at() permissions in specific cases where we
     can prove that the caller had sufficient privileges to open a file

   - Switch timespec64 fields in struct inode to discrete integers
     freeing up 4 bytes

  Fixes:

   - Fix false positive circular locking warning in hfsplus

   - Initialize hfs_inode_info after hfs_alloc_inode() in hfs

   - Avoid accidental overflows in vfs_fallocate()

   - Don't interrupt fallocate with EINTR in tmpfs to avoid constantly
     restarting shmem_fallocate()

   - Add missing quote in comment in fs/readdir

  Cleanups:

   - Don't assign and test in an if statement in mqueue. Move the
     assignment out of the if statement

   - Reflow the logic in may_create_in_sticky()

   - Remove the usage of the deprecated ida_simple_xx() API from procfs

   - Reject FSCONFIG_CMD_CREATE_EXCL requets that depend on the new
     mount api early

   - Rename variables in copy_tree() to make it easier to understand

   - Replace WARN(down_read_trylock, ...) abuse with proper asserts in
     various places in the VFS

   - Get rid of user_path_at_empty() and drop the empty argument from
     getname_flags()

   - Check for error while copying and no path in one branch in
     getname_flags()

   - Avoid redundant smp_mb() for THP handling in do_dentry_open()

   - Rename parent_ino to d_parent_ino and make it use RCU

   - Remove unused header include in fs/readdir

   - Export in_group_capable() helper and switch f2fs and fuse over to
     it instead of open-coding the logic in both places"

* tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
  ipc: mqueue: remove assignment from IS_ERR argument
  vfs: rename parent_ino to d_parent_ino and make it use RCU
  vfs: support statx(..., NULL, AT_EMPTY_PATH, ...)
  stat: use vfs_empty_path() helper
  fs: new helper vfs_empty_path()
  fs: reflow may_create_in_sticky()
  vfs: remove redundant smp_mb for thp handling in do_dentry_open
  fuse: Use in_group_or_capable() helper
  f2fs: Use in_group_or_capable() helper
  fs: Export in_group_or_capable()
  vfs: reorder checks in may_create_in_sticky
  hfs: fix to initialize fields of hfs_inode_info after hfs_alloc_inode()
  proc: Remove usage of the deprecated ida_simple_xx() API
  hfsplus: fix to avoid false alarm of circular locking
  Improve readability of copy_tree
  vfs: shave a branch in getname_flags
  vfs: retire user_path_at_empty and drop empty arg from getname_flags
  vfs: stop using user_path_at_empty in do_readlinkat
  tmpfs: don't interrupt fallocate with EINTR
  fs: don't block i_writecount during exec
  ...
2024-07-15 10:52:51 -07:00
Masahiro Yamada c442db3f49 kbuild: remove PROVIDE() for kallsyms symbols
This reimplements commit 951bcae6c5 ("kallsyms: Avoid weak references
for kallsyms symbols") because I am not a big fan of PROVIDE().

As an alternative solution, this commit prepends one more kallsyms step.

    KSYMS   .tmp_vmlinux.kallsyms0.S          # added
    AS      .tmp_vmlinux.kallsyms0.o          # added
    LD      .tmp_vmlinux.btf
    BTF     .btf.vmlinux.bin.o
    LD      .tmp_vmlinux.kallsyms1
    NM      .tmp_vmlinux.kallsyms1.syms
    KSYMS   .tmp_vmlinux.kallsyms1.S
    AS      .tmp_vmlinux.kallsyms1.o
    LD      .tmp_vmlinux.kallsyms2
    NM      .tmp_vmlinux.kallsyms2.syms
    KSYMS   .tmp_vmlinux.kallsyms2.S
    AS      .tmp_vmlinux.kallsyms2.o
    LD      vmlinux

Step 0 takes /dev/null as input, and generates .tmp_vmlinux.kallsyms0.o,
which has a valid kallsyms format with the empty symbol list, and can be
linked to vmlinux. Since it is really small, the added compile-time cost
is negligible.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-07-16 01:08:36 +09:00
Vlastimil Babka 436381eaf2 Merge branch 'slab/for-6.11/buckets' into slab/for-next
Merge all the slab patches previously collected on top of v6.10-rc1,
over cleanups/fixes that had to be based on rc6.
2024-07-15 10:44:16 +02:00
Lai Jiangshan 58629d4871 workqueue: Always queue work items to the newest PWQ for order workqueues
To ensure non-reentrancy, __queue_work() attempts to enqueue a work
item to the pool of the currently executing worker. This is not only
unnecessary for an ordered workqueue, where order inherently suggests
non-reentrancy, but it could also disrupt the sequence if the item is
not enqueued on the newest PWQ.

Just queue it to the newest PWQ and let order management guarantees
non-reentrancy.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Fixes: 4c065dbce1 ("workqueue: Enable unbound cpumask update on ordered workqueues")
Cc: stable@vger.kernel.org # v6.9+
Signed-off-by: Tejun Heo <tj@kernel.org>
(cherry picked from commit 74347be3edfd11277799242766edf844c43dd5d3)
2024-07-14 18:20:19 -10:00
Tejun Heo 9283ff5be1 Merge branch 'for-6.10-fixes' into for-6.11 2024-07-14 18:04:03 -10:00
Kent Overstreet 1a616c2fe9 lockdep: lockdep_set_notrack_class()
Add a new helper to disable lockdep tracking entirely for a given class.

This is needed for bcachefs, which takes too many btree node locks for
lockdep to track. Instead, we have a single lockdep_map for "btree_trans
has any btree nodes locked", which makes more since given that we have
centralized lock management and a cycle detector.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-07-14 19:00:16 -04:00
Linus Torvalds 365346980e - Fix a performance regression when measuring the CPU time of a thread
(clock_gettime(CLOCK_THREAD_CPUTIME_ID,...)) due to the addition of
   PSI IRQ time accounting in the hotpath
 
 - Fix a task_struct leak due to missing to decrement the refcount when
   the task is enqueued before the timer which is supposed to do that,
   expires
 
 - Revert an attempt to expedite detaching of movable tasks, as finding
   those could become very costly. Turns out the original issue wasn't
   even hit by anyone
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Merge tag 'sched_urgent_for_v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Borislav Petkov:

 - Fix a performance regression when measuring the CPU time of a thread
   (clock_gettime(CLOCK_THREAD_CPUTIME_ID,...)) due to the addition of
   PSI IRQ time accounting in the hotpath

 - Fix a task_struct leak due to missing to decrement the refcount when
   the task is enqueued before the timer which is supposed to do that,
   expires

 - Revert an attempt to expedite detaching of movable tasks, as finding
   those could become very costly. Turns out the original issue wasn't
   even hit by anyone

* tag 'sched_urgent_for_v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpath
  sched/deadline: Fix task_struct reference leak
  Revert "sched/fair: Make sure to try to detach at least one movable task"
2024-07-14 10:18:25 -07:00
Thomas Gleixner b7625d67eb - Remove unnecessary local variables initialization as they will be
initialized in the code path anyway right after on the ARM arch
   timer and the ARM global timer (Li kunyu)
 
 - Fix a race condition in the interrupt leading to a deadlock on the
   SH CMT driver. Note that this fix was not tested on the platform
   using this timer but the fix seems reasonable enough to be picked
   confidently (Niklas Söderlund)
 
 - Increase the rating of the gic-timer and use the configured width
   clocksource register on the MIPS architecture (Jiaxun Yang)
 
 - Add the DT bindings for the TMU on the Renesas platforms (Geert
   Uytterhoeven)
 
 - Add the DT bindings for the SOPHGO SG2002 clint on RiscV (Thomas
   Bonnefille)
 
 - Add the rtl-otto timer driver along with the DT bindings for the
   Realtek platform (Chris Packham)
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Merge tag 'timers-v6.11-rc1' of https://git.linaro.org/people/daniel.lezcano/linux into timers/core

Pull clocksource/event driver updates from Daniel Lezcano:

  - Remove unnecessary local variables initialization as they will be
    initialized in the code path anyway right after on the ARM arch
    timer and the ARM global timer (Li kunyu)

  - Fix a race condition in the interrupt leading to a deadlock on the
    SH CMT driver. Note that this fix was not tested on the platform
    using this timer but the fix seems reasonable enough to be picked
    confidently (Niklas Söderlund)

  - Increase the rating of the gic-timer and use the configured width
    clocksource register on the MIPS architecture (Jiaxun Yang)

  - Add the DT bindings for the TMU on the Renesas platforms (Geert
    Uytterhoeven)

  - Add the DT bindings for the SOPHGO SG2002 clint on RiscV (Thomas
    Bonnefille)

  - Add the rtl-otto timer driver along with the DT bindings for the
    Realtek platform (Chris Packham)

Link: https://lore.kernel.org/all/91cd05de-4c5d-4242-a381-3b8a4fe6a2a2@linaro.org
2024-07-13 12:07:10 +02:00
Yang Li b69bdba5a3 swiotlb: fix kernel-doc description for swiotlb_del_transient
Describe the pool argument in the kernel-doc comment for
swiotlb_del_transient.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-07-13 07:36:10 +02:00
Jakub Kicinski 26f453176a bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-07-12

We've added 23 non-merge commits during the last 3 day(s) which contain
a total of 18 files changed, 234 insertions(+), 243 deletions(-).

The main changes are:

1) Improve BPF verifier by utilizing overflow.h helpers to check
   for overflows, from Shung-Hsi Yu.

2) Fix NULL pointer dereference in resolve_prog_type() for BPF_PROG_TYPE_EXT
   when attr->attach_prog_fd was not specified, from Tengda Wu.

3) Fix arm64 BPF JIT when generating code for BPF trampolines with
   BPF_TRAMP_F_CALL_ORIG which corrupted upper address bits,
   from Puranjay Mohan.

4) Remove test_run callback from lwt_seg6local_prog_ops which never worked
   in the first place and caused syzbot reports,
   from Sebastian Andrzej Siewior.

5) Relax BPF verifier to accept non-zero offset on KF_TRUSTED_ARGS/
   /KF_RCU-typed BPF kfuncs, from Matt Bobrowski.

6) Fix a long standing bug in libbpf with regards to handling of BPF
   skeleton's forward and backward compatibility, from Andrii Nakryiko.

7) Annotate btf_{seq,snprintf}_show functions with __printf,
   from Alan Maguire.

8) BPF selftest improvements to reuse common network helpers in sk_lookup
   test and dropping the open-coded inetaddr_len() and make_socket() ones,
   from Geliang Tang.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (23 commits)
  selftests/bpf: Test for null-pointer-deref bugfix in resolve_prog_type()
  bpf: Fix null pointer dereference in resolve_prog_type() for BPF_PROG_TYPE_EXT
  selftests/bpf: DENYLIST.aarch64: Skip fexit_sleep again
  bpf: use check_sub_overflow() to check for subtraction overflows
  bpf: use check_add_overflow() to check for addition overflows
  bpf: fix overflow check in adjust_jmp_off()
  bpf: Eliminate remaining "make W=1" warnings in kernel/bpf/btf.o
  bpf: annotate BTF show functions with __printf
  bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG
  selftests/bpf: Close obj in error path in xdp_adjust_tail
  selftests/bpf: Null checks for links in bpf_tcp_ca
  selftests/bpf: Use connect_fd_to_fd in sk_lookup
  selftests/bpf: Use start_server_addr in sk_lookup
  selftests/bpf: Use start_server_str in sk_lookup
  selftests/bpf: Close fd in error path in drop_on_reuseport
  selftests/bpf: Add ASSERT_OK_FD macro
  selftests/bpf: Add backlog for network_helper_opts
  selftests/bpf: fix compilation failure when CONFIG_NF_FLOW_TABLE=m
  bpf: Remove tst_run from lwt_seg6local_prog_ops.
  bpf: relax zero fixed offset constraint on KF_TRUSTED_ARGS/KF_RCU
  ...
====================

Link: https://patch.msgid.link/20240712212448.5378-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-12 22:25:54 -07:00
Kees Cook 0fe2356434 tsacct: replace strncpy() with strscpy()
Replace the deprecated[1] use of strncpy() in bacct_add_tsk().  Since this
is UAPI, include trailing padding in the copy.

Link: https://github.com/KSPP/linux/issues/90 [1]
Link: https://lkml.kernel.org/r/20240711171308.work.995-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Cc: "Dr. Thomas Orgis" <thomas.orgis@uni-hamburg.de>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ismael Luceno <ismael@iodev.co.uk>
Cc: Peng Liu <liupeng256@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 16:39:53 -07:00
Christophe Leroy 18d095b255 mm: define __pte_leaf_size() to also take a PMD entry
On powerpc 8xx, when a page is 8M size, the information is in the PMD
entry.  So allow architectures to provide __pte_leaf_size() instead of
pte_leaf_size() and provide the PMD entry to that function.

When __pte_leaf_size() is not defined, define it as a pte_leaf_size() so
that architectures not interested in the PMD arguments are not impacted.

Only define a default pte_leaf_size() when __pte_leaf_size() is not
defined to make sure nobody adds new calls to pte_leaf_size() in the core.

Link: https://lkml.kernel.org/r/c7c008f0a314bf8029ad7288fdc908db1ec7e449.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:15 -07:00
Xiu Jianfeng 6a26f9c689 cgroup/misc: Introduce misc.events.local
Currently the event counting provided by misc.events is hierarchical,
it's not practical if user is only concerned with events of a
specified cgroup. Therefore, introduce misc.events.local collect events
specific to the given cgroup.

This is analogous to memory.events.local and pids.events.local.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-12 06:45:23 -10:00
Shung-Hsi Yu deac5871eb bpf: use check_sub_overflow() to check for subtraction overflows
Similar to previous patch that drops signed_add*_overflows() and uses
(compiler) builtin-based check_add_overflow(), do the same for
signed_sub*_overflows() and replace them with the generic
check_sub_overflow() to make future refactoring easier and have the
checks implemented more efficiently.

Unsigned overflow check for subtraction does not use helpers and are
simple enough already, so they're left untouched.

After the change GCC 13.3.0 generates cleaner assembly on x86_64:

	if (check_sub_overflow(*dst_smin, src_reg->smax_value, dst_smin) ||
   139bf:	mov    0x28(%r12),%rax
   139c4:	mov    %edx,0x54(%r12)
   139c9:	sub    %r11,%rax
   139cc:	mov    %rax,0x28(%r12)
   139d1:	jo     14627 <adjust_reg_min_max_vals+0x1237>
	    check_sub_overflow(*dst_smax, src_reg->smin_value, dst_smax)) {
   139d7:	mov    0x30(%r12),%rax
   139dc:	sub    %r9,%rax
   139df:	mov    %rax,0x30(%r12)
	if (check_sub_overflow(*dst_smin, src_reg->smax_value, dst_smin) ||
   139e4:	jo     14627 <adjust_reg_min_max_vals+0x1237>
   ...
		*dst_smin = S64_MIN;
   14627:	movabs $0x8000000000000000,%rax
   14631:	mov    %rax,0x28(%r12)
		*dst_smax = S64_MAX;
   14636:	sub    $0x1,%rax
   1463a:	mov    %rax,0x30(%r12)

Before the change it gives:

	if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
   13a50:	mov    0x28(%r12),%rdi
   13a55:	mov    %edx,0x54(%r12)
		dst_reg->smax_value = S64_MAX;
   13a5a:	movabs $0x7fffffffffffffff,%rdx
   13a64:	mov    %eax,0x50(%r12)
		dst_reg->smin_value = S64_MIN;
   13a69:	movabs $0x8000000000000000,%rax
	s64 res = (s64)((u64)a - (u64)b);
   13a73:	mov    %rdi,%rsi
   13a76:	sub    %rcx,%rsi
	if (b < 0)
   13a79:	test   %rcx,%rcx
   13a7c:	js     145ea <adjust_reg_min_max_vals+0x119a>
	if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
   13a82:	cmp    %rsi,%rdi
   13a85:	jl     13ac7 <adjust_reg_min_max_vals+0x677>
	    signed_sub_overflows(dst_reg->smax_value, smin_val)) {
   13a87:	mov    0x30(%r12),%r8
	s64 res = (s64)((u64)a - (u64)b);
   13a8c:	mov    %r8,%rax
   13a8f:	sub    %r9,%rax
	return res > a;
   13a92:	cmp    %rax,%r8
   13a95:	setl   %sil
	if (b < 0)
   13a99:	test   %r9,%r9
   13a9c:	js     147d1 <adjust_reg_min_max_vals+0x1381>
		dst_reg->smax_value = S64_MAX;
   13aa2:	movabs $0x7fffffffffffffff,%rdx
		dst_reg->smin_value = S64_MIN;
   13aac:	movabs $0x8000000000000000,%rax
	if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
   13ab6:	test   %sil,%sil
   13ab9:	jne    13ac7 <adjust_reg_min_max_vals+0x677>
		dst_reg->smin_value -= smax_val;
   13abb:	mov    %rdi,%rax
		dst_reg->smax_value -= smin_val;
   13abe:	mov    %r8,%rdx
		dst_reg->smin_value -= smax_val;
   13ac1:	sub    %rcx,%rax
		dst_reg->smax_value -= smin_val;
   13ac4:	sub    %r9,%rdx
   13ac7:	mov    %rax,0x28(%r12)
   ...
   13ad1:	mov    %rdx,0x30(%r12)
   ...
	if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
   145ea:	cmp    %rsi,%rdi
   145ed:	jg     13ac7 <adjust_reg_min_max_vals+0x677>
   145f3:	jmp    13a87 <adjust_reg_min_max_vals+0x637>

Suggested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240712080127.136608-4-shung-hsi.yu@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-12 08:54:08 -07:00
Shung-Hsi Yu 28a4411076 bpf: use check_add_overflow() to check for addition overflows
signed_add*_overflows() was added back when there was no overflow-check
helper. With the introduction of such helpers in commit f0907827a8
("compiler.h: enable builtin overflow checkers and add fallback code"), we
can drop signed_add*_overflows() in kernel/bpf/verifier.c and use the
generic check_add_overflow() instead.

This will make future refactoring easier, and takes advantage of
compiler-emitted hardware instructions that efficiently implement these
checks.

After the change GCC 13.3.0 generates cleaner assembly on x86_64:

	err = adjust_scalar_min_max_vals(env, insn, dst_reg, *src_reg);
   13625:	mov    0x28(%rbx),%r9  /*  r9 = src_reg->smin_value */
   13629:	mov    0x30(%rbx),%rcx /* rcx = src_reg->smax_value */
   ...
	if (check_add_overflow(*dst_smin, src_reg->smin_value, dst_smin) ||
   141c1:	mov    %r9,%rax
   141c4:	add    0x28(%r12),%rax
   141c9:	mov    %rax,0x28(%r12)
   141ce:	jo     146e4 <adjust_reg_min_max_vals+0x1294>
	    check_add_overflow(*dst_smax, src_reg->smax_value, dst_smax)) {
   141d4:	add    0x30(%r12),%rcx
   141d9:	mov    %rcx,0x30(%r12)
	if (check_add_overflow(*dst_smin, src_reg->smin_value, dst_smin) ||
   141de:	jo     146e4 <adjust_reg_min_max_vals+0x1294>
   ...
		*dst_smin = S64_MIN;
   146e4:	movabs $0x8000000000000000,%rax
   146ee:	mov    %rax,0x28(%r12)
		*dst_smax = S64_MAX;
   146f3:	sub    $0x1,%rax
   146f7:	mov    %rax,0x30(%r12)

Before the change it gives:

	s64 smin_val = src_reg->smin_value;
     675:	mov    0x28(%rsi),%r8
	s64 smax_val = src_reg->smax_value;
	u64 umin_val = src_reg->umin_value;
	u64 umax_val = src_reg->umax_value;
     679:	mov    %rdi,%rax /* rax = dst_reg */
	if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
     67c:	mov    0x28(%rdi),%rdi /* rdi = dst_reg->smin_value */
	u64 umin_val = src_reg->umin_value;
     680:	mov    0x38(%rsi),%rdx
	u64 umax_val = src_reg->umax_value;
     684:	mov    0x40(%rsi),%rcx
	s64 res = (s64)((u64)a + (u64)b);
     688:	lea    (%r8,%rdi,1),%r9 /* r9 = dst_reg->smin_value + src_reg->smin_value */
	return res < a;
     68c:	cmp    %r9,%rdi
     68f:	setg   %r10b /* r10b = (dst_reg->smin_value + src_reg->smin_value) > dst_reg->smin_value */
	if (b < 0)
     693:	test   %r8,%r8
     696:	js     72b <scalar_min_max_add+0xbb>
	    signed_add_overflows(dst_reg->smax_value, smax_val)) {
		dst_reg->smin_value = S64_MIN;
		dst_reg->smax_value = S64_MAX;
     69c:	movabs $0x7fffffffffffffff,%rdi
	s64 smax_val = src_reg->smax_value;
     6a6:	mov    0x30(%rsi),%r8
		dst_reg->smin_value = S64_MIN;
     6aa:	00 00 00 	movabs $0x8000000000000000,%rsi
	if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
     6b4:	test   %r10b,%r10b /* (dst_reg->smin_value + src_reg->smin_value) > dst_reg->smin_value ? goto 6cb */
     6b7:	jne    6cb <scalar_min_max_add+0x5b>
	    signed_add_overflows(dst_reg->smax_value, smax_val)) {
     6b9:	mov    0x30(%rax),%r10   /* r10 = dst_reg->smax_value */
	s64 res = (s64)((u64)a + (u64)b);
     6bd:	lea    (%r10,%r8,1),%r11 /* r11 = dst_reg->smax_value + src_reg->smax_value */
	if (b < 0)
     6c1:	test   %r8,%r8
     6c4:	js     71e <scalar_min_max_add+0xae>
	if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
     6c6:	cmp    %r11,%r10 /* (dst_reg->smax_value + src_reg->smax_value) <= dst_reg->smax_value ? goto 723 */
     6c9:	jle    723 <scalar_min_max_add+0xb3>
	} else {
		dst_reg->smin_value += smin_val;
		dst_reg->smax_value += smax_val;
	}
     6cb:	mov    %rsi,0x28(%rax)
     ...
     6d5:	mov    %rdi,0x30(%rax)
     ...
	if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
     71e:	cmp    %r11,%r10
     721:	jl     6cb <scalar_min_max_add+0x5b>
		dst_reg->smin_value += smin_val;
     723:	mov    %r9,%rsi
		dst_reg->smax_value += smax_val;
     726:	mov    %r11,%rdi
     729:	jmp    6cb <scalar_min_max_add+0x5b>
		return res > a;
     72b:	cmp    %r9,%rdi
     72e:	setl   %r10b
     732:	jmp    69c <scalar_min_max_add+0x2c>
     737:	nopw   0x0(%rax,%rax,1)

Note: unlike adjust_ptr_min_max_vals() and scalar*_min_max_add(), it is
necessary to introduce intermediate variable in adjust_jmp_off() to keep
the functional behavior unchanged. Without an intermediate variable
imm/off will be altered even on overflow.

Suggested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20240712080127.136608-3-shung-hsi.yu@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-12 08:54:08 -07:00
Shung-Hsi Yu 4a04b4f0de bpf: fix overflow check in adjust_jmp_off()
adjust_jmp_off() incorrectly used the insn->imm field for all overflow check,
which is incorrect as that should only be done or the BPF_JMP32 | BPF_JA case,
not the general jump instruction case. Fix it by using insn->off for overflow
check in the general case.

Fixes: 5337ac4c9b ("bpf: Fix the corner case with may_goto and jump to the 1st insn.")
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20240712080127.136608-2-shung-hsi.yu@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-12 08:54:07 -07:00
Alan Maguire 2454075f8e bpf: Eliminate remaining "make W=1" warnings in kernel/bpf/btf.o
As reported by Mirsad [1] we still see format warnings in kernel/bpf/btf.o
at W=1 warning level:

  CC      kernel/bpf/btf.o
./kernel/bpf/btf.c: In function ‘btf_type_seq_show_flags’:
./kernel/bpf/btf.c:7553:21: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format]
 7553 |         sseq.showfn = btf_seq_show;
      |                     ^
./kernel/bpf/btf.c: In function ‘btf_type_snprintf_show’:
./kernel/bpf/btf.c:7604:31: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format]
 7604 |         ssnprintf.show.showfn = btf_snprintf_show;
      |                               ^

Combined with CONFIG_WERROR=y these can halt the build.

The fix (annotating the structure field with __printf())
suggested by Mirsad resolves these. Apologies I missed this last time.
No other W=1 warnings were observed in kernel/bpf after this fix.

[1] https://lore.kernel.org/bpf/92c9d047-f058-400c-9c7d-81d4dc1ef71b@gmail.com/

Fixes: b3470da314 ("bpf: annotate BTF show functions with __printf")
Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Suggested-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240712092859.1390960-1-alan.maguire@oracle.com
2024-07-12 17:02:26 +02:00
Lai Jiangshan b2b1f93384 workqueue: Rename wq_update_pod() to unbound_wq_update_pwq()
What wq_update_pod() does is just to update the pwq of the specific
cpu.  Rename it and update the comments.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-11 12:50:35 -10:00
Lai Jiangshan d160a58de5 workqueue: Remove the arguments @hotplug_cpu and @online from wq_update_pod()
The arguments @hotplug_cpu and @online are not used in wq_update_pod()
since the functions called by wq_update_pod() don't need them.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-11 12:50:35 -10:00
Lai Jiangshan 88a41b185d workqueue: Remove the argument @cpu_going_down from wq_calc_pod_cpumask()
wq_calc_pod_cpumask() uses wq_online_cpumask, which excludes the cpu
going down, so the argument cpu_going_down is unused and can be removed.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-11 12:50:34 -10:00
Lai Jiangshan 2cb61f76be workqueue: Remove the unneeded cpumask empty check in wq_calc_pod_cpumask()
The cpumask empty check in wq_calc_pod_cpumask() has long been useless.
It just works purely as documents which states that the cpumask is not
possible empty after the function returns.

Now the code above is even more explicit that the cpumask is not empty,
so the document-only empty check can be removed.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-11 12:50:34 -10:00
Lai Jiangshan 19af457573 workqueue: Remove cpus_read_lock() from apply_wqattrs_lock()
1726a17135 ("workqueue: Put PWQ allocation and WQ enlistment in the same
lock C.S.") led to the following possible deadlock:

  WARNING: possible recursive locking detected
  6.10.0-rc5-00004-g1d4c6111406c #1 Not tainted
   --------------------------------------------
   swapper/0/1 is trying to acquire lock:
   c27760f4 (cpu_hotplug_lock){++++}-{0:0}, at: alloc_workqueue (kernel/workqueue.c:5152 kernel/workqueue.c:5730) 
  
   but task is already holding lock:
   c27760f4 (cpu_hotplug_lock){++++}-{0:0}, at: padata_alloc (kernel/padata.c:1007) 
   ...  
   stack backtrace:
   ...
   cpus_read_lock (include/linux/percpu-rwsem.h:53 kernel/cpu.c:488) 
   alloc_workqueue (kernel/workqueue.c:5152 kernel/workqueue.c:5730) 
   padata_alloc (kernel/padata.c:1007 (discriminator 1)) 
   pcrypt_init_padata (crypto/pcrypt.c:327 (discriminator 1)) 
   pcrypt_init (crypto/pcrypt.c:353) 
   do_one_initcall (init/main.c:1267) 
   do_initcalls (init/main.c:1328 (discriminator 1) init/main.c:1345 (discriminator 1)) 
   kernel_init_freeable (init/main.c:1364) 
   kernel_init (init/main.c:1469) 
   ret_from_fork (arch/x86/kernel/process.c:153) 
   ret_from_fork_asm (arch/x86/entry/entry_32.S:737) 
   entry_INT80_32 (arch/x86/entry/entry_32.S:944) 

This is caused by pcrypt allocating a workqueue while holding
cpus_read_lock(), so workqueue code can't do it again as that can lead to
deadlocks if down_write starts after the first down_read.

The pwq creations and installations have been reworked based on
wq_online_cpumask rather than cpu_online_mask making cpus_read_lock() is
unneeded during wqattrs changes. Fix the deadlock by removing
cpus_read_lock() from apply_wqattrs_lock().

tj: Updated changelog.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Fixes: 1726a17135 ("workqueue: Put PWQ allocation and WQ enlistment in the same lock C.S.")
Link: http://lkml.kernel.org/r/202407081521.83b627c1-lkp@intel.com
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-11 12:50:34 -10:00
Lai Jiangshan fbb3d4c15d workqueue: Simplify wq_calc_pod_cpumask() with wq_online_cpumask
Avoid relying on cpu_online_mask for wqattrs changes so that
cpus_read_lock() can be removed from apply_wqattrs_lock().

And with wq_online_cpumask, attrs->__pod_cpumask doesn't need to be
reused as a temporary storage to calculate if the pod have any online
CPUs @attrs wants since @cpu_going_down is not in the wq_online_cpumask.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-11 12:50:34 -10:00
Lai Jiangshan 8d84baf760 workqueue: Add wq_online_cpumask
The new wq_online_mask mirrors the cpu_online_mask except during
hotplugging; specifically, it differs between the hotplugging stages
of workqueue_offline_cpu() and workqueue_online_cpu(), during which
the transitioning CPU is not represented in the mask.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-11 12:50:34 -10:00
Alan Maguire b3470da314 bpf: annotate BTF show functions with __printf
-Werror=suggest-attribute=format warns about two functions
in kernel/bpf/btf.c [1]; add __printf() annotations to silence
these warnings since for CONFIG_WERROR=y they will trigger
build failures.

[1] https://lore.kernel.org/bpf/a8b20c72-6631-4404-9e1f-0410642d7d20@gmail.com/

Fixes: 31d0bc8163 ("bpf: Move to generic BTF show support, apply it to seq files/strings")
Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Tested-by: Mirsad Todorovac <mtodorovac69@yahoo.com>
Link: https://lore.kernel.org/r/20240711182321.963667-1-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-11 14:15:17 -07:00
Jakub Kicinski 7c8267275d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/sched/act_ct.c
  26488172b0 ("net/sched: Fix UAF when resolving a clash")
  3abbd7ed8b ("act_ct: prepare for stolen verdict coming from conntrack and nat engine")

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-11 12:58:13 -07:00
Yu Liao f7d43dd206 tick/broadcast: Make takeover of broadcast hrtimer reliable
Running the LTP hotplug stress test on a aarch64 machine results in
rcu_sched stall warnings when the broadcast hrtimer was owned by the
un-plugged CPU. The issue is the following:

CPU1 (owns the broadcast hrtimer)	CPU2

				tick_broadcast_enter()
				  // shutdown local timer device
				  broadcast_shutdown_local()
				...
				tick_broadcast_exit()
				  clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT)
				  // timer device is not programmed
				  cpumask_set_cpu(cpu, tick_broadcast_force_mask)

				initiates offlining of CPU1
take_cpu_down()
/*
 * CPU1 shuts down and does not
 * send broadcast IPI anymore
 */
				takedown_cpu()
				  hotplug_cpu__broadcast_tick_pull()
				    // move broadcast hrtimer to this CPU
				    clockevents_program_event()
				      bc_set_next()
					hrtimer_start()
					/*
					 * timer device is not programmed
					 * because only the first expiring
					 * timer will trigger clockevent
					 * device reprogramming
					 */

What happens is that CPU2 exits broadcast mode with force bit set, then the
local timer device is not reprogrammed and CPU2 expects to receive the
expired event by the broadcast IPI. But this does not happen because CPU1
is offlined by CPU2. CPU switches the clockevent device to ONESHOT state,
but does not reprogram the device.

The subsequent reprogramming of the hrtimer broadcast device does not
program the clockevent device of CPU2 either because the pending expiry
time is already in the past and the CPU expects the event to be delivered.
As a consequence all CPUs which wait for a broadcast event to be delivered
are stuck forever.

Fix this issue by reprogramming the local timer device if the broadcast
force bit of the CPU is set so that the broadcast hrtimer is delivered.

[ tglx: Massage comment and change log. Add Fixes tag ]

Fixes: 989dcb645c ("tick: Handle broadcast wakeup of multiple cpus")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240711124843.64167-1-liaoyu15@huawei.com
2024-07-11 18:00:24 +02:00
Juergen Gross 9fe6a8c5b2 x86/xen: remove deprecated xen_nopvspin boot parameter
The xen_nopvspin boot parameter is deprecated since 2019. nopvspin
can be used instead.

Remove the xen_nopvspin boot parameter and replace the xen_pvspin
variable use cases with nopvspin.

This requires to move the nopvspin variable out of the .initdata
section, as it needs to be accessed for cpuhotplug, too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Message-ID: <20240710110139.22300-1-jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2024-07-11 16:33:51 +02:00
Ingo Molnar 011b1134b8 Merge branch 'sched/urgent' into sched/core, to pick up fixes and refresh the branch
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-07-11 10:42:33 +02:00
Pavel Begunkov 943ad0b62e kernel: rerun task_work while freezing in get_signal()
io_uring can asynchronously add a task_work while the task is getting
freezed. TIF_NOTIFY_SIGNAL will prevent the task from sleeping in
do_freezer_trap(), and since the get_signal()'s relock loop doesn't
retry task_work, the task will spin there not being able to sleep
until the freezing is cancelled / the task is killed / etc.

Run task_works in the freezer path. Keep the patch small and simple
so it can be easily back ported, but we might need to do some cleaning
after and look if there are other places with similar problems.

Cc: stable@vger.kernel.org
Link: https://github.com/systemd/systemd/issues/33626
Fixes: 12db8b6900 ("entry: Add support for TIF_NOTIFY_SIGNAL")
Reported-by: Julian Orth <ju.orth@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/89ed3a52933370deaaf61a0a620a6ac91f1e754d.1720634146.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-11 01:51:44 -06:00
Kumar Kartikeya Dwivedi a6fcd19d7e bpf: Defer work in bpf_timer_cancel_and_free
Currently, the same case as previous patch (two timer callbacks trying
to cancel each other) can be invoked through bpf_map_update_elem as
well, or more precisely, freeing map elements containing timers. Since
this relies on hrtimer_cancel as well, it is prone to the same deadlock
situation as the previous patch.

It would be sufficient to use hrtimer_try_to_cancel to fix this problem,
as the timer cannot be enqueued after async_cancel_and_free. Once
async_cancel_and_free has been done, the timer must be reinitialized
before it can be armed again. The callback running in parallel trying to
arm the timer will fail, and freeing bpf_hrtimer without waiting is
sufficient (given kfree_rcu), and bpf_timer_cb will return
HRTIMER_NORESTART, preventing the timer from being rearmed again.

However, there exists a UAF scenario where the callback arms the timer
before entering this function, such that if cancellation fails (due to
timer callback invoking this routine, or the target timer callback
running concurrently). In such a case, if the timer expiration is
significantly far in the future, the RCU grace period expiration
happening before it will free the bpf_hrtimer state and along with it
the struct hrtimer, that is enqueued.

Hence, it is clear cancellation needs to occur after
async_cancel_and_free, and yet it cannot be done inline due to deadlock
issues. We thus modify bpf_timer_cancel_and_free to defer work to the
global workqueue, adding a work_struct alongside rcu_head (both used at
_different_ points of time, so can share space).

Update existing code comments to reflect the new state of affairs.

Fixes: b00628b1c7 ("bpf: Introduce bpf timers.")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240709185440.1104957-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-10 15:59:44 -07:00
Kumar Kartikeya Dwivedi d4523831f0 bpf: Fail bpf_timer_cancel when callback is being cancelled
Given a schedule:

timer1 cb			timer2 cb

bpf_timer_cancel(timer2);	bpf_timer_cancel(timer1);

Both bpf_timer_cancel calls would wait for the other callback to finish
executing, introducing a lockup.

Add an atomic_t count named 'cancelling' in bpf_hrtimer. This keeps
track of all in-flight cancellation requests for a given BPF timer.
Whenever cancelling a BPF timer, we must check if we have outstanding
cancellation requests, and if so, we must fail the operation with an
error (-EDEADLK) since cancellation is synchronous and waits for the
callback to finish executing. This implies that we can enter a deadlock
situation involving two or more timer callbacks executing in parallel
and attempting to cancel one another.

Note that we avoid incrementing the cancelling counter for the target
timer (the one being cancelled) if bpf_timer_cancel is not invoked from
a callback, to avoid spurious errors. The whole point of detecting
cur->cancelling and returning -EDEADLK is to not enter a busy wait loop
(which may or may not lead to a lockup). This does not apply in case the
caller is in a non-callback context, the other side can continue to
cancel as it sees fit without running into errors.

Background on prior attempts:

Earlier versions of this patch used a bool 'cancelling' bit and used the
following pattern under timer->lock to publish cancellation status.

lock(t->lock);
t->cancelling = true;
mb();
if (cur->cancelling)
	return -EDEADLK;
unlock(t->lock);
hrtimer_cancel(t->timer);
t->cancelling = false;

The store outside the critical section could overwrite a parallel
requests t->cancelling assignment to true, to ensure the parallely
executing callback observes its cancellation status.

It would be necessary to clear this cancelling bit once hrtimer_cancel
is done, but lack of serialization introduced races. Another option was
explored where bpf_timer_start would clear the bit when (re)starting the
timer under timer->lock. This would ensure serialized access to the
cancelling bit, but may allow it to be cleared before in-flight
hrtimer_cancel has finished executing, such that lockups can occur
again.

Thus, we choose an atomic counter to keep track of all outstanding
cancellation requests and use it to prevent lockups in case callbacks
attempt to cancel each other while executing in parallel.

Reported-by: Dohyun Kim <dohyunkim@google.com>
Reported-by: Neel Natu <neelnatu@google.com>
Fixes: b00628b1c7 ("bpf: Introduce bpf timers.")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240709185440.1104957-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-10 15:59:44 -07:00
Mohammad Shehar Yaar Tausif af253aef18 bpf: fix order of args in call to bpf_map_kvcalloc
The original function call passed size of smap->bucket before the number of
buckets which raises the error 'calloc-transposed-args' on compilation.

Vlastimil Babka added:

The order of parameters can be traced back all the way to 6ac99e8f23
("bpf: Introduce bpf sk local storage") accross several refactorings,
and that's why the commit is used as a Fixes: tag.

In v6.10-rc1, a different commit 2c321f3f70 ("mm: change inlined
allocation helpers to account at the call site") however exposed the
order of args in a way that gcc-14 has enough visibility to start
warning about it, because (in !CONFIG_MEMCG case) bpf_map_kvcalloc is
then a macro alias for kvcalloc instead of a static inline wrapper.

To sum up the warning happens when the following conditions are all met:

- gcc-14 is used (didn't see it with gcc-13)
- commit 2c321f3f70 is present
- CONFIG_MEMCG is not enabled in .config
- CONFIG_WERROR turns this from a compiler warning to error

Fixes: 6ac99e8f23 ("bpf: Introduce bpf sk local storage")
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Mohammad Shehar Yaar Tausif <sheharyaar48@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20240710100521.15061-2-vbabka@suse.cz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-10 15:31:19 -07:00
Zqiang 77aeb1b685 smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()
For CONFIG_DEBUG_OBJECTS_WORK=y kernels sscs.work defined by
INIT_WORK_ONSTACK() is initialized by debug_object_init_on_stack() for
the debug check in __init_work() to work correctly.

But this lacks the counterpart to remove the tracked object from debug
objects again, which will cause a debug object warning once the stack is
freed.

Add the missing destroy_work_on_stack() invocation to cure that.

[ tglx: Massaged changelog ]

Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240704065213.13559-1-qiang.zhang1211@gmail.com
2024-07-10 22:40:39 +02:00
Wei Yang 9325585288 kernel/fork.c: put set_max_threads()/task_struct_whitelist() in __init section
The functions set_max_threads() and task_struct_whitelist() are only used
by fork_init() during bootup.

Let's add __init tag to them.

Link: https://lkml.kernel.org/r/20240701013410.17260-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10 12:14:54 -07:00
Wei Yang 66b4aaf733 kernel/fork.c: get totalram_pages from memblock to calculate max_threads
Since we plan to move the accounting into __free_pages_core(),
totalram_pages may not represent the total usable pages on system at this
point when defer_init is enabled.

Instead we can get the total usable pages from memblock directly.

Link: https://lkml.kernel.org/r/20240701013410.17260-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10 12:14:54 -07:00
Johannes Weiner 3a3b7fec39 mm: remove CONFIG_MEMCG_KMEM
CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab
tracking is enabled.  It has been default-enabled and equivalent to
CONFIG_MEMCG for almost a decade.  We've only grown more kernel memory
accounting sites since, and there is no imaginable cgroup usecase going
forward that wants to track user pages but not the multitude of
user-drivable kernel allocations.

Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10 12:14:54 -07:00
Arnd Bergmann 505d66d1ab clone3: drop __ARCH_WANT_SYS_CLONE3 macro
When clone3() was introduced, it was not obvious how each architecture
deals with setting up the stack and keeping the register contents in
a fork()-like system call, so this was left for the architecture
maintainers to implement, with __ARCH_WANT_SYS_CLONE3 defined by those
that already implement it.

Five years later, we still have a few architectures left that are missing
clone3(), and the macro keeps getting in the way as it's fundamentally
different from all the other __ARCH_WANT_SYS_* macros that are meant
to provide backwards-compatibility with applications using older
syscalls that are no longer provided by default.

Address this by reversing the polarity of the macro, adding an
__ARCH_BROKEN_SYS_CLONE3 macro to all architectures that don't
already provide the syscall, and remove __ARCH_WANT_SYS_CLONE3
from all the other ones.

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-10 14:23:38 +02:00
Michael Kelley 7296f2301a swiotlb: reduce swiotlb pool lookups
With CONFIG_SWIOTLB_DYNAMIC enabled, each round-trip map/unmap pair
in the swiotlb results in 6 calls to swiotlb_find_pool(). In multiple
places, the pool is found and used in one function, and then must
be found again in the next function that is called because only the
tlb_addr is passed as an argument. These are the six call sites:

dma_direct_map_page:
 1. swiotlb_map -> swiotlb_tbl_map_single -> swiotlb_bounce

dma_direct_unmap_page:
 2. dma_direct_sync_single_for_cpu -> is_swiotlb_buffer
 3. dma_direct_sync_single_for_cpu -> swiotlb_sync_single_for_cpu ->
	swiotlb_bounce
 4. is_swiotlb_buffer
 5. swiotlb_tbl_unmap_single -> swiotlb_del_transient
 6. swiotlb_tbl_unmap_single -> swiotlb_release_slots

Reduce the number of calls by finding the pool at a higher level, and
passing it as an argument instead of searching again. A key change is
for is_swiotlb_buffer() to return a pool pointer instead of a boolean,
and then pass this pool pointer to subsequent swiotlb functions.

There are 9 occurrences of is_swiotlb_buffer() used to test if a buffer
is a swiotlb buffer before calling a swiotlb function. To reduce code
duplication in getting the pool pointer and passing it as an argument,
introduce inline wrappers for this pattern. The generated code is
essentially unchanged.

Since is_swiotlb_buffer() no longer returns a boolean, rename some
functions to reflect the change:

 * swiotlb_find_pool() becomes __swiotlb_find_pool()
 * is_swiotlb_buffer() becomes swiotlb_find_pool()
 * is_xen_swiotlb_buffer() becomes xen_swiotlb_find_pool()

With these changes, a round-trip map/unmap pair requires only 2 pool
lookups (listed using the new names and wrappers):

dma_direct_unmap_page:
 1. dma_direct_sync_single_for_cpu -> swiotlb_find_pool
 2. swiotlb_tbl_unmap_single -> swiotlb_find_pool

These changes come from noticing the inefficiencies in a code review,
not from performance measurements. With CONFIG_SWIOTLB_DYNAMIC,
__swiotlb_find_pool() is not trivial, and it uses an RCU read lock,
so avoiding the redundant calls helps performance in a hot path.
When CONFIG_SWIOTLB_DYNAMIC is *not* set, the code size reduction
is minimal and the perf benefits are likely negligible, but no
harm is done.

No functional change is intended.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr@tesarici.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-07-10 07:59:03 +02:00
Matt Bobrowski 605c96997d bpf: relax zero fixed offset constraint on KF_TRUSTED_ARGS/KF_RCU
Currently, BPF kfuncs which accept trusted pointer arguments
i.e. those flagged as KF_TRUSTED_ARGS, KF_RCU, or KF_RELEASE, all
require an original/unmodified trusted pointer argument to be supplied
to them. By original/unmodified, it means that the backing register
holding the trusted pointer argument that is to be supplied to the BPF
kfunc must have its fixed offset set to zero, or else the BPF verifier
will outright reject the BPF program load. However, this zero fixed
offset constraint that is currently enforced by the BPF verifier onto
BPF kfuncs specifically flagged to accept KF_TRUSTED_ARGS or KF_RCU
trusted pointer arguments is rather unnecessary, and can limit their
usability in practice. Specifically, it completely eliminates the
possibility of constructing a derived trusted pointer from an original
trusted pointer. To put it simply, a derived pointer is a pointer
which points to one of the nested member fields of the object being
pointed to by the original trusted pointer.

This patch relaxes the zero fixed offset constraint that is enforced
upon BPF kfuncs which specifically accept KF_TRUSTED_ARGS, or KF_RCU
arguments. Although, the zero fixed offset constraint technically also
applies to BPF kfuncs accepting KF_RELEASE arguments, relaxing this
constraint for such BPF kfuncs has subtle and unwanted
side-effects. This was discovered by experimenting a little further
with an initial version of this patch series [0]. The primary issue
with relaxing the zero fixed offset constraint on BPF kfuncs accepting
KF_RELEASE arguments is that it'd would open up the opportunity for
BPF programs to supply both trusted pointers and derived trusted
pointers to them. For KF_RELEASE BPF kfuncs specifically, this could
be problematic as resources associated with the backing pointer could
be released by the backing BPF kfunc and cause instabilities for the
rest of the kernel.

With this new fixed offset semantic in-place for BPF kfuncs accepting
KF_TRUSTED_ARGS and KF_RCU arguments, we now have more flexibility
when it comes to the BPF kfuncs that we're able to introduce moving
forward.

Early discussions covering the possibility of relaxing the zero fixed
offset constraint can be found using the link below. This will provide
more context on where all this has stemmed from [1].

Notably, pre-existing tests have been updated such that they provide
coverage for the updated zero fixed offset
functionality. Specifically, the nested offset test was converted from
a negative to positive test as it was already designed to assert zero
fixed offset semantics of a KF_TRUSTED_ARGS BPF kfunc.

[0] https://lore.kernel.org/bpf/ZnA9ndnXKtHOuYMe@google.com/
[1] https://lore.kernel.org/bpf/ZhkbrM55MKQ0KeIV@google.com/

Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240709210939.1544011-1-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-09 19:11:47 -07:00
Masami Hiramatsu (Google) b10545b6b8 tracing/kprobes: Fix build error when find_module() is not available
The kernel test robot reported that the find_module() is not available
if CONFIG_MODULES=n.
Fix this error by hiding find_modules() in #ifdef CONFIG_MODULES with
related rcu locks as try_module_get_by_name().

Link: https://lore.kernel.org/all/172056819167.201571.250053007194508038.stgit@devnote2/

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407070744.RcLkn8sq-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202407070917.VVUCBlaS-lkp@intel.com/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-07-10 09:47:00 +09:00
Paolo Abeni 7b769adc26 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-07-08

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

We've added 102 non-merge commits during the last 28 day(s) which contain
a total of 127 files changed, 4606 insertions(+), 980 deletions(-).

The main changes are:

1) Support resilient split BTF which cuts down on duplication and makes BTF
   as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman.

2) Add support for dumping kfunc prototypes from BTF which enables both detecting
   as well as dumping compilable prototypes for kfuncs, from Daniel Xu.

3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement
   support for BPF exceptions, from Ilya Leoshkevich.

4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support
   for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui.

5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option
   for skbs and add coverage along with it, from Vadim Fedorenko.

6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives
   a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan.

7) Extend the BPF verifier to track the delta between linked registers in order
   to better deal with recent LLVM code optimizations, from Alexei Starovoitov.

8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should
   have been a pointer to the map value, from Benjamin Tissoires.

9) Extend BPF selftests to add regular expression support for test output matching
   and adjust some of the selftest when compiled under gcc, from Cupertino Miranda.

10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always
    iterates exactly once anyway, from Dan Carpenter.

11) Add the capability to offload the netfilter flowtable in XDP layer through
    kfuncs, from Florian Westphal & Lorenzo Bianconi.

12) Various cleanups in networking helpers in BPF selftests to shave off a few
    lines of open-coded functions on client/server handling, from Geliang Tang.

13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so
    that x86 JIT does not need to implement detection, from Leon Hwang.

14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an
    out-of-bounds memory access for dynpointers, from Matt Bobrowski.

15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as
    it might lead to problems on 32-bit archs, from Jiri Olsa.

16) Enhance traffic validation and dynamic batch size support in xsk selftests,
    from Tushar Vyavahare.

bpf-next-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits)
  selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep
  selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature
  bpf: helpers: fix bpf_wq_set_callback_impl signature
  libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
  selftests/bpf: Remove exceptions tests from DENYLIST.s390x
  s390/bpf: Implement exceptions
  s390/bpf: Change seen_reg to a mask
  bpf: Remove unnecessary loop in task_file_seq_get_next()
  riscv, bpf: Optimize stack usage of trampoline
  bpf, devmap: Add .map_alloc_check
  selftests/bpf: Remove arena tests from DENYLIST.s390x
  selftests/bpf: Add UAF tests for arena atomics
  selftests/bpf: Introduce __arena_global
  s390/bpf: Support arena atomics
  s390/bpf: Enable arena
  s390/bpf: Support address space cast instruction
  s390/bpf: Support BPF_PROBE_MEM32
  s390/bpf: Land on the next JITed instruction after exception
  s390/bpf: Introduce pre- and post- probe functions
  s390/bpf: Get rid of get_probe_mem_regno()
  ...
====================

Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-09 17:01:46 +02:00
Sebastian Andrzej Siewior 2b84def990 perf: Split __perf_pending_irq() out of perf_pending_irq()
perf_pending_irq() invokes perf_event_wakeup() and __perf_pending_irq().
The former is in charge of waking any tasks which waits to be woken up
while the latter disables perf-events.

The irq_work perf_pending_irq(), while this an irq_work, the callback
is invoked in thread context on PREEMPT_RT. This is needed because all
the waking functions (wake_up_all(), kill_fasync()) acquire sleep locks
which must not be used with disabled interrupts.
Disabling events, as done by __perf_pending_irq(), expects a hardirq
context and disabled interrupts. This requirement is not fulfilled on
PREEMPT_RT.

Split functionality based on perf_event::pending_disable into irq_work
named `pending_disable_irq' and invoke it in hardirq context on
PREEMPT_RT. Rename the split out callback to perf_pending_disable().

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20240704170424.1466941-8-bigeasy@linutronix.de
2024-07-09 13:26:37 +02:00
Sebastian Andrzej Siewior 16b9569df9 perf: Don't disable preemption in perf_pending_task().
perf_pending_task() is invoked in task context and disables preemption
because perf_swevent_get_recursion_context() used to access per-CPU
variables. The other reason is to create a RCU read section while
accessing the perf_event.

The recursion counter is no longer a per-CPU accounter so disabling
preemption is no longer required. The RCU section is needed and must be
created explicit.

Replace the preemption-disable section with a explicit RCU-read section.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20240704170424.1466941-7-bigeasy@linutronix.de
2024-07-09 13:26:36 +02:00
Sebastian Andrzej Siewior 0d40a6d83e perf: Move swevent_htable::recursion into task_struct.
The swevent_htable::recursion counter is used to avoid creating an
swevent while an event is processed to avoid recursion. The counter is
per-CPU and preemption must be disabled to have a stable counter.
perf_pending_task() disables preemption to access the counter and then
signal. This is problematic on PREEMPT_RT because sending a signal uses
a spinlock_t which must not be acquired in atomic on PREEMPT_RT because
it becomes a sleeping lock.

The atomic context can be avoided by moving the counter into the
task_struct. There is a 4 byte hole between futex_state (usually always
on) and the following perf pointer (perf_event_ctxp). After the
recursion lost some weight it fits perfectly.

Move swevent_htable::recursion into task_struct.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20240704170424.1466941-6-bigeasy@linutronix.de
2024-07-09 13:26:36 +02:00
Sebastian Andrzej Siewior 5af42f928f perf: Shrink the size of the recursion counter.
There are four recursion counter, one for each context. The type of the
counter is `int' but the counter is used as `bool' since it is only
incremented if zero.
The main goal here is to shrink the whole struct into 32bit int which
can later be added task_struct into an existing hole.

Reduce the type of the recursion counter to an unsigned char, keep the
increment/ decrement operation.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20240704170424.1466941-5-bigeasy@linutronix.de
2024-07-09 13:26:35 +02:00
Sebastian Andrzej Siewior c5d93d23a2 perf: Enqueue SIGTRAP always via task_work.
A signal is delivered by raising irq_work() which works from any context
including NMI. irq_work() can be delayed if the architecture does not
provide an interrupt vector. In order not to lose a signal, the signal
is injected via task_work during event_sched_out().

Instead going via irq_work, the signal could be added directly via
task_work. The signal is sent to current and can be enqueued on its
return path to userland.

Queue signal via task_work and consider possible NMI context. Remove
perf_event::pending_sigtrap and and use perf_event::pending_work
instead.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20240704170424.1466941-4-bigeasy@linutronix.de
2024-07-09 13:26:35 +02:00
Sebastian Andrzej Siewior 466e4d801c task_work: Add TWA_NMI_CURRENT as an additional notify mode.
Adding task_work from NMI context requires the following:
- The kasan_record_aux_stack() is not NMU safe and must be avoided.
- Using TWA_RESUME is NMI safe. If the NMI occurs while the CPU is in
  userland then it will continue in userland and not invoke the `work'
  callback.

Add TWA_NMI_CURRENT as an additional notify mode. In this mode skip
kasan and use irq_work in hardirq-mode to for needed interrupt. Set
TIF_NOTIFY_RESUME within the irq_work callback due to k[ac]san
instrumentation in test_and_set_bit() which does not look NMI safe in
case of a report.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240704170424.1466941-3-bigeasy@linutronix.de
2024-07-09 13:26:34 +02:00
Sebastian Andrzej Siewior 058244c683 perf: Move irq_work_queue() where the event is prepared.
Only if perf_event::pending_sigtrap is zero, the irq_work accounted by
increminging perf_event::nr_pending. The member perf_event::pending_addr
might be overwritten by a subsequent event if the signal was not yet
delivered and is expected. The irq_work will not be enqeueued again
because it has a check to be only enqueued once.

Move irq_work_queue() to where the counter is incremented and
perf_event::pending_sigtrap is set to make it more obvious that the
irq_work is scheduled once.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20240704170424.1466941-2-bigeasy@linutronix.de
2024-07-09 13:26:34 +02:00
Frederic Weisbecker 3a5465418f perf: Fix event leak upon exec and file release
The perf pending task work is never waited upon the matching event
release. In the case of a child event, released via free_event()
directly, this can potentially result in a leaked event, such as in the
following scenario that doesn't even require a weak IRQ work
implementation to trigger:

schedule()
   prepare_task_switch()
=======> <NMI>
      perf_event_overflow()
         event->pending_sigtrap = ...
         irq_work_queue(&event->pending_irq)
<======= </NMI>
      perf_event_task_sched_out()
          event_sched_out()
              event->pending_sigtrap = 0;
              atomic_long_inc_not_zero(&event->refcount)
              task_work_add(&event->pending_task)
   finish_lock_switch()
=======> <IRQ>
   perf_pending_irq()
      //do nothing, rely on pending task work
<======= </IRQ>

begin_new_exec()
   perf_event_exit_task()
      perf_event_exit_event()
         // If is child event
         free_event()
            WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1)
            // event is leaked

Similar scenarios can also happen with perf_event_remove_on_exec() or
simply against concurrent perf_event_release().

Fix this with synchonizing against the possibly remaining pending task
work while freeing the event, just like is done with remaining pending
IRQ work. This means that the pending task callback neither need nor
should hold a reference to the event, preventing it from ever beeing
freed.

Fixes: 517e6a301f ("perf: Fix perf_pending_task() UaF")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-5-frederic@kernel.org
2024-07-09 13:26:33 +02:00
Frederic Weisbecker 2fd5ad3f31 perf: Fix event leak upon exit
When a task is scheduled out, pending sigtrap deliveries are deferred
to the target task upon resume to userspace via task_work.

However failures while adding an event's callback to the task_work
engine are ignored. And since the last call for events exit happen
after task work is eventually closed, there is a small window during
which pending sigtrap can be queued though ignored, leaking the event
refcount addition such as in the following scenario:

    TASK A
    -----

    do_exit()
       exit_task_work(tsk);

       <IRQ>
       perf_event_overflow()
          event->pending_sigtrap = pending_id;
          irq_work_queue(&event->pending_irq);
       </IRQ>
    =========> PREEMPTION: TASK A -> TASK B
       event_sched_out()
          event->pending_sigtrap = 0;
          atomic_long_inc_not_zero(&event->refcount)
          // FAILS: task work has exited
          task_work_add(&event->pending_task)
       [...]
       <IRQ WORK>
       perf_pending_irq()
          // early return: event->oncpu = -1
       </IRQ WORK>
       [...]
    =========> TASK B -> TASK A
       perf_event_exit_task(tsk)
          perf_event_exit_event()
             free_event()
                WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1)
                // leak event due to unexpected refcount == 2

As a result the event is never released while the task exits.

Fix this with appropriate task_work_add()'s error handling.

Fixes: 517e6a301f ("perf: Fix perf_pending_task() UaF")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-4-frederic@kernel.org
2024-07-09 13:26:33 +02:00
Frederic Weisbecker f409530e4d task_work: Introduce task_work_cancel() again
Re-introduce task_work_cancel(), this time to cancel an actual callback
and not *any* callback pointing to a given function. This is going to be
needed for perf events event freeing.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-3-frederic@kernel.org
2024-07-09 13:26:32 +02:00
Frederic Weisbecker 68cbd415dd task_work: s/task_work_cancel()/task_work_cancel_func()/
A proper task_work_cancel() API that actually cancels a callback and not
*any* callback pointing to a given function is going to be needed for
perf events event freeing. Do the appropriate rename to prepare for
that.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-2-frederic@kernel.org
2024-07-09 13:26:31 +02:00
John Stultz e81859fe64 locking/rwsem: Add __always_inline annotation to __down_write_common() and inlined callers
Apparently despite it being marked inline, the compiler
may not inline __down_write_common() which makes it difficult
to identify the cause of lock contention, as the wchan of the
blocked function will always be listed as __down_write_common().

So add __always_inline annotation to the common function (as
well as the inlined helper callers) to force it to be inlined
so a more useful blocking function will be listed (via wchan).

This mirrors commit 92cc5d00a4 ("locking/rwsem: Add
__always_inline annotation to __down_read_common() and inlined
callers") which did the same for __down_read_common.

I sort of worry that I'm playing wack-a-mole here, and talking
with compiler people, they tell me inline means nothing, which
makes me want to cry a little. So I'm wondering if we need to
replace all the inlines with __always_inline, or remove them
because either we mean something by it, or not.

Fixes: c995e638cc ("locking/rwsem: Fold __down_{read,write}*()")
Reported-by: Tim Murray <timmurray@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20240709060831.495366-1-jstultz@google.com
2024-07-09 13:26:26 +02:00
Yicong Yang 54624acf88 dma-mapping: benchmark: Don't starve others when doing the test
The test thread will start N benchmark kthreads and then schedule out
until the test time finished and notify the benchmark kthreads to stop.
The benchmark kthreads will keep running until notified to stop.
There's a problem with current implementation when the benchmark
kthreads number is equal to the CPUs on a non-preemptible kernel:
since the scheduler will balance the kthreads across the CPUs and
when the test time's out the test thread won't get a chance to be
scheduled on any CPU then cannot notify the benchmark kthreads to stop.

This can be easily reproduced on a VM (simulated with 16 CPUs) with
PREEMPT_VOLUNTARY:
estuary:/mnt$ ./dma_map_benchmark -t 16 -s 1
 rcu: INFO: rcu_sched self-detected stall on CPU
 rcu:     10-...!: (5221 ticks this GP) idle=ed24/1/0x4000000000000000 softirq=142/142 fqs=0
 rcu:     (t=5254 jiffies g=-559 q=45 ncpus=16)
 rcu: rcu_sched kthread starved for 5255 jiffies! g-559 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=12
 rcu:     Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
 rcu: RCU grace-period kthread stack dump:
 task:rcu_sched       state:R  running task     stack:0     pid:16    tgid:16    ppid:2      flags:0x00000008
 Call trace
  __switch_to+0xec/0x138
  __schedule+0x2f8/0x1080
  schedule+0x30/0x130
  schedule_timeout+0xa0/0x188
  rcu_gp_fqs_loop+0x128/0x528
  rcu_gp_kthread+0x1c8/0x208
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20
 Sending NMI from CPU 10 to CPUs 0:
 NMI backtrace for cpu 0
 CPU: 0 PID: 332 Comm: dma-map-benchma Not tainted 6.10.0-rc1-vanilla-LSE #8
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : arm_smmu_cmdq_issue_cmdlist+0x218/0x730
 lr : arm_smmu_cmdq_issue_cmdlist+0x488/0x730
 sp : ffff80008748b630
 x29: ffff80008748b630 x28: 0000000000000000 x27: ffff80008748b780
 x26: 0000000000000000 x25: 000000000000bc70 x24: 000000000001bc70
 x23: ffff0000c12af080 x22: 0000000000010000 x21: 000000000000ffff
 x20: ffff80008748b700 x19: ffff0000c12af0c0 x18: 0000000000010000
 x17: 0000000000000001 x16: 0000000000000040 x15: ffffffffffffffff
 x14: 0001ffffffffffff x13: 000000000000ffff x12: 00000000000002f1
 x11: 000000000001ffff x10: 0000000000000031 x9 : ffff800080b6b0b8
 x8 : ffff0000c2a48000 x7 : 000000000001bc71 x6 : 0001800000000000
 x5 : 00000000000002f1 x4 : 01ffffffffffffff x3 : 000000000009aaf1
 x2 : 0000000000000018 x1 : 000000000000000f x0 : ffff0000c12af18c
 Call trace:
  arm_smmu_cmdq_issue_cmdlist+0x218/0x730
  __arm_smmu_tlb_inv_range+0xe0/0x1a8
  arm_smmu_iotlb_sync+0xc0/0x128
  __iommu_dma_unmap+0x248/0x320
  iommu_dma_unmap_page+0x5c/0xe8
  dma_unmap_page_attrs+0x38/0x1d0
  map_benchmark_thread+0x118/0x2c0
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20

Solve this by adding scheduling point in the kthread loop,
so if there're other threads in the system they may have
a chance to run, especially the thread to notify the test
end. However this may degrade the test concurrency so it's
recommended to run this on an idle system.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-07-09 07:48:32 +02:00
Benjamin Tissoires f56f4d541e bpf: helpers: fix bpf_wq_set_callback_impl signature
I realized this while having a map containing both a struct bpf_timer and
a struct bpf_wq: the third argument provided to the bpf_wq callback is
not the struct bpf_wq pointer itself, but the pointer to the value in
the map.

Which means that the users need to double cast the provided "value" as
this is not a struct bpf_wq *.

This is a change of API, but there doesn't seem to be much users of bpf_wq
right now, so we should be able to go with this right now.

Fixes: 81f1d7a583 ("bpf: wq: add bpf_wq_set_callback_impl")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240708-fix-wq-v2-1-667e5c9fbd99@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-08 10:01:48 -07:00
Dan Carpenter bc239eb271 bpf: Remove unnecessary loop in task_file_seq_get_next()
After commit 0ede61d858 ("file: convert to SLAB_TYPESAFE_BY_RCU") this
loop always iterates exactly one time.  Delete the for statement and pull
the code in a tab.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/ZoWJF51D4zWb6f5t@stanley.mountain
2024-07-08 16:23:19 +02:00
Masami Hiramatsu (Google) 9d8616034f tracing/kprobes: Add symbol counting check when module loads
Currently, kprobe event checks whether the target symbol name is unique
or not, so that it does not put a probe on an unexpected place. But this
skips the check if the target is on a module because the module may not
be loaded.

To fix this issue, this patch checks the number of probe target symbols
in a target module when the module is loaded. If the probe is not on the
unique name symbols in the module, it will be rejected at that point.

Note that the symbol which has a unique name in the target module,
it will be accepted even if there are same-name symbols in the
kernel or other modules,

Link: https://lore.kernel.org/all/172016348553.99543.2834679315611882137.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-06 09:27:47 +09:00
Lai Jiangshan 449b31ad29 workqueue: Init rescuer's affinities as the wq's effective cpumask
Make it consistent with apply_wqattrs_commit().

Link: https://lore.kernel.org/lkml/20240203154334.791910-5-longman@redhat.com/
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-05 09:14:40 -10:00
Lai Jiangshan 1726a17135 workqueue: Put PWQ allocation and WQ enlistment in the same lock C.S.
The PWQ allocation and WQ enlistment are not within the same lock-held
critical section; therefore, their states can become out of sync when
the user modifies the unbound mask or if CPU hotplug events occur in
the interim since those operations only update the WQs that are already
in the list.

Make the PWQ allocation and WQ enlistment atomic.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-05 09:14:40 -10:00
Lai Jiangshan 4e9a37389e workqueue: Move kthread_flush_worker() out of alloc_and_link_pwqs()
kthread_flush_worker() can't be called with wq_pool_mutex held.

Prepare for moving wq_pool_mutex and cpu hotplug lock out of
alloc_and_link_pwqs().

Cc: Zqiang <qiang.zhang1211@gmail.com>
Link: https://lore.kernel.org/lkml/20230920060704.24981-1-qiang.zhang1211@gmail.com/
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-05 09:14:40 -10:00
Lai Jiangshan c5178e6ca6 workqueue: Make rescuer initialization as the last step of the creation of a new wq
For early wq allocation, rescuer initialization is the last step of the
creation of a new wq.  Make the behavior the same for all allocations.

Prepare for initializing rescuer's affinities with the default pwq's
affinities.

Prepare for moving the whole workqueue initializing procedure into
wq_pool_mutex and cpu hotplug locks.

Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-05 09:14:40 -10:00
Lai Jiangshan c3138f3881 workqueue: Register sysfs after the whole creation of the new wq
workqueue creation includes adding it to the workqueue list.

Prepare for moving the whole workqueue initializing procedure into
wq_pool_mutex and cpu hotplug locks.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-05 09:14:40 -10:00
Chen Ridong b824766504 cgroup/rstat: add force idle show helper
In the function cgroup_base_stat_cputime_show, there are five
instances of #ifdef, which makes the code not concise.
To address this, add the function cgroup_force_idle_show
to make the code more succinct.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-05 08:32:08 -10:00
Oleg Nesterov 8ac5dc6659 get_task_mm: check PF_KTHREAD lockless
Nowadays PF_KTHREAD is sticky and it was never protected by ->alloc_lock. 
Move the PF_KTHREAD check outside of task_lock() section to make this code
more understandable.

Link: https://lkml.kernel.org/r/20240626191017.GA20031@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:58 -07:00
Oleg Nesterov d73d003521 memcg: mm_update_next_owner: move for_each_thread() into try_to_set_owner()
mm_update_next_owner() checks the children / real_parent->children to
avoid the "everything else" loop in the likely case, but this won't work
if a child/sibling has a zombie leader with ->mm == NULL.

Move the for_each_thread() logic into try_to_set_owner(), if nothing else
this makes the children/siblings/everything searches more consistent.

Link: https://lkml.kernel.org/r/20240626152930.GA17936@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jinliang Zheng <alexjlzheng@tencent.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Tycho Andersen <tandersen@netflix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:58 -07:00
Oleg Nesterov 2a22b773b1 memcg: mm_update_next_owner: kill the "retry" logic
Add the new helper, try_to_set_owner(), which tries to update mm->owner
once we see c->mm == mm.  This way mm_update_next_owner() doesn't need to
restart the list_for_each_entry/for_each_process loops from the very
beginning if it races with exit/exec, it can just continue.

Unlike the current code, try_to_set_owner() re-checks tsk->mm == mm before
it drops tasklist_lock, so it doesn't need get/put_task_struct().

Link: https://lkml.kernel.org/r/20240626152924.GA17933@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jinliang Zheng <alexjlzheng@tencent.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Tycho Andersen <tandersen@netflix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:57 -07:00
Jakub Kicinski 76ed626479 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/phy/aquantia/aquantia.h
  219343755e ("net: phy: aquantia: add missing include guards")
  61578f6793 ("net: phy: aquantia: add support for PHY LEDs")

drivers/net/ethernet/wangxun/libwx/wx_hw.c
  bd07a98178 ("net: txgbe: remove separate irq request for MSI and INTx")
  b501d261a5 ("net: txgbe: add FDIR ATR support")
https://lore.kernel.org/all/20240703112936.483c1975@canb.auug.org.au/

include/linux/mlx5/mlx5_ifc.h
  048a403648 ("net/mlx5: IFC updates for changing max EQs")
  99be56171f ("net/mlx5e: SHAMPO, Re-enable HW-GRO")
https://lore.kernel.org/all/20240701133951.6926b2e3@canb.auug.org.au/

Adjacent changes:

drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
  4130c67cd1 ("wifi: iwlwifi: mvm: check vif for NULL/ERR_PTR before dereference")
  3f3126515f ("wifi: iwlwifi: mvm: add mvm-specific guard")

include/net/mac80211.h
  816c6bec09 ("wifi: mac80211: fix BSS_CHANGED_UNSOL_BCAST_PROBE_RESP")
  5a009b42e0 ("wifi: mac80211: track changes in AP's TPE")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-04 14:16:11 -07:00
Paul E. McKenney 02219caa92 Merge branches 'doc.2024.06.06a', 'fixes.2024.07.04a', 'mb.2024.06.28a', 'nocb.2024.06.03a', 'rcu-tasks.2024.06.06a', 'rcutorture.2024.06.06a' and 'srcu.2024.06.18a' into HEAD
doc.2024.06.06a: Documentation updates.
fixes.2024.07.04a: Miscellaneous fixes.
mb.2024.06.28a: Grace-period memory-barrier redundancy removal.
nocb.2024.06.03a: No-CB CPU updates.
rcu-tasks.2024.06.06a: RCU-Tasks updates.
rcutorture.2024.06.06a: Torture-test updates.
srcu.2024.06.18a: SRCU polled-grace-period updates.
2024-07-04 13:54:17 -07:00
Frederic Weisbecker 55d4669ef1 rcu: Fix rcu_barrier() VS post CPUHP_TEARDOWN_CPU invocation
When rcu_barrier() calls rcu_rdp_cpu_online() and observes a CPU off
rnp->qsmaskinitnext, it means that all accesses from the offline CPU
preceding the CPUHP_TEARDOWN_CPU are visible to RCU barrier, including
callbacks expiration and counter updates.

However interrupts can still fire after stop_machine() re-enables
interrupts and before rcutree_report_cpu_dead(). The related accesses
happening between CPUHP_TEARDOWN_CPU and rnp->qsmaskinitnext clearing
are _NOT_ guaranteed to be seen by rcu_barrier() without proper
ordering, especially when callbacks are invoked there to the end, making
rcutree_migrate_callback() bypass barrier_lock.

The following theoretical race example can make rcu_barrier() hang:

CPU 0                                               CPU 1
-----                                               -----
//cpu_down()
smpboot_park_threads()
//ksoftirqd is parked now
<IRQ>
rcu_sched_clock_irq()
   invoke_rcu_core()
do_softirq()
   rcu_core()
      rcu_do_batch()
         // callback storm
         // rcu_do_batch() returns
         // before completing all
         // of them
   // do_softirq also returns early because of
   // timeout. It defers to ksoftirqd but
   // it's parked
</IRQ>
stop_machine()
   take_cpu_down()
                                                    rcu_barrier()
                                                        spin_lock(barrier_lock)
                                                        // observes rcu_segcblist_n_cbs(&rdp->cblist) != 0
<IRQ>
do_softirq()
   rcu_core()
      rcu_do_batch()
         //completes all pending callbacks
         //smp_mb() implied _after_ callback number dec
</IRQ>

rcutree_report_cpu_dead()
   rnp->qsmaskinitnext &= ~rdp->grpmask;

rcutree_migrate_callback()
   // no callback, early return without locking
   // barrier_lock
                                                        //observes !rcu_rdp_cpu_online(rdp)
                                                        rcu_barrier_entrain()
                                                           rcu_segcblist_entrain()
                                                              // Observe rcu_segcblist_n_cbs(rsclp) == 0
                                                              // because no barrier between reading
                                                              // rnp->qsmaskinitnext and rsclp->len
                                                              rcu_segcblist_add_len()
                                                                 smp_mb__before_atomic()
                                                                 // will now observe the 0 count and empty
                                                                 // list, but too late, we enqueue regardless
                                                                 WRITE_ONCE(rsclp->len, rsclp->len + v);
                                                        // ignored barrier callback
                                                        // rcu barrier stall...

This could be solved with a read memory barrier, enforcing the message
passing between rnp->qsmaskinitnext and rsclp->len, matching the full
memory barrier after rsclp->len addition in rcu_segcblist_add_len()
performed at the end of rcu_do_batch().

However the rcu_barrier() is complicated enough and probably doesn't
need too many more subtleties. CPU down is a slowpath and the
barrier_lock seldom contended. Solve the issue with unconditionally
locking the barrier_lock on rcutree_migrate_callbacks(). This makes sure
that either rcu_barrier() sees the empty queue or its entrained
callback will be migrated.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2024-07-04 13:48:57 -07:00
Oleg Nesterov 6f4cec22c3 rcu: Eliminate lockless accesses to rcu_sync->gp_count
The rcu_sync structure's ->gp_count field is always accessed under the
protection of that same structure's ->rss_lock field, with the exception
of a pair of WARN_ON_ONCE() calls just prior to acquiring that lock in
functions rcu_sync_exit() and rcu_sync_dtor().  These lockless accesses
are unnecessary and impair KCSAN's ability to catch bugs that might be
inserted via other lockless accesses.

This commit therefore moves those WARN_ON_ONCE() calls under the lock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2024-07-04 13:48:57 -07:00
Paul E. McKenney 68d124b099 rcu: Add rcutree.nohz_full_patience_delay to reduce nohz_full OS jitter
If a CPU is running either a userspace application or a guest OS in
nohz_full mode, it is possible for a system call to occur just as an
RCU grace period is starting.  If that CPU also has the scheduling-clock
tick enabled for any reason (such as a second runnable task), and if the
system was booted with rcutree.use_softirq=0, then RCU can add insult to
injury by awakening that CPU's rcuc kthread, resulting in yet another
task and yet more OS jitter due to switching to that task, running it,
and switching back.

In addition, in the common case where that system call is not of
excessively long duration, awakening the rcuc task is pointless.
This pointlessness is due to the fact that the CPU will enter an extended
quiescent state upon returning to the userspace application or guest OS.
In this case, the rcuc kthread cannot do anything that the main RCU
grace-period kthread cannot do on its behalf, at least if it is given
a few additional milliseconds (for example, given the time duration
specified by rcutree.jiffies_till_first_fqs, give or take scheduling
delays).

This commit therefore adds a rcutree.nohz_full_patience_delay kernel
boot parameter that specifies the grace period age (in milliseconds,
rounded to jiffies) before which RCU will refrain from awakening the
rcuc kthread.  Preliminary experimentation suggests a value of 1000,
that is, one second.  Increasing rcutree.nohz_full_patience_delay will
increase grace-period latency and in turn increase memory footprint,
so systems with constrained memory might choose a smaller value.
Systems with less-aggressive OS-jitter requirements might choose the
default value of zero, which keeps the traditional immediate-wakeup
behavior, thus avoiding increases in grace-period latency.

[ paulmck: Apply Leonardo Bras feedback.  ]

Link: https://lore.kernel.org/all/20240328171949.743211-1-leobras@redhat.com/

Reported-by: Leonardo Bras <leobras@redhat.com>
Suggested-by: Leonardo Bras <leobras@redhat.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Leonardo Bras <leobras@redhat.com>
2024-07-04 13:47:39 -07:00
Peter Zijlstra 0c8ea05e9b Merge branch 'tip/x86/cpu'
The Lunarlake patches rely on the new VFM stuff.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2024-07-04 16:00:24 +02:00
Adrian Hunter 0ca4da2412 perf: Make rb_alloc_aux() return an error immediately if nr_pages <= 0
rb_alloc_aux() should not be called with nr_pages <= 0. Make it more robust
and readable by returning an error immediately in that case.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-8-adrian.hunter@intel.com
2024-07-04 16:00:23 +02:00
Adrian Hunter 43deb76b19 perf: Fix default aux_watermark calculation
The default aux_watermark is half the AUX area buffer size. In general,
on a 64-bit architecture, the AUX area buffer size could be a bigger than
fits in a 32-bit type, but the calculation does not allow for that
possibility.

However the aux_watermark value is recorded in a u32, so should not be
more than U32_MAX either.

Fix by doing the calculation in a correctly sized type, and limiting the
result to U32_MAX.

Fixes: d68e6799a5 ("perf: Cap allocation order at aux_watermark")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-7-adrian.hunter@intel.com
2024-07-04 16:00:23 +02:00
Adrian Hunter dbc48c8f41 perf: Prevent passing zero nr_pages to rb_alloc_aux()
nr_pages is unsigned long but gets passed to rb_alloc_aux() as an int,
and is stored as an int.

Only power-of-2 values are accepted, so if nr_pages is a 64_bit value, it
will be passed to rb_alloc_aux() as zero.

That is not ideal because:
 1. the value is incorrect
 2. rb_alloc_aux() is at risk of misbehaving, although it manages to
 return -ENOMEM in that case, it is a result of passing zero to get_order()
 even though the get_order() result is documented to be undefined in that
 case.

Fix by simply validating the maximum supported value in the first place.
Use -ENOMEM error code for consistency with the current error code that
is returned in that case.

Fixes: 45bfb2e504 ("perf: Add AUX area to ring buffer for raw data streams")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-6-adrian.hunter@intel.com
2024-07-04 16:00:22 +02:00
Adrian Hunter 3df94a5b10 perf: Fix perf_aux_size() for greater-than 32-bit size
perf_buffer->aux_nr_pages uses a 32-bit type, so a cast is needed to
calculate a 64-bit size.

Fixes: 45bfb2e504 ("perf: Add AUX area to ring buffer for raw data streams")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-5-adrian.hunter@intel.com
2024-07-04 16:00:22 +02:00
Tejun Heo d329605287 sched/fair: set_load_weight() must also call reweight_task() for SCHED_IDLE tasks
When a task's weight is being changed, set_load_weight() is called with
@update_load set. As weight changes aren't trivial for the fair class,
set_load_weight() calls fair.c::reweight_task() for fair class tasks.

However, set_load_weight() first tests task_has_idle_policy() on entry and
skips calling reweight_task() for SCHED_IDLE tasks. This is buggy as
SCHED_IDLE tasks are just fair tasks with a very low weight and they would
incorrectly skip load, vlag and position updates.

Fix it by updating reweight_task() to take struct load_weight as idle weight
can't be expressed with prio and making set_load_weight() call
reweight_task() for SCHED_IDLE tasks too when @update_load is set.

Fixes: 9059393e4e ("sched/fair: Use reweight_entity() for set_user_nice()")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # v4.15+
Link: http://lkml.kernel.org/r/20240624102331.GI31592@noisy.programming.kicks-ass.net
2024-07-04 15:59:52 +02:00
Tvrtko Ursulin 0ec208ce98 sched/psi: Optimise psi_group_change a bit
The current code loops over the psi_states only to call a helper which
then resolves back to the action needed for each state using a switch
statement. That is effectively creating a double indirection of a kind
which, given how all the states need to be explicitly listed and handled
anyway, we can simply remove. Both the for loop and the switch statement
that is.

The benefit is both in the code size and CPU time spent in this function.
YMMV but on my Steam Deck, while in a game, the patch makes the CPU usage
go from ~2.4% down to ~1.2%. Text size at the same time went from 0x323 to
0x2c1.

Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20240625135000.38652-1-tursulin@igalia.com
2024-07-04 15:59:52 +02:00
Tony Lindgren 7640f1a44e printk: Add match_devname_and_update_preferred_console()
Let's add match_devname_and_update_preferred_console() for driver
subsystems to call during init when the console is ready, and it's
character device name is known. For now, we use it only for the serial
layer to allow console=DEVNAME:0.0 style hardware based addressing for
consoles.

The earlier attempt on doing this caused a regression with the kernel
command line console order as it added calling __add_preferred_console()
again later on during init. A better approach was suggested by Petr where
we add the deferred console to the console_cmdline[] and update it later
on when the console is ready.

Suggested-by: Petr Mladek <pmladek@suse.com>
Co-developed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Tony Lindgren <tony.lindgren@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240703100615.118762-2-tony.lindgren@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-04 15:41:44 +02:00
Bartosz Golaszewski 011f583781 genirq/irq_sim: add an extended irq_sim initializer
Currently users of the interrupt simulator don't have any way of being
notified about interrupts from the simulated domain being requested or
released. This causes a problem for one of the users - the GPIO
simulator - which is unable to lock the pins as interrupts.

Define a structure containing callbacks to be executed on various
irq_sim-related events (for now: irq request and release) and provide an
extended function for creating simulated interrupt domains that takes it
and a pointer to custom user data (to be passed to said callbacks) as
arguments.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240624093934.17089-2-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-07-04 09:25:59 +02:00
Ilya Leoshkevich c02525a339 ftrace: unpoison ftrace_regs in ftrace_ops_list_func()
Patch series "kmsan: Enable on s390", v7.


Architectures use assembly code to initialize ftrace_regs and call
ftrace_ops_list_func().  Therefore, from the KMSAN's point of view,
ftrace_regs is poisoned on ftrace_ops_list_func entry().  This causes
KMSAN warnings when running the ftrace testsuite.

Fix by trusting the architecture-specific assembly code and always
unpoisoning ftrace_regs in ftrace_ops_list_func.

The issue was not encountered on x86_64 so far only by accident:
assembly-allocated ftrace_regs was overlapping a stale partially
unpoisoned stack frame.  Poisoning stack frames before returns [1] makes
the issue appear on x86_64 as well.

[1] https://github.com/iii-i/llvm-project/commits/msan-poison-allocas-before-returning-2024-06-12/

Link: https://lkml.kernel.org/r/20240621113706.315500-1-iii@linux.ibm.com
Link: https://lkml.kernel.org/r/20240621113706.315500-2-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:21 -07:00
Barry Song 15bde4abab mm: extend rmap flags arguments for folio_add_new_anon_rmap
Patch series "mm: clarify folio_add_new_anon_rmap() and
__folio_add_anon_rmap()", v2.

This patchset is preparatory work for mTHP swapin.

folio_add_new_anon_rmap() assumes that new anon rmaps are always
exclusive.  However, this assumption doesn’t hold true for cases like
do_swap_page(), where a new anon might be added to the swapcache and is
not necessarily exclusive.

The patchset extends the rmap flags to allow folio_add_new_anon_rmap() to
handle both exclusive and non-exclusive new anon folios.  The
do_swap_page() function is updated to use this extended API with rmap
flags.  Consequently, all new anon folios now consistently use
folio_add_new_anon_rmap().  The special case for !folio_test_anon() in
__folio_add_anon_rmap() can be safely removed.

In conclusion, new anon folios always use folio_add_new_anon_rmap(),
regardless of exclusivity.  Old anon folios continue to use
__folio_add_anon_rmap() via folio_add_anon_rmap_pmd() and
folio_add_anon_rmap_ptes().


This patch (of 3):

In the case of a swap-in, a new anonymous folio is not necessarily
exclusive.  This patch updates the rmap flags to allow a new anonymous
folio to be treated as either exclusive or non-exclusive.  To maintain the
existing behavior, we always use EXCLUSIVE as the default setting.

[akpm@linux-foundation.org: cleanup and constifications per David and akpm]
[v-songbaohua@oppo.com: fix missing doc for flags of folio_add_new_anon_rmap()]
  Link: https://lkml.kernel.org/r/20240619210641.62542-1-21cnbao@gmail.com
[v-songbaohua@oppo.com: enhance doc for extend rmap flags arguments for folio_add_new_anon_rmap]
  Link: https://lkml.kernel.org/r/20240622030256.43775-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240617231137.80726-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240617231137.80726-2-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Tested-by: Shuai Yuan <yuanshuai@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:18 -07:00
Jinliang Zheng 76ba6acfcc mm: optimize the redundant loop of mm_update_owner_next()
When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or
/proc or ptrace or page migration (get_task_mm()), it is impossible to
find an appropriate task_struct in the loop whose mm_struct is the same as
the target mm_struct.

If the above race condition is combined with the stress-ng-zombie and
stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in
write_lock_irq() for tasklist_lock.

Recognize this situation in advance and exit early.

Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tycho Andersen <tandersen@netflix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:15 -07:00
Barry Song 54f7a49c20 mm: remove the implementation of swap_free() and always use swap_free_nr()
To streamline maintenance efforts, we propose removing the implementation
of swap_free().  Instead, we can simply invoke swap_free_nr() with nr set
to 1.  swap_free_nr() is designed with a bitmap consisting of only one
long, resulting in overhead that can be ignored for cases where nr equals
1.

A prime candidate for leveraging swap_free_nr() lies within
kernel/power/swap.c.  Implementing this change facilitates the adoption of
batch processing for hibernation.

Link: https://lkml.kernel.org/r/20240529082824.150954-3-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Suggested-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Chris Li <chrisl@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:01 -07:00
Anna-Maria Behnsen 59dbee7d4d tick/sched: Combine WARN_ON_ONCE and print_once
When the WARN_ON_ONCE() triggers, the printk() of the additional
information related to the warning will not happen in print level
"warn". When reading dmesg with a restriction to level "warn", the
information published by the printk_once() will not show up there.

Transform WARN_ON_ONCE() and printk_once() into a WARN_ONCE().

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240610103552.25252-1-anna-maria@linutronix.de
2024-07-03 21:32:55 +02:00
Jinliang Zheng cf3f9a593d mm: optimize the redundant loop of mm_update_owner_next()
When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or
/proc or ptrace or page migration (get_task_mm()), it is impossible to
find an appropriate task_struct in the loop whose mm_struct is the same as
the target mm_struct.

If the above race condition is combined with the stress-ng-zombie and
stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in
write_lock_irq() for tasklist_lock.

Recognize this situation in advance and exit early.

Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tycho Andersen <tandersen@netflix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 12:29:24 -07:00
Waiman Long 57b56d1680 cgroup: Protect css->cgroup write under css_set_lock
The writing of css->cgroup associated with the cgroup root in
rebind_subsystems() is currently protected only by cgroup_mutex.
However, the reading of css->cgroup in both proc_cpuset_show() and
proc_cgroup_show() is protected just by css_set_lock. That makes the
readers susceptible to racing problems like data tearing or caching.
It is also a problem that can be reported by KCSAN.

This can be fixed by using READ_ONCE() and WRITE_ONCE() to access
css->cgroup. Alternatively, the writing of css->cgroup can be moved
under css_set_lock as well which is done by this patch.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-03 08:59:06 -10:00
Xiu Jianfeng 1028f391d5 cgroup/misc: Introduce misc.peak
Introduce misc.peak to record the historical maximum usage of the
resource, as in some scenarios the value of misc.max could be
adjusted based on the peak usage of the resource.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-07-03 08:08:43 -10:00