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* workqueue: Fold rebind_worker() within rebind_workers()Valentin Schneider2023-01-131-8/+5
| | | | | | | | | | | !CONFIG_SMP builds complain about rebind_worker() being unused. Its only user, rebind_workers() is indeed only defined for CONFIG_SMP, so just fold the two lines back up there. Link: http://lore.kernel.org/r/20230113143102.2e94d74f@canb.auug.org.au Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Unbind kworkers before sending them to exit()Valentin Schneider2023-01-121-12/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | It has been reported that isolated CPUs can suffer from interference due to per-CPU kworkers waking up just to die. A surge of workqueue activity during initial setup of a latency-sensitive application (refresh_vm_stats() being one of the culprits) can cause extra per-CPU kworkers to be spawned. Then, said latency-sensitive task can be running merrily on an isolated CPU only to be interrupted sometime later by a kworker marked for death (cf. IDLE_WORKER_TIMEOUT, 5 minutes after last kworker activity). Prevent this by affining kworkers to the wq_unbound_cpumask (which doesn't contain isolated CPUs, cf. HK_TYPE_WQ) before waking them up after marking them with WORKER_DIE. Changing the affinity does require a sleepable context, leverage the newly introduced pool->idle_cull_work to get that. Remove dying workers from pool->workers and keep track of them in a separate list. This intentionally prevents for_each_loop_worker() from iterating over workers that are marked for death. Rename destroy_worker() to set_working_dying() to better reflect its effects and relationship with wake_dying_workers(). Signed-off-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Don't hold any lock while rcuwait'ing for !POOL_MANAGER_ACTIVEValentin Schneider2023-01-121-17/+19
| | | | | | | | | | | | | | | | | | | | | | | | put_unbound_pool() currently passes wq_manager_inactive() as exit condition to rcuwait_wait_event(), which grabs pool->lock to check for pool->flags & POOL_MANAGER_ACTIVE A later patch will require destroy_worker() to be invoked with wq_pool_attach_mutex held, which needs to be acquired before pool->lock. A mutex cannot be acquired within rcuwait_wait_event(), as it could clobber the task state set by rcuwait_wait_event() Instead, restructure the waiting logic to acquire any necessary lock outside of rcuwait_wait_event(). Since further work cannot be inserted into unbound pwqs that have reached ->refcnt==0, this is bound to make forward progress as eventually the worklist will be drained and need_more_worker(pool) will remain false, preventing any worker from stealing the manager position from us. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Convert the idle_timer to a timer + work_structValentin Schneider2023-01-121-2/+50
| | | | | | | | | | | | | | | | A later patch will require a sleepable context in the idle worker timeout function. Converting worker_pool.idle_timer to a delayed_work gives us just that, however this would imply turning all idle_timer expiries into scheduler events (waking up a worker to handle the dwork). Instead, implement a "custom dwork" where the timer callback does some extra checks before queuing the associated work. No change in functionality intended. Signed-off-by: Valentin Schneider <vschneid@redhat.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Factorize unbind/rebind_workers() logicValentin Schneider2023-01-121-12/+21
| | | | | | | | Later patches will reuse this code, move it into reusable functions. Signed-off-by: Valentin Schneider <vschneid@redhat.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Protects wq_unbound_cpumask with wq_pool_attach_mutexLai Jiangshan2023-01-121-25/+16
| | | | | | | | | | | | | | When unbind_workers() reads wq_unbound_cpumask to set the affinity of freshly-unbound kworkers, it only holds wq_pool_attach_mutex. This isn't sufficient as wq_unbound_cpumask is only protected by wq_pool_mutex. Make wq_unbound_cpumask protected with wq_pool_attach_mutex and also remove the need of temporary saved_cpumask. Fixes: 10a5a651e3af ("workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUs") Reported-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Make show_pwq() use run-length encodingPaul E. McKenney2023-01-071-5/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The show_pwq() function dumps out a pool_workqueue structure's activity, including the pending work-queue handlers: Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 0: cpus=0 node=0 flags=0x1 nice=0 active=10/256 refcnt=11 in-flight: 7:test_work_func, 64:test_work_func, 249:test_work_func pending: test_work_func, test_work_func, test_work_func1, test_work_func1, test_work_func1, test_work_func1, test_work_func1 When large systems are facing certain types of hang conditions, it is not unusual for this "pending" list to contain runs of hundreds of identical function names. This "wall of text" is difficult to read, and worse yet, it can be interleaved with other output such as stack traces. Therefore, make show_pwq() use run-length encoding so that the above printout instead looks like this: Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 0: cpus=0 node=0 flags=0x1 nice=0 active=10/256 refcnt=11 in-flight: 7:test_work_func, 64:test_work_func, 249:test_work_func pending: 2*test_work_func, 5*test_work_func1 When no comma would be printed, including the WORK_STRUCT_LINKED case, a new run is started unconditionally. This output is more readable, places less stress on the hardware, firmware, and software on the console-log path, and reduces interference with other output. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Add a new flag to spot the potential UAF errorRichard Clark2023-01-041-3/+12
| | | | | | | | | | | | | | | Currently if the user queues a new work item unintentionally into a wq after the destroy_workqueue(wq), the work still can be queued and scheduled without any noticeable kernel message before the end of a RCU grace period. As a debug-aid facility, this commit adds a new flag __WQ_DESTROYING to spot that issue by triggering a kernel WARN message. Signed-off-by: Richard Clark <richard.xnu.clark@gmail.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Make queue_rcu_work() use call_rcu_hurry()Uladzislau Rezki2022-11-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Earlier commits in this series allow battery-powered systems to build their kernels with the default-disabled CONFIG_RCU_LAZY=y Kconfig option. This Kconfig option causes call_rcu() to delay its callbacks in order to batch them. This means that a given RCU grace period covers more callbacks, thus reducing the number of grace periods, in turn reducing the amount of energy consumed, which increases battery lifetime which can be a very good thing. This is not a subtle effect: In some important use cases, the battery lifetime is increased by more than 10%. This CONFIG_RCU_LAZY=y option is available only for CPUs that offload callbacks, for example, CPUs mentioned in the rcu_nocbs kernel boot parameter passed to kernels built with CONFIG_RCU_NOCB_CPU=y. Delaying callbacks is normally not a problem because most callbacks do nothing but free memory. If the system is short on memory, a shrinker will kick all currently queued lazy callbacks out of their laziness, thus freeing their memory in short order. Similarly, the rcu_barrier() function, which blocks until all currently queued callbacks are invoked, will also kick lazy callbacks, thus enabling rcu_barrier() to complete in a timely manner. However, there are some cases where laziness is not a good option. For example, synchronize_rcu() invokes call_rcu(), and blocks until the newly queued callback is invoked. It would not be a good for synchronize_rcu() to block for ten seconds, even on an idle system. Therefore, synchronize_rcu() invokes call_rcu_hurry() instead of call_rcu(). The arrival of a non-lazy call_rcu_hurry() callback on a given CPU kicks any lazy callbacks that might be already queued on that CPU. After all, if there is going to be a grace period, all callbacks might as well get full benefit from it. Yes, this could be done the other way around by creating a call_rcu_lazy(), but earlier experience with this approach and feedback at the 2022 Linux Plumbers Conference shifted the approach to call_rcu() being lazy with call_rcu_hurry() for the few places where laziness is inappropriate. And another call_rcu() instance that cannot be lazy is the one in queue_rcu_work(), given that callers to queue_rcu_work() are not necessarily OK with long delays. Therefore, make queue_rcu_work() use call_rcu_hurry() in order to revert to the old behavior. [ paulmck: Apply s/call_rcu_flush/call_rcu_hurry/ feedback from Tejun Heo. ] Signed-off-by: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* Merge tag 'kcfi-v6.1-rc1' of ↵Linus Torvalds2022-10-041-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull kcfi updates from Kees Cook: "This replaces the prior support for Clang's standard Control Flow Integrity (CFI) instrumentation, which has required a lot of special conditions (e.g. LTO) and work-arounds. The new implementation ("Kernel CFI") is specific to C, directly designed for the Linux kernel, and takes advantage of architectural features like x86's IBT. This series retains arm64 support and adds x86 support. GCC support is expected in the future[1], and additional "generic" architectural support is expected soon[2]. Summary: - treewide: Remove old CFI support details - arm64: Replace Clang CFI support with Clang KCFI support - x86: Introduce Clang KCFI support" Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107048 [1] Link: https://github.com/samitolvanen/llvm-project/commits/kcfi_generic [2] * tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits) x86: Add support for CONFIG_CFI_CLANG x86/purgatory: Disable CFI x86: Add types to indirectly called assembly functions x86/tools/relocs: Ignore __kcfi_typeid_ relocations kallsyms: Drop CONFIG_CFI_CLANG workarounds objtool: Disable CFI warnings objtool: Preserve special st_shndx indexes in elf_update_symbol treewide: Drop __cficanonical treewide: Drop WARN_ON_FUNCTION_MISMATCH treewide: Drop function_nocfi init: Drop __nocfi from __init arm64: Drop unneeded __nocfi attributes arm64: Add CFI error handling arm64: Add types to indirect called assembly functions psci: Fix the function type for psci_initcall_t lkdtm: Emit an indirect call for CFI tests cfi: Add type helper macros cfi: Switch to -fsanitize=kcfi cfi: Drop __CFI_ADDRESSABLE cfi: Remove CONFIG_CFI_CLANG_SHADOW ...
| * treewide: Drop WARN_ON_FUNCTION_MISMATCHSami Tolvanen2022-09-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_CFI_CLANG no longer breaks cross-module function address equality, which makes WARN_ON_FUNCTION_MISMATCH unnecessary. Remove the definition and switch back to WARN_ON_ONCE. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-15-samitolvanen@google.com
* | workqueue: don't skip lockdep work dependency in cancel_work_sync()Tetsuo Handa2022-08-161-4/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like Hillf Danton mentioned syzbot should have been able to catch cancel_work_sync() in work context by checking lockdep_map in __flush_work() for both flush and cancel. in [1], being unable to report an obvious deadlock scenario shown below is broken. From locking dependency perspective, sync version of cancel request should behave as if flush request, for it waits for completion of work if that work has already started execution. ---------- #include <linux/module.h> #include <linux/sched.h> static DEFINE_MUTEX(mutex); static void work_fn(struct work_struct *work) { schedule_timeout_uninterruptible(HZ / 5); mutex_lock(&mutex); mutex_unlock(&mutex); } static DECLARE_WORK(work, work_fn); static int __init test_init(void) { schedule_work(&work); schedule_timeout_uninterruptible(HZ / 10); mutex_lock(&mutex); cancel_work_sync(&work); mutex_unlock(&mutex); return -EINVAL; } module_init(test_init); MODULE_LICENSE("GPL"); ---------- The check this patch restores was added by commit 0976dfc1d0cd80a4 ("workqueue: Catch more locking problems with flush_work()"). Then, lockdep's crossrelease feature was added by commit b09be676e0ff25bd ("locking/lockdep: Implement the 'crossrelease' feature"). As a result, this check was once removed by commit fd1a5b04dfb899f8 ("workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes"). But lockdep's crossrelease feature was removed by commit e966eaeeb623f099 ("locking/lockdep: Remove the cross-release locking checks"). At this point, this check should have been restored. Then, commit d6e89786bed977f3 ("workqueue: skip lockdep wq dependency in cancel_work_sync()") introduced a boolean flag in order to distinguish flush_work() and cancel_work_sync(), for checking "struct workqueue_struct" dependency when called from cancel_work_sync() was causing false positives. Then, commit 87915adc3f0acdf0 ("workqueue: re-add lockdep dependencies for flushing") tried to restore "struct work_struct" dependency check, but by error checked this boolean flag. Like an example shown above indicates, "struct work_struct" dependency needs to be checked for both flush_work() and cancel_work_sync(). Link: https://lkml.kernel.org/r/20220504044800.4966-1-hdanton@sina.com [1] Reported-by: Hillf Danton <hdanton@sina.com> Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com> Fixes: 87915adc3f0acdf0 ("workqueue: re-add lockdep dependencies for flushing") Cc: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge tag 'drm-next-2022-08-03' of git://anongit.freedesktop.org/drm/drmLinus Torvalds2022-08-041-0/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull drm updates from Dave Airlie: "Highlights: - New driver for logicvc - which is a display IP core. - EDID parser rework to add new extensions - fbcon scrolling improvements - i915 has some more DG2 work but not enabled by default, but should have enough features for userspace to work now. Otherwise it's lots of work all over the place. Detailed summary: New driver: - logicvc vfio: - use aperture API core: - of: Add data-lane helpers and convert drivers - connector: Remove deprecated ida_simple_get() media: - Add various RGB666 and RGB888 format constants panel: - Add HannStar HSD101PWW - Add ETML0700Y5DHA dma-buf: - add sync-file API - set dma mask for udmabuf devices fbcon: - Improve scrolling performance - Sanitize input fbdev: - device unregistering fixes - vesa: Support COMPILE_TEST - Disable firmware-device registration when first native driver loads aperture: - fix segfault during hot-unplug - export for use with other subsystems client: - use driver validated modes dp: - aux: make probing more reliable - mst: Read extended DPCD capabilities during system resume - Support waiting for HDP signal - Port-validation fixes edid: - CEA data-block iterators - struct drm_edid introduction - implement HF-EEODB extension gem: - don't use fb format non-existing planes probe-helper: - use 640x480 as displayport fallback scheduler: - don't kill jobs in interrupt context bridge: - Add support for i.MX8qxp and i.MX8qm - lots of fixes/cleanups - Add TI-DLPC3433 - fy07024di26a30d: Optional GPIO reset - ldb: Add reg and reg-name properties to bindings, Kconfig fixes - lt9611: Fix display sensing; - tc358767: DSI/DPI refactoring and DSI-to-eDP support, DSI lane handling - tc358775: Fix clock settings - ti-sn65dsi83: Allow GPIO to sleep - adv7511: I2C fixes - anx7625: Fix error handling; DPI fixes; Implement HDP timeout via callback - fsl-ldb: Drop DE flip - ti-sn65dsi86: Convert to atomic modesetting amdgpu: - use atomic fence helpers in DM - fix VRAM address calculations - export CRTC bpc via debugfs - Initial devcoredump support - Enable high priority gfx queue on asics which support it - Adjust GART size on newer APUs for S/G display - Soft reset for GFX 11 / SDMA 6 - Add gfxoff status query for vangogh - Fix timestamps for cursor only commits - Adjust GART size on newer APUs for S/G display - fix buddy memory corruption amdkfd: - MMU notifier fixes - P2P DMA support using dma-buf - Add available memory IOCTL - HMM profiler support - Simplify GPUVM validation - Unified memory for CWSR save/restore area i915: - General driver clean-up - DG2 enabling (still under force probe) - DG2 small BAR memory support - HuC loading support - DG2 workarounds - DG2/ATS-M device IDs added - Ponte Vecchio prep work and new blitter engines - add Meteorlake support - Fix sparse warnings - DMC MMIO range checks - Audio related fixes - Runtime PM fixes - PSR fixes - Media freq factor and per-gt enhancements - DSI fixes for ICL+ - Disable DMC flip queue handlers - ADL_P voltage swing updates - Use more the VBT for panel information - Fix on Type-C ports with TBT mode - Improve fastset and allow seamless M/N changes - Accept more fixed modes with VRR/DMRRS panels - Disable connector polling for a headless SKU - ADL-S display PLL w/a - Enable THP on Icelake and beyond - Fix i915_gem_object_ggtt_pin_ww regression on old platforms - Expose per tile media freq factor in sysfs - Fix dma_resv fence handling in multi-batch execbuf - Improve on suspend / resume time with VT-d enabled - export CRTC bpc settings via debugfs msm: - gpu: a619 support - gpu: Fix for unclocked GMU register access - gpu: Devcore dump enhancements - client utilization via fdinfo support - fix fence rollover issue - gem: Lockdep false-positive warning fix - gem: Switch to pfn mappings - WB support on sc7180 - dp: dropped custom bulk clock implementation - fix link retraining on resolution change - hdmi: dropped obsolete GPIO support tegra: - context isolation for host1x engines - tegra234 soc support mediatek: - add vdosys0/1 for mt8195 - add MT8195 dp_intf driver exynos: - Fix resume function issue of exynos decon driver by calling clk_disable_unprepare() properly if clk_prepare_enable() failed. nouveau: - set of misc fixes/cleanups - display cleanups gma500: - Cleanup connector I2C handling hyperv: - Unify VRAM allocation of Gen1 and Gen2 meson: - Support YUV422 output; Refcount fixes mgag200: - Support damage clipping - Support gamma handling - Protect concurrent HW access - Fixes to connector - Store model-specific limits in device-info structure - fix PCI register init panfrost: - Valhall support r128: - Fix bit-shift overflow rockchip: - Locking fixes in error path ssd130x: - Fix built-in linkage udl: - Always advertize VGA connector ast: - Support multiple outputs - fix black screen on resume sun4i: - HDMI PHY cleanups vc4: - Add support for BCM2711 vkms: - Allocate output buffer with vmalloc() mcde: - Fix ref-count leak mxsfb/lcdif: - Support i.MX8MP LCD controller stm/ltdc: - Support dynamic Z order - Support mirroring ingenic: - Fix display at maximum resolution" * tag 'drm-next-2022-08-03' of git://anongit.freedesktop.org/drm/drm: (1480 commits) drm/amd/display: Fix a compilation failure on PowerPC caused by FPU code drm/amdgpu: enable support for psp 13.0.4 block drm/amdgpu: add files for PSP 13.0.4 drm/amdgpu: add header files for MP 13.0.4 drm/amdgpu: correct RLC_RLCS_BOOTLOAD_STATUS offset and index drm/amdgpu: send msg to IMU for the front-door loading drm/amdkfd: use time_is_before_jiffies(a + b) to replace "jiffies - a > b" drm/amdgpu: fix hive reference leak when reflecting psp topology info drm/amd/pm: enable GFX ULV feature support for SMU13.0.0 drm/amd/pm: update driver if header for SMU 13.0.0 drm/amdgpu: move mes self test after drm sched re-started drm/amdgpu: drop non-necessary call trace dump drm/amdgpu: enable VCN cg and JPEG cg/pg drm/amdgpu: vcn_4_0_2 video codec query drm/amdgpu: add VCN_4_0_2 firmware support drm/amdgpu: add VCN function in NBIO v7.7 drm/amdgpu: fix a vcn4 boot poll bug in emulation mode drm/amd/amdgpu: add memory training support for PSP_V13 drm/amdkfd: remove an unnecessary amdgpu_bo_ref drm/amd/pm: Add get_gfx_off_status interface for yellow carp ...
| * Merge tag 'amd-drm-next-5.20-2022-07-05' of ↵Dave Airlie2022-07-121-0/+9
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | https://gitlab.freedesktop.org/agd5f/linux into drm-next amd-drm-next-5.20-2022-07-05: amdgpu: - Various spelling and grammer fixes - Various eDP fixes - Various DMCUB fixes - VCN fixes - GMC 11 fixes - RAS fixes - TMZ support for GC 10.3.7 - GPUVM TLB flush fixes - SMU 13.0.x updates - DCN 3.2 Support - DCN 3.2.1 Support - MES updates - GFX11 modifiers support - USB-C fixes - MMHUB 3.0.1 support - SDMA 6.0 doorbell fixes - Initial devcoredump support - Enable high priority gfx queue on asics which support it - Enable GPU reset for SMU 13.0.4 - OLED display fixes - MPO fixes - DC frame size fixes - ASPM support for PCIE 7.4/7.6 - GPU reset support for SMU 13.0.0 - GFX11 updates - VCN JPEG fix - BACO support for SMU 13.0.7 - VCN instance handling fix - GFX8 GPUVM TLB flush fix - GPU reset rework - VCN 4.0.2 support - GTT size fixes - DP link training fixes - LSDMA 6.0.1 support - Various backlight fixes - Color encoding fixes - Backlight config cleanup - VCN 4.x unified queue cleanup amdkfd: - MMU notifier fixes - Updates for GC 10.3.6 and 10.3.7 - P2P DMA support using dma-buf - Add available memory IOCTL - SDMA 6.0.1 fix - MES fixes - HMM profiler support radeon: - License fix - Backlight config cleanup UAPI: - Add available memory IOCTL to amdkfd Proposed userspace: https://www.mail-archive.com/amd-gfx@lists.freedesktop.org/msg75743.html - HMM profiler support for amdkfd Proposed userspace: https://lists.freedesktop.org/archives/amd-gfx/2022-June/080805.html Signed-off-by: Dave Airlie <airlied@redhat.com> From: Alex Deucher <alexander.deucher@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220705212633.6037-1-alexander.deucher@amd.com
| | * Revert "workqueue: remove unused cancel_work()"Andrey Grodzovsky2022-06-101-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 6417250d3f894e66a68ba1cd93676143f2376a6f. amdpgu need this function in order to prematurly stop pending reset works when another reset work already in progress. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com> Reviewed-by: Lai Jiangshan<jiangshanlai@gmail.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
* | | workqueue: Avoid a false warning in unbind_workers()Lai Jiangshan2022-07-291-1/+4
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Doing set_cpus_allowed_ptr() with wq_unbound_cpumask can be possible fails and trigger the false warning. Use cpu_possible_mask instead when wq_unbound_cpumask has no active CPUs. It is very easy to trigger the warning: Set wq_unbound_cpumask to a small set of CPUs. Offline all the CPUs of wq_unbound_cpumask. Offline an extra CPU and trigger the warning. Fixes: 10a5a651e3af ("workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUs") Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Wrap flush_workqueue() using a macroTetsuo Handa2022-06-071-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since flush operation synchronously waits for completion, flushing system-wide WQs (e.g. system_wq) might introduce possibility of deadlock due to unexpected locking dependency. Tejun Heo commented at [1] that it makes no sense at all to call flush_workqueue() on the shared WQs as the caller has no idea what it's gonna end up waiting for. Although there is flush_scheduled_work() which flushes system_wq WQ with "Think twice before calling this function! It's very easy to get into trouble if you don't take great care." warning message, syzbot found a circular locking dependency caused by flushing system_wq WQ [2]. Therefore, let's change the direction to that developers had better use their local WQs if flush_scheduled_work()/flush_workqueue(system_*_wq) is inevitable. Steps for converting system-wide WQs into local WQs are explained at [3], and a conversion to stop flushing system-wide WQs is in progress. Now we want some mechanism for preventing developers who are not aware of this conversion from again start flushing system-wide WQs. Since I found that WARN_ON() is complete but awkward approach for teaching developers about this problem, let's use __compiletime_warning() for incomplete but handy approach. For completeness, we will also insert WARN_ON() into __flush_workqueue() after all in-tree users stopped calling flush_scheduled_work(). Link: https://lore.kernel.org/all/YgnQGZWT%2Fn3VAITX@slm.duckdns.org/ [1] Link: https://syzkaller.appspot.com/bug?extid=bde0f89deacca7c765b8 [2] Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp [3] Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUsZqiang2022-04-221-1/+1
|/ | | | | | | | | | When a CPU is going offline, all workers on the CPU's pool will have their cpus_allowed cleared to cpu_possible_mask and can run on any CPUs including the isolated ones. Instead, set cpus_allowed to wq_unbound_cpumask so that the can avoid isolated CPUs. Signed-off-by: Zqiang <qiang1.zhang@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge branch 'for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2022-03-231-38/+20
|\ | | | | | | | | | | | | | | | | | | | | | | Pull workqueue updates from Tejun Heo: "Nothing major. Just follow-up cleanups from Lai after the earlier synchronization simplification" * 'for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Convert the type of pool->nr_running to int workqueue: Use wake_up_worker() in wq_worker_sleeping() instead of open code workqueue: Change the comments of the synchronization about the idle_list workqueue: Remove the mb() pair between wq_worker_sleeping() and insert_work()
| * workqueue: Convert the type of pool->nr_running to intLai Jiangshan2022-01-121-13/+16
| | | | | | | | | | | | | | | | | | It is only modified in associated CPU, so it doesn't need to be atomic. tj: Comment updated. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * workqueue: Use wake_up_worker() in wq_worker_sleeping() instead of open codeLai Jiangshan2022-01-121-6/+3
| | | | | | | | | | | | | | The wakeup code in wq_worker_sleeping() is the same as wake_up_worker(). Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * workqueue: Change the comments of the synchronization about the idle_listLai Jiangshan2022-01-121-9/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The access to idle_list in wq_worker_sleeping() is changed to be protected by pool->lock, so the comments above idle_list can be changed to "L:" which is the meaning of "access with pool->lock held". And the outdated comments in wq_worker_sleeping() is removed since the function is not called with rq lock held any more, idle_list is dereferenced with pool lock now. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * workqueue: Remove the mb() pair between wq_worker_sleeping() and insert_work()Lai Jiangshan2022-01-121-11/+0
| | | | | | | | | | | | | | | | In wq_worker_sleeping(), the access to worklist is protected by the pool->lock, so the memory barrier is unneeded. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | sched/isolation: Use single feature type while referring to housekeeping cpumaskFrederic Weisbecker2022-02-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Refer to housekeeping APIs using single feature types instead of flags. This prevents from passing multiple isolation features at once to housekeeping interfaces, which soon won't be possible anymore as each isolation features will have their own cpumask. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org
* | workqueue: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetchFrederic Weisbecker2022-02-161-2/+2
|/ | | | | | | | | | | | | | | | | | | To prepare for supporting each feature of the housekeeping cpumask toward cpuset, prepare each of the HK_FLAG_* entries to move to their own cpumask with enforcing to fetch them individually. The new constraint is that multiple HK_FLAG_* entries can't be mixed together anymore in a single call to housekeeping cpumask(). This will later allow, for example, to runtime modify the cpulist passed through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot parameters. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220207155910.527133-3-frederic@kernel.org
* Merge branch 'workqueue/for-5.16-fixes' into workqueue/for-5.17Tejun Heo2022-01-101-1/+21
|\ | | | | | | | | | | for-5.16-fixes contains two subtle race conditions which were introduced by scheduler side code cleanups. The branch didn't get pushed out, so merge into for-5.17.
| * workqueue: Fix unbind_workers() VS wq_worker_sleeping() raceFrederic Weisbecker2021-12-031-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At CPU-hotplug time, unbind_workers() may preempt a worker while it is going to sleep. In that case the following scenario can happen: unbind_workers() wq_worker_sleeping() -------------- ------------------- if (worker->flags & WORKER_NOT_RUNNING) return; //PREEMPTED by unbind_workers worker->flags |= WORKER_UNBOUND; [...] atomic_set(&pool->nr_running, 0); //resume to worker atomic_dec_and_test(&pool->nr_running); After unbind_worker() resets pool->nr_running, the value is expected to remain 0 until the pool ever gets rebound in case cpu_up() is called on the target CPU in the future. But here the race leaves pool->nr_running with a value of -1, triggering the following warning when the worker goes idle: WARNING: CPU: 3 PID: 34 at kernel/workqueue.c:1823 worker_enter_idle+0x95/0xc0 Modules linked in: CPU: 3 PID: 34 Comm: kworker/3:0 Not tainted 5.16.0-rc1+ #34 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Workqueue: 0x0 (rcu_par_gp) RIP: 0010:worker_enter_idle+0x95/0xc0 Code: 04 85 f8 ff ff ff 39 c1 7f 09 48 8b 43 50 48 85 c0 74 1b 83 e2 04 75 99 8b 43 34 39 43 30 75 91 8b 83 00 03 00 00 85 c0 74 87 <0f> 0b 5b c3 48 8b 35 70 f1 37 01 48 8d 7b 48 48 81 c6 e0 93 0 RSP: 0000:ffff9b7680277ed0 EFLAGS: 00010086 RAX: 00000000ffffffff RBX: ffff93465eae9c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff9346418a0000 RDI: ffff934641057140 RBP: ffff934641057170 R08: 0000000000000001 R09: ffff9346418a0080 R10: ffff9b768027fdf0 R11: 0000000000002400 R12: ffff93465eae9c20 R13: ffff93465eae9c20 R14: ffff93465eae9c70 R15: ffff934641057140 FS: 0000000000000000(0000) GS:ffff93465eac0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000001cc0c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> worker_thread+0x89/0x3d0 ? process_one_work+0x400/0x400 kthread+0x162/0x190 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x22/0x30 </TASK> Also due to this incorrect "nr_running == -1", all sorts of hazards can happen, starting with queued works being ignored because no workers are awaken at insert_work() time. Fix this with checking again the worker flags while pool->lock is locked. Fixes: b945efcdd07d ("sched: Remove pointless preemption disable in sched_submit_work()") Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Tested-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * workqueue: Fix unbind_workers() VS wq_worker_running() raceFrederic Weisbecker2021-12-021-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At CPU-hotplug time, unbind_worker() may preempt a worker while it is waking up. In that case the following scenario can happen: unbind_workers() wq_worker_running() -------------- ------------------- if (!(worker->flags & WORKER_NOT_RUNNING)) //PREEMPTED by unbind_workers worker->flags |= WORKER_UNBOUND; [...] atomic_set(&pool->nr_running, 0); //resume to worker atomic_inc(&worker->pool->nr_running); After unbind_worker() resets pool->nr_running, the value is expected to remain 0 until the pool ever gets rebound in case cpu_up() is called on the target CPU in the future. But here the race leaves pool->nr_running with a value of 1, triggering the following warning when the worker goes idle: WARNING: CPU: 3 PID: 34 at kernel/workqueue.c:1823 worker_enter_idle+0x95/0xc0 Modules linked in: CPU: 3 PID: 34 Comm: kworker/3:0 Not tainted 5.16.0-rc1+ #34 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Workqueue: 0x0 (rcu_par_gp) RIP: 0010:worker_enter_idle+0x95/0xc0 Code: 04 85 f8 ff ff ff 39 c1 7f 09 48 8b 43 50 48 85 c0 74 1b 83 e2 04 75 99 8b 43 34 39 43 30 75 91 8b 83 00 03 00 00 85 c0 74 87 <0f> 0b 5b c3 48 8b 35 70 f1 37 01 48 8d 7b 48 48 81 c6 e0 93 0 RSP: 0000:ffff9b7680277ed0 EFLAGS: 00010086 RAX: 00000000ffffffff RBX: ffff93465eae9c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff9346418a0000 RDI: ffff934641057140 RBP: ffff934641057170 R08: 0000000000000001 R09: ffff9346418a0080 R10: ffff9b768027fdf0 R11: 0000000000002400 R12: ffff93465eae9c20 R13: ffff93465eae9c20 R14: ffff93465eae9c70 R15: ffff934641057140 FS: 0000000000000000(0000) GS:ffff93465eac0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000001cc0c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> worker_thread+0x89/0x3d0 ? process_one_work+0x400/0x400 kthread+0x162/0x190 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x22/0x30 </TASK> Also due to this incorrect "nr_running == 1", further queued work may end up not being served, because no worker is awaken at work insert time. This raises rcutorture writer stalls for example. Fix this with disabling preemption in the right place in wq_worker_running(). It's worth noting that if the worker migrates and runs concurrently with unbind_workers(), it is guaranteed to see the WORKER_UNBOUND flag update due to set_cpus_allowed_ptr() acquiring/releasing rq->lock. Fixes: 6d25be5782e4 ("sched/core, workqueues: Distangle worker accounting from rq lock") Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Tested-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * workqueue: Upgrade queue_work_on() commentPaul E. McKenney2021-12-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The current queue_work_on() docbook comment says that the caller must ensure that the specified CPU can't go away, but does not spell out the consequences, which turn out to be quite mild. Therefore expand this comment to explicitly say that the penalty for failing to nail down the specified CPU is that the workqueue handler might find itself executing on some other CPU. Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Remove the cacheline_aligned for nr_runningLai Jiangshan2021-12-091-8/+4
| | | | | | | | | | | | | | | | | | | | | | nr_running is never modified remotely after the schedule callback in wakeup path is removed. Rather nr_running is often accessed with other fields in the pool together, so the cacheline_aligned for nr_running isn't needed. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Move the code of waking a worker up in unbind_workers()Lai Jiangshan2021-12-091-23/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In unbind_workers(), there are two pool->lock held sections separated by the code of zapping nr_running. wake_up_worker() needs to be in pool->lock held section and after zapping nr_running. And zapping nr_running had to be after schedule() when the local wake up functionality was in use. Now, the call to schedule() has been removed along with the local wake up functionality, so the code can be merged into the same pool->lock held section. The diffstat shows that it is other code moved down because the diff tools can not know the meaning of merging lock sections by swapping two code blocks. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Remove schedule() in unbind_workers()Lai Jiangshan2021-12-091-8/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 6d25be5782e4 ("sched/core, workqueues: Distangle worker accounting from rq lock") changed the schedule callbacks for workqueue and moved the schedule callback from the wakeup code to at end of schedule() in the worker's process context. It means that the callback wq_worker_running() is guaranteed that it sees the %WORKER_UNBOUND flag after scheduled since unbind_workers() is running on the same CPU that all the pool's workers bound to. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Remove outdated comment about exceptional workers in unbind_workers()Lai Jiangshan2021-12-091-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Long time before, workers are not ALL bound after CPU_ONLINE, they can still be running in other CPUs before self rebinding. But the commit a9ab775bcadf ("workqueue: directly restore CPU affinity of workers from CPU_ONLINE") makes rebind_workers() bind them all. So all workers are on the CPU before the CPU is down. And the comment in unbind_workers() refers to the workers "which are still executing works from before the last CPU down" is outdated. Just removed it. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Remove the advanced kicking of the idle workers in rebind_workers()Lai Jiangshan2021-12-091-11/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 6d25be5782e4 ("sched/core, workqueues: Distangle worker accounting from rq lock") changed the schedule callbacks for workqueue and removed the local-wake-up functionality. Now the wakingup of workers is done by normal fashion and workers not yet migrated to the specific CPU in concurrency managed pool can also be woken up by workers that already bound to the specific cpu now. So this advanced kicking of the idle workers to migrate them to the associated CPU is unneeded now. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: Remove the outdated comment before wq_worker_sleeping()Lai Jiangshan2021-12-091-2/+1
|/ | | | | | | It isn't called with preempt disabled now. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2021-11-061-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...
| * workqueue, kasan: avoid alloc_pages() when recording stackMarco Elver2021-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Shuah Khan reported: | When CONFIG_PROVE_RAW_LOCK_NESTING=y and CONFIG_KASAN are enabled, | kasan_record_aux_stack() runs into "BUG: Invalid wait context" when | it tries to allocate memory attempting to acquire spinlock in page | allocation code while holding workqueue pool raw_spinlock. | | There are several instances of this problem when block layer tries | to __queue_work(). Call trace from one of these instances is below: | | kblockd_mod_delayed_work_on() | mod_delayed_work_on() | __queue_delayed_work() | __queue_work() (rcu_read_lock, raw_spin_lock pool->lock held) | insert_work() | kasan_record_aux_stack() | kasan_save_stack() | stack_depot_save() | alloc_pages() | __alloc_pages() | get_page_from_freelist() | rm_queue() | rm_queue_pcplist() | local_lock_irqsave(&pagesets.lock, flags); | [ BUG: Invalid wait context triggered ] The default kasan_record_aux_stack() calls stack_depot_save() with GFP_NOWAIT, which in turn can then call alloc_pages(GFP_NOWAIT, ...). In general, however, it is not even possible to use either GFP_ATOMIC nor GFP_NOWAIT in certain non-preemptive contexts, including raw_spin_locks (see gfp.h and commmit ab00db216c9c7). Fix it by instructing stackdepot to not expand stack storage via alloc_pages() in case it runs out by using kasan_record_aux_stack_noalloc(). While there is an increased risk of failing to insert the stack trace, this is typically unlikely, especially if the same insertion had already succeeded previously (stack depot hit). For frequent calls from the same location, it therefore becomes extremely unlikely that kasan_record_aux_stack_noalloc() fails. Link: https://lkml.kernel.org/r/20210902200134.25603-1-skhan@linuxfoundation.org Link: https://lkml.kernel.org/r/20210913112609.2651084-7-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Reported-by: Shuah Khan <skhan@linuxfoundation.org> Tested-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Taras Madan <tarasmadan@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Walter Wu <walter-zh.wu@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | workqueue: Introduce show_one_worker_pool and show_one_workqueue.Imran Khan2021-10-201-76/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently show_workqueue_state shows the state of all workqueues and of all worker pools. In certain cases we may need to dump state of only a specific workqueue or worker pool. For example in destroy_workqueue we only need to show state of the workqueue which is getting destroyed. So rename show_workqueue_state to show_all_workqueues(to signify it dumps state of all busy workqueues) and divide it into more granular functions (show_one_workqueue and show_one_worker_pool), that would show states of individual workqueues and worker pools and can be used in cases such as the one mentioned above. Also, as mentioned earlier, make destroy_workqueue dump data pertaining to only the workqueue that is being destroyed and make user(s) of earlier interface(show_workqueue_state), use new interface (show_all_workqueues). Signed-off-by: Imran Khan <imran.f.khan@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | workqueue: make sysfs of unbound kworker cpumask more cleverMenglong Dong2021-10-191-4/+11
|/ | | | | | | | | | | | | | Some unfriendly component, such as dpdk, write the same mask to unbound kworker cpumask again and again. Every time it write to this interface some work is queue to cpu, even though the mask is same with the original mask. So, fix it by return success and do nothing if the cpumask is equal with the old one. Signed-off-by: Mengen Sun <mengensun@tencent.com> Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: fix state-dump console deadlockJohan Hovold2021-10-111-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Console drivers often queue work while holding locks also taken in their console write paths, something which can lead to deadlocks on SMP when dumping workqueue state (e.g. sysrq-t or on suspend failures). For serial console drivers this could look like: CPU0 CPU1 ---- ---- show_workqueue_state(); lock(&pool->lock); <IRQ> lock(&port->lock); schedule_work(); lock(&pool->lock); printk(); lock(console_owner); lock(&port->lock); where workqueues are, for example, used to push data to the line discipline, process break signals and handle modem-status changes. Line disciplines and serdev drivers can also queue work on write-wakeup notifications, etc. Reworking every console driver to avoid queuing work while holding locks also taken in their write paths would complicate drivers and is neither desirable or feasible. Instead use the deferred-printk mechanism to avoid printing while holding pool locks when dumping workqueue state. Note that there are a few WARN_ON() assertions in the workqueue code which could potentially also trigger a deadlock. Hopefully the ongoing printk rework will provide a general solution for this eventually. This was originally reported after a lockdep splat when executing sysrq-t with the imx serial driver. Fixes: 3494fc30846d ("workqueue: dump workqueues on sysrq-t") Cc: stable@vger.kernel.org # 4.0 Reported-by: Fabio Estevam <festevam@denx.de> Tested-by: Fabio Estevam <festevam@denx.de> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Assign a color to barrier work itemsLai Jiangshan2021-08-171-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was no strong reason to or not to flush barrier work items in flush_workqueue(). And we have to make barrier work items not participate in nr_active so we had been using WORK_NO_COLOR for them which also makes them can't be flushed by flush_workqueue(). And the users of flush_workqueue() often do not intend to wait barrier work items issued by flush_work(). That made the choice sound perfect. But barrier work items have reference to internal structure (pool_workqueue) and the worker thread[s] is/are still busy for the workqueue user when the barrrier work items are not done. So it is reasonable to make flush_workqueue() also watch for flush_work() to make it more robust. And a problem[1] reported by Li Zhe shows that we need such robustness. The warning logs are listed below: WARNING: CPU: 0 PID: 19336 at kernel/workqueue.c:4430 destroy_workqueue+0x11a/0x2f0 ***** destroy_workqueue: test_workqueue9 has the following busy pwq pwq 4: cpus=2 node=0 flags=0x0 nice=0 active=0/1 refcnt=2 in-flight: 5658:wq_barrier_func Showing busy workqueues and worker pools: ***** It shows that even after drain_workqueue() returns, the barrier work item is still in flight and the pwq (and a worker) is still busy on it. The problem is caused by flush_workqueue() not watching flush_work(): Thread A Worker /* normal work item with linked */ process_scheduled_works() destroy_workqueue() process_one_work() drain_workqueue() /* run normal work item */ /-- pwq_dec_nr_in_flight() flush_workqueue() <---/ /* the last normal work item is done */ sanity_check process_one_work() /-- raw_spin_unlock_irq(&pool->lock) raw_spin_lock_irq(&pool->lock) <-/ /* maybe preempt */ *WARNING* wq_barrier_func() /* maybe preempt by cond_resched() */ Thread A can get the pool lock after the Worker unlocks the pool lock before running wq_barrier_func(). And if there is any preemption happen around wq_barrier_func(), destroy_workqueue()'s sanity check is more likely to get the lock and catch it. (Note: preemption is not necessary to cause the bug, the unlocking is enough to possibly trigger the WARNING.) A simple solution might be just executing all linked barrier work items once without releasing pool lock after the head work item's pwq_dec_nr_in_flight(). But this solution has two problems: 1) the head work item might also be barrier work item when the user-queued work item is cancelled. For example: thread 1: thread 2: queue_work(wq, &my_work) flush_work(&my_work) cancel_work_sync(&my_work); /* Neiter my_work nor the barrier work is scheduled. */ destroy_workqueue(wq); /* This is an easier way to catch the WARNING. */ 2) there might be too much linked barrier work items and running them all once without releasing pool lock just causes trouble. The only solution is to make flush_workqueue() aslo watch barrier work items. So we have to assign a color to these barrier work items which is the color of the head (user-queued) work item. Assigning a color doesn't cause any problem in ative management, because the prvious patch made barrier work items not participate in nr_active via WORK_STRUCT_INACTIVE rather than reliance on the (old) WORK_NO_COLOR. [1]: https://lore.kernel.org/lkml/20210812083814.32453-1-lizhe.67@bytedance.com/ Reported-by: Li Zhe <lizhe.67@bytedance.com> Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Mark barrier work with WORK_STRUCT_INACTIVELai Jiangshan2021-08-171-8/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, WORK_NO_COLOR has two meanings: Not participate in flushing Not participate in nr_active And only non-barrier work items are marked with WORK_STRUCT_INACTIVE when they are in inactive_works list. The barrier work items are not marked INACTIVE even linked in inactive_works list since these tail items are always moved together with the head work item. These definitions are simple, clean and practical. (Except a small blemish that only the first meaning of WORK_NO_COLOR is documented in include/linux/workqueue.h while both meanings are in workqueue.c) But dual-purpose WORK_NO_COLOR used for barrier work items has proven to be problematical[1]. Only the second purpose is obligatory. So we plan to make barrier work items participate in flushing but keep them still not participating in nr_active. So the plan is to mark barrier work items inactive without using WORK_NO_COLOR in this patch so that we can assign a flushing color to them in next patch. The reasonable way is to add or reuse a bit in work data of the work item. But adding a bit will double the size of pool_workqueue. Currently, WORK_STRUCT_INACTIVE is only used in try_to_grab_pending() for user-queued work items and try_to_grab_pending() can't work for barrier work items. So we extend WORK_STRUCT_INACTIVE to also mark barrier work items no matter which list they are in because we don't need to determind which list a barrier work item is in. So the meaning of WORK_STRUCT_INACTIVE becomes just "the work items don't participate in nr_active" (no matter whether it is a barrier work item or a user-queued work item). And WORK_STRUCT_INACTIVE for user-queued work items means they are in inactive_works list. This patch does it by setting WORK_STRUCT_INACTIVE for barrier work items in insert_wq_barrier() and checking WORK_STRUCT_INACTIVE first in pwq_dec_nr_in_flight(). And the meaning of WORK_NO_COLOR is reduced to only "not participating in flushing". There is no functionality change intended in this patch. Because WORK_NO_COLOR+WORK_STRUCT_INACTIVE represents the previous WORK_NO_COLOR in meaning and try_to_grab_pending() doesn't use for barrier work items and avoids being confused by this extended WORK_STRUCT_INACTIVE. A bunch of comment for nr_active & WORK_STRUCT_INACTIVE is also added for documenting how WORK_STRUCT_INACTIVE works in nr_active management. [1]: https://lore.kernel.org/lkml/20210812083814.32453-1-lizhe.67@bytedance.com/ Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Change the code of calculating work_flags in insert_wq_barrier()Lai Jiangshan2021-08-171-4/+3
| | | | | | | | | | | | | Add a local var @work_flags to calculate work_flags step by step, so that we don't need to squeeze several flags in only the last line of code. Parepare for next patch to add a bit to barrier work item's flag. Not squshing this to next patch makes it clear that what it will have changed. No functional change intended. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Change arguement of pwq_dec_nr_in_flight()Lai Jiangshan2021-08-171-8/+10
| | | | | | | | | | | | Make pwq_dec_nr_in_flight() use work_data rather just work_color. Prepare for later patch to get WORK_STRUCT_INACTIVE bit from work_data in pwq_dec_nr_in_flight(). No functional change intended. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Rename "delayed" (delayed by active management) to "inactive"Lai Jiangshan2021-08-171-29/+29
| | | | | | | | | | | | | | | | | | | | | | There are two kinds of "delayed" work items in workqueue subsystem. One is for timer-delayed work items which are visible to workqueue users. The other kind is for work items delayed by active management which can not be directly visible to workqueue users. We mixed the word "delayed" for both kinds and caused somewhat ambiguity. This patch renames the later one (delayed by active management) to "inactive", because it is used for workqueue active management and most of its related symbols are named with "active" or "activate". All "delayed" and "DELAYED" are carefully checked and renamed one by one to avoid accidentally changing the name of the other kind for timer-delayed. No functional change intended. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Replace deprecated CPU-hotplug functions.Sebastian Andrzej Siewior2021-08-101-11/+11
| | | | | | | | | | | | | | The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Cc: Tejun Heo <tj@kernel.org> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Replace deprecated ida_simple_*() with ida_alloc()/ida_free()Zhen Lei2021-08-101-7/+6
| | | | | | | | | | | | Replace ida_simple_get() with ida_alloc() and ida_simple_remove() with ida_free(), the latter is more concise and intuitive. In addition, if ida_alloc() fails, NULL is returned directly. This eliminates unnecessary initialization of two local variables and an 'if' judgment. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Fix typo in commentsCai Huoqing2021-08-101-3/+3
| | | | | | | | | | | | | | | Fix typo: *assing ==> assign *alloced ==> allocated *Retun ==> Return *excute ==> execute v1->v2: *reverse 'iff' *update changelog Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: Fix possible memory leaks in wq_numa_init()Zhen Lei2021-07-291-5/+7
| | | | | | | | | | | | | In error handling branch "if (WARN_ON(node == NUMA_NO_NODE))", the previously allocated memories are not released. Doing this before allocating memory eliminates memory leaks. tj: Note that the condition only occurs when the arch code is pretty broken and the WARN_ON might as well be BUG_ON(). Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* workqueue: fix UAF in pwq_unbound_release_workfn()Yang Yingliang2021-07-211-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I got a UAF report when doing fuzz test: [ 152.880091][ T8030] ================================================================== [ 152.881240][ T8030] BUG: KASAN: use-after-free in pwq_unbound_release_workfn+0x50/0x190 [ 152.882442][ T8030] Read of size 4 at addr ffff88810d31bd00 by task kworker/3:2/8030 [ 152.883578][ T8030] [ 152.883932][ T8030] CPU: 3 PID: 8030 Comm: kworker/3:2 Not tainted 5.13.0+ #249 [ 152.885014][ T8030] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 152.886442][ T8030] Workqueue: events pwq_unbound_release_workfn [ 152.887358][ T8030] Call Trace: [ 152.887837][ T8030] dump_stack_lvl+0x75/0x9b [ 152.888525][ T8030] ? pwq_unbound_release_workfn+0x50/0x190 [ 152.889371][ T8030] print_address_description.constprop.10+0x48/0x70 [ 152.890326][ T8030] ? pwq_unbound_release_workfn+0x50/0x190 [ 152.891163][ T8030] ? pwq_unbound_release_workfn+0x50/0x190 [ 152.891999][ T8030] kasan_report.cold.15+0x82/0xdb [ 152.892740][ T8030] ? pwq_unbound_release_workfn+0x50/0x190 [ 152.893594][ T8030] __asan_load4+0x69/0x90 [ 152.894243][ T8030] pwq_unbound_release_workfn+0x50/0x190 [ 152.895057][ T8030] process_one_work+0x47b/0x890 [ 152.895778][ T8030] worker_thread+0x5c/0x790 [ 152.896439][ T8030] ? process_one_work+0x890/0x890 [ 152.897163][ T8030] kthread+0x223/0x250 [ 152.897747][ T8030] ? set_kthread_struct+0xb0/0xb0 [ 152.898471][ T8030] ret_from_fork+0x1f/0x30 [ 152.899114][ T8030] [ 152.899446][ T8030] Allocated by task 8884: [ 152.900084][ T8030] kasan_save_stack+0x21/0x50 [ 152.900769][ T8030] __kasan_kmalloc+0x88/0xb0 [ 152.901416][ T8030] __kmalloc+0x29c/0x460 [ 152.902014][ T8030] alloc_workqueue+0x111/0x8e0 [ 152.902690][ T8030] __btrfs_alloc_workqueue+0x11e/0x2a0 [ 152.903459][ T8030] btrfs_alloc_workqueue+0x6d/0x1d0 [ 152.904198][ T8030] scrub_workers_get+0x1e8/0x490 [ 152.904929][ T8030] btrfs_scrub_dev+0x1b9/0x9c0 [ 152.905599][ T8030] btrfs_ioctl+0x122c/0x4e50 [ 152.906247][ T8030] __x64_sys_ioctl+0x137/0x190 [ 152.906916][ T8030] do_syscall_64+0x34/0xb0 [ 152.907535][ T8030] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 152.908365][ T8030] [ 152.908688][ T8030] Freed by task 8884: [ 152.909243][ T8030] kasan_save_stack+0x21/0x50 [ 152.909893][ T8030] kasan_set_track+0x20/0x30 [ 152.910541][ T8030] kasan_set_free_info+0x24/0x40 [ 152.911265][ T8030] __kasan_slab_free+0xf7/0x140 [ 152.911964][ T8030] kfree+0x9e/0x3d0 [ 152.912501][ T8030] alloc_workqueue+0x7d7/0x8e0 [ 152.913182][ T8030] __btrfs_alloc_workqueue+0x11e/0x2a0 [ 152.913949][ T8030] btrfs_alloc_workqueue+0x6d/0x1d0 [ 152.914703][ T8030] scrub_workers_get+0x1e8/0x490 [ 152.915402][ T8030] btrfs_scrub_dev+0x1b9/0x9c0 [ 152.916077][ T8030] btrfs_ioctl+0x122c/0x4e50 [ 152.916729][ T8030] __x64_sys_ioctl+0x137/0x190 [ 152.917414][ T8030] do_syscall_64+0x34/0xb0 [ 152.918034][ T8030] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 152.918872][ T8030] [ 152.919203][ T8030] The buggy address belongs to the object at ffff88810d31bc00 [ 152.919203][ T8030] which belongs to the cache kmalloc-512 of size 512 [ 152.921155][ T8030] The buggy address is located 256 bytes inside of [ 152.921155][ T8030] 512-byte region [ffff88810d31bc00, ffff88810d31be00) [ 152.922993][ T8030] The buggy address belongs to the page: [ 152.923800][ T8030] page:ffffea000434c600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d318 [ 152.925249][ T8030] head:ffffea000434c600 order:2 compound_mapcount:0 compound_pincount:0 [ 152.926399][ T8030] flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) [ 152.927515][ T8030] raw: 057ff00000010200 dead000000000100 dead000000000122 ffff888009c42c80 [ 152.928716][ T8030] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 152.929890][ T8030] page dumped because: kasan: bad access detected [ 152.930759][ T8030] [ 152.931076][ T8030] Memory state around the buggy address: [ 152.931851][ T8030] ffff88810d31bc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 152.932967][ T8030] ffff88810d31bc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 152.934068][ T8030] >ffff88810d31bd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 152.935189][ T8030] ^ [ 152.935763][ T8030] ffff88810d31bd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 152.936847][ T8030] ffff88810d31be00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 152.937940][ T8030] ================================================================== If apply_wqattrs_prepare() fails in alloc_workqueue(), it will call put_pwq() which invoke a work queue to call pwq_unbound_release_workfn() and use the 'wq'. The 'wq' allocated in alloc_workqueue() will be freed in error path when apply_wqattrs_prepare() fails. So it will lead a UAF. CPU0 CPU1 alloc_workqueue() alloc_and_link_pwqs() apply_wqattrs_prepare() fails apply_wqattrs_cleanup() schedule_work(&pwq->unbound_release_work) kfree(wq) worker_thread() pwq_unbound_release_workfn() <- trigger uaf here If apply_wqattrs_prepare() fails, the new pwq are not linked, it doesn't hold any reference to the 'wq', 'wq' is invalid to access in the worker, so add check pwq if linked to fix this. Fixes: 2d5f0764b526 ("workqueue: split apply_workqueue_attrs() into 3 stages") Cc: stable@vger.kernel.org # v4.2+ Reported-by: Hulk Robot <hulkci@huawei.com> Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Tested-by: Pavel Skripkin <paskripkin@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>