linux/kernel/rcu, branch v5.9

Merge tag 'pm-5.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2020-09-25T17:39:22Z

Pull power management fixes from Rafael Wysocki: "These fix more fallout of recent RCU-lockdep changes in CPU idle code and two devfreq issues. Specifics: - Export rcu_idle_{enter,exit} to modules to fix build issues introduced by recent RCU-lockdep fixes (Borislav Petkov) - Add missing return statement to a stub function in the ACPI processor driver to fix a build issue introduced by recent RCU-lockdep fixes (Rafael Wysocki) - Fix recently introduced suspicious RCU usage warnings in the PSCI cpuidle driver and drop stale comments regarding RCU_NONIDLE() usage from enter_s2idle_proper() (Ulf Hansson) - Fix error code path in the tegra30 devfreq driver (Dan Carpenter) - Add missing information to devfreq_summary debugfs (Chanwoo Choi)" * tag 'pm-5.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: processor: Fix build for ARCH_APICTIMER_STOPS_ON_C3 unset PM / devfreq: tegra30: Disable clock on error in probe PM / devfreq: Add timer type to devfreq_summary debugfs cpuidle: Drop misleading comments about RCU usage cpuidle: psci: Fix suspicious RCU usage rcu/tree: Export rcu_idle_{enter,exit} to modules

rcu/tree: Export rcu_idle_{enter,exit} to modules

2020-09-21T13:37:21Z

Fix this link error: ERROR: modpost: "rcu_idle_enter" [drivers/acpi/processor.ko] undefined! ERROR: modpost: "rcu_idle_exit" [drivers/acpi/processor.ko] undefined! when CONFIG_ACPI_PROCESSOR is built as module. PeterZ says that in light of ARM needing those soon too, they should simply be exported. Fixes: 1fecfdbb7acc ("ACPI: processor: Take over RCU-idle for C3-BM idle") Reported-by: Sven Joachim Suggested-by: Peter Zijlstra Signed-off-by: Borislav Petkov Reviewed-by: Paul E. McKenney Signed-off-by: Rafael J. Wysocki

rcu-tasks: Prevent complaints of unused show_rcu_tasks_classic_gp_kthread()

2020-09-16T23:32:36Z

Commit 8344496e8b49 ("rcu-tasks: Conditionally compile show_rcu_tasks_gp_kthreads()") introduced conditional compilation of several functions, but forgot one occurrence of show_rcu_tasks_classic_gp_kthread() that causes the compiler to warn of an unused static function. This commit uses "static inline" to avoid these complaints and possibly also to avoid emitting an actual definition of this function. Fixes: 8344496e8b49 ("rcu-tasks: Conditionally compile show_rcu_tasks_gp_kthreads()") Cc: # 5.8.x Reported-by: Laurent Pinchart Signed-off-by: Paul E. McKenney

rcu: kasan: record and print call_rcu() call stack

2020-08-07T18:33:28Z

Patch series "kasan: memorize and print call_rcu stack", v8. This patchset improves KASAN reports by making them to have call_rcu() call stack information. It is useful for programmers to solve use-after-free or double-free memory issue. The KASAN report was as follows(cleaned up slightly): BUG: KASAN: use-after-free in kasan_rcu_reclaim+0x58/0x60 Freed by task 0: kasan_save_stack+0x24/0x50 kasan_set_track+0x24/0x38 kasan_set_free_info+0x18/0x20 __kasan_slab_free+0x10c/0x170 kasan_slab_free+0x10/0x18 kfree+0x98/0x270 kasan_rcu_reclaim+0x1c/0x60 Last call_rcu(): kasan_save_stack+0x24/0x50 kasan_record_aux_stack+0xbc/0xd0 call_rcu+0x8c/0x580 kasan_rcu_uaf+0xf4/0xf8 Generic KASAN will record the last two call_rcu() call stacks and print up to 2 call_rcu() call stacks in KASAN report. it is only suitable for generic KASAN. This feature considers the size of struct kasan_alloc_meta and kasan_free_meta, we try to optimize the structure layout and size, lets it get better memory consumption. [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ This patch (of 4): This feature will record the last two call_rcu() call stacks and prints up to 2 call_rcu() call stacks in KASAN report. When call_rcu() is called, we store the call_rcu() call stack into slub alloc meta-data, so that the KASAN report can print rcu stack. [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ [walter-zh.wu@mediatek.com: build fix] Link: http://lkml.kernel.org/r/20200710162401.23816-1-walter-zh.wu@mediatek.com Suggested-by: Dmitry Vyukov Signed-off-by: Walter Wu Signed-off-by: Andrew Morton Tested-by: Dmitry Vyukov Reviewed-by: Dmitry Vyukov Reviewed-by: Andrey Konovalov Acked-by: Paul E. McKenney Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Josh Triplett Cc: Mathieu Desnoyers Cc: Lai Jiangshan Cc: Joel Fernandes Cc: Jonathan Corbet Cc: Matthias Brugger Link: http://lkml.kernel.org/r/20200710162123.23713-1-walter-zh.wu@mediatek.com Link: http://lkml.kernel.org/r/20200601050847.1096-1-walter-zh.wu@mediatek.com Link: http://lkml.kernel.org/r/20200601050927.1153-1-walter-zh.wu@mediatek.com Signed-off-by: Linus Torvalds

Merge tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-08-06T18:55:43Z

Pull sched/fifo updates from Ingo Molnar: "This adds the sched_set_fifo*() encapsulation APIs to remove static priority level knowledge from non-scheduler code. The three APIs for non-scheduler code to set SCHED_FIFO are: - sched_set_fifo() - sched_set_fifo_low() - sched_set_normal() These are two FIFO priority levels: default (high), and a 'low' priority level, plus sched_set_normal() to set the policy back to non-SCHED_FIFO. Since the changes affect a lot of non-scheduler code, we kept this in a separate tree" * tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) sched,tracing: Convert to sched_set_fifo() sched: Remove sched_set_*() return value sched: Remove sched_setscheduler*() EXPORTs sched,psi: Convert to sched_set_fifo_low() sched,rcutorture: Convert to sched_set_fifo_low() sched,rcuperf: Convert to sched_set_fifo_low() sched,locktorture: Convert to sched_set_fifo() sched,irq: Convert to sched_set_fifo() sched,watchdog: Convert to sched_set_fifo() sched,serial: Convert to sched_set_fifo() sched,powerclamp: Convert to sched_set_fifo() sched,ion: Convert to sched_set_normal() sched,powercap: Convert to sched_set_fifo*() sched,spi: Convert to sched_set_fifo*() sched,mmc: Convert to sched_set_fifo*() sched,ivtv: Convert to sched_set_fifo*() sched,drm/scheduler: Convert to sched_set_fifo*() sched,msm: Convert to sched_set_fifo*() sched,psci: Convert to sched_set_fifo*() sched,drbd: Convert to sched_set_fifo*() ...

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2020-07-30T22:15:53Z

Pull the v5.9 RCU bits from Paul E. McKenney: - Documentation updates - Miscellaneous fixes - kfree_rcu updates - RCU tasks updates - Read-side scalability tests - SRCU updates - Torture-test updates Signed-off-by: Ingo Molnar

Merge tag 'core-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-07-05T19:21:28Z

Pull rcu fixlet from Thomas Gleixner: "A single fix for a printk format warning in RCU" * tag 'core-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcuperf: Fix printk format warning

Merge branches 'doc.2020.06.29a', 'fixes.2020.06.29a', 'kfree_rcu.2020.06.29a', 'rcu-tasks.2020.06.29a', 'scale.2020.06.29a', 'srcu.2020.06.29a' and 'torture.2020.06.29a' into HEAD

2020-06-29T19:03:15Z

doc.2020.06.29a: Documentation updates. fixes.2020.06.29a: Miscellaneous fixes. kfree_rcu.2020.06.29a: kfree_rcu() updates. rcu-tasks.2020.06.29a: RCU Tasks updates. scale.2020.06.29a: Read-side scalability tests. srcu.2020.06.29a: SRCU updates. torture.2020.06.29a: Torture-test updates.

rcutorture: Check for unwatched readers

2020-06-29T19:01:44Z

RCU is supposed to be watching all non-idle kernel code and also all softirq handlers. This commit adds some teeth to this statement by adding a WARN_ON_ONCE(). Signed-off-by: Paul E. McKenney

rcu/rcutorture: Replace 0 with false

2020-06-29T19:01:44Z

Coccinelle reports a warning WARNING: Assignment of 0/1 to bool variable The root cause is that the variable lastphase is a bool, but is initialised with integer 0. This commit therefore replaces the 0 with a false. Signed-off-by: Jules Irenge Signed-off-by: Paul E. McKenney