wireguard-linux/kernel/time, branch jd/orphan-parallel

Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-10-18T21:34:50Z

Pull RCU changes from Ingo Molnar: - Debugging for smp_call_function() - RT raw/non-raw lock ordering fixes - Strict grace periods for KASAN - New smp_call_function() torture test - Torture-test updates - Documentation updates - Miscellaneous fixes [ This doesn't actually pull the tag - I've dropped the last merge from the RCU branch due to questions about the series. - Linus ] * tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) smp: Make symbol 'csd_bug_count' static kernel/smp: Provide CSD lock timeout diagnostics smp: Add source and destination CPUs to __call_single_data rcu: Shrink each possible cpu krcp rcu/segcblist: Prevent useless GP start if no CBs to accelerate torture: Add gdb support rcutorture: Allow pointer leaks to test diagnostic code rcutorture: Hoist OOM registry up one level refperf: Avoid null pointer dereference when buf fails to allocate rcutorture: Properly synchronize with OOM notifier rcutorture: Properly set rcu_fwds for OOM handling torture: Add kvm.sh --help and update help message rcutorture: Add CONFIG_PROVE_RCU_LIST to TREE05 torture: Update initrd documentation rcutorture: Replace HTTP links with HTTPS ones locktorture: Make function torture_percpu_rwsem_init() static torture: document --allcpus argument added to the kvm.sh script rcutorture: Output number of elapsed grace periods rcutorture: Remove KCSAN stubs rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp() ...

Merge tag 'locking-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-10-12T20:06:20Z

Pull locking updates from Ingo Molnar: "These are the locking updates for v5.10: - Add deadlock detection for recursive read-locks. The rationale is outlined in commit 224ec489d3cd ("lockdep/ Documention: Recursive read lock detection reasoning") The main deadlock pattern we want to detect is: TASK A: TASK B: read_lock(X); write_lock(X); read_lock_2(X); - Add "latch sequence counters" (seqcount_latch_t): A sequence counter variant where the counter even/odd value is used to switch between two copies of protected data. This allows the read path, typically NMIs, to safely interrupt the write side critical section. We utilize this new variant for sched-clock, and to make x86 TSC handling safer. - Other seqlock cleanups, fixes and enhancements - KCSAN updates - LKMM updates - Misc updates, cleanups and fixes" * tag 'locking-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits) lockdep: Revert "lockdep: Use raw_cpu_*() for per-cpu variables" lockdep: Fix lockdep recursion lockdep: Fix usage_traceoverflow locking/atomics: Check atomic-arch-fallback.h too locking/seqlock: Tweak DEFINE_SEQLOCK() kernel doc lockdep: Optimize the memory usage of circular queue seqlock: Unbreak lockdep seqlock: PREEMPT_RT: Do not starve seqlock_t writers seqlock: seqcount_LOCKNAME_t: Introduce PREEMPT_RT support seqlock: seqcount_t: Implement all read APIs as statement expressions seqlock: Use unique prefix for seqcount_t property accessors seqlock: seqcount_LOCKNAME_t: Standardize naming convention seqlock: seqcount latch APIs: Only allow seqcount_latch_t rbtree_latch: Use seqcount_latch_t x86/tsc: Use seqcount_latch_t timekeeping: Use seqcount_latch_t time/sched_clock: Use seqcount_latch_t seqlock: Introduce seqcount_latch_t mm/swap: Do not abuse the seqcount_t latching API time/sched_clock: Use raw_read_seqcount_latch() during suspend ...

Merge tag 'timers-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-10-12T18:27:54Z

Pull timekeeping updates from Thomas Gleixner: "Updates for timekeeping, timers and related drivers: Core: - Early boot support for the NMI safe timekeeper by utilizing local_clock() up to the point where timekeeping is initialized. This allows printk() to store multiple timestamps in the ringbuffer which is useful for coordinating dmesg information across a fleet of machines. - Provide a multi-timestamp accessor for printk() - Make timer init more robust by checking for invalid timer flags. - Comma vs semicolon fixes Drivers: - Support for new platforms in existing drivers (SP804 and Renesas CMT) - Comma vs semicolon fixes * tag 'timers-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/armada-370-xp: Use semicolons rather than commas to separate statements clocksource/drivers/mps2-timer: Use semicolons rather than commas to separate statements timers: Mask invalid flags in do_init_timer() clocksource/drivers/sp804: Enable Hisilicon sp804 timer 64bit mode clocksource/drivers/sp804: Add support for Hisilicon sp804 timer clocksource/drivers/sp804: Support non-standard register offset clocksource/drivers/sp804: Prepare for support non-standard register offset clocksource/drivers/sp804: Remove a mismatched comment clocksource/drivers/sp804: Delete the leading "__" of some functions clocksource/drivers/sp804: Remove unused sp804_timer_disable() and timer-sp804.h clocksource/drivers/sp804: Cleanup clk_get_sys() dt-bindings: timer: renesas,cmt: Document r8a774e1 CMT support dt-bindings: timer: renesas,cmt: Document r8a7742 CMT support alarmtimer: Convert comma to semicolon timekeeping: Provide multi-timestamp accessor to NMI safe timekeeper timekeeping: Utilize local_clock() for NMI safe timekeeper during early boot

Merge branch 'locking/urgent' into locking/core, to pick up fixes

2020-10-09T06:55:17Z

Signed-off-by: Ingo Molnar

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

2020-10-09T06:21:56Z

Pull v5.10 RCU changes from Paul E. McKenney: - Debugging for smp_call_function(). - Strict grace periods for KASAN. The point of this series is to find RCU-usage bugs, so the corresponding new RCU_STRICT_GRACE_PERIOD Kconfig option depends on both DEBUG_KERNEL and RCU_EXPERT, and is further disabled by dfefault. Finally, the help text includes a goodly list of scary caveats. - New smp_call_function() torture test. - Torture-test updates. - Documentation updates. - Miscellaneous fixes. Signed-off-by: Ingo Molnar

timers: Mask invalid flags in do_init_timer()

2020-09-24T20:12:18Z

do_init_timer() accepts any combination of timer flags handed in by the caller without a sanity check, but only TIMER_DEFFERABLE, TIMER_PINNED and TIMER_IRQSAFE are valid. If the supplied flags have other bits set, this could result in malfunction. If bits are set in TIMER_CPUMASK the first timer usage could deference a cpu base which is outside the range of possible CPUs. If TIMER_MIGRATION is set, then the switch_timer_base() will live lock. Prevent that with a sanity check which warns when invalid flags are supplied and masks them out. [ tglx: Made it WARN_ON_ONCE() and added context to the changelog ] Signed-off-by: Qianli Zhao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/9d79a8aa4eb56713af7379f99f062dedabcde140.1597326756.git.zhaoqianli@xiaomi.com

treewide: Make all debug_obj_descriptors const

2020-09-24T19:56:25Z

This should make it harder for the kernel to corrupt the debug object descriptor, used to call functions to fixup state and track debug objects, by moving the structure to read-only memory. Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20200815004027.2046113-3-swboyd@chromium.org

timekeeping: Use seqcount_latch_t

2020-09-10T09:19:29Z

Latch sequence counters are a multiversion concurrency control mechanism where the seqcount_t counter even/odd value is used to switch between two data storage copies. This allows the seqcount_t read path to safely interrupt its write side critical section (e.g. from NMIs). Initially, latch sequence counters were implemented as a single write function, raw_write_seqcount_latch(), above plain seqcount_t. The read path was expected to use plain seqcount_t raw_read_seqcount(). A specialized read function was later added, raw_read_seqcount_latch(), and became the standardized way for latch read paths. Having unique read and write APIs meant that latch sequence counters are basically a data type of their own -- just inappropriately overloading plain seqcount_t. The seqcount_latch_t data type was thus introduced at seqlock.h. Use that new data type instead of seqcount_raw_spinlock_t. This ensures that only latch-safe APIs are to be used with the sequence counter. Note that the use of seqcount_raw_spinlock_t was not very useful in the first place. Only the "raw_" subset of seqcount_t APIs were used at timekeeping.c. This subset was created for contexts where lockdep cannot be used. seqcount_LOCKTYPE_t's raison d'être -- verifying that the seqcount_t writer serialization lock is held -- cannot thus be done. References: 0c3351d451ae ("seqlock: Use raw_ prefix instead of _no_lockdep") References: 55f3560df975 ("seqlock: Extend seqcount API with associated locks") Signed-off-by: Ahmed S. Darwish Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200827114044.11173-6-a.darwish@linutronix.de

time/sched_clock: Use seqcount_latch_t

2020-09-10T09:19:29Z

Latch sequence counters have unique read and write APIs, and thus seqcount_latch_t was recently introduced at seqlock.h. Use that new data type instead of plain seqcount_t. This adds the necessary type-safety and ensures only latching-safe seqcount APIs are to be used. Signed-off-by: Ahmed S. Darwish Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200827114044.11173-5-a.darwish@linutronix.de

time/sched_clock: Use raw_read_seqcount_latch() during suspend

2020-09-10T09:19:28Z

sched_clock uses seqcount_t latching to switch between two storage places protected by the sequence counter. This allows it to have interruptible, NMI-safe, seqcount_t write side critical sections. Since 7fc26327b756 ("seqlock: Introduce raw_read_seqcount_latch()"), raw_read_seqcount_latch() became the standardized way for seqcount_t latch read paths. Due to the dependent load, it has one read memory barrier less than the currently used raw_read_seqcount() API. Use raw_read_seqcount_latch() for the suspend path. Commit aadd6e5caaac ("time/sched_clock: Use raw_read_seqcount_latch()") missed changing that instance of raw_read_seqcount(). References: 1809bfa44e10 ("timers, sched/clock: Avoid deadlock during read from NMI") Signed-off-by: Ahmed S. Darwish Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200715092345.GA231464@debian-buster-darwi.lab.linutronix.de