openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity
linux/kernel/time
History
Eric Dumazet ff229eee3d hrtimer: Annotate lockless access to timer->base 
Followup to commit dd2261ed45 ("hrtimer: Protect lockless access
to timer->base")

lock_hrtimer_base() fetches timer->base without lock exclusion.

Compiler is allowed to read timer->base twice (even if considered dumb)
which could end up trying to lock migration_base and return
&migration_base.

  base = timer->base;
  if (likely(base != &migration_base)) {

       /* compiler reads timer->base again, and now (base == &migration_base)

       raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
       if (likely(base == timer->base))
            return base; /* == &migration_base ! */

Similarly the write sides must use WRITE_ONCE() to avoid store tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191008173204.180879-1-edumazet@google.com
 		2019-10-14 15:51:49 +02:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile timekeeping: Provide a generic update_vsyscall() implementation 2019-06-22 21:21:06 +02:00
alarmtimer.c Power management updates for 5.4-rc1 2019-09-17 19:15:14 -07:00
clockevents.c tick: Remove outgoing CPU from broadcast masks 2019-03-23 18:26:43 +01:00
clocksource.c clocksource: Move inline keyword to the beginning of function declarations 2019-06-14 17:04:03 +02:00
hrtimer.c hrtimer: Annotate lockless access to timer->base 2019-10-14 15:51:49 +02:00
itimer.c posix-cpu-timers: Switch thread group sampling to array 2019-08-28 11:50:39 +02:00
jiffies.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 14:50:46 -07:00
ntp.c ntp: Limit TAI-UTC offset 2019-06-22 11:28:53 +02:00
ntp_internal.h ntp: Audit NTP parameters adjustment 2019-04-15 18:14:01 -04:00
posix-clock.c timex: use __kernel_timex internally 2019-02-07 00:13:27 +01:00
posix-cpu-timers.c posix-cpu-timers: Fix permission check regression 2019-09-10 12:13:07 +01:00
posix-stubs.c y2038: syscalls: rename y2038 compat syscalls 2019-02-07 00:13:27 +01:00
posix-timers.c hrtimer: Improve comments on handling priority inversion against softirq kthread 2019-08-20 22:05:46 +02:00
posix-timers.h posix-timers: Use a callback for cancel synchronization on PREEMPT_RT 2019-08-20 22:05:46 +02:00
sched_clock.c Printk changes for 5.2 2019-05-07 09:18:12 -07:00
test_udelay.c time/debug: Remove license boilerplate 2018-11-23 11:51:21 +01:00
tick-broadcast-hrtimer.c tick: broadcast-hrtimer: Fix a race in bc_set_next 2019-09-27 14:45:55 +02:00
tick-broadcast.c tick: Fix typos in comments 2019-04-19 19:17:04 +02:00
tick-common.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 14:50:46 -07:00
tick-internal.h tick: Remove outgoing CPU from broadcast masks 2019-03-23 18:26:43 +01:00
tick-oneshot.c hrtimers/tick/clockevents: Remove sloppy license references 2018-11-23 11:51:21 +01:00
tick-sched.c tick: Mark sched_timer to expire in hard interrupt context 2019-08-28 13:01:26 +02:00
tick-sched.h tick/sched: Update tick_sched struct documentation 2019-03-24 20:29:32 +01:00
time.c time: Validate user input in compat_settimeofday() 2019-07-07 12:05:40 +02:00
timeconst.bc time: Add SPDX license identifiers 2018-11-23 11:51:20 +01:00
timeconv.c time: Add SPDX license identifiers 2018-11-23 11:51:20 +01:00
timecounter.c time: Remove license boilerplate 2018-11-23 11:51:21 +01:00
timekeeping.c timekeeping/vsyscall: Prevent math overflow in BOOTTIME update 2019-08-23 02:12:11 +02:00
timekeeping.h timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze() 2019-04-18 14:34:53 +02:00
timekeeping_debug.c timekeeping/debug: No need to check return value of debugfs_create functions 2019-01-29 20:08:41 +01:00
timekeeping_internal.h timekeeping/ntp: Constify some function arguments 2018-07-19 17:08:05 -07:00
timer.c timer: Read jiffies once when forwarding base clk 2019-09-19 17:50:11 +02:00
timer_list.c timer_list: Guard procfs specific code 2019-06-23 00:08:52 +02:00
vsyscall.c timekeeping/vsyscall: Prevent math overflow in BOOTTIME update 2019-08-23 02:12:11 +02:00