Eric Dumazet a31889a691 tick/sched: Annotate lockless access to last_jiffies_update ... commit de95a991bb72e009f47e0c4bbc90fc5f594588d5 upstream. syzbot (KCSAN) reported a data-race in tick_do_update_jiffies64(): BUG: KCSAN: data-race in tick_do_update_jiffies64 / tick_do_update_jiffies64 write to 0xffffffff8603d008 of 8 bytes by interrupt on cpu 1: tick_do_update_jiffies64+0x100/0x250 kernel/time/tick-sched.c:73 tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:138 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1292 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:436 check_access kernel/kcsan/core.c:466 [inline] __tsan_read1 kernel/kcsan/core.c:593 [inline] __tsan_read1+0xc2/0x100 kernel/kcsan/core.c:593 kallsyms_expand_symbol.constprop.0+0x70/0x160 kernel/kallsyms.c:79 kallsyms_lookup_name+0x7f/0x120 kernel/kallsyms.c:170 insert_report_filterlist kernel/kcsan/debugfs.c:155 [inline] debugfs_write+0x14b/0x2d0 kernel/kcsan/debugfs.c:256 full_proxy_write+0xbd/0x100 fs/debugfs/file.c:225 __vfs_write+0x67/0xc0 fs/read_write.c:494 vfs_write fs/read_write.c:558 [inline] vfs_write+0x18a/0x390 fs/read_write.c:542 ksys_write+0xd5/0x1b0 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x4c/0x60 fs/read_write.c:620 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffffffff8603d008 of 8 bytes by task 0 on cpu 0: tick_do_update_jiffies64+0x2b/0x250 kernel/time/tick-sched.c:62 tick_nohz_update_jiffies kernel/time/tick-sched.c:505 [inline] tick_nohz_irq_enter kernel/time/tick-sched.c:1257 [inline] tick_irq_enter+0x139/0x1c0 kernel/time/tick-sched.c:1274 irq_enter+0x4f/0x60 kernel/softirq.c:354 entering_irq arch/x86/include/asm/apic.h:517 [inline] entering_ack_irq arch/x86/include/asm/apic.h:523 [inline] smp_apic_timer_interrupt+0x55/0x280 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x1af/0x280 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 rest_init+0xec/0xf6 init/main.c:452 arch_call_rest_init+0x17/0x37 start_kernel+0x838/0x85e init/main.c:786 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Use READ_ONCE() and WRITE_ONCE() to annotate this expected race. Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191205045619.204946-1-edumazet@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-01-23 08:21:37 +01:00
..
alarmtimer.c	alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP	2019-10-05 13:10:07 +02:00
clockevents.c	clockevents: Warn if cpu_all_mask is used as cpumask	2018-08-02 14:55:53 +02:00
clocksource.c	clocksource: Revert "Remove kthread"	2018-09-06 23:38:35 +02:00
hrtimer.c	hrtimer: Annotate lockless access to timer->state	2020-01-04 19:13:32 +01:00
itimer.c	pid: Implement PIDTYPE_TGID	2018-07-21 10:43:12 -05:00
jiffies.c	jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC	2017-03-07 11:03:28 +01:00
Kconfig	sched/isolation: Eliminate NO_HZ_FULL_ALL	2018-02-15 15:40:37 -08:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
ntp.c	ntp: Limit TAI-UTC offset	2019-07-26 09:14:10 +02:00
ntp_internal.h	timekeeping/ntp: Constify some function arguments	2018-07-19 17:08:05 -07:00
posix-clock.c	ptp: fix the race between the release of ptp_clock and cdev	2020-01-04 19:13:35 +01:00
posix-cpu-timers.c	posix-cpu-timers: Sanitize bogus WARNONS	2019-10-05 13:09:47 +02:00
posix-stubs.c	posix-timers: Use new ktime_get_*_ts64() helpers	2018-06-19 09:56:27 +02:00
posix-timers.c	posix-timers: Fix division by zero bug	2018-12-29 13:37:56 +01:00
posix-timers.h	posix-timers: Make forward callback return s64	2018-07-02 11:33:25 +02:00
sched_clock.c	timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()	2019-04-27 09:36:38 +02:00
test_udelay.c	time: Avoid timespec in udelay_test	2016-06-20 12:47:26 -07:00
tick-broadcast-hrtimer.c	tick: broadcast-hrtimer: Fix a race in bc_set_next	2019-10-11 18:21:28 +02:00
tick-broadcast.c	tick/broadcast: Use for_each_cpu() specially on UP kernels	2018-05-15 22:45:54 +02:00
tick-common.c	timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()	2019-04-27 09:36:38 +02:00
tick-internal.h	Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME	2018-04-26 14:53:32 +02:00
tick-oneshot.c	clockevents: Fix kernel messages split across multiple lines	2018-04-17 17:18:04 +02:00
tick-sched.c	tick/sched: Annotate lockless access to last_jiffies_update	2020-01-23 08:21:37 +01:00
tick-sched.h	nohz: Gather tick_sched booleans under a common flag field	2018-04-09 11:54:57 +02:00
time.c	y2038: make do_gettimeofday() and get_seconds() inline	2019-11-20 18:45:24 +01:00
timeconst.bc	time: Introduce jiffies64_to_nsecs()	2017-02-01 09:13:45 +01:00
timeconv.c
timecounter.c	clocksource: Use a plain u64 instead of cycle_t	2016-12-25 11:04:12 +01:00
timekeeping.c	y2038: make do_gettimeofday() and get_seconds() inline	2019-11-20 18:45:24 +01:00
timekeeping.h	timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()	2019-04-27 09:36:38 +02:00
timekeeping_debug.c	timekeeping/ntp: Constify some function arguments	2018-07-19 17:08:05 -07:00
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	2019-10-11 18:20:59 +02:00
timer_list.c	timer_list: Guard procfs specific code	2019-07-26 09:14:10 +02:00