Eric Dumazet de95a991bb tick/sched: Annotate lockless access to last_jiffies_update ... 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		2020-01-15 10:54:12 +01:00
..
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	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-12-03 12:20:25 -08:00
itimer.c	y2038: alarm: fix half-second cut-off	2019-11-25 21:52:35 +01:00
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/y2038: Remove incorrect time_t truncation	2019-11-12 08:13:44 +01:00
ntp_internal.h	ntp: Audit NTP parameters adjustment	2019-04-15 18:14:01 -04:00
posix-clock.c	ptp: fix the race between the release of ptp_clock and cdev	2019-12-30 20:19:27 -08:00
posix-cpu-timers.c	posix-cpu-timers: Fix two trivial comments	2019-10-23 14:48:24 +02:00
posix-stubs.c	time/posix-stubs: Provide compat itimer supoprt for alpha	2020-01-09 18:20:23 +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	timers/sched_clock: Include local timekeeping.h for missing declarations	2019-10-23 14:48:23 +02:00
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/sched: Annotate lockless access to last_jiffies_update	2020-01-15 10:54:12 +01:00
tick-sched.h	tick/sched: Update tick_sched struct documentation	2019-03-24 20:29:32 +01:00
time.c	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-12-03 12:20:25 -08:00
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: Update VDSO data unconditionally	2019-11-04 23:02:53 +01:00