From: Shinya Kuribayashi Date: Wed, 19 Jun 2013 00:05:33 +0000 (+1000) Subject: hrtimer: one more expiry time overflow check in hrtimer_interrupt X-Git-Tag: next-20130619~2^2~615 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0e2a9e95352d40931c5d373932c42aefd42a0e37;p=karo-tx-linux.git hrtimer: one more expiry time overflow check in hrtimer_interrupt When executing a date command to set the system date and time to a few seconds before the 2038 problem expiration time, we got a WARN_ON_ONCE() like this: root@renesas:~# date -s "2038-1-19 3:14:00" Tue Jan 19 03:14:00 GMT 2038 (then wait for 7-8 seconds) root@renesas:~# [ 27.662658] ------------[ cut here ]------------ [ 27.667297] WARNING: at kernel/time/clockevents.c:209 clockevents_program_event+0x3c/0x138() [ 27.675720] Modules linked in: [ 27.678802] [] (unwind_backtrace+0x0/0xe0) from [] (warn_slowpath_common+0x4c/0x64) [ 27.688201] [] (warn_slowpath_common+0x4c/0x64) from [] (warn_slowpath_null+0x18/0x1c) [ 27.697845] [] (warn_slowpath_null+0x18/0x1c) from [] (clockevents_program_event+0x3c/0x138) [ 27.708007] [] (clockevents_program_event+0x3c/0x138) from [] (tick_program_event+0x2c/0x34) [ 27.718170] [] (tick_program_event+0x2c/0x34) from [] (hrtimer_interrupt+0x268/0x2a8) [ 27.727752] [] (hrtimer_interrupt+0x268/0x2a8) from [] (cmt_timer_interrupt+0x2c/0x34) [ 27.737396] [] (cmt_timer_interrupt+0x2c/0x34) from [] (handle_irq_event_percpu+0xb0/0x2a8) [ 27.747467] [] (handle_irq_event_percpu+0xb0/0x2a8) from [] (handle_irq_event+0x58/0x74) [ 27.757293] [] (handle_irq_event+0x58/0x74) from [] (handle_fasteoi_irq+0xc0/0x148) [ 27.766662] [] (handle_fasteoi_irq+0xc0/0x148) from [] (generic_handle_irq+0x20/0x30) [ 27.776245] [] (generic_handle_irq+0x20/0x30) from [] (handle_IRQ+0x60/0x84) [ 27.785003] [] (handle_IRQ+0x60/0x84) from [] (gic_handle_irq+0x34/0x4c) [ 27.793426] [] (gic_handle_irq+0x34/0x4c) from [] (__irq_svc+0x40/0x70) [ 27.801788] Exception stack(0xc04aff68 to 0xc04affb0) [ 27.806823] ff60: 00000000 f0100000 00000001 00000000 c04ae000 c04ec388 [ 27.815002] ff80: c04b604c c0840d80 40004059 412fc093 00000000 00000000 c04ce140 c04affb0 [ 27.823150] ffa0: c000f064 c000f068 60000013 ffffffff [ 27.828216] [] (__irq_svc+0x40/0x70) from [] (default_idle+0x24/0x2c) [ 27.836395] [] (default_idle+0x24/0x2c) from [] (cpu_idle+0x74/0xc8) [ 27.844451] [] (cpu_idle+0x74/0xc8) from [] (start_kernel+0x248/0x288) [ 27.852722] ---[ end trace 9d8ad385bde80fd3 ]--- [ 27.857330] hrtimer: interrupt took 0 ns This is triggered with our v3.4-based custom ARM kernel, but we confirmed that v3.10-rc can still have the same problem. I found a similar issue fixed in v3.9 by Prarit Bhargava in commit 8f294b5a13 ("hrtimer: Add expiry time overflow check in hrtimer_interrupt", 2013-04-08). It tried to resolve a overflow issue detected around 1970 + 100 seconds. On the other hand, we have another call site of tick_program_event() at the bottom of hrtimer_interrupt(). The warning this time is triggered there, so we need to apply the same fix to it. Signed-off-by: Shinya Kuribayashi Reported-by: Hiroyuki Yokoyama Cc: Prarit Bhargava Cc: John Stultz Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 3ee4d06c6fc2..ef0dd04c3a60 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1392,6 +1392,8 @@ retry: expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC); else expires_next = ktime_add(now, delta); + if (expires_next.tv64 < 0) + expires_next.tv64 = KTIME_MAX; tick_program_event(expires_next, 1); printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n", ktime_to_ns(delta));