From d6bd0e6b32ea72be91e5789b1e838c244f8a05d9 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Tue, 14 Mar 2006 23:46:58 +0000 Subject: [PATCH] [MIPS] Protect more of timer_interrupt() by xtime_lock. From Dave Johnson : * do_timer() expects the arch-specific handler to take the lock as it modifies jiffies[_64] and xtime. * writing timerhi/lo in timer_interrupt() will mess up fixed_rate_gettimeoffset() which reads timerhi/lo. Signed-off-by: Ralf Baechle --- arch/mips/kernel/time.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c index 42c94c771afb..51273b7297a7 100644 --- a/arch/mips/kernel/time.c +++ b/arch/mips/kernel/time.c @@ -424,6 +424,8 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) unsigned long j; unsigned int count; + write_seqlock(&xtime_lock); + count = mips_hpt_read(); mips_timer_ack(); @@ -441,7 +443,6 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) * CMOS clock accordingly every ~11 minutes. rtc_set_time() has to be * called as close as possible to 500 ms before the new second starts. */ - write_seqlock(&xtime_lock); if (ntp_synced() && xtime.tv_sec > last_rtc_update + 660 && (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && @@ -453,7 +454,6 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) last_rtc_update = xtime.tv_sec - 600; } } - write_sequnlock(&xtime_lock); /* * If jiffies has overflown in this timer_interrupt, we must @@ -496,6 +496,8 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) } } + write_sequnlock(&xtime_lock); + /* * In UP mode, we call local_timer_interrupt() to do profiling * and process accouting. -- 2.20.1