From: Jeff Dike Date: Fri, 30 Jun 2006 08:55:56 +0000 (-0700) Subject: [PATCH] uml: add locking to xtime accesses X-Git-Tag: MMI-PSA29.97-13-9~48658 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=572e614750c3ed27da1ec6b75dc486066a11fffd;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git [PATCH] uml: add locking to xtime accesses do_timer must be called with xtime_lock held. I'm not sure boot_timer_handler needs this, however I don't think it hurts: it simply disables irq and takes a spinlock. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/um/kernel/time_kern.c b/arch/um/kernel/time_kern.c index 87cdbc560d36..08dd727e79e4 100644 --- a/arch/um/kernel/time_kern.c +++ b/arch/um/kernel/time_kern.c @@ -96,11 +96,15 @@ void time_init_kern(void) void do_boot_timer_handler(struct sigcontext * sc) { + unsigned long flags; struct pt_regs regs; CHOOSE_MODE((void) (UPT_SC(®s.regs) = sc), (void) (regs.regs.skas.is_user = 0)); + + write_seqlock_irqsave(&xtime_lock, flags); do_timer(®s); + write_sequnlock_irqrestore(&xtime_lock, flags); } static DEFINE_SPINLOCK(timer_spinlock); @@ -125,15 +129,17 @@ irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs) unsigned long long nsecs; unsigned long flags; + write_seqlock_irqsave(&xtime_lock, flags); + do_timer(regs); - write_seqlock_irqsave(&xtime_lock, flags); nsecs = get_time() + local_offset; xtime.tv_sec = nsecs / NSEC_PER_SEC; xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC; + write_sequnlock_irqrestore(&xtime_lock, flags); - return(IRQ_HANDLED); + return IRQ_HANDLED; } long um_time(int __user *tloc)