From 97075c4b3b7fdd6a083eea075c3a4a601f0d64d8 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 18 Jan 2008 11:20:46 -0500 Subject: [PATCH] [IA64] Fix the order of atomic operations in restore_previous_kprobes on ia64 Fix the order of atomic operations to prevent overwriting prev_kprobe[0]. To pop values from stack, we must decrement stack index right AFTER reading values. Signed-off-by: Masami Hiramatsu Signed-off-by: Tony Luck --- arch/ia64/kernel/kprobes.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index fc4d2676264..b618487cdc8 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -381,9 +381,10 @@ static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) { unsigned int i; - i = atomic_sub_return(1, &kcb->prev_kprobe_index); - __get_cpu_var(current_kprobe) = kcb->prev_kprobe[i].kp; - kcb->kprobe_status = kcb->prev_kprobe[i].status; + i = atomic_read(&kcb->prev_kprobe_index); + __get_cpu_var(current_kprobe) = kcb->prev_kprobe[i-1].kp; + kcb->kprobe_status = kcb->prev_kprobe[i-1].status; + atomic_sub(1, &kcb->prev_kprobe_index); } static void __kprobes set_current_kprobe(struct kprobe *p, -- 2.41.1