Messages in this thread | | | Subject | Re: [PATCH]Fix the order of atomic operations in restore_previous_kprobes on ia64 | From | Shaohua Li <> | Date | Tue, 22 Jan 2008 09:07:46 +0800 |
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On Sat, 2008-01-19 at 00:20 +0800, Masami Hiramatsu wrote: > From: Masami Hiramatsu <mhiramat@redhat.com> > > 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 <mhiramat@redhat.com> > --- > Details of this issue was reported to > http://sources.redhat.com/bugzilla/show_bug.cgi?id=2071 > > arch/ia64/kernel/kprobes.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > Index: 2.6.24-rc8/arch/ia64/kernel/kprobes.c > =================================================================== > --- 2.6.24-rc8.orig/arch/ia64/kernel/kprobes.c 2008-01-17 > 21:14:01.000000000 -0500 > +++ 2.6.24-rc8/arch/ia64/kernel/kprobes.c 2008-01-17 > 21:14:01.000000000 -0500 > @@ -381,9 +381,10 @@ > 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, Acked. Thanks for the patch.
Thanks, Shaohua
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