Commit acb5b8a2 authored by Yakov Lerner's avatar Yakov Lerner Committed by Ingo Molnar

x86, kprobes: correct post-eip value in post_hander()

I was trying to get the address of instruction to be executed
next after the kprobed instruction.  But regs->eip in post_handler()
contains value which is useless to the user. It's pre-corrected value.
This value is difficult to use without access to resume_execution(), which
is not exported anyway.
I moved the invocation of post_handler() to *after* resume_execution().
Now regs->eip contains meaningful value in post_handler().

I do not think this change breaks any backward-compatibility.
To make meaning of the old value, post_handler() would need access to
resume_execution() which is not exported.  I have difficulty to believe
that previous, uncorrected, regs->eip can be meaningfully used in
post_handler().
Signed-off-by: default avatarYakov Lerner <iler.ml@gmail.com>
Acked-by: default avatarAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 0f540910
...@@ -858,15 +858,15 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs) ...@@ -858,15 +858,15 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
if (!cur) if (!cur)
return 0; return 0;
resume_execution(cur, regs, kcb);
regs->flags |= kcb->kprobe_saved_flags;
trace_hardirqs_fixup_flags(regs->flags);
if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
kcb->kprobe_status = KPROBE_HIT_SSDONE; kcb->kprobe_status = KPROBE_HIT_SSDONE;
cur->post_handler(cur, regs, 0); cur->post_handler(cur, regs, 0);
} }
resume_execution(cur, regs, kcb);
regs->flags |= kcb->kprobe_saved_flags;
trace_hardirqs_fixup_flags(regs->flags);
/* Restore back the original saved kprobes variables and continue. */ /* Restore back the original saved kprobes variables and continue. */
if (kcb->kprobe_status == KPROBE_REENTER) { if (kcb->kprobe_status == KPROBE_REENTER) {
restore_previous_kprobe(kcb); restore_previous_kprobe(kcb);
......
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