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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2017-10-17 13:48:34 +0530 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-10-18 15:21:35 +0200 |
| commit | 4f3a871443669c6b4d458a60ac8d8ca5eedc3f97 (patch) | |
| tree | 44ee4a6308eca2341ed70dc9accc001bb75300f8 /kernel/kprobes.c | |
| parent | 4b50239a769e78bbe362fc92c3f8bd5415a4a5f5 (diff) | |
| download | lwn-4f3a871443669c6b4d458a60ac8d8ca5eedc3f97.tar.gz lwn-4f3a871443669c6b4d458a60ac8d8ca5eedc3f97.zip | |
Revert "kprobes: Warn if optprobe handler tries to change execution path"
This reverts commit:
e863d539614641 ("kprobes: Warn if optprobe handler tries to change execution path")
On PowerPC, we place a probe at kretprobe_trampoline to catch function
returns and with CONFIG_OPTPROBES=y, this probe gets optimized. This
works for us due to the way we handle the optprobe as described in
commit:
762df10bad6954 ("powerpc/kprobes: Optimize kprobe in kretprobe_trampoline()")
With the above commit, we end up with a warning. As such, revert this change.
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171017081834.3629-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 2d28377a0e32..15fba7fe57c8 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -387,10 +387,7 @@ void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) list_for_each_entry_rcu(kp, &p->list, list) { if (kp->pre_handler && likely(!kprobe_disabled(kp))) { set_kprobe_instance(kp); - if (kp->pre_handler(kp, regs)) { - if (WARN_ON_ONCE(1)) - pr_err("Optprobe ignores instruction pointer changing.(%pF)\n", p->addr); - } + kp->pre_handler(kp, regs); } reset_kprobe_instance(); } |