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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2017-09-19 19:00:19 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-28 09:23:04 +0200 |
| commit | e863d5396146411b615231cae0c518cb2a23371c (patch) | |
| tree | 5e687c4220dfce99482755fe51bfeb2102287044 /kernel/kprobes.c | |
| parent | cd52edad55fbcd8064877a77d31445b2fb4b85c3 (diff) | |
| download | lwn-e863d5396146411b615231cae0c518cb2a23371c.tar.gz lwn-e863d5396146411b615231cae0c518cb2a23371c.zip | |
kprobes: Warn if optprobe handler tries to change execution path
Warn if optprobe handler tries to change execution path.
As described in Documentation/kprobes.txt, with optprobe
user handler can not change instruction pointer. In that
case user must avoid optimizing the kprobes by setting
post_handler or break_handler.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/150581521955.32348.3615624715034787365.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 15fba7fe57c8..2d28377a0e32 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -387,7 +387,10 @@ 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); - kp->pre_handler(kp, regs); + if (kp->pre_handler(kp, regs)) { + if (WARN_ON_ONCE(1)) + pr_err("Optprobe ignores instruction pointer changing.(%pF)\n", p->addr); + } } reset_kprobe_instance(); } |