Messages in this thread | | | Date | Tue, 3 Dec 2013 21:39:04 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH -tip v4 6/6] [RFC] kprobes/x86: Call exception handlers directly from do_int3/do_debug |
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On Wed, 04 Dec 2013 01:28:56 +0000 Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> To avoid a kernel crash by probing on lockdep code, call > kprobe_int3_handler and kprobe_debug_handler directly > from do_int3 and do_debug. Since there is a locking code > in notify_die, lockdep code can be invoked. And because > the lockdep involves printk() related things, theoretically, > we need to prohibit probing on much more code... > > Anyway, most of the int3 handlers in the kernel are already > called from do_int3 directly, e.g. ftrace_int3_handler, > poke_int3_handler, kgdb_ll_trap. Actually only > kprobe_exceptions_notify is on the notifier_call_chain. > > So I think this is not a crazy thing.
What? Oh, yeah. No, using notifiers in int3 handler is the crazy thing ;-)
Hmm, if there's no users of the int3 notifier, should we just remove it?
-- Steve
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