Re: [PATCH -tip tracing/kprobes 1/6] kprobes/x86: Call BUG() whenreentering probe into KPROBES_HIT_SS

From: Ananth N Mavinakayanahalli
Date: Fri Aug 28 2009 - 00:39:00 EST


On Thu, Aug 27, 2009 at 01:22:58PM -0400, Masami Hiramatsu wrote:
> Call BUG() when a probe have been hit on the way of kprobe processing path,
> because that kind of probes are currently unrecoverable (recovering it will
> cause an infinit loop and stack overflow).
>
> The original code seems to assume that it will be caused by an int3 which
> another subsystem inserted on out-of-line singlestep buffer if the hitting
> probe is same as current probe. However, in that case, int3-hitting-address
> is on the out-of-line buffer and should be different from first (current)
> int3 address.
> Thus, I decided to remove the code.
>
> I also removes arch_disarm_kprobe() because it will involve other stuffs
> in text_poke().
>
> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>

Acked-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
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