Messages in this thread | | | Date | Tue, 29 Jan 2008 11:32:04 +0530 | From | Ananth N Mavinakayanahalli <> | Subject | Re: [PATCH 0/3][RFC] x86: Catch stray non-kprobe breakpoints |
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On Sun, Jan 27, 2008 at 02:38:56PM +0530, Abhishek Sagar wrote: > Greetings, > > Non kprobe breakpoints in the kernel might lie inside the .kprobes.text section. Such breakpoints can easily be identified by in_kprobes_functions and can be caught early. These are problematic and a warning should be emitted to discourage them (in any rare case, if they actually occur).
Why? As Masami indicated in an earlier reply, the annotation is to prevent *only* kprobes.
> For this, a check can route the trap handling of such breakpoints away from kprobe_handler (which ends up calling even more functions marked as __kprobes) from inside kprobe_exceptions_notify.
Well.. we pass on control of a !kprobe breakpoint to the kernel. This is exactly what permits debuggers like xmon to work fine now. I don't see any harm in such breakpoints being handled autonomously without any sort of kprobe influence.
Ananth
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