LKML Archive on
help / color / mirror / Atom feed
From: Ananth N Mavinakayanahalli <>
To: Abhishek Sagar <>
Cc: LKML <>,, Masami Hiramatsu <>,
	Ingo Molnar <>
Subject: Re: [PATCH 0/3][RFC] x86: Catch stray non-kprobe breakpoints
Date: Tue, 29 Jan 2008 11:32:04 +0530	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

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.


  reply	other threads:[~2008-01-29  6:01 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-27  9:08 Abhishek Sagar
2008-01-29  6:02 ` Ananth N Mavinakayanahalli [this message]
2008-01-29 10:40   ` Abhishek Sagar
2008-01-29 13:18     ` Ananth N Mavinakayanahalli
2008-01-29 17:24       ` Abhishek Sagar
2008-01-29 15:13     ` Masami Hiramatsu
2008-01-29 18:08       ` Abhishek Sagar
2008-01-29 19:29         ` Masami Hiramatsu
2008-01-30  4:07           ` Ananth N Mavinakayanahalli

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \
    --subject='Re: [PATCH 0/3][RFC] x86: Catch stray non-kprobe breakpoints' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).