LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: fche@redhat.com (Frank Ch. Eigler)
To: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Richard J Moore <richardj_moore@uk.ibm.com>,
	Andrew Morton <akpm@osdl.org>,
	Greg Kroah-Hartman <gregkh@suse.de>,
	linux-kernel@vger.kernel.org,
	"Martin J. Bligh" <mbligh@mbligh.org>,
	Christoph Hellwig <hch@infradead.org>,
	Douglas Niehaus <niehaus@eecs.ku.edu>,
	Ingo Molnar <mingo@redhat.com>,
	ltt-dev@shafik.org, systemtap@sources.redhat.com,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 0/4 update] Linux Kernel Markers - i386 : pIII erratum 49 : XMC
Date: 16 Jan 2007 13:35:21 -0500	[thread overview]
Message-ID: <y0mzm8izuom.fsf@ton.toronto.redhat.com> (raw)
In-Reply-To: <20070116174158.GA16084@Krystal>

Mathieu Desnoyers <compudj@krystal.dyndns.org> writes:

> [...]
> It would be nice to push the study of the kprobes debug trap handler so it can
> become possible to use it to put breakpoints in trap handlers. For now, kprobes
> refuses to insert breakpoints in __kprobes marked functions. However, as we
> instrument specific spots of the functions (not necessarily the function entry),
> it is sometimes correct to use kprobes on a marker within the function even if 
> it is not correct to use it in the prologue. [...]

It may help to note that the issue with __kprobes attributes is
separate from putting probes in the prologue vs. elsewhere.  The
__kprobes functions are so marked because they can cause infinite
regress if probed.  Examples are fault handlers that would service
vmalloc-related faults, and some other functions unavoidably callable
from early probe handling context.  Over time, the list has shrunk.

Indeed, __kprobes marking is a conservative measure, in that there may
be spots in such functions that are immune from recursion hazards.
But so far, we haven't encountered enough examples of this to warrant
refining this blacklist somehow.

- FChE

  reply	other threads:[~2007-01-16 18:46 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-20 23:52 [PATCH 0/4] Linux Kernel Markers Mathieu Desnoyers
2006-12-20 23:57 ` [PATCH 1/4] Linux Kernel Markers : Architecture agnostic code Mathieu Desnoyers
2006-12-20 23:59 ` [PATCH 2/4] Linux Kernel Markers : kconfig menus Mathieu Desnoyers
2006-12-21  0:00 ` [PATCH 3/4] Linux Kernel Markers : i386 optimisation Mathieu Desnoyers
2006-12-21  0:01 ` [PATCH 4/4] Linux Kernel Markers : powerpc optimisation Mathieu Desnoyers
2007-01-13  1:33 ` [PATCH 0/4] Linux Kernel Markers Richard J Moore
2007-01-13  5:45   ` Mathieu Desnoyers
2007-01-16 17:41     ` [PATCH 0/4 update] Linux Kernel Markers - i386 : pIII erratum 49 : XMC Mathieu Desnoyers
2007-01-16 18:35       ` Frank Ch. Eigler [this message]
2007-01-16 21:27       ` [PATCH 0/4 update] kprobes and traps Mathieu Desnoyers
2007-01-17 12:25         ` S. P. Prasanna
2007-01-16 17:56   ` [PATCH 1/2] lockdep missing barrier() Mathieu Desnoyers
2007-01-24  4:26     ` Andrew Morton
2007-01-24 16:51       ` Mathieu Desnoyers
2007-01-24 17:24         ` [PATCH] order of lockdep off/on in vprintk() should be changed Mathieu Desnoyers
2007-01-24 17:55           ` [PATCH] minimize lockdep_on/off side-effect Mathieu Desnoyers
2007-01-16 17:56   ` [PATCH 2/2] lockdep reentrancy Mathieu Desnoyers
2007-01-24  4:29     ` Andrew Morton
2007-01-24 16:55       ` Mathieu Desnoyers

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=y0mzm8izuom.fsf@ton.toronto.redhat.com \
    --to=fche@redhat.com \
    --cc=akpm@osdl.org \
    --cc=compudj@krystal.dyndns.org \
    --cc=gregkh@suse.de \
    --cc=hch@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ltt-dev@shafik.org \
    --cc=mbligh@mbligh.org \
    --cc=mingo@redhat.com \
    --cc=niehaus@eecs.ku.edu \
    --cc=richardj_moore@uk.ibm.com \
    --cc=systemtap@sources.redhat.com \
    --cc=tglx@linutronix.de \
    --subject='Re: [PATCH 0/4 update] Linux Kernel Markers - i386 : pIII erratum 49 : XMC' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* 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).