From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: linas@austin.ibm.com
Cc: linas@linas.org, ppc@suse.de,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: ptrace patch fails stress testing
Date: 02 Apr 2003 12:49:48 +0100 [thread overview]
Message-ID: <1049284187.16276.32.camel@dhcp22.swansea.linux.org.uk> (raw)
In-Reply-To: <20030401122256.A34952@forte.austin.ibm.com>
On Tue, 2003-04-01 at 19:22, linas@austin.ibm.com wrote:
> The problem appears to be that task->mm is dereferenced without
> looking to see if mm is NULL. e.g. in the sched.h in the
> is_dumpable() macro, we have task->mm->dumpable . I'm sitting
> in front of a KDB session and I'm clearly looking at task->mm
> which is NULL.
> Why, how and under what conditions this race condition occurs,
> I don't know. What the best fix is, I don't know.
Zombie process. The patch checks ->mm but must also check ->mm != NULL
first.
> I can try to just add a check for NULL, but I'd like someone
> to tell me that 'yes this is the right way to fix this.'
It is I think.
Alan
next prev parent reply other threads:[~2003-04-02 12:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-01 18:22 linas
2003-04-01 21:25 ` John M Flinchbaugh
2003-04-02 11:49 ` Alan Cox [this message]
2003-04-02 14:45 ` Keith Owens
2003-04-03 15:22 James Cownie
2003-04-03 19:53 ` Chris Wright
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=1049284187.16276.32.camel@dhcp22.swansea.linux.org.uk \
--to=alan@lxorguk.ukuu.org.uk \
--cc=linas@austin.ibm.com \
--cc=linas@linas.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ppc@suse.de \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®