From: Paul Mackerras <paulus@samba.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Li Zefan <lizf@cn.fujitsu.com>
Subject: Re: [PATCH 1/2] tracing: Check total refcount before releasing bufs in profile_enable failure
Date: Wed, 7 Oct 2009 14:08:27 +1100 [thread overview]
Message-ID: <19148.1579.573095.98045@cargo.ozlabs.ibm.com> (raw)
In-Reply-To: <1254577650-5623-2-git-send-email-fweisbec@gmail.com>
Frederic Weisbecker writes:
> When we call the profile_enable() callback of an event, we release the
> shared perf event tracing buffers unconditionnaly in the failure path.
> This is wrong because there may be other users of these. Then check the
> total refcount before doing this.
[snip]
> - kfree(trace_profile_buf_nmi);
> fail_buf_nmi:
> - kfree(trace_profile_buf);
> + if (!total_profile_count) {
A small problem here: total_profile_count will be 1, not 0, in the
case where we need to free...
> + kfree(trace_profile_buf_nmi);
> + kfree(trace_profile_buf);
> + trace_profile_buf_nmi = NULL;
> + trace_profile_buf = NULL;
> + }
> fail_buf:
> - total_profile_count--;
since we don't decrement total_profile_count until here.
Paul.
next prev parent reply other threads:[~2009-10-07 3:09 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-01 4:50 Possible bug in ftrace_profile_enable_event Paul Mackerras
2009-10-01 6:20 ` Steven Rostedt
2009-10-02 12:13 ` Frédéric Weisbecker
2009-10-03 13:47 ` [GIT PULL] tracing: Perf tracing fixes Frederic Weisbecker
2009-10-03 13:57 ` Frederic Weisbecker
2009-10-05 17:54 ` Frederic Weisbecker
2009-10-06 12:30 ` Ingo Molnar
2009-10-03 13:47 ` [PATCH 1/2] tracing: Check total refcount before releasing bufs in profile_enable failure Frederic Weisbecker
2009-10-07 3:08 ` Paul Mackerras [this message]
2009-10-08 21:43 ` Frederic Weisbecker
2009-10-08 21:53 ` Paul Mackerras
2009-10-03 13:47 ` [PATCH 2/2] tracing: Use free_percpu instead of kfree Frederic Weisbecker
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=19148.1579.573095.98045@cargo.ozlabs.ibm.com \
--to=paulus@samba.org \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lizf@cn.fujitsu.com \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
/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®