From: David Rientjes <rientjes@google.com>
To: Michal Nazarewicz <mina86@mina86.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
John Stultz <john.stultz@linaro.org>, Ted Ts'o <tytso@mit.edu>,
Jiri Slaby <jirislaby@gmail.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org
Subject: Re: [PATCH 3/3] checkpatch.pl: Add check for task comm references
Date: Mon, 16 May 2011 14:34:14 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.00.1105161431550.4353@chino.kir.corp.google.com> (raw)
In-Reply-To: <op.vvlfaobx3l0zgt@mnazarewicz-glaptop>
On Mon, 16 May 2011, Michal Nazarewicz wrote:
> > Now that accessing current->comm needs to be protected,
> > @@ -2868,6 +2868,10 @@ sub process {
> > WARN("usage of NR_CPUS is often wrong - consider using
> > cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc\n" .
> > $herecurr);
> > }
> > +# check for current->comm usage
> > + if ($line =~ /\b(?:current|task|tsk|t)\s*->\s*comm\b/) {
>
> Not a checkpatch.pl expert but as far as I'm concerned, that looks reasonable.
>
> I was sort of worried that t->comm could produce quite a few false positives
> but all its appearances in the kernel (seem to) refer to task.
>
It's guaranteed to generate false positives since perf events uses a field
of the same name to store a thread's comm, so I think the most important
thing is for the checkpatch output to specify that this _may_ be a
dereference of a thread's comm that needs get_task_comm() or %ptc.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-05-16 21:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-16 21:19 [PATCH 0/3] v4 Improve task->comm locking situation John Stultz
2011-05-16 21:19 ` [PATCH 1/3] comm: Introduce comm_lock seqlock to protect task->comm access John Stultz
2011-05-16 22:01 ` Jiri Slaby
2011-05-17 1:47 ` John Stultz
2011-05-18 0:28 ` KOSAKI Motohiro
2011-05-16 21:19 ` [PATCH 2/3] printk: Add %ptc to safely print a task's comm John Stultz
2011-05-16 21:54 ` Jiri Slaby
2011-05-16 23:10 ` John Stultz
2011-05-16 23:56 ` Joe Perches
2011-05-17 0:11 ` John Stultz
2011-05-17 7:21 ` Jiri Slaby
2011-05-18 0:32 ` KOSAKI Motohiro
2011-05-16 21:19 ` [PATCH 3/3] checkpatch.pl: Add check for task comm references John Stultz
2011-05-16 21:29 ` Michal Nazarewicz
2011-05-16 21:34 ` David Rientjes [this message]
2011-05-16 23:04 ` Joe Perches
2011-05-16 23:11 ` Michal Nazarewicz
2011-05-16 23:22 ` Joe Perches
2011-05-17 20:47 [PATCH 0/3] v5 Improve task->comm locking situation John Stultz
2011-05-17 20:47 ` [PATCH 3/3] checkpatch.pl: Add check for task comm references John Stultz
2011-05-17 20:58 ` Jiri Slaby
2011-05-17 21:04 ` Michal Nazarewicz
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=alpine.DEB.2.00.1105161431550.4353@chino.kir.corp.google.com \
--to=rientjes@google.com \
--cc=akpm@linux-foundation.org \
--cc=dave@linux.vnet.ibm.com \
--cc=jirislaby@gmail.com \
--cc=john.stultz@linaro.org \
--cc=kosaki.motohiro@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mina86@mina86.com \
--cc=tytso@mit.edu \
/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