linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Joe Perches <joe@perches.com>
To: David Rientjes <rientjes@google.com>, Andy Whitcroft <apw@canonical.com>
Cc: John Stultz <john.stultz@linaro.org>,
	LKML <linux-kernel@vger.kernel.org>, Ted Ts'o <tytso@mit.edu>,
	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 2/3] printk: Add %ptc to safely print a task's comm
Date: Thu, 12 May 2011 15:29:02 -0700	[thread overview]
Message-ID: <1305239342.6124.77.camel@Joe-Laptop> (raw)
In-Reply-To: <alpine.DEB.2.00.1105121510330.9130@chino.kir.corp.google.com>

On Thu, 2011-05-12 at 15:12 -0700, David Rientjes wrote:
> On Tue, 10 May 2011, Joe Perches wrote:
> > > Although I'm not sure if there's precedent for a %p value that didn't
> > > take a argument. Thoughts on that? Anyone else have an opinion here?
> > The uses of %ptc must add an argument or else gcc will complain.
> > I suggest you just ignore the argument value and use current.
> That doesn't make any sense, why would you needlessly restrict this to 
> current when accesses to other threads' ->comm needs to be protected in 
> the same way?  I'd like to use this in the oom killer and try to get rid 
> of taking task_lock() for every thread group leader in the tasklist dump.

I suppose another view is coder stuffed up, let them suffer...

At some point, gcc may let us extend printf argument type
verification so it may not be a continuing problem.

Adding a checkpatch rule for this is non-trivial as it can
be written as:

	printk("%ptc\n",
	       current);

and checkpatch is mostly line oriented.

Andy, do you have a suggestion on how to verify
vsprintf argument types for checkpatch?

--
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>

  reply	other threads:[~2011-05-12 22:29 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-11  0:23 [RFC][PATCH 0/3] v2 Improve task->comm locking situation John Stultz
2011-05-11  0:23 ` [PATCH 1/3] comm: Introduce comm_lock seqlock to protect task->comm access John Stultz
2011-05-11 17:39   ` Andi Kleen
2011-05-12 22:00   ` David Rientjes
2011-05-11  0:23 ` [PATCH 2/3] printk: Add %ptc to safely print a task's comm John Stultz
2011-05-11  0:51   ` Joe Perches
2011-05-11  1:10     ` John Stultz
2011-05-11  1:16       ` john stultz
2011-05-11  1:20       ` Joe Perches
2011-05-12 22:12         ` David Rientjes
2011-05-12 22:29           ` Joe Perches [this message]
2011-05-13 21:56             ` David Rientjes
2011-05-12 22:10       ` David Rientjes
2011-05-11  9:33   ` Américo Wang
2011-05-11 21:02     ` John Stultz
2011-05-12 10:43       ` Américo Wang
2011-05-12 10:45         ` Américo Wang
2011-05-12 18:01         ` John Stultz
2011-05-11 17:36   ` Andi Kleen
2011-05-11 21:04     ` John Stultz
2011-05-11  0:23 ` [PATCH 3/3] comm: ext4: Protect task->comm access by using %ptc John Stultz
2011-05-12 22:14   ` David Rientjes
2011-05-12 22:29     ` John Stultz
2011-05-12 22:34       ` Andrew Morton
  -- strict thread matches above, loose matches on Subject: below --
2011-05-12 23:02 [PATCH 0/3] v3 Improve task->comm locking situation John Stultz
2011-05-12 23:02 ` [PATCH 2/3] printk: Add %ptc to safely print a task's comm John Stultz
2011-05-16 21:19 [PATCH 0/3] v4 Improve task->comm locking situation John Stultz
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
2011-05-17 20:47 [PATCH 0/3] v5 Improve task->comm locking situation John Stultz
2011-05-17 20:47 ` [PATCH 2/3] printk: Add %ptc to safely print a task's comm John Stultz
2011-05-17 21:42   ` Jiri Slaby
2011-05-17 21:52     ` Joe Perches
2011-05-17 22:04       ` Jiri Slaby
2011-05-17 22:17         ` Joe Perches
2011-05-17 22:17     ` John Stultz

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=1305239342.6124.77.camel@Joe-Laptop \
    --to=joe@perches.com \
    --cc=akpm@linux-foundation.org \
    --cc=apw@canonical.com \
    --cc=dave@linux.vnet.ibm.com \
    --cc=john.stultz@linaro.org \
    --cc=kosaki.motohiro@jp.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=rientjes@google.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;
as well as URLs for NNTP newsgroup(s).