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From: Jiri Slaby <jirislaby@gmail.com>
To: John Stultz <john.stultz@linaro.org>
Cc: LKML <linux-kernel@vger.kernel.org>, "Ted Ts'o" <tytso@mit.edu>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	David Rientjes <rientjes@google.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 current->comm references
Date: Fri, 13 May 2011 08:33:39 +0200	[thread overview]
Message-ID: <4DCCD0C3.9090908@gmail.com> (raw)
In-Reply-To: <1305241371-25276-4-git-send-email-john.stultz@linaro.org>

On 05/13/2011 01:02 AM, John Stultz wrote:
> Now that accessing current->comm needs to be protected,
> avoid new current->comm usage by adding a warning to
> checkpatch.pl.
> 
> Fair warning: I know zero perl, so this was written in the
> style of "monkey see, monkey do". It does appear to work
> in my testing though.
> 
> Close review and feedback would be appreciated.
> 
> CC: Ted Ts'o <tytso@mit.edu>
> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> CC: David Rientjes <rientjes@google.com>
> CC: Dave Hansen <dave@linux.vnet.ibm.com>
> CC: Andrew Morton <akpm@linux-foundation.org>
> CC: linux-mm@kvack.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
>  scripts/checkpatch.pl |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index d867081..9d2eab5 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -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 =~ /current->comm/) {

This should be something like \b(current|task|tsk|t)->comm\b to catch
also non-current comm accesses...

> +			WARN("comm access needs to be protected. Use get_task_comm, or printk's \%ptc formatting.\n" . $herecurr);
> +		}
>  # check for %L{u,d,i} in strings
>  		my $string;
>  		while ($line =~ /(?:^|")([X\t]*)(?:"|$)/g) {


-- 
js

WARNING: multiple messages have this Message-ID (diff)
From: Jiri Slaby <jirislaby@gmail.com>
To: John Stultz <john.stultz@linaro.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Ted Ts'o <tytso@mit.edu>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	David Rientjes <rientjes@google.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 current->comm references
Date: Fri, 13 May 2011 08:33:39 +0200	[thread overview]
Message-ID: <4DCCD0C3.9090908@gmail.com> (raw)
In-Reply-To: <1305241371-25276-4-git-send-email-john.stultz@linaro.org>

On 05/13/2011 01:02 AM, John Stultz wrote:
> Now that accessing current->comm needs to be protected,
> avoid new current->comm usage by adding a warning to
> checkpatch.pl.
> 
> Fair warning: I know zero perl, so this was written in the
> style of "monkey see, monkey do". It does appear to work
> in my testing though.
> 
> Close review and feedback would be appreciated.
> 
> CC: Ted Ts'o <tytso@mit.edu>
> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> CC: David Rientjes <rientjes@google.com>
> CC: Dave Hansen <dave@linux.vnet.ibm.com>
> CC: Andrew Morton <akpm@linux-foundation.org>
> CC: linux-mm@kvack.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
>  scripts/checkpatch.pl |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index d867081..9d2eab5 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -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 =~ /current->comm/) {

This should be something like \b(current|task|tsk|t)->comm\b to catch
also non-current comm accesses...

> +			WARN("comm access needs to be protected. Use get_task_comm, or printk's \%ptc formatting.\n" . $herecurr);
> +		}
>  # check for %L{u,d,i} in strings
>  		my $string;
>  		while ($line =~ /(?:^|")([X\t]*)(?:"|$)/g) {


-- 
js

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  reply	other threads:[~2011-05-13  6:33 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-12 23:02 [PATCH 0/3] v3 Improve task->comm locking situation John Stultz
2011-05-12 23:02 ` John Stultz
2011-05-12 23:02 ` [PATCH 1/3] comm: Introduce comm_lock seqlock to protect task->comm access John Stultz
2011-05-12 23:02   ` John Stultz
2011-05-13 11:13   ` KOSAKI Motohiro
2011-05-13 11:13     ` KOSAKI Motohiro
2011-05-13 18:27     ` John Stultz
2011-05-13 18:27       ` John Stultz
2011-05-14 11:12       ` KOSAKI Motohiro
2011-05-14 11:12         ` KOSAKI Motohiro
2011-05-16 20:34         ` John Stultz
2011-05-16 20:34           ` John Stultz
2011-05-12 23:02 ` [PATCH 2/3] printk: Add %ptc to safely print a task's comm John Stultz
2011-05-12 23:02   ` John Stultz
2011-05-12 23:02 ` [PATCH 3/3] checkpatch.pl: Add check for current->comm references John Stultz
2011-05-12 23:02   ` John Stultz
2011-05-13  6:33   ` Jiri Slaby [this message]
2011-05-13  6:33     ` Jiri Slaby
2011-05-13 11:02     ` Michal Nazarewicz
2011-05-13 11:02       ` Michal Nazarewicz
2011-05-16 21:23       ` David Rientjes
2011-05-16 21:23         ` David Rientjes
2011-05-13 11:13   ` KOSAKI Motohiro
2011-05-13 11:13     ` KOSAKI Motohiro
2011-05-13 18:28     ` John Stultz
2011-05-13 18:28       ` John Stultz

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