From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] Fix uninitialized spinlock of printk_ratelimited()
Date: Thu, 20 May 2010 05:44:59 +0900 [thread overview]
Message-ID: <871vd7oc38.fsf@devron.myhome.or.jp> (raw)
In-Reply-To: <20100519132659.b787d17f.akpm@linux-foundation.org> (Andrew Morton's message of "Wed, 19 May 2010 13:26:59 -0700")
Andrew Morton <akpm@linux-foundation.org> writes:
>> #ifdef CONFIG_PRINTK
>> -#define printk_ratelimited(fmt, ...) ({ \
>> - static struct ratelimit_state _rs = { \
>> - .interval = DEFAULT_RATELIMIT_INTERVAL, \
>> - .burst = DEFAULT_RATELIMIT_BURST, \
>> - }; \
>> - \
>> - if (__ratelimit(&_rs)) \
>> - printk(fmt, ##__VA_ARGS__); \
>> +#define printk_ratelimited(fmt, ...) ({ \
>> + static DEFINE_RATELIMIT_STATE(_rs, \
>> + DEFAULT_RATELIMIT_INTERVAL, \
>> + DEFAULT_RATELIMIT_BURST); \
>> + \
>> + if (__ratelimit(&_rs)) \
>> + printk(fmt, ##__VA_ARGS__); \
>> })
>
> hm, yes, that spinlock will get the all-zeroes pattern.
>
> It's been like this since December 2009. I'm a bit surprised that none
> of our spinlock-debugging goodies picked this up. All the
> CONFIG_DEBUG_SPINLOCK spinlock fields end up zeroed out also.
The reason that dynamic analysis didn't pick up is simple - nobody is
using this for now :)
Thanks.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
prev parent reply other threads:[~2010-05-19 20:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-16 23:57 [PATCH] Fix uninitialized spinlock of printk_ratelimited() OGAWA Hirofumi
2010-05-19 20:26 ` Andrew Morton
2010-05-19 20:44 ` OGAWA Hirofumi [this message]
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