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From: Rusty Russell <rusty@rustcorp.com.au>
To: Andrey Tsyvarev <tsyvarev@ispras.ru>
Cc: linux-kernel@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH] kernel/module.c: Free lock-classes if parse_args failed
In-Reply-To: <54BE082A.20207@ispras.ru>
References: <1421216708-1975-1-git-send-email-tsyvarev@ispras.ru> <87iog2arfk.fsf@rustcorp.com.au> <54BE082A.20207@ispras.ru>
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Date: Wed, 21 Jan 2015 12:10:53 +1030
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Andrey Tsyvarev <tsyvarev@ispras.ru> writes:
> 20.01.2015 9:37, Rusty Russell пишет:
>> Andrey Tsyvarev <tsyvarev@ispras.ru> writes:
>>> parse_args call module parameters' .set handlers, which may use locks defined in the module.
>>> So, these classes should be freed in case parse_args returns error(e.g. due to incorrect parameter passed).
>> Thanks, this seems right.  Applied.
>>
>> But this makes me ask: where is lockdep_free_key_range() called on the
>> module init code?  It doesn't seem to be at all...
> As I understand, locks are not allowed to be defined in the module init 
> section. So, no needs to call lockdep_free_key_range() for it.
> This has a sense: objects from that section are allowed to be used only 
> by module->init() function. But a single function call doesn't require 
> any synchronization wrt itself.

I don't know that we have any __initdata locks; it would be really
weird.

But change 'static DEFINE_MUTEX(mutex_param);' to 'static __initdata
DEFINE_MUTEX(mutex_param);' to test.

Cheers,
Rusty.