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Date: Mon, 9 Feb 2009 11:16:42 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org,
       Ralf Baechle <ralf@linux-mips.org>,
       "David S. Miller" <davem@davemloft.net>,
       Al Viro <viro@zeniv.linux.org.uk>, Mike Travis <travis@sgi.com>
Subject: Re: [PATCH 1/3] cpumask: remove dangerous CPU_MASK_ALL_PTR,
	&CPU_MASK_ALL.
Message-ID: <20090209101642.GG20467@elte.hu>
References: <200902071809.17953.rusty@rustcorp.com.au>
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* Rusty Russell <rusty@rustcorp.com.au> wrote:

> (Thanks to Al Viro for reminding me of this, via Ingo)
> 
> CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:
> 
> 	#define CPU_MASK_ALL (cpumask_t) { { ... } }
> 
> Taking the address of such a temporary is questionable at best,
> unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
> CPU_MASK_ALL_PTR:
> 
> 	#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)
> 
> Which formalizes this practice.  One day gcc could bite us over this
> usage (though we seem to have gotten away with it so far).
> 
> So replace everywhere which used &CPU_MASK_ALL or CPU_MASK_ALL_PTR
> with the modern "cpu_all_mask" (a real struct cpumask *), and remove
> CPU_MASK_ALL_PTR altogether.
> 
> Also remove the confusing and deprecated large-NR_CPUS-only
> "cpu_mask_all".
> 
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Al Viro <viro@zeniv.linux.org.uk>

In general this should be expressed via this tag:

	Reported-by: Al Viro <viro@zeniv.linux.org.uk>

Thanks,

	Ingo