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From: Jean Sacren <sakiwit@gmail.com>
To: Linux ACPI <linux-acpi@vger.kernel.org>
Subject: Re: [PATCH 1/1] acpi: Fix warning: 'num_cpus' may be used uninitialized in this function
Date: Sun, 12 Sep 2010 18:39:37 -0600	[thread overview]
Message-ID: <20100913003937.GA1457@mail.gmail.com> (raw)
In-Reply-To: <20100911164037.GB12989@khazad-dum.debian.net>

On Sat, Sep 11, 2010 at 01:40:37PM -0300, Henrique de Moraes Holschuh wrote:
> On Sat, 11 Sep 2010, Jean Sacren wrote:
> > warning: 'num_cpus' may be used uninitialized in this function
> > 
> > Initialize 'num_cpus' variable to zero so that gcc doesn't complain.
> 
> acpi_pad_pur() is referenced only once, so it should end up inlined, at
> which point gcc really has no excuse to not determine with perfect
> confidence whether num_cpus is being used unitialized or not.
>
If acpi_pad_pur() is called and returns with non-zero value,
acpi_pad_handle_notify() happily returns, but num_cpus is referenced by
address without being initialized, so gcc gives the warning.
> 
> Looking at the code, it realy does look like a false positive.
>
Unfortunately it is _not_ a false positive. Here gcc does what it's
supposed to do. Therefore, the patch is correct.

-- 
Jean Sacren
Bring LAMP To People

  reply	other threads:[~2010-09-13  0:39 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-11  6:22 [PATCH 0/1] acpi: Fix warning: 'num_cpus' may be used uninitialized in this function Jean Sacren
2010-09-11  6:24 ` [PATCH 1/1] " Jean Sacren
2010-09-11 16:40   ` Henrique de Moraes Holschuh
2010-09-13  0:39     ` Jean Sacren [this message]
2010-09-13 21:01       ` Henrique de Moraes Holschuh

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