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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Linus Walleij <linus.walleij@linaro.org>, linux-gpio@vger.kernel.org
Subject: Re: [bug report] pinctrl: berlin: Don't leak memory if krealloc() fails
Date: Wed, 12 Oct 2016 14:19:24 +0300	[thread overview]
Message-ID: <20161012111924.GJ5630@mwanda> (raw)
In-Reply-To: <20161012094436.3k7abjx64wlyjnyc@linux-x5ow.site>

On Wed, Oct 12, 2016 at 11:44:36AM +0200, Johannes Thumshirn wrote:
> On Wed, Oct 12, 2016 at 11:45:27AM +0300, Dan Carpenter wrote:
> > On Wed, Oct 12, 2016 at 10:30:02AM +0200, Johannes Thumshirn wrote:
> > > Oh I see. Damn, missed the devm_kzalloc(). But shouldn't we avoid krealloc()
> > > on devm_kzalloc() in general? krealloc() calls kfree() if the reallocation
> > > succeeded and this will break the devres tracking, wouldn't it?
> > 
> > Good point.  I will update my test to check for that.
> 
> Well the initial problem still stands, how do we fix the possible double
> free? I think I could "just" change the devm_kzalloc() to kzalloc() (and
> introduce cleanups) but I'm not sure this is a good solution. The whoule point
> of these devm stuff is to apply a safety net, isn't it?

No.  It's just a convenience because we allocate so much stuff on probe.
A few people use it like that, where they try to manage their own memory
and use devm_ at the same time and it annoys me.

Just use kzalloc().  But make sure there is a free somewhere.

regards,
dan carpenter


  reply	other threads:[~2016-10-12 11:19 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-12  8:14 [bug report] pinctrl: berlin: Don't leak memory if krealloc() fails Dan Carpenter
2016-10-12  8:30 ` Johannes Thumshirn
2016-10-12  8:45   ` Dan Carpenter
2016-10-12  9:44     ` Johannes Thumshirn
2016-10-12 11:19       ` Dan Carpenter [this message]
2016-10-12 12:36         ` Johannes Thumshirn
2016-10-12 17:06           ` Dan Carpenter
2016-10-13 13:09             ` Johannes Thumshirn
2016-10-18 12:34               ` Linus Walleij
2016-10-18 14:12                 ` Johannes Thumshirn

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