Date: Tue, 20 Sep 2005 13:07:39 +0300 (EEST)
From: Pekka J Enberg <penberg@cs.Helsinki.FI>
To: Al Viro <viro@ftp.linux.org.uk>
cc: Robert Love <rml@novell.com>, Russell King <rmk+lkml@arm.linux.org.uk>,
       Linux Kernel List <linux-kernel@vger.kernel.org>,
       Linus Torvalds <torvalds@osdl.org>
Subject: Re: p = kmalloc(sizeof(*p), )
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On Tue, Sep 20, 2005 at 12:47:32PM +0300, Pekka J Enberg wrote:
> > To find candidates, something like:
> > 
> > grep "kmalloc(sizeof([^*]" -r drivers/ | grep -v "sizeof(struct"
> > 
> > And then use my eyes to find real bugs.

On Tue, 20 Sep 2005, Al Viro wrote:
> "grep for kmallocs that do not have _either_ form and look for bugs among
> them" is hardly usable as an argument in favour of one of them...

I would disagree with that. The _common case_ for allocation is:

	p = kmalloc(sizeof(*p), ...);

For which you know that you are allocating enough memory for the struct. 
Now the only way to screw it up is to write:

	p = kmalloc(sizeof(p), ...);

That is trivial to grep for.

Yes, currently, typedefs and open-coded kcalloc's give false positives but
that's what kernel janitors are for...

			Pekka
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