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From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH RESEND] Fix misuse of calloc() in linux/compat.h header
Date: Sat, 9 Jun 2012 01:48:40 +0200	[thread overview]
Message-ID: <201206090148.40933.marex@denx.de> (raw)
In-Reply-To: <20120608234343.3874A2000F5@gemini.denx.de>

Dear Wolfgang Denk,

> Dear Marek Vasut,
> 
> In message <1339176514-13137-1-git-send-email-marex@denx.de> you wrote:
> > -#define kzalloc(size, flags)	calloc(size, 1)
> > +#define kzalloc(size, flags)	calloc(1, size)
> 
> Does this make any practical difference?
> 
> I mean, are you aware of any problem that gets fixed by this patch, or
> even any kind of performance degradation?

No, I just blindly found it out when I was enraged and was hacking on filesystem 
code.

> "common/dlmalloc.src" says:
> 
> 	calloc(size_t unit, size_t quantity);
> 	   Returns a pointer to quantity * unit bytes, with all locations
> 	   set to zero.
> 
> Multiplication being commutative, I see zero effect in this patch?

Weeeeell, not in every algebraic system. It has zero effect, it's only about 
correctness [1]. Will applying this break anything?

[1] http://pubs.opengroup.org/onlinepubs/009695399/functions/calloc.html
> Best regards,
> 
> Wolfgang Denk

Best regards,
Marek Vasut

  reply	other threads:[~2012-06-08 23:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-08 17:28 [U-Boot] [PATCH RESEND] Fix misuse of calloc() in linux/compat.h header Marek Vasut
2012-06-08 23:43 ` Wolfgang Denk
2012-06-08 23:48   ` Marek Vasut [this message]
2012-06-08 23:58     ` Wolfgang Denk
2012-06-09  0:04       ` Marek Vasut

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