All of lore.kernel.org
 help / color / mirror / Atom feed
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=201206090148.40933.marex@denx.de \
    --to=marex@denx.de \
    --cc=u-boot@lists.denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.