mailing list of musl libc
 help / color / mirror / code / Atom feed
From: Rich Felker <dalias@aerifal.cx>
To: musl@lists.openwall.com
Subject: Re: Weekly reports: A
Date: Fri, 27 May 2011 22:02:38 -0400	[thread overview]
Message-ID: <20110528020238.GZ277@brightrain.aerifal.cx> (raw)
In-Reply-To: <4DE043DA.1020104@gmail.com>

On Sat, May 28, 2011 at 02:37:46AM +0200, Luka Marčetić wrote:
> On 05/24/2011 03:13 AM, Rich Felker wrote:
> >>>  For "low and high byte content", I suggest that you include ability to
> >>>  test all byte values (for non-wide chars).  glibc and many other libc's
> >>>  include implementations of string functions that use adds/bitmasks;
> >>>  these might contain bugs that only show up with specific byte values in
> >>>  specific character positions when the libc is built for specific CPUs.
> >I agree. I don't believe any such issues affect the current C
> >implementations in musl, but it would be nice to have the tests in
> >place in case anyone wants to add arch-specific asm versions.
> 
> Hey guys.
> I would just like to point out that the above, combined with the
> "all alignments" requirement from the wiki means I'm essentially
> brute-forcing string.h functions. While I generally dislike the
> idea, it's a.. thorough approach.. I guess. As a slight remedy I'll

The whole point is to brute force all combinations of input that are
expected to make a difference to what paths the code might take.

> "brute force" with smaller buffers, and only do basic tests with
> huge ones. I hope that won't miss the point then. Will report how

Indeed of course you can't brute force all possible sequences of bytes
up to several GB. :-) I'll leave coming up with a reasonable
evalulation of what's needed and what's not as part of your task.

Rich


      reply	other threads:[~2011-05-28  2:02 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-23 17:42 Luka Marčetić
2011-05-24  1:00 ` Solar Designer
2011-05-24  1:13   ` Rich Felker
2011-05-28  0:37     ` Luka Marčetić
2011-05-28  2:02       ` Rich Felker [this message]

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=20110528020238.GZ277@brightrain.aerifal.cx \
    --to=dalias@aerifal.cx \
    --cc=musl@lists.openwall.com \
    /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.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/musl/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).