From: Vasily Kulikov <segoon@openwall.com>
To: musl@lists.openwall.com
Subject: Re: musl as a framework to test applications' compatibility with POSIX (was: NULL)
Date: Mon, 14 Jan 2013 18:30:25 +0400 [thread overview]
Message-ID: <20130114143025.GA12142@cachalot> (raw)
In-Reply-To: <20130114140334.GA29049@brightrain.aerifal.cx>
On Mon, Jan 14, 2013 at 09:03 -0500, Rich Felker wrote:
> On Mon, Jan 14, 2013 at 12:45:27PM +0400, Vasily Kulikov wrote:
> > In musl libc it can be implemented as -DI_WANT_TO_DETECT_GCCISMS.
>
> At the very least, this would have to be a macro in the reserved
> namespace. However, I'm skeptical of using musl as a tool for checking
> this, especially since the check only works on 64-bit systems and does
> not help the compiler produce a warning/error, but only causes random,
> hard-to-diagnose crashes. It looks like cppcheck is adding (or has
> already added?) a test for incorrectly passing NULL to variadic
> functions, which is probably where the check belongs.
My thought related to this specific bug was a bit more complex:
1) on each call of a variadic function save the list of all types
2) on each call to va_arg(ap, T) check whether the current argument was
pushed as T in the saved list
It would catch not only NULL/(void *)NULL, but also int/long or
void*/long bugs.
Now I see that while it is possible to implement (2) in libc redefining
va_XXX() macros, but it looks like (1) has to be implemented in compiler.
So, yeah, it is not a musl issue.
Thanks,
--
Vasily Kulikov
http://www.openwall.com - bringing security into open computing environments
next prev parent reply other threads:[~2013-01-14 14:30 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-09 11:02 NULL John Spencer
2013-01-09 12:18 ` NULL Szabolcs Nagy
2013-01-09 13:36 ` NULL John Spencer
2013-01-12 6:32 ` NULL Rob Landley
2013-01-12 6:46 ` NULL Rich Felker
2013-01-12 7:15 ` NULL Luca Barbato
2013-01-12 13:33 ` NULL Rich Felker
2013-01-12 11:39 ` NULL Jens Staal
2013-01-09 13:09 ` NULL croco
2013-01-09 13:47 ` NULL John Spencer
2013-01-09 14:49 ` NULL croco
2013-01-09 14:42 ` NULL Luca Barbato
2013-01-09 14:47 ` NULL Rich Felker
2013-01-09 15:03 ` NULL Luca Barbato
2013-01-09 15:18 ` NULL John Spencer
2013-01-09 15:36 ` NULL Rich Felker
2013-01-09 21:11 ` NULL Rob
2013-01-09 21:53 ` NULL Szabolcs Nagy
2013-01-09 22:17 ` NULL Rob
2013-01-09 23:42 ` NULL Szabolcs Nagy
2013-01-12 6:56 ` NULL Rob Landley
2013-01-12 7:07 ` NULL Bobby Bingham
2013-01-12 13:31 ` NULL Rich Felker
2013-01-13 14:29 ` NULL Rob Landley
2013-01-13 14:56 ` NULL Luca Barbato
2013-01-13 16:29 ` NULL Rob Landley
2013-01-13 17:14 ` NULL Luca Barbato
2013-01-13 15:23 ` NULL Strake
2013-01-13 17:17 ` NULL Luca Barbato
2013-01-13 17:47 ` NULL Szabolcs Nagy
2013-01-13 19:46 ` NULL Rob Landley
2013-01-14 6:11 ` NULL Rich Felker
2013-01-14 8:45 ` musl as a framework to test applications' compatibility with POSIX (was: NULL) Vasily Kulikov
2013-01-14 14:03 ` Rich Felker
2013-01-14 14:30 ` Vasily Kulikov [this message]
2013-01-14 15:02 ` Szabolcs Nagy
2013-01-14 15:14 ` Rich Felker
2013-01-14 13:19 ` NULL Rob Landley
2013-01-12 5:56 ` NULL Rob Landley
2013-01-12 6:42 ` NULL Rich Felker
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