From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from scc-mailout-kit-02.scc.kit.edu (scc-mailout-kit-02.scc.kit.edu [129.13.231.82]);
	by fantadrom.bsd.lv (OpenSMTPD) with ESMTP id a958d78d;
	for <tech@mdocml.bsd.lv>;
	Fri, 20 Mar 2015 10:45:18 -0500 (EST)
Received: from asta-nat.asta.uni-karlsruhe.de ([172.22.63.82] helo=hekate.usta.de)
	by scc-mailout-kit-02.scc.kit.edu with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256)
	(envelope-from <schwarze@usta.de>)
	id 1YYz6q-0003Wj-2P; Fri, 20 Mar 2015 16:45:17 +0100
Received: from donnerwolke.usta.de ([172.24.96.3])
	by hekate.usta.de with esmtp (Exim 4.77)
	(envelope-from <schwarze@usta.de>)
	id 1YYz6p-00078E-Tc; Fri, 20 Mar 2015 16:45:15 +0100
Received: from athene.usta.de ([172.24.96.10])
	by donnerwolke.usta.de with esmtp (Exim 4.80)
	(envelope-from <schwarze@usta.de>)
	id 1YYz6p-0003sC-Oi; Fri, 20 Mar 2015 16:45:15 +0100
Received: from localhost (1031@localhost [local]);
	by localhost (OpenSMTPD) with ESMTPA id 3eaa8ff7;
	Fri, 20 Mar 2015 16:45:15 +0100 (CET)
Date: Fri, 20 Mar 2015 16:45:15 +0100
From: Ingo Schwarze <schwarze@usta.de>
To: Christian Neukirchen <chneukirchen@gmail.com>
Cc: tech@mdocml.bsd.lv
Subject: Re: compat_vasprintf.c: use va_copy
Message-ID: <20150320154515.GC27243@athene.usta.de>
References: <87vbhv7n26.fsf@gmail.com>
X-Mailinglist: mdocml-tech
Reply-To: tech@mdocml.bsd.lv
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87vbhv7n26.fsf@gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)

Hi Christian,

Christian Neukirchen wrote on Fri, Mar 20, 2015 at 03:36:49PM +0100:

> When building CVS HEAD on Linux x86_64/glibc, the vasprintf check
> fails when -D_GNU_SOURCE is not passed, and mdocml falls back to
> compat_vasprintf.c.  This version of vasprintf.c segfaults on glibc,
> because the same va_list is used twice.  Probably affects other
> architectures too.
> 
> The solution is to use va_copy to get a second va_list.

I have put this in, it can hardly do harm.

Besides, i have added _GNU_SOURCE to test-vasprintf.c, you are
right that it was missing, see the patch below.  Note that the
other files using vasprintf() don't need it because config.h
already defines it.

Thanks,
  Ingo


> --- compat_vasprintf.c
> +++ compat_vasprintf.c
> @@ -38,9 +38,13 @@ vasprintf(char **ret, const char *format, va_list ap)
>  {
>  	char	 buf[2];
>  	int	 sz;
> +	va_list	 ap2;
>  
> -	if ((sz = vsnprintf(buf, sizeof(buf), format, ap)) != -1 &&
> -	    (*ret = malloc(sz + 1)) != NULL) {
> +	va_copy(ap2, ap);
> +	sz = vsnprintf(buf, sizeof(buf), format, ap2);
> +	va_end(ap2);
> +
> +	if (sz != -1 && (*ret = malloc(sz + 1)) != NULL) {
>  		if (vsnprintf(*ret, sz + 1, format, ap) == sz)
>  			return(sz);
>  		free(*ret);


Log Message:
-----------
vasprintf(3) needs _GNU_SOURCE on Linux;
pointed out by Christian Neukirchen <chneukirchen at gmail dot com>.

Modified Files:
--------------
    mdocml:
        test-vasprintf.c

Revision Data
-------------
Index: test-vasprintf.c
===================================================================
RCS file: /home/cvs/mdocml/mdocml/test-vasprintf.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -Ltest-vasprintf.c -Ltest-vasprintf.c -u -p -r1.1 -r1.2
--- test-vasprintf.c
+++ test-vasprintf.c
@@ -15,6 +15,10 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#if defined(__linux__) || defined(__MINT__)
+#define _GNU_SOURCE /* vasprintf() */
+#endif
+
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
--
 To unsubscribe send an email to tech+unsubscribe@mdocml.bsd.lv