[PATCH] qemu/block-vvfat.c: fix warnings with _FORTIFY_SOURCE

[PATCH] qemu/block-vvfat.c: fix warnings with _FORTIFY_SOURCE

[Olaf Hering]

In function 'snprintf',
    inlined from 'init_directories' at block-vvfat.c:868:10,
    inlined from 'vvfat_open' at block-vvfat.c:1065:24:
/usr/include/bits/stdio2.h:65:3: warning: call to __builtin___snprintf_chk will always overflow destination buffer

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Olaf Hering <olaf@aepfle.de>

---
 ioemu-remote/block-vvfat.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- xen-unstable.hg-4.1.22285.orig/ioemu-remote/block-vvfat.c
+++ xen-unstable.hg-4.1.22285/ioemu-remote/block-vvfat.c
@@ -865,7 +865,8 @@ static int init_directories(BDRVVVFATSta
     {
 	direntry_t* entry=array_get_next(&(s->directory));
 	entry->attributes=0x28; /* archive | volume label */
-	snprintf((char*)entry->name,11,"QEMU VVFAT");
+	memcpy(entry->name,"QEMU VVF",8);
+	memcpy(entry->extension,"AT",3);
     }
 
     /* Now build FAT, and write back information into directory */

Re: [PATCH] qemu/block-vvfat.c: fix warnings with _FORTIFY_SOURCE

[Ian Jackson]

Olaf Hering writes ("[Xen-devel] [PATCH] qemu/block-vvfat.c: fix warnings with _FORTIFY_SOURCE"):
> In function 'snprintf',
>     inlined from 'init_directories' at block-vvfat.c:868:10,
>     inlined from 'vvfat_open' at block-vvfat.c:1065:24:
> /usr/include/bits/stdio2.h:65:3: warning: call to __builtin___snprintf_chk will always overflow destination buffer

Thanks, I have applied both of these patches to qemu-xen-unstable.

However: have you checked whether these problems exist in qemu
upstream ?  With Anthony's work on upstreaming Xen support in qemu
coming along well, we should be thinking about sending fixes like this
upstream.

When we switch to the upstream-based qemu we won't want to carry a lot
of patches like this one.

Regards,
Ian.

Re: [PATCH] qemu/block-vvfat.c: fix warnings with _FORTIFY_SOURCE

[Olaf Hering]

On Wed, Nov 03, Ian Jackson wrote:

> However: have you checked whether these problems exist in qemu
> upstream ?  With Anthony's work on upstreaming Xen support in qemu
> coming along well, we should be thinking about sending fixes like this
> upstream.

The vvfat patch is already upstream, the other one should be there too.
But I havent verified it, the website does not resolve for me right now.

Olaf

Re: [PATCH] qemu/block-vvfat.c: fix warnings with _FORTIFY_SOURCE

[Ian Jackson]

Olaf Hering writes ("Re: [Xen-devel] [PATCH] qemu/block-vvfat.c: fix warnings with _FORTIFY_SOURCE"):
> On Wed, Nov 03, Ian Jackson wrote:
> > However: have you checked whether these problems exist in qemu
> > upstream ?  With Anthony's work on upstreaming Xen support in qemu
> > coming along well, we should be thinking about sending fixes like this
> > upstream.
> 
> The vvfat patch is already upstream, the other one should be there too.
> But I havent verified it, the website does not resolve for me right now.

Great, thanks.  I guess in this case if it gets dropped the compiler
will tell us in due course.

Ian.