[libvirt] Error in virt-install

[Daniel Veillard]

On Tue, Mar 10, 2009 at 10:16:26AM +0100, Daniel Veillard wrote:
> > Starting install...
> > *** glibc detected *** /usr/bin/python: free(): invalid next size (fast): 
> 
>   Yes I'm seeing this too on 0.6.1 on RHEL-5.3, I'm trying to chase it
> down, it's a bit hard to find out where the memory corruption occurs.
> 
> > I've memtested the memory and its fine. If i use a file as the target (instead 
> > of a block device) it also works:
> > 
> > virt-install -n test -r 512 --vnc --file=/tmp/test-os --file-size=2 --
> > location=ftp://mirrors/centos/5/os/i386
> 
>   yes I get the crash with a file based target too.
>   I'm investigating ...

  I guess I nailed it down, it's something we introduced when converting
memory allocation, and since the block getting allocated includes both
char * and char we failed to allocate enough space for the leading
char * array.
  With this patch I was able to create a new guest and have it load
with virt-install (but just in serial concole, graphics didn't work
for some reason), it disapeared from the domain list too after being
restarted at the end of the installation, so there is more stuff to
be fixed on RHEL/Centos Xen, but that one seems solved,

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/
-------------- next part --------------
Index: src/xend_internal.c
===================================================================
RCS file: /data/cvs/libxen/src/xend_internal.c,v
retrieving revision 1.251
diff -u -r1.251 xend_internal.c
--- src/xend_internal.c	13 Feb 2009 18:23:23 -0000	1.251
+++ src/xend_internal.c	10 Mar 2009 10:00:28 -0000
@@ -904,7 +904,15 @@
         count++;
     }
 
-    if (VIR_ALLOC_N(ptr, count + 1 + extra) < 0)
+    /*
+     * We can'tuse the normal allocation routines as we are mixing
+     * an array of char * at the beginning followed by an array of char
+     * ret points to the NULL terminated array of char *
+     * ptr points to the current string after that array but in the same
+     * allocated block
+     */
+    if (virAlloc((void *)&ptr,
+                 (count + 1) * sizeof(char *) + extra * sizeof(char)) < 0)
         goto error;
 
     ret = (char **) ptr;