Build break (uninitialized variable)

["Grégoire Sutre" <gregoire.sutre@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 1613 bytes --]

The compiler complains about `totsize' being possibly uninitialized
in grub-core/disk/diskfilter.c, function grub_diskfilter_make_raid().
I get this error with gcc 4.5.3 on NetBSD, and also with gcc 4.6.2 on
Debian GNU/Linux.

I'm not familiar with that code.  The attached patch fixes this by
returning NULL when the argument `level' has an unexpected value.

Grégoire

gcc -DHAVE_CONFIG_H -I. -I..  -Wall -W -I../include -I../include 
-DGRUB_MACHINE_PCBIOS=1 -DGRUB_MACHINE=I386_PC -DGRUB_TARGET_CPU_I386=1 
-m32 -DGRUB_FILE=\"disk/diskfilter.c\" -I. -I. -I.. -I.. -I../include 
-I../include     -Os -Wall -W -Wshadow -Wpointer-arith 
-Wmissing-prototypes -Wundef -Wstrict-prototypes -g -falign-jumps=1 
-falign-loops=1 -falign-functions=1 -mno-mmx -mno-sse -mno-sse2 
-mno-3dnow -fno-dwarf2-cfi-asm -fno-asynchronous-unwind-tables -m32 
-fno-stack-protector -mno-stack-arg-probe -Werror   -mrtd -mregparm=3 
   -ffreestanding   -MT disk/diskfilter_module-diskfilter.o -MD -MP -MF 
disk/.deps-core/diskfilter_module-diskfilter.Tpo -c -o 
disk/diskfilter_module-diskfilter.o `test -f 'disk/diskfilter.c' || echo 
'./'`disk/diskfilter.c
cc1: warnings being treated as errors
disk/diskfilter.c: In function 'grub_diskfilter_make_raid':
disk/diskfilter.c:813:17: error: 'totsize' may be used uninitialized in 
this function
gmake[3]: *** [disk/diskfilter_module-diskfilter.o] Error 1
gmake[3]: Leaving directory `/tmp/grub/grub-core'
gmake[2]: *** [all] Error 2
gmake[2]: Leaving directory `/tmp/grub/grub-core'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/tmp/grub'
gmake: *** [all] Error 2

[-- Attachment #2: diskfilter-totsize.diff --]
[-- Type: text/x-patch, Size: 407 bytes --]

=== modified file 'grub-core/disk/diskfilter.c'
--- grub-core/disk/diskfilter.c	2012-01-29 13:28:01 +0000
+++ grub-core/disk/diskfilter.c	2012-02-03 18:21:07 +0000
@@ -837,6 +837,9 @@ grub_diskfilter_make_raid (grub_size_t u
     case 6:
       totsize = (nmemb - level / 3) * disk_size;
       break;
+
+    default:
+      return NULL;
     }
 
   array = grub_diskfilter_get_vg_by_uuid (uuidlen, uuid);