+ kasan-avoid-wmaybe-uninitialized-warning-v3.patch added to -mm tree

+ kasan-avoid-wmaybe-uninitialized-warning-v3.patch added to -mm tree

[akpm]

The patch titled
     Subject: kasan: avoid -Wmaybe-uninitialized warning
has been added to the -mm tree.  Its filename is
     kasan-avoid-wmaybe-uninitialized-warning-v3.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/kasan-avoid-wmaybe-uninitialized-warning-v3.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/kasan-avoid-wmaybe-uninitialized-warning-v3.patch

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------------------------------------------------------
From: Arnd Bergmann <arnd@arndb.de>
Subject: kasan: avoid -Wmaybe-uninitialized warning

gcc-7 produces this warning:

mm/kasan/report.c: In function 'kasan_report':
mm/kasan/report.c:351:3: error: 'info.first_bad_addr' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   print_shadow_for_address(info->first_bad_addr);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/kasan/report.c:360:27: note: 'info.first_bad_addr' was declared here

The code seems fine as we only print info.first_bad_addr when there is a shadow,
and we always initialize it in that case, but this is relatively hard
for gcc to figure out after the latest rework. Adding an intialization
to the most likely value together with the other struct members
shuts up that warning.

Fixes: b235b9808664 ("kasan: unify report headers")
Link: https://patchwork.kernel.org/patch/9641417/
Link: http://lkml.kernel.org/r/20170725152739.4176967-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Alexander Potapenko <glider@google.com>
Suggested-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kasan/report.c |    1 +
 1 file changed, 1 insertion(+)

diff -puN mm/kasan/report.c~kasan-avoid-wmaybe-uninitialized-warning-v3 mm/kasan/report.c
--- a/mm/kasan/report.c~kasan-avoid-wmaybe-uninitialized-warning-v3
+++ a/mm/kasan/report.c
@@ -401,6 +401,7 @@ void kasan_report(unsigned long addr, si
 	disable_trace_on_warning();
 
 	info.access_addr = (void *)addr;
+	info.first_bad_addr = (void *)addr;
 	info.access_size = size;
 	info.is_write = is_write;
 	info.ip = ip;
_

Patches currently in -mm which might be from arnd@arndb.de are

kasan-avoid-wmaybe-uninitialized-warning-v3.patch
scsi-megaraid-fix-format-overflow-warning.patch
scsi-mpt3sas-fix-format-overflow-warning.patch
scsi-fusion-fix-string-overflow-warning.patch
scsi-gdth-avoid-buffer-overflow-warning.patch
scsi-fnic-fix-format-string-overflow-warning.patch
scsi-gdth-increase-the-procfs-event-buffer-size.patch
block-dac960-shut-up-format-overflow-warning.patch
fscache-fix-fscache_objlist_show-format-processing.patch
ib-mlx4-fix-sprintf-format-warning.patch