linux/mm/kasan
Nathan Chancellor 0600597c85 kasan: initialize tag to 0xff in __kasan_kmalloc
When building with -Wuninitialized and CONFIG_KASAN_SW_TAGS unset, Clang
warns:

mm/kasan/common.c:484:40: warning: variable 'tag' is uninitialized when
used here [-Wuninitialized]
        kasan_unpoison_shadow(set_tag(object, tag), size);
                                              ^~~

set_tag ignores tag in this configuration but clang doesn't realize it at
this point in its pipeline, as it points to arch_kasan_set_tag as being
the point where it is used, which will later be expanded to (void
*)(object) without a use of tag.  Initialize tag to 0xff, as it removes
this warning and doesn't change the meaning of the code.

Link: https://github.com/ClangBuiltLinux/linux/issues/465
Link: http://lkml.kernel.org/r/20190502163057.6603-1-natechancellor@gmail.com
Fixes: 7f94ffbc4c ("kasan: add hooks implementation for tag-based mode")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-01 15:51:31 -07:00
..
common.c kasan: initialize tag to 0xff in __kasan_kmalloc 2019-06-01 15:51:31 -07:00
generic_report.c kasan: remove use after scope bugs detection. 2019-03-05 21:07:13 -08:00
generic.c kasan: remove use after scope bugs detection. 2019-03-05 21:07:13 -08:00
init.c treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
kasan.h kasan: fix variable 'tag' set but not used warning 2019-03-29 10:01:36 -07:00
Makefile arm64 updates for 5.2 2019-05-06 17:54:22 -07:00
quarantine.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
report.c Merge branch 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-06 13:11:48 -07:00
tags_report.c kasan: add SPDX-License-Identifier mark to source files 2018-12-28 12:11:44 -08:00
tags.c kasan: fix random seed generation for tag-based mode 2019-02-21 09:01:00 -08:00