ubsan: entirely disable alignment checks under UBSAN_TRAP
authorKees Cook <keescook@chromium.org>
Tue, 2 Jun 2020 04:52:46 +0000 (21:52 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 2 Jun 2020 17:59:12 +0000 (10:59 -0700)
commit9380ce246a052a1e00121cd480028b6907aeae38
tree4a031adb90a6030aad710d36e9b2f76f752349cd
parentca734cc67e3c8ce20eb75dd1e45ae86e10be102b
ubsan: entirely disable alignment checks under UBSAN_TRAP

Commit 8d58f222e85f ("ubsan: disable UBSAN_ALIGNMENT under
COMPILE_TEST") tried to fix the pathological results of UBSAN_ALIGNMENT
with UBSAN_TRAP (which objtool would rightly scream about), but it made
an assumption about how COMPILE_TEST gets set (it is not set for
randconfig).  As a result, we need a bigger hammer here: just don't
allow the alignment checks with the trap mode.

Fixes: 8d58f222e85f ("ubsan: disable UBSAN_ALIGNMENT under COMPILE_TEST")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Elena Petrova <lenaptr@google.com>
Link: http://lkml.kernel.org/r/202005291236.000FCB6@keescook
Link: https://lore.kernel.org/lkml/742521db-1e8c-0d7a-1ed4-a908894fb497@infradead.org/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/Kconfig.ubsan