diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2017-01-11 15:56:44 +0100 |
|---|---|---|
| committer | Michael Bestas <mkbestas@lineageos.org> | 2020-02-02 01:41:07 +0200 |
| commit | 9baaf4b3d95fb11826612b22b8e397691371279d (patch) | |
| tree | 60ed681ba15c5cc92170433a7622bd46148365dd | |
| parent | 8c0050c75a7dc7f67d74e70499041cd4b58b0c3c (diff) | |
BACKPORT: lkdtm: hide stack overflow warning for corrupt-stack test
After the latest change to make sure the compiler actually does a memset,
it is now smart enough to flag the stack overflow at compile time,
at least with gcc-7.0:
drivers/misc/lkdtm.c: In function 'lkdtm_CORRUPT_STACK':
drivers/misc/lkdtm.c:88:144: warning: 'memset' writing 64 bytes into a region of size 8 overflows the destination [-Wstringop-overflow=]
To outsmart the compiler again, this moves the memset into a noinline
function where (for now) it doesn't see that we intentionally write
broken code here.
Fixes: c55d240003ae ("lkdtm: Prevent the compiler from optimising lkdtm_CORRUPT_STACK()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://git.kernel.org/linus/7a11a1d1b58873b2e5a6922dcdc23b6b339b14ba
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
| -rw-r--r-- | drivers/misc/lkdtm.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c index ba6b80715c39..7b8b2024b810 100644 --- a/drivers/misc/lkdtm.c +++ b/drivers/misc/lkdtm.c @@ -343,12 +343,17 @@ static void do_overwritten(void) return; } +static noinline void __lkdtm_CORRUPT_STACK(void *stack) +{ + memset(stack, 'a', 64); +} + static noinline void corrupt_stack(void) { /* Use default char array length that triggers stack protection. */ char data[8]; + __lkdtm_CORRUPT_STACK(&data); - memset((void *)data, 'a', 64); pr_info("Corrupted stack with '%16s'...\n", data); } |