lkdtm: hide stack overflow warning for corrupt-stack test
authorArnd Bergmann <arnd@arndb.de>
Wed, 11 Jan 2017 14:56:44 +0000 (15:56 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 19 Jan 2017 11:42:25 +0000 (12:42 +0100)
commit7a11a1d1b58873b2e5a6922dcdc23b6b339b14ba
tree822667e7c3c8d81f37ed1363a672bbe8f4e5c6af
parent4474f4c40a9c607c7317e686b23619b7b768004f
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_bugs.c: In function 'lkdtm_CORRUPT_STACK':
drivers/misc/lkdtm_bugs.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>
drivers/misc/lkdtm_bugs.c