diff options
| author | Jonathan Corbet <corbet@lwn.net> | 2019-06-14 14:18:53 -0600 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2019-06-14 14:18:53 -0600 |
| commit | 8afecfb0ec961e37e61b2d19c4fa71617a9482de (patch) | |
| tree | c43ea51a47b1e76b762caa4c1b0c356249e5e874 /drivers/misc/lkdtm/bugs.c | |
| parent | ce1a5ea18ef9bf4c62c75abe7c540a29264ec988 (diff) | |
| parent | d1fdb6d8f6a4109a4263176c84b899076a5f8008 (diff) | |
Merge tag 'v5.2-rc4' into mauro
We need to pick up post-rc1 changes to various document files so they don't
get lost in Mauro's massive RST conversion push.
Diffstat (limited to 'drivers/misc/lkdtm/bugs.c')
| -rw-r--r-- | drivers/misc/lkdtm/bugs.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 7eebbdfbcacd..17f839dee976 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -32,12 +32,20 @@ static int recur_count = REC_NUM_DEFAULT; static DEFINE_SPINLOCK(lock_me_up); -static int recursive_loop(int remaining) +/* + * Make sure compiler does not optimize this function or stack frame away: + * - function marked noinline + * - stack variables are marked volatile + * - stack variables are written (memset()) and read (pr_info()) + * - function has external effects (pr_info()) + * */ +static int noinline recursive_loop(int remaining) { - char buf[REC_STACK_SIZE]; + volatile char buf[REC_STACK_SIZE]; - /* Make sure compiler does not optimize this away. */ - memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE); + memset((void *)buf, remaining & 0xFF, sizeof(buf)); + pr_info("loop %d/%d ...\n", (int)buf[remaining % sizeof(buf)], + recur_count); if (!remaining) return 0; else @@ -81,9 +89,12 @@ void lkdtm_LOOP(void) ; } -void lkdtm_OVERFLOW(void) +void lkdtm_EXHAUST_STACK(void) { - (void) recursive_loop(recur_count); + pr_info("Calling function with %d frame size to depth %d ...\n", + REC_STACK_SIZE, recur_count); + recursive_loop(recur_count); + pr_info("FAIL: survived without exhausting stack?!\n"); } static noinline void __lkdtm_CORRUPT_STACK(void *stack) |