diff options
| author | Ingo Molnar <mingo@kernel.org> | 2019-06-17 12:29:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-06-17 12:29:16 +0200 |
| commit | bddb3636737f658886a0a02b64db5366bba3428e (patch) | |
| tree | 8f7ffcb42803fa0bb3378ef969545e4a5e57262c /drivers/misc/lkdtm/bugs.c | |
| parent | 3384c78631dd722c2cdc5c57fbdd39fc1b5a9f2d (diff) | |
| parent | cbb99c0f588737ec98c333558922ce47e9a95827 (diff) | |
Merge branch 'x86/cpu' into perf/core, to pick up dependent changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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) |