From eb972eab0794dedeef5b3b1845e5f9a78793f184 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 6 Dec 2025 20:01:16 +0100 Subject: [PATCH] lkdtm/bugs: Add cases for BUG and PANIC occurring in hardirq context Add lkdtm cases to trigger a BUG() or panic() from hardirq context. This is useful for testing pstore behavior being invoked from such contexts. Reviewed-by: Kees Cook Signed-off-by: Ard Biesheuvel Signed-off-by: Catalin Marinas --- drivers/misc/lkdtm/bugs.c | 53 +++++++++++++++++++++++++ tools/testing/selftests/lkdtm/tests.txt | 2 + 2 files changed, 55 insertions(+) diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 376047beea3d6..fa05d77acb558 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -8,6 +8,7 @@ #include "lkdtm.h" #include #include +#include #include #include #include @@ -100,11 +101,61 @@ static void lkdtm_PANIC_STOP_IRQOFF(void) stop_machine(panic_stop_irqoff_fn, &v, cpu_online_mask); } +static bool wait_for_panic; + +static enum hrtimer_restart panic_in_hardirq(struct hrtimer *timer) +{ + panic("from hard IRQ context"); + + wait_for_panic = false; + return HRTIMER_NORESTART; +} + +static void lkdtm_PANIC_IN_HARDIRQ(void) +{ + struct hrtimer timer; + + wait_for_panic = true; + hrtimer_setup_on_stack(&timer, panic_in_hardirq, + CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); + hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD); + + while (wait_for_panic) + ; + + hrtimer_cancel(&timer); +} + static void lkdtm_BUG(void) { BUG(); } +static bool wait_for_bug; + +static enum hrtimer_restart bug_in_hardirq(struct hrtimer *timer) +{ + BUG(); + + wait_for_bug = false; + return HRTIMER_NORESTART; +} + +static void lkdtm_BUG_IN_HARDIRQ(void) +{ + struct hrtimer timer; + + wait_for_bug = true; + hrtimer_setup_on_stack(&timer, bug_in_hardirq, + CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); + hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD); + + while (wait_for_bug) + ; + + hrtimer_cancel(&timer); +} + static int warn_counter; static void lkdtm_WARNING(void) @@ -696,7 +747,9 @@ static noinline void lkdtm_CORRUPT_PAC(void) static struct crashtype crashtypes[] = { CRASHTYPE(PANIC), CRASHTYPE(PANIC_STOP_IRQOFF), + CRASHTYPE(PANIC_IN_HARDIRQ), CRASHTYPE(BUG), + CRASHTYPE(BUG_IN_HARDIRQ), CRASHTYPE(WARNING), CRASHTYPE(WARNING_MESSAGE), CRASHTYPE(EXCEPTION), diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt index cff124c1eddd3..67cd53715d932 100644 --- a/tools/testing/selftests/lkdtm/tests.txt +++ b/tools/testing/selftests/lkdtm/tests.txt @@ -1,6 +1,8 @@ #PANIC #PANIC_STOP_IRQOFF Crashes entire system +#PANIC_IN_HARDIRQ Crashes entire system BUG kernel BUG at +#BUG_IN_HARDIRQ Crashes entire system WARNING WARNING: WARNING_MESSAGE message trigger EXCEPTION -- 2.47.3