diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2025-12-19 15:09:09 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2025-12-19 15:09:09 +0000 |
| commit | f4ea8e05f2a857d5447c25f7daf00807d38b307d (patch) | |
| tree | 962412bf671e418ca82ad5eaaa675ec369ddbafb | |
| parent | 98a97bf41528ef738b06eb07ec2b2eb1cfde6ce6 (diff) | |
lkdtm/bugs: Do not confuse the clang/objtool with busy wait loop
Since commit eb972eab0794 ("lkdtm/bugs: Add cases for BUG and PANIC
occurring in hardirq context"), building with clang for x86_64 results
in the following warnings:
vmlinux.o: warning: objtool: lkdtm_PANIC_IN_HARDIRQ(): unexpected end of section .text.lkdtm_PANIC_IN_HARDIRQ
vmlinux.o: warning: objtool: lkdtm_BUG_IN_HARDIRQ(): unexpected end of section .text.lkdtm_BUG_IN_HARDIRQ
caused by busy "while (wait_for_...);" loops. Add READ_ONCE() and
cpu_relax() to better indicate the intention and avoid any unwanted
compiler optimisations.
Fixes: eb972eab0794 ("lkdtm/bugs: Add cases for BUG and PANIC occurring in hardirq context")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202512190111.jxFSqxUH-lkp@intel.com/
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | drivers/misc/lkdtm/bugs.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index fa05d77acb55..502059078b45 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -120,8 +120,8 @@ static void lkdtm_PANIC_IN_HARDIRQ(void) CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD); - while (wait_for_panic) - ; + while (READ_ONCE(wait_for_panic)) + cpu_relax(); hrtimer_cancel(&timer); } @@ -150,8 +150,8 @@ static void lkdtm_BUG_IN_HARDIRQ(void) CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD); - while (wait_for_bug) - ; + while (READ_ONCE(wait_for_bug)) + cpu_relax(); hrtimer_cancel(&timer); } |