On 2025-03-31, Nam Cao namcao@linutronix.de wrote:
The test waits for coredump to finish by busy-waiting for the stackdump_values file to be created. The maximum wait time is 10 seconds.
This doesn't work for slow machine (qemu-system-riscv64), because coredump takes longer.
Switch to use waitpid().
Note that you are now assuming that returning from waitpid() means that:
1. the coredumping has completed
and
2. the STACKDUMP_FILE with all its contents are visible to the parent process
With this, the stack_values file doesn't need to be atomically written by coredump anymore, therefore simplify the stackdump script.
Fixes: 15858da53542 ("selftests: coredump: Add stackdump test") Signed-off-by: Nam Cao namcao@linutronix.de
tools/testing/selftests/coredump/stackdump | 6 +----- tools/testing/selftests/coredump/stackdump_test.c | 13 ++++++------- 2 files changed, 7 insertions(+), 12 deletions(-)
diff --git a/tools/testing/selftests/coredump/stackdump b/tools/testing/selftests/coredump/stackdump index 96714ce42d12..ad487fd5ff15 100755 --- a/tools/testing/selftests/coredump/stackdump +++ b/tools/testing/selftests/coredump/stackdump @@ -4,11 +4,7 @@ CRASH_PROGRAM_ID=$1 STACKDUMP_FILE=$2 -TMP=$(mktemp)
for t in /proc/$CRASH_PROGRAM_ID/task/*; do tid=$(basename $t)
- cat /proc/$tid/stat | awk '{print $29}' >> $TMP
- cat /proc/$tid/stat | awk '{print $29}' >> $STACKDUMP_FILE
done
-mv $TMP $STACKDUMP_FILE
I would leave this as it was. Then the availability of STACKDUMP_FILE means the full contents are available.
diff --git a/tools/testing/selftests/coredump/stackdump_test.c b/tools/testing/selftests/coredump/stackdump_test.c index 1dc54e128586..733feaa0f895 100644 --- a/tools/testing/selftests/coredump/stackdump_test.c +++ b/tools/testing/selftests/coredump/stackdump_test.c @@ -96,7 +96,7 @@ TEST_F(coredump, stackdump) char *test_dir, *line; size_t line_length; char buf[PATH_MAX];
- int ret, i;
- int ret, i, status; FILE *file; pid_t pid;
@@ -131,12 +131,11 @@ TEST_F(coredump, stackdump) /* * Step 3: Wait for the stackdump script to write the stack pointers to the stackdump file */
- for (i = 0; i < 10; ++i) {
file = fopen(STACKDUMP_FILE, "r");if (file)break;sleep(1);- }
- waitpid(pid, &status, 0);
- ASSERT_TRUE(WIFSIGNALED(status));
- ASSERT_TRUE(WCOREDUMP(status));
Why not just put these 3 lines above the for-loop? So you would wait for the process to end, then go into the 20-second timeout loop waiting for STACKDUMP_FILE to show up.
John Ogness