Re: [PATCH] selftests/mm: handle fork() failure in migration tests

[Donet Tom <donettom@linux.ibm.com>]

Hi

On 5/11/26 3:04 PM, Hu Song wrote:
> From: Song Hu <husong@kylinos.cn>
>
> When fork() fails and returns -1, the code falls into the else branch
> and stores -1 into self->pids[i]. Later, kill(-1, SIGTERM) is called
> which sends SIGTERM to every process the user has permission to signal,
> potentially killing the entire user session.
>
> Add an explicit check for fork() returning -1 (pid < 0). On failure,
> clean up any already-forked children before failing the test via
> ASSERT_GE(pid, 0). This fix is applied to all three fork() call sites
> in shared_anon, shared_anon_thp, and shared_anon_htlb tests.
>
> Signed-off-by: Hu Song <husong@kylinos.cn>

I am seeing the below issue in checkpatch.pl.

WARNING: From:/Signed-off-by: email name mismatch: 'From: Song Hu 
<husong@kylinos.cn>' != 'Signed-off-by: Hu Song <husong@kylinos.cn>'

-Donet

> ---
>   tools/testing/selftests/mm/migration.c | 15 +++++++++++++++
>   1 file changed, 15 insertions(+)
>
> diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c
> index 60e78bbfc0e3..f433e4f195ad 100644
> --- a/tools/testing/selftests/mm/migration.c
> +++ b/tools/testing/selftests/mm/migration.c
> @@ -163,6 +163,11 @@ TEST_F_TIMEOUT(migration, shared_anon, 2*RUNTIME)
>   	memset(ptr, 0xde, TWOMEG);
>   	for (i = 0; i < self->nthreads - 1; i++) {
>   		pid = fork();
> +		if (pid < 0) {
> +			while (--i >= 0)
> +				kill(self->pids[i], SIGTERM);
> +			ASSERT_GE(pid, 0);
> +		}
>   		if (!pid) {
>   			prctl(PR_SET_PDEATHSIG, SIGHUP);
>   			/* Parent may have died before prctl so check now. */
> @@ -235,6 +240,11 @@ TEST_F_TIMEOUT(migration, shared_anon_thp, 2*RUNTIME)
>   	memset(ptr, 0xde, TWOMEG);
>   	for (i = 0; i < self->nthreads - 1; i++) {
>   		pid = fork();
> +		if (pid < 0) {
> +			while (--i >= 0)
> +				kill(self->pids[i], SIGTERM);
> +			ASSERT_GE(pid, 0);
> +		}
>   		if (!pid) {
>   			prctl(PR_SET_PDEATHSIG, SIGHUP);
>   			/* Parent may have died before prctl so check now. */
> @@ -295,6 +305,11 @@ TEST_F_TIMEOUT(migration, shared_anon_htlb, 2*RUNTIME)
>   	memset(ptr, 0xde, TWOMEG);
>   	for (i = 0; i < self->nthreads - 1; i++) {
>   		pid = fork();
> +		if (pid < 0) {
> +			while (--i >= 0)
> +				kill(self->pids[i], SIGTERM);
> +			ASSERT_GE(pid, 0);
> +		}
>   		if (!pid) {
>   			prctl(PR_SET_PDEATHSIG, SIGHUP);
>   			/* Parent may have died before prctl so check now. */