[LTP] [PATCH 3/5] mq_timedsend01: Workaround segfault on libc variant on 32 bit

[Jan Stancek]

On Thu, Nov 14, 2024 at 3:40 PM Petr Vorel <pvorel@suse.cz> wrote:
>
> EFAULT test segfaults on newer kernels (e.g. 6.4) on libc variant on
> 32bit.  Similarly to 1d4d5a0750 use typical LTP workaround to test by
> forked child + checking the terminating signal.
>
> Signed-off-by: Petr Vorel <pvorel@suse.cz>
> ---
>  .../syscalls/mq_timedsend/mq_timedsend01.c    | 87 ++++++++++++++-----
>  1 file changed, 63 insertions(+), 24 deletions(-)
>
> diff --git a/testcases/kernel/syscalls/mq_timedsend/mq_timedsend01.c b/testcases/kernel/syscalls/mq_timedsend/mq_timedsend01.c
> index 35bf4445f5..2cec749f48 100644
> --- a/testcases/kernel/syscalls/mq_timedsend/mq_timedsend01.c
> +++ b/testcases/kernel/syscalls/mq_timedsend/mq_timedsend01.c
> @@ -143,34 +143,15 @@ static void setup(void)
>         setup_common();
>  }
>
> -static void do_test(unsigned int i)
> +static void verify_mqt_send_receive(unsigned int i, pid_t pid)
>  {
>         struct time64_variants *tv = &variants[tst_variant];
>         const struct test_case *tc = &tcase[i];
>         unsigned int j;
>         unsigned int prio;
> -       size_t len = MAX_MSGSIZE;
> -       char rmsg[len];
> -       pid_t pid = -1;
> +       char rmsg[MAX_MSGSIZE];
>         void *msg_ptr, *abs_timeout;
>
> -       tst_ts_set_sec(&ts, tc->tv_sec);
> -       tst_ts_set_nsec(&ts, tc->tv_nsec);
> -
> -       if (tc->signal)
> -               pid = set_sig(tc->rq, tv->clock_gettime);
> -
> -       if (tc->timeout)
> -               set_timeout(tc->rq, tv->clock_gettime);
> -
> -       if (tc->send) {
> -               for (j = 0; j < MSG_LENGTH; j++)
> -                       if (tv->mqt_send(*tc->fd, smsg, tc->len, tc->prio, NULL) < 0) {
> -                               tst_res(TFAIL | TTERRNO, "mq_timedsend() failed");
> -                               return;
> -                       }
> -       }
> -
>         if (tc->bad_msg_addr)
>                 msg_ptr = bad_addr;
>         else
> @@ -200,7 +181,7 @@ static void do_test(unsigned int i)
>                 return;
>         }
>
> -       TEST(tv->mqt_receive(*tc->fd, rmsg, len, &prio, tst_ts_get(tc->rq)));
> +       TEST(tv->mqt_receive(*tc->fd, rmsg, MAX_MSGSIZE, &prio, tst_ts_get(tc->rq)));
>
>         if (*tc->fd == fd)
>                 cleanup_queue(fd);
> @@ -241,8 +222,66 @@ static void do_test(unsigned int i)
>                 }
>         }
>
> -       tst_res(TPASS, "mq_timedreceive() returned %ld, priority %u, length: %zu",
> -                       TST_RET, prio, len);
> +       tst_res(TPASS, "mq_timedreceive() returned %ld, priority %u, length: %i",
> +                       TST_RET, prio, MAX_MSGSIZE);
> +}
> +
> +static void test_bad_addr(unsigned int i)
> +{
> +       struct time64_variants *tv = &variants[tst_variant];
> +       pid_t pid;
> +       int status;
> +
> +       pid = SAFE_FORK();
> +       if (!pid) {
> +               verify_mqt_send_receive(i, pid);
> +               _exit(0);
> +       }
> +
> +       SAFE_WAITPID(pid, &status, 0);
> +
> +       if (WIFEXITED(status) && !WEXITSTATUS(status))
> +               return;
> +
> +       if (tv->ts_type == TST_LIBC_TIMESPEC &&
> +               WIFSIGNALED(status) && WTERMSIG(status) == SIGSEGV) {
> +               tst_res(TPASS, "Child killed by expected signal");
> +               return;
> +       }
> +
> +       tst_res(TFAIL, "Child %s", tst_strstatus(status));
> +}
> +
> +static void do_test(unsigned int i)
> +{
> +       struct time64_variants *tv = &variants[tst_variant];
> +       const struct test_case *tc = &tcase[i];
> +       unsigned int j;
> +       pid_t pid = -1;
> +
> +       tst_ts_set_sec(&ts, tc->tv_sec);
> +       tst_ts_set_nsec(&ts, tc->tv_nsec);
> +
> +       if (tc->bad_ts_addr) {

Would it make sense to run bad_msg_addr/EFAULT test also in child?

> +               test_bad_addr(i);
> +               return;
> +       }
> +
> +       if (tc->signal)
> +               pid = set_sig(tc->rq, tv->clock_gettime);
> +
> +       if (tc->timeout)
> +               set_timeout(tc->rq, tv->clock_gettime);
> +
> +       if (tc->send) {
> +               for (j = 0; j < MSG_LENGTH; j++)
> +                       if (tv->mqt_send(*tc->fd, smsg, tc->len, tc->prio, NULL) < 0) {
> +                               tst_res(TFAIL | TTERRNO, "mq_timedsend() failed");
> +                               return;
> +                       }
> +       }
> +
> +       verify_mqt_send_receive(i, pid);
>  }
>
>  static struct tst_test test = {
> --
> 2.45.2
>