Am Di., 28. Okt. 2025 um 09:47 Uhr schrieb Christian Brauner
<brauner@kernel.org>:
>
> PIDFD_INFO_COREDUMP is only retrievable until the task has exited. After
> it has exited task->mm is NULL. So if the task didn't actually coredump
> we can't retrieve it's dumpability settings anymore. Only if the task
> did coredump will we have stashed the coredump information in the
> respective struct pid.
>
> Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> ---
> tools/testing/selftests/coredump/coredump_socket_test.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/coredump/coredump_socket_test.c b/tools/testing/selftests/coredump/coredump_socket_test.c
> index 658f3966064f..5103d9f13003 100644
> --- a/tools/testing/selftests/coredump/coredump_socket_test.c
> +++ b/tools/testing/selftests/coredump/coredump_socket_test.c
> @@ -271,22 +271,26 @@ TEST_F(coredump, socket_detect_userspace_client)
> _exit(EXIT_FAILURE);
>
> close(fd_socket);
> + pause();
> _exit(EXIT_SUCCESS);
> }
>
> pidfd = sys_pidfd_open(pid, 0);
> ASSERT_GE(pidfd, 0);
>
> - waitpid(pid, &status, 0);
> - ASSERT_TRUE(WIFEXITED(status));
> - ASSERT_EQ(WEXITSTATUS(status), 0);
> -
> ASSERT_TRUE(get_pidfd_info(pidfd, &info));
> ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
> ASSERT_EQ((info.coredump_mask & PIDFD_COREDUMPED), 0);
>
> wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
>
> + ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0), 0);
> + ASSERT_EQ(close(pidfd), 0);
> +
> + waitpid(pid, &status, 0);
> + ASSERT_TRUE(WIFSIGNALED(status));
> + ASSERT_EQ(WTERMSIG(status), SIGKILL);
> +
> ASSERT_NE(stat("/tmp/coredump.file", &st), 0);
> ASSERT_EQ(errno, ENOENT);
> }
>
> --
> 2.47.3
>