selftests/coredump: add second PIDFD_INFO_COREDUMP_SIGNAL test

Verify that when using simple socket-based coredump (@ pattern),
the coredump_signal field is correctly exposed as SIGABRT.

Link: https://patch.msgid.link/20251028-work-coredump-signal-v1-22-ca449b7b7aa0@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/tools/testing/selftests/coredump/coredump_socket_test.c b/tools/testing/selftests/coredump/coredump_socket_test.c
index 9d5507fa75ecbb60a3ae3818eff66818ca972cb8..7e26d4a6a15db7c8391f0f3228f9148231be26f8 100644 (file)
--- a/tools/testing/selftests/coredump/coredump_socket_test.c
+++ b/tools/testing/selftests/coredump/coredump_socket_test.c
@@ -576,6 +576,152 @@ out:
        wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
 }
 
+/*
+ * Test: PIDFD_INFO_COREDUMP_SIGNAL via simple socket coredump with SIGABRT
+ *
+ * Verify that when using simple socket-based coredump (@ pattern),
+ * the coredump_signal field is correctly exposed as SIGABRT.
+ */
+TEST_F(coredump, socket_coredump_signal_sigabrt)
+{
+       int pidfd, ret, status;
+       pid_t pid, pid_coredump_server;
+       struct pidfd_info info = {};
+       int ipc_sockets[2];
+       char c;
+
+       ASSERT_TRUE(set_core_pattern("@/tmp/coredump.socket"));
+
+       ret = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets);
+       ASSERT_EQ(ret, 0);
+
+       pid_coredump_server = fork();
+       ASSERT_GE(pid_coredump_server, 0);
+       if (pid_coredump_server == 0) {
+               int fd_server = -1, fd_coredump = -1, fd_peer_pidfd = -1, fd_core_file = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: create_and_listen_unix_socket failed: %m\n");
+                       goto out;
+               }
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: write_nointr to ipc socket failed: %m\n");
+                       goto out;
+               }
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: accept4 failed: %m\n");
+                       goto out;
+               }
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: get_peer_pidfd failed\n");
+                       goto out;
+               }
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: get_pidfd_info failed\n");
+                       goto out;
+               }
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: PIDFD_INFO_COREDUMP not set in mask\n");
+                       goto out;
+               }
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: PIDFD_COREDUMPED not set in coredump_mask\n");
+                       goto out;
+               }
+
+               /* Verify coredump_signal is available and correct */
+               if (!(info.mask & PIDFD_INFO_COREDUMP_SIGNAL)) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: PIDFD_INFO_COREDUMP_SIGNAL not set in mask\n");
+                       goto out;
+               }
+
+               if (info.coredump_signal != SIGABRT) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: coredump_signal=%d, expected SIGABRT=%d\n",
+                               info.coredump_signal, SIGABRT);
+                       goto out;
+               }
+
+               fd_core_file = open_coredump_tmpfile(self->fd_tmpfs_detached);
+               if (fd_core_file < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: open_coredump_tmpfile failed: %m\n");
+                       goto out;
+               }
+
+               for (;;) {
+                       char buffer[4096];
+                       ssize_t bytes_read, bytes_write;
+
+                       bytes_read = read(fd_coredump, buffer, sizeof(buffer));
+                       if (bytes_read < 0) {
+                               fprintf(stderr, "socket_coredump_signal_sigabrt: read from coredump socket failed: %m\n");
+                               goto out;
+                       }
+
+                       if (bytes_read == 0)
+                               break;
+
+                       bytes_write = write(fd_core_file, buffer, bytes_read);
+                       if (bytes_read != bytes_write) {
+                               fprintf(stderr, "socket_coredump_signal_sigabrt: write to core file failed (read=%zd, write=%zd): %m\n",
+                                       bytes_read, bytes_write);
+                               goto out;
+                       }
+               }
+
+               exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_coredump_signal_sigabrt: completed successfully\n");
+out:
+               if (fd_core_file >= 0)
+                       close(fd_core_file);
+               if (fd_peer_pidfd >= 0)
+                       close(fd_peer_pidfd);
+               if (fd_coredump >= 0)
+                       close(fd_coredump);
+               if (fd_server >= 0)
+                       close(fd_server);
+               _exit(exit_code);
+       }
+       self->pid_coredump_server = pid_coredump_server;
+
+       EXPECT_EQ(close(ipc_sockets[1]), 0);
+       ASSERT_EQ(read_nointr(ipc_sockets[0], &c, 1), 1);
+       EXPECT_EQ(close(ipc_sockets[0]), 0);
+
+       pid = fork();
+       ASSERT_GE(pid, 0);
+       if (pid == 0)
+               abort();
+
+       pidfd = sys_pidfd_open(pid, 0);
+       ASSERT_GE(pidfd, 0);
+
+       waitpid(pid, &status, 0);
+       ASSERT_TRUE(WIFSIGNALED(status));
+       ASSERT_EQ(WTERMSIG(status), SIGABRT);
+       ASSERT_TRUE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_TRUE(!!(info.mask & PIDFD_INFO_COREDUMP));
+       ASSERT_TRUE(!!(info.mask & PIDFD_INFO_COREDUMP_SIGNAL));
+       ASSERT_EQ(info.coredump_signal, SIGABRT);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
 TEST_F(coredump, socket_invalid_paths)
 {
        ASSERT_FALSE(set_core_pattern("@ /tmp/coredump.socket"));