selftests/coredump: add debug logging to coredump socket protocol tests

So it's easier to figure out bugs.

Link: https://patch.msgid.link/20251028-work-coredump-signal-v1-19-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_protocol_test.c b/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
index cc7364499c55729b1894b9a9a82afc56943df8b5..566545e96d7f8278d3e7377ad4fd1df68057085c 100644 (file)
--- a/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
+++ b/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
@@ -101,67 +101,97 @@ TEST_F(coredump, socket_request_kernel)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_request_kernel: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_request_kernel: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_request_kernel: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_request_kernel: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_request_kernel: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_request_kernel: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_request_kernel: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
                fd_core_file = creat("/tmp/coredump.file", 0644);
-               if (fd_core_file < 0)
+               if (fd_core_file < 0) {
+                       fprintf(stderr, "socket_request_kernel: creat coredump file failed: %m\n");
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_request_kernel: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                        COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                                       COREDUMP_REJECT | COREDUMP_WAIT)) {
+                       fprintf(stderr, "socket_request_kernel: check_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
-                                      COREDUMP_KERNEL | COREDUMP_WAIT, 0))
+                                      COREDUMP_KERNEL | COREDUMP_WAIT, 0)) {
+                       fprintf(stderr, "socket_request_kernel: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK)) {
+                       fprintf(stderr, "socket_request_kernel: read_marker COREDUMP_MARK_REQACK failed\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)
+                       if (bytes_read < 0) {
+                               fprintf(stderr, "socket_request_kernel: 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)
+                       if (bytes_read != bytes_write) {
+                               fprintf(stderr, "socket_request_kernel: write to core file failed (read=%zd, write=%zd): %m\n",
+                                       bytes_read, bytes_write);
                                goto out;
+                       }
                }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_request_kernel: completed successfully\n");
 out:
                if (fd_core_file >= 0)
                        close(fd_core_file);
@@ -225,62 +255,89 @@ TEST_F(coredump, socket_request_userspace)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_request_userspace: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_request_userspace: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_request_userspace: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_request_userspace: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_request_userspace: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_request_userspace: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_request_userspace: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_request_userspace: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                        COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                                       COREDUMP_REJECT | COREDUMP_WAIT)) {
+                       fprintf(stderr, "socket_request_userspace: check_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
-                                      COREDUMP_USERSPACE | COREDUMP_WAIT, 0))
+                                      COREDUMP_USERSPACE | COREDUMP_WAIT, 0)) {
+                       fprintf(stderr, "socket_request_userspace: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK)) {
+                       fprintf(stderr, "socket_request_userspace: read_marker COREDUMP_MARK_REQACK failed\n");
                        goto out;
+               }
 
                for (;;) {
                        char buffer[4096];
                        ssize_t bytes_read;
 
                        bytes_read = read(fd_coredump, buffer, sizeof(buffer));
-                       if (bytes_read > 0)
+                       if (bytes_read > 0) {
+                               fprintf(stderr, "socket_request_userspace: unexpected data received (expected no coredump data)\n");
                                goto out;
+                       }
 
-                       if (bytes_read < 0)
+                       if (bytes_read < 0) {
+                               fprintf(stderr, "socket_request_userspace: read from coredump socket failed: %m\n");
                                goto out;
+                       }
 
                        if (bytes_read == 0)
                                break;
                }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_request_userspace: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -338,62 +395,89 @@ TEST_F(coredump, socket_request_reject)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_request_reject: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_request_reject: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_request_reject: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_request_reject: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_request_reject: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_request_reject: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_request_reject: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_request_reject: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                        COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                                       COREDUMP_REJECT | COREDUMP_WAIT)) {
+                       fprintf(stderr, "socket_request_reject: check_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
-                                      COREDUMP_REJECT | COREDUMP_WAIT, 0))
+                                      COREDUMP_REJECT | COREDUMP_WAIT, 0)) {
+                       fprintf(stderr, "socket_request_reject: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK)) {
+                       fprintf(stderr, "socket_request_reject: read_marker COREDUMP_MARK_REQACK failed\n");
                        goto out;
+               }
 
                for (;;) {
                        char buffer[4096];
                        ssize_t bytes_read;
 
                        bytes_read = read(fd_coredump, buffer, sizeof(buffer));
-                       if (bytes_read > 0)
+                       if (bytes_read > 0) {
+                               fprintf(stderr, "socket_request_reject: unexpected data received (expected no coredump data for REJECT)\n");
                                goto out;
+                       }
 
-                       if (bytes_read < 0)
+                       if (bytes_read < 0) {
+                               fprintf(stderr, "socket_request_reject: read from coredump socket failed: %m\n");
                                goto out;
+                       }
 
                        if (bytes_read == 0)
                                break;
                }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_request_reject: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -451,47 +535,70 @@ TEST_F(coredump, socket_request_invalid_flag_combination)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                        COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                                       COREDUMP_REJECT | COREDUMP_WAIT)) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: check_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
-                                      COREDUMP_KERNEL | COREDUMP_REJECT | COREDUMP_WAIT, 0))
+                                      COREDUMP_KERNEL | COREDUMP_REJECT | COREDUMP_WAIT, 0)) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_CONFLICTING))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_CONFLICTING)) {
+                       fprintf(stderr, "socket_request_invalid_flag_combination: read_marker COREDUMP_MARK_CONFLICTING failed\n");
                        goto out;
+               }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_request_invalid_flag_combination: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -549,46 +656,69 @@ TEST_F(coredump, socket_request_unknown_flag)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_request_unknown_flag: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_request_unknown_flag: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_request_unknown_flag: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_request_unknown_flag: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_request_unknown_flag: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_request_unknown_flag: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_request_unknown_flag: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_request_unknown_flag: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                        COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                                       COREDUMP_REJECT | COREDUMP_WAIT)) {
+                       fprintf(stderr, "socket_request_unknown_flag: check_coredump_req failed\n");
                        goto out;
+               }
 
-               if (!send_coredump_ack(fd_coredump, &req, (1ULL << 63), 0))
+               if (!send_coredump_ack(fd_coredump, &req, (1ULL << 63), 0)) {
+                       fprintf(stderr, "socket_request_unknown_flag: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_UNSUPPORTED))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_UNSUPPORTED)) {
+                       fprintf(stderr, "socket_request_unknown_flag: read_marker COREDUMP_MARK_UNSUPPORTED failed\n");
                        goto out;
+               }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_request_unknown_flag: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -646,48 +776,71 @@ TEST_F(coredump, socket_request_invalid_size_small)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_small: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_small: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_small: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_small: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_request_invalid_size_small: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_request_invalid_size_small: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_request_invalid_size_small: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_request_invalid_size_small: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                        COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                                       COREDUMP_REJECT | COREDUMP_WAIT)) {
+                       fprintf(stderr, "socket_request_invalid_size_small: check_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
                                       COREDUMP_REJECT | COREDUMP_WAIT,
-                                      COREDUMP_ACK_SIZE_VER0 / 2))
+                                      COREDUMP_ACK_SIZE_VER0 / 2)) {
+                       fprintf(stderr, "socket_request_invalid_size_small: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_MINSIZE))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_MINSIZE)) {
+                       fprintf(stderr, "socket_request_invalid_size_small: read_marker COREDUMP_MARK_MINSIZE failed\n");
                        goto out;
+               }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_request_invalid_size_small: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -745,48 +898,71 @@ TEST_F(coredump, socket_request_invalid_size_large)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_large: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_large: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_large: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_request_invalid_size_large: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_request_invalid_size_large: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_request_invalid_size_large: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_request_invalid_size_large: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_request_invalid_size_large: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                        COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                                       COREDUMP_REJECT | COREDUMP_WAIT)) {
+                       fprintf(stderr, "socket_request_invalid_size_large: check_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
                                       COREDUMP_REJECT | COREDUMP_WAIT,
-                                      COREDUMP_ACK_SIZE_VER0 + PAGE_SIZE))
+                                      COREDUMP_ACK_SIZE_VER0 + PAGE_SIZE)) {
+                       fprintf(stderr, "socket_request_invalid_size_large: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_MAXSIZE))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_MAXSIZE)) {
+                       fprintf(stderr, "socket_request_invalid_size_large: read_marker COREDUMP_MARK_MAXSIZE failed\n");
                        goto out;
+               }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_request_invalid_size_large: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -850,49 +1026,75 @@ TEST_F(coredump, socket_coredump_signal_sigsegv)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: 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)
+               if (fd_coredump < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: accept4 failed: %m\n");
                        goto out;
+               }
 
                fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-               if (fd_peer_pidfd < 0)
+               if (fd_peer_pidfd < 0) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: get_peer_pidfd failed\n");
                        goto out;
+               }
 
-               if (!get_pidfd_info(fd_peer_pidfd, &info))
+               if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: get_pidfd_info failed\n");
                        goto out;
+               }
 
-               if (!(info.mask & PIDFD_INFO_COREDUMP))
+               if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: PIDFD_INFO_COREDUMP not set in mask\n");
                        goto out;
+               }
 
-               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+               if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: PIDFD_COREDUMPED not set in coredump_mask\n");
                        goto out;
+               }
 
                /* Verify coredump_signal is available and correct */
-               if (!(info.mask & PIDFD_INFO_COREDUMP_SIGNAL))
+               if (!(info.mask & PIDFD_INFO_COREDUMP_SIGNAL)) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: PIDFD_INFO_COREDUMP_SIGNAL not set in mask\n");
                        goto out;
+               }
 
-               if (info.coredump_signal != SIGSEGV)
+               if (info.coredump_signal != SIGSEGV) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: coredump_signal=%d, expected SIGSEGV=%d\n",
+                               info.coredump_signal, SIGSEGV);
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
-                                      COREDUMP_REJECT | COREDUMP_WAIT, 0))
+                                      COREDUMP_REJECT | COREDUMP_WAIT, 0)) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK)) {
+                       fprintf(stderr, "socket_coredump_signal_sigsegv: read_marker COREDUMP_MARK_REQACK failed\n");
                        goto out;
+               }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_coredump_signal_sigsegv: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -957,49 +1159,75 @@ TEST_F(coredump, socket_coredump_signal_sigabrt)
                close(ipc_sockets[0]);
 
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               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)
+               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)
+               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)
+               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))
+               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))
+               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))
+               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))
+               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)
+               if (info.coredump_signal != SIGABRT) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: coredump_signal=%d, expected SIGABRT=%d\n",
+                               info.coredump_signal, SIGABRT);
                        goto out;
+               }
 
-               if (!read_coredump_req(fd_coredump, &req))
+               if (!read_coredump_req(fd_coredump, &req)) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: read_coredump_req failed\n");
                        goto out;
+               }
 
                if (!send_coredump_ack(fd_coredump, &req,
-                                      COREDUMP_REJECT | COREDUMP_WAIT, 0))
+                                      COREDUMP_REJECT | COREDUMP_WAIT, 0)) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: send_coredump_ack failed\n");
                        goto out;
+               }
 
-               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK)) {
+                       fprintf(stderr, "socket_coredump_signal_sigabrt: read_marker COREDUMP_MARK_REQACK failed\n");
                        goto out;
+               }
 
                exit_code = EXIT_SUCCESS;
+               fprintf(stderr, "socket_coredump_signal_sigabrt: completed successfully\n");
 out:
                if (fd_peer_pidfd >= 0)
                        close(fd_peer_pidfd);
@@ -1213,11 +1441,15 @@ TEST_F_TIMEOUT(coredump, socket_multiple_crashing_coredumps_epoll_workers, 500)
                n_conns = 0;
                close(ipc_sockets[0]);
                fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
-               if (fd_server < 0)
+               if (fd_server < 0) {
+                       fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: create_and_listen_unix_socket failed: %m\n");
                        goto out;
+               }
 
-               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: write_nointr to ipc socket failed: %m\n");
                        goto out;
+               }
                close(ipc_sockets[1]);
 
                while (n_conns < NUM_CRASHING_COREDUMPS) {
@@ -1227,28 +1459,45 @@ TEST_F_TIMEOUT(coredump, socket_multiple_crashing_coredumps_epoll_workers, 500)
                        if (fd_coredump < 0) {
                                if (errno == EAGAIN || errno == EWOULDBLOCK)
                                        continue;
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: accept4 failed: %m\n");
                                goto out;
                        }
                        fd_peer_pidfd = get_peer_pidfd(fd_coredump);
-                       if (fd_peer_pidfd < 0)
+                       if (fd_peer_pidfd < 0) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: get_peer_pidfd failed\n");
                                goto out;
-                       if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       }
+                       if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: get_pidfd_info failed\n");
                                goto out;
-                       if (!(info.mask & PIDFD_INFO_COREDUMP) || !(info.coredump_mask & PIDFD_COREDUMPED))
+                       }
+                       if (!(info.mask & PIDFD_INFO_COREDUMP) || !(info.coredump_mask & PIDFD_COREDUMPED)) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: missing PIDFD_INFO_COREDUMP or PIDFD_COREDUMPED\n");
                                goto out;
-                       if (!read_coredump_req(fd_coredump, &req))
+                       }
+                       if (!read_coredump_req(fd_coredump, &req)) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: read_coredump_req failed\n");
                                goto out;
+                       }
                        if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
                                                COREDUMP_KERNEL | COREDUMP_USERSPACE |
-                                               COREDUMP_REJECT | COREDUMP_WAIT))
+                                               COREDUMP_REJECT | COREDUMP_WAIT)) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: check_coredump_req failed\n");
                                goto out;
-                       if (!send_coredump_ack(fd_coredump, &req, COREDUMP_KERNEL | COREDUMP_WAIT, 0))
+                       }
+                       if (!send_coredump_ack(fd_coredump, &req, COREDUMP_KERNEL | COREDUMP_WAIT, 0)) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: send_coredump_ack failed\n");
                                goto out;
-                       if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+                       }
+                       if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK)) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: read_marker failed\n");
                                goto out;
+                       }
                        fd_core_file = open_coredump_tmpfile(self->fd_tmpfs_detached);
-                       if (fd_core_file < 0)
+                       if (fd_core_file < 0) {
+                               fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: open_coredump_tmpfile failed: %m\n");
                                goto out;
+                       }
                        pid_t worker = fork();
                        if (worker == 0) {
                                close(fd_server);