From: Christian Brauner Date: Tue, 28 Oct 2025 08:46:06 +0000 (+0100) Subject: selftests/coredump: add first PIDFD_INFO_COREDUMP_SIGNAL test X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=619e2227cc324155e99bce56a8c9e751cbf777e5;p=thirdparty%2Fkernel%2Flinux.git selftests/coredump: add first PIDFD_INFO_COREDUMP_SIGNAL test Verify that when using simple socket-based coredump (@ pattern), the coredump_signal field is correctly exposed as SIGSEGV. Link: https://patch.msgid.link/20251028-work-coredump-signal-v1-21-ca449b7b7aa0@kernel.org Reviewed-by: Alexander Mikhalitsyn Signed-off-by: Christian Brauner --- diff --git a/tools/testing/selftests/coredump/coredump_socket_test.c b/tools/testing/selftests/coredump/coredump_socket_test.c index da558a0e37aaa..9d5507fa75ecb 100644 --- a/tools/testing/selftests/coredump/coredump_socket_test.c +++ b/tools/testing/selftests/coredump/coredump_socket_test.c @@ -430,6 +430,152 @@ out: wait_and_check_coredump_server(pid_coredump_server, _metadata, self); } +/* + * Test: PIDFD_INFO_COREDUMP_SIGNAL via simple socket coredump + * + * Verify that when using simple socket-based coredump (@ pattern), + * the coredump_signal field is correctly exposed as SIGSEGV. + */ +TEST_F(coredump, socket_coredump_signal_sigsegv) +{ + 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_sigsegv: create_and_listen_unix_socket failed: %m\n"); + goto out; + } + + 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) { + 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) { + fprintf(stderr, "socket_coredump_signal_sigsegv: get_peer_pidfd failed\n"); + goto out; + } + + 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)) { + fprintf(stderr, "socket_coredump_signal_sigsegv: PIDFD_INFO_COREDUMP not set in mask\n"); + goto out; + } + + 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)) { + fprintf(stderr, "socket_coredump_signal_sigsegv: PIDFD_INFO_COREDUMP_SIGNAL not set in mask\n"); + goto out; + } + + if (info.coredump_signal != SIGSEGV) { + fprintf(stderr, "socket_coredump_signal_sigsegv: coredump_signal=%d, expected SIGSEGV=%d\n", + info.coredump_signal, SIGSEGV); + goto out; + } + + fd_core_file = open_coredump_tmpfile(self->fd_tmpfs_detached); + if (fd_core_file < 0) { + fprintf(stderr, "socket_coredump_signal_sigsegv: 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_sigsegv: 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_sigsegv: 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_sigsegv: 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) + crashing_child(); + + pidfd = sys_pidfd_open(pid, 0); + ASSERT_GE(pidfd, 0); + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFSIGNALED(status)); + ASSERT_EQ(WTERMSIG(status), SIGSEGV); + 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, SIGSEGV); + + wait_and_check_coredump_server(pid_coredump_server, _metadata, self); +} + TEST_F(coredump, socket_invalid_paths) { ASSERT_FALSE(set_core_pattern("@ /tmp/coredump.socket"));