[PATCH RFC v2 6/6] selftests/coredump: add tests for AF_UNIX coredumps

From: Christian Brauner
Date: Fri May 02 2025 - 08:45:08 EST


Add a simple test for generating coredumps via AF_UNIX sockets.

Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
tools/testing/selftests/coredump/stackdump_test.c | 50 +++++++++++++++++++++++
1 file changed, 50 insertions(+)

diff --git a/tools/testing/selftests/coredump/stackdump_test.c b/tools/testing/selftests/coredump/stackdump_test.c
index fe3c728cd6be..ccaee98dbee3 100644
--- a/tools/testing/selftests/coredump/stackdump_test.c
+++ b/tools/testing/selftests/coredump/stackdump_test.c
@@ -5,7 +5,9 @@
#include <linux/limits.h>
#include <pthread.h>
#include <string.h>
+#include <sys/mount.h>
#include <sys/resource.h>
+#include <sys/stat.h>
#include <unistd.h>

#include "../kselftest_harness.h"
@@ -154,4 +156,52 @@ TEST_F_TIMEOUT(coredump, stackdump, 120)
fclose(file);
}

+TEST_F(coredump, socket)
+{
+ int fd, ret, status;
+ FILE *file;
+ pid_t pid, pid_socat;
+ struct stat st;
+ char core_file[PATH_MAX];
+
+ ASSERT_EQ(unshare(CLONE_NEWNS), 0);
+ ASSERT_EQ(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL), 0);
+ ASSERT_EQ(mount(NULL, "/tmp", "tmpfs", 0, NULL), 0);
+
+ pid_socat = fork();
+ ASSERT_GE(pid_socat, 0);
+ if (pid_socat == 0) {
+ execlp("socat", "socat",
+ "unix-listen:/tmp/coredump.socket,fork",
+ "FILE:/tmp/coredump_file,create,append,trunc",
+ (char *)NULL);
+ _exit(EXIT_FAILURE);
+ }
+
+ file = fopen("/proc/sys/kernel/core_pattern", "w");
+ ASSERT_NE(NULL, file);
+
+ ret = fprintf(file, ":/tmp/coredump.socket");
+ ASSERT_EQ(ret, strlen(":/tmp/coredump.socket"));
+ ASSERT_EQ(fclose(file), 0);
+
+ pid = fork();
+ ASSERT_GE(pid, 0);
+ if (pid == 0)
+ crashing_child();
+
+ waitpid(pid, &status, 0);
+ ASSERT_TRUE(WIFSIGNALED(status));
+ ASSERT_TRUE(WCOREDUMP(status));
+
+ ASSERT_EQ(kill(pid_socat, SIGTERM), 0);
+ waitpid(pid_socat, &status, 0);
+ ASSERT_TRUE(WIFEXITED(status));
+ ASSERT_EQ(WEXITSTATUS(status), 143);
+
+ /* We should somehow validate the produced core file. */
+ ASSERT_EQ(stat("/tmp/coredump_file", &st), 0);
+ ASSERT_GT(st.st_size, 0);
+}
+
TEST_HARNESS_MAIN

--
2.47.2