]> git.ipfire.org Git - thirdparty/kernel/stable.git/commitdiff
selftests/coredump: add coredump server selftests
authorChristian Brauner <brauner@kernel.org>
Tue, 3 Jun 2025 13:31:59 +0000 (15:31 +0200)
committerChristian Brauner <brauner@kernel.org>
Thu, 12 Jun 2025 12:00:32 +0000 (14:00 +0200)
This adds extensive tests for the coredump server.

Link: https://lore.kernel.org/20250603-work-coredump-socket-protocol-v2-5-05a5f0c18ecc@kernel.org
Acked-by: Lennart Poettering <lennart@poettering.net>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
tools/testing/selftests/coredump/Makefile
tools/testing/selftests/coredump/config [new file with mode: 0644]
tools/testing/selftests/coredump/stackdump_test.c

index bc287a85b8255c77c0d912d1595a78ae05d8449a..77b3665c73c7c8dc7e7f9b45a3a9634cb4618ccf 100644 (file)
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
-CFLAGS = -Wall -O0 $(KHDR_INCLUDES)
+CFLAGS += -Wall -O0 -g $(KHDR_INCLUDES) $(TOOLS_INCLUDES)
 
 TEST_GEN_PROGS := stackdump_test
 TEST_FILES := stackdump
diff --git a/tools/testing/selftests/coredump/config b/tools/testing/selftests/coredump/config
new file mode 100644 (file)
index 0000000..a05ef11
--- /dev/null
@@ -0,0 +1,3 @@
+CONFIG_COREDUMP=y
+CONFIG_NET=y
+CONFIG_UNIX=y
index 4d922e5f89fe9d347b9994fd427f56b98dcc6157..9a789156f27ea30eca88c2abf8c427bb9fcb0105 100644 (file)
@@ -4,10 +4,15 @@
 #include <fcntl.h>
 #include <inttypes.h>
 #include <libgen.h>
+#include <limits.h>
+#include <linux/coredump.h>
+#include <linux/fs.h>
 #include <linux/limits.h>
 #include <pthread.h>
 #include <string.h>
 #include <sys/mount.h>
+#include <poll.h>
+#include <sys/epoll.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
@@ -15,6 +20,7 @@
 #include <unistd.h>
 
 #include "../kselftest_harness.h"
+#include "../filesystems/wrappers.h"
 #include "../pidfd/pidfd.h"
 
 #define STACKDUMP_FILE "stack_values"
@@ -49,14 +55,32 @@ FIXTURE(coredump)
 {
        char original_core_pattern[256];
        pid_t pid_coredump_server;
+       int fd_tmpfs_detached;
 };
 
+static int create_detached_tmpfs(void)
+{
+       int fd_context, fd_tmpfs;
+
+       fd_context = sys_fsopen("tmpfs", 0);
+       if (fd_context < 0)
+               return -1;
+
+       if (sys_fsconfig(fd_context, FSCONFIG_CMD_CREATE, NULL, NULL, 0) < 0)
+               return -1;
+
+       fd_tmpfs = sys_fsmount(fd_context, 0, 0);
+       close(fd_context);
+       return fd_tmpfs;
+}
+
 FIXTURE_SETUP(coredump)
 {
        FILE *file;
        int ret;
 
        self->pid_coredump_server = -ESRCH;
+       self->fd_tmpfs_detached = -1;
        file = fopen("/proc/sys/kernel/core_pattern", "r");
        ASSERT_NE(NULL, file);
 
@@ -65,6 +89,8 @@ FIXTURE_SETUP(coredump)
        ASSERT_LT(ret, sizeof(self->original_core_pattern));
 
        self->original_core_pattern[ret] = '\0';
+       self->fd_tmpfs_detached = create_detached_tmpfs();
+       ASSERT_GE(self->fd_tmpfs_detached, 0);
 
        ret = fclose(file);
        ASSERT_EQ(0, ret);
@@ -103,6 +129,15 @@ FIXTURE_TEARDOWN(coredump)
                goto fail;
        }
 
+       if (self->fd_tmpfs_detached >= 0) {
+               ret = close(self->fd_tmpfs_detached);
+               if (ret < 0) {
+                       reason = "Unable to close detached tmpfs";
+                       goto fail;
+               }
+               self->fd_tmpfs_detached = -1;
+       }
+
        return;
 fail:
        /* This should never happen */
@@ -192,7 +227,7 @@ static int create_and_listen_unix_socket(const char *path)
        if (ret < 0)
                goto out;
 
-       ret = listen(fd, 1);
+       ret = listen(fd, 128);
        if (ret < 0)
                goto out;
 
@@ -551,4 +586,1222 @@ out:
        wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
 }
 
+static ssize_t recv_marker(int fd)
+{
+       enum coredump_mark mark = COREDUMP_MARK_REQACK;
+       ssize_t ret;
+
+       ret = recv(fd, &mark, sizeof(mark), MSG_WAITALL);
+       if (ret != sizeof(mark))
+               return -1;
+
+       switch (mark) {
+       case COREDUMP_MARK_REQACK:
+               fprintf(stderr, "Received marker: ReqAck\n");
+               return COREDUMP_MARK_REQACK;
+       case COREDUMP_MARK_MINSIZE:
+               fprintf(stderr, "Received marker: MinSize\n");
+               return COREDUMP_MARK_MINSIZE;
+       case COREDUMP_MARK_MAXSIZE:
+               fprintf(stderr, "Received marker: MaxSize\n");
+               return COREDUMP_MARK_MAXSIZE;
+       case COREDUMP_MARK_UNSUPPORTED:
+               fprintf(stderr, "Received marker: Unsupported\n");
+               return COREDUMP_MARK_UNSUPPORTED;
+       case COREDUMP_MARK_CONFLICTING:
+               fprintf(stderr, "Received marker: Conflicting\n");
+               return COREDUMP_MARK_CONFLICTING;
+       default:
+               fprintf(stderr, "Received unknown marker: %u\n", mark);
+               break;
+       }
+       return -1;
+}
+
+static bool read_marker(int fd, enum coredump_mark mark)
+{
+       ssize_t ret;
+
+       ret = recv_marker(fd);
+       if (ret < 0)
+               return false;
+       return ret == mark;
+}
+
+static bool read_coredump_req(int fd, struct coredump_req *req)
+{
+       ssize_t ret;
+       size_t field_size, user_size, ack_size, kernel_size, remaining_size;
+
+       memset(req, 0, sizeof(*req));
+       field_size = sizeof(req->size);
+
+       /* Peek the size of the coredump request. */
+       ret = recv(fd, req, field_size, MSG_PEEK | MSG_WAITALL);
+       if (ret != field_size)
+               return false;
+       kernel_size = req->size;
+
+       if (kernel_size < COREDUMP_ACK_SIZE_VER0)
+               return false;
+       if (kernel_size >= PAGE_SIZE)
+               return false;
+
+       /* Use the minimum of user and kernel size to read the full request. */
+       user_size = sizeof(struct coredump_req);
+       ack_size = user_size < kernel_size ? user_size : kernel_size;
+       ret = recv(fd, req, ack_size, MSG_WAITALL);
+       if (ret != ack_size)
+               return false;
+
+       fprintf(stderr, "Read coredump request with size %u and mask 0x%llx\n",
+               req->size, (unsigned long long)req->mask);
+
+       if (user_size > kernel_size)
+               remaining_size = user_size - kernel_size;
+       else
+               remaining_size = kernel_size - user_size;
+
+       if (PAGE_SIZE <= remaining_size)
+               return false;
+
+       /*
+        * Discard any additional data if the kernel's request was larger than
+        * what we knew about or cared about.
+        */
+       if (remaining_size) {
+               char buffer[PAGE_SIZE];
+
+               ret = recv(fd, buffer, sizeof(buffer), MSG_WAITALL);
+               if (ret != remaining_size)
+                       return false;
+               fprintf(stderr, "Discarded %zu bytes of data after coredump request\n", remaining_size);
+       }
+
+       return true;
+}
+
+static bool send_coredump_ack(int fd, const struct coredump_req *req,
+                             __u64 mask, size_t size_ack)
+{
+       ssize_t ret;
+       /*
+        * Wrap struct coredump_ack in a larger struct so we can
+        * simulate sending to much data to the kernel.
+        */
+       struct large_ack_for_size_testing {
+               struct coredump_ack ack;
+               char buffer[PAGE_SIZE];
+       } large_ack = {};
+
+       if (!size_ack)
+               size_ack = sizeof(struct coredump_ack) < req->size_ack ?
+                                  sizeof(struct coredump_ack) :
+                                  req->size_ack;
+       large_ack.ack.mask = mask;
+       large_ack.ack.size = size_ack;
+       ret = send(fd, &large_ack, size_ack, MSG_NOSIGNAL);
+       if (ret != size_ack)
+               return false;
+
+       fprintf(stderr, "Sent coredump ack with size %zu and mask 0x%llx\n",
+               size_ack, (unsigned long long)mask);
+       return true;
+}
+
+static bool check_coredump_req(const struct coredump_req *req, size_t min_size,
+                              __u64 required_mask)
+{
+       if (req->size < min_size)
+               return false;
+       if ((req->mask & required_mask) != required_mask)
+               return false;
+       if (req->mask & ~required_mask)
+               return false;
+       return true;
+}
+
+TEST_F(coredump, socket_request_kernel)
+{
+       int pidfd, ret, status;
+       pid_t pid, pid_coredump_server;
+       struct stat st;
+       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) {
+               struct coredump_req req = {};
+               int fd_server = -1, fd_coredump = -1, fd_core_file = -1, fd_peer_pidfd = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0)
+                       goto out;
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0)
+                       goto out;
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       goto out;
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP))
+                       goto out;
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+                       goto out;
+
+               fd_core_file = creat("/tmp/coredump.file", 0644);
+               if (fd_core_file < 0)
+                       goto out;
+
+               if (!read_coredump_req(fd_coredump, &req))
+                       goto out;
+
+               if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                       COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                       goto out;
+
+               if (!send_coredump_ack(fd_coredump, &req,
+                                      COREDUMP_KERNEL | COREDUMP_WAIT, 0))
+                       goto out;
+
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+                       goto out;
+
+               for (;;) {
+                       char buffer[4096];
+                       ssize_t bytes_read, bytes_write;
+
+                       bytes_read = read(fd_coredump, buffer, sizeof(buffer));
+                       if (bytes_read < 0)
+                               goto out;
+
+                       if (bytes_read == 0)
+                               break;
+
+                       bytes_write = write(fd_core_file, buffer, bytes_read);
+                       if (bytes_read != bytes_write)
+                               goto out;
+               }
+
+               exit_code = EXIT_SUCCESS;
+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_TRUE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+       ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+
+       ASSERT_EQ(stat("/tmp/coredump.file", &st), 0);
+       ASSERT_GT(st.st_size, 0);
+       system("file /tmp/coredump.file");
+}
+
+TEST_F(coredump, socket_request_userspace)
+{
+       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) {
+               struct coredump_req req = {};
+               int fd_server = -1, fd_coredump = -1, fd_peer_pidfd = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0)
+                       goto out;
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0)
+                       goto out;
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       goto out;
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP))
+                       goto out;
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+                       goto out;
+
+               if (!read_coredump_req(fd_coredump, &req))
+                       goto out;
+
+               if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                       COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                       goto out;
+
+               if (!send_coredump_ack(fd_coredump, &req,
+                                      COREDUMP_USERSPACE | COREDUMP_WAIT, 0))
+                       goto out;
+
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+                       goto out;
+
+               for (;;) {
+                       char buffer[4096];
+                       ssize_t bytes_read;
+
+                       bytes_read = read(fd_coredump, buffer, sizeof(buffer));
+                       if (bytes_read > 0)
+                               goto out;
+
+                       if (bytes_read < 0)
+                               goto out;
+
+                       if (bytes_read == 0)
+                               break;
+               }
+
+               exit_code = EXIT_SUCCESS;
+out:
+               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_TRUE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+       ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
+TEST_F(coredump, socket_request_reject)
+{
+       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) {
+               struct coredump_req req = {};
+               int fd_server = -1, fd_coredump = -1, fd_peer_pidfd = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0)
+                       goto out;
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0)
+                       goto out;
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       goto out;
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP))
+                       goto out;
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+                       goto out;
+
+               if (!read_coredump_req(fd_coredump, &req))
+                       goto out;
+
+               if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                       COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                       goto out;
+
+               if (!send_coredump_ack(fd_coredump, &req,
+                                      COREDUMP_REJECT | COREDUMP_WAIT, 0))
+                       goto out;
+
+               if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+                       goto out;
+
+               for (;;) {
+                       char buffer[4096];
+                       ssize_t bytes_read;
+
+                       bytes_read = read(fd_coredump, buffer, sizeof(buffer));
+                       if (bytes_read > 0)
+                               goto out;
+
+                       if (bytes_read < 0)
+                               goto out;
+
+                       if (bytes_read == 0)
+                               break;
+               }
+
+               exit_code = EXIT_SUCCESS;
+out:
+               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_FALSE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+       ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
+TEST_F(coredump, socket_request_invalid_flag_combination)
+{
+       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) {
+               struct coredump_req req = {};
+               int fd_server = -1, fd_coredump = -1, fd_peer_pidfd = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0)
+                       goto out;
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0)
+                       goto out;
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       goto out;
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP))
+                       goto out;
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+                       goto out;
+
+               if (!read_coredump_req(fd_coredump, &req))
+                       goto out;
+
+               if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                       COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                       goto out;
+
+               if (!send_coredump_ack(fd_coredump, &req,
+                                      COREDUMP_KERNEL | COREDUMP_REJECT | COREDUMP_WAIT, 0))
+                       goto out;
+
+               if (!read_marker(fd_coredump, COREDUMP_MARK_CONFLICTING))
+                       goto out;
+
+               exit_code = EXIT_SUCCESS;
+out:
+               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_FALSE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+       ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
+TEST_F(coredump, socket_request_unknown_flag)
+{
+       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) {
+               struct coredump_req req = {};
+               int fd_server = -1, fd_coredump = -1, fd_peer_pidfd = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0)
+                       goto out;
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0)
+                       goto out;
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       goto out;
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP))
+                       goto out;
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+                       goto out;
+
+               if (!read_coredump_req(fd_coredump, &req))
+                       goto out;
+
+               if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                       COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                       goto out;
+
+               if (!send_coredump_ack(fd_coredump, &req, (1ULL << 63), 0))
+                       goto out;
+
+               if (!read_marker(fd_coredump, COREDUMP_MARK_UNSUPPORTED))
+                       goto out;
+
+               exit_code = EXIT_SUCCESS;
+out:
+               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_FALSE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+       ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
+TEST_F(coredump, socket_request_invalid_size_small)
+{
+       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) {
+               struct coredump_req req = {};
+               int fd_server = -1, fd_coredump = -1, fd_peer_pidfd = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0)
+                       goto out;
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0)
+                       goto out;
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       goto out;
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP))
+                       goto out;
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+                       goto out;
+
+               if (!read_coredump_req(fd_coredump, &req))
+                       goto out;
+
+               if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                       COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                       goto out;
+
+               if (!send_coredump_ack(fd_coredump, &req,
+                                      COREDUMP_REJECT | COREDUMP_WAIT,
+                                      COREDUMP_ACK_SIZE_VER0 / 2))
+                       goto out;
+
+               if (!read_marker(fd_coredump, COREDUMP_MARK_MINSIZE))
+                       goto out;
+
+               exit_code = EXIT_SUCCESS;
+out:
+               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_FALSE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+       ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
+TEST_F(coredump, socket_request_invalid_size_large)
+{
+       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) {
+               struct coredump_req req = {};
+               int fd_server = -1, fd_coredump = -1, fd_peer_pidfd = -1;
+               int exit_code = EXIT_FAILURE;
+
+               close(ipc_sockets[0]);
+
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+
+               close(ipc_sockets[1]);
+
+               fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+               if (fd_coredump < 0)
+                       goto out;
+
+               fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+               if (fd_peer_pidfd < 0)
+                       goto out;
+
+               if (!get_pidfd_info(fd_peer_pidfd, &info))
+                       goto out;
+
+               if (!(info.mask & PIDFD_INFO_COREDUMP))
+                       goto out;
+
+               if (!(info.coredump_mask & PIDFD_COREDUMPED))
+                       goto out;
+
+               if (!read_coredump_req(fd_coredump, &req))
+                       goto out;
+
+               if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                       COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                       COREDUMP_REJECT | COREDUMP_WAIT))
+                       goto out;
+
+               if (!send_coredump_ack(fd_coredump, &req,
+                                      COREDUMP_REJECT | COREDUMP_WAIT,
+                                      COREDUMP_ACK_SIZE_VER0 + PAGE_SIZE))
+                       goto out;
+
+               if (!read_marker(fd_coredump, COREDUMP_MARK_MAXSIZE))
+                       goto out;
+
+               exit_code = EXIT_SUCCESS;
+out:
+               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_FALSE(WCOREDUMP(status));
+
+       ASSERT_TRUE(get_pidfd_info(pidfd, &info));
+       ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+       ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
+static int open_coredump_tmpfile(int fd_tmpfs_detached)
+{
+       return openat(fd_tmpfs_detached, ".", O_TMPFILE | O_RDWR | O_EXCL, 0600);
+}
+
+#define NUM_CRASHING_COREDUMPS 5
+
+TEST_F_TIMEOUT(coredump, socket_multiple_crashing_coredumps, 500)
+{
+       int pidfd[NUM_CRASHING_COREDUMPS], status[NUM_CRASHING_COREDUMPS];
+       pid_t pid[NUM_CRASHING_COREDUMPS], pid_coredump_server;
+       struct pidfd_info info = {};
+       int ipc_sockets[2];
+       char c;
+
+       ASSERT_TRUE(set_core_pattern("@@/tmp/coredump.socket"));
+
+       ASSERT_EQ(socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets), 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;
+               struct coredump_req req = {};
+
+               close(ipc_sockets[0]);
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0) {
+                       fprintf(stderr, "Failed to create and listen on unix socket\n");
+                       goto out;
+               }
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0) {
+                       fprintf(stderr, "Failed to notify parent via ipc socket\n");
+                       goto out;
+               }
+               close(ipc_sockets[1]);
+
+               for (int i = 0; i < NUM_CRASHING_COREDUMPS; i++) {
+                       fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+                       if (fd_coredump < 0) {
+                               fprintf(stderr, "accept4 failed: %m\n");
+                               goto out;
+                       }
+
+                       fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+                       if (fd_peer_pidfd < 0) {
+                               fprintf(stderr, "get_peer_pidfd failed for fd %d: %m\n", fd_coredump);
+                               goto out;
+                       }
+
+                       if (!get_pidfd_info(fd_peer_pidfd, &info)) {
+                               fprintf(stderr, "get_pidfd_info failed for fd %d\n", fd_peer_pidfd);
+                               goto out;
+                       }
+
+                       if (!(info.mask & PIDFD_INFO_COREDUMP)) {
+                               fprintf(stderr, "pidfd info missing PIDFD_INFO_COREDUMP for fd %d\n", fd_peer_pidfd);
+                               goto out;
+                       }
+                       if (!(info.coredump_mask & PIDFD_COREDUMPED)) {
+                               fprintf(stderr, "pidfd info missing PIDFD_COREDUMPED for fd %d\n", fd_peer_pidfd);
+                               goto out;
+                       }
+
+                       if (!read_coredump_req(fd_coredump, &req)) {
+                               fprintf(stderr, "read_coredump_req failed for fd %d\n", fd_coredump);
+                               goto out;
+                       }
+
+                       if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                               COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                               COREDUMP_REJECT | COREDUMP_WAIT)) {
+                               fprintf(stderr, "check_coredump_req failed for fd %d\n", fd_coredump);
+                               goto out;
+                       }
+
+                       if (!send_coredump_ack(fd_coredump, &req,
+                                              COREDUMP_KERNEL | COREDUMP_WAIT, 0)) {
+                               fprintf(stderr, "send_coredump_ack failed for fd %d\n", fd_coredump);
+                               goto out;
+                       }
+
+                       if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK)) {
+                               fprintf(stderr, "read_marker failed for fd %d\n", fd_coredump);
+                               goto out;
+                       }
+
+                       fd_core_file = open_coredump_tmpfile(self->fd_tmpfs_detached);
+                       if (fd_core_file < 0) {
+                               fprintf(stderr, "%m - open_coredump_tmpfile failed for fd %d\n", fd_coredump);
+                               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, "read failed for fd %d: %m\n", fd_coredump);
+                                       goto out;
+                               }
+
+                               if (bytes_read == 0)
+                                       break;
+
+                               bytes_write = write(fd_core_file, buffer, bytes_read);
+                               if (bytes_read != bytes_write) {
+                                       fprintf(stderr, "write failed for fd %d: %m\n", fd_core_file);
+                                       goto out;
+                               }
+                       }
+
+                       close(fd_core_file);
+                       close(fd_peer_pidfd);
+                       close(fd_coredump);
+                       fd_peer_pidfd = -1;
+                       fd_coredump = -1;
+               }
+
+               exit_code = EXIT_SUCCESS;
+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);
+
+       for (int i = 0; i < NUM_CRASHING_COREDUMPS; i++) {
+               pid[i] = fork();
+               ASSERT_GE(pid[i], 0);
+               if (pid[i] == 0)
+                       crashing_child();
+               pidfd[i] = sys_pidfd_open(pid[i], 0);
+               ASSERT_GE(pidfd[i], 0);
+       }
+
+       for (int i = 0; i < NUM_CRASHING_COREDUMPS; i++) {
+               waitpid(pid[i], &status[i], 0);
+               ASSERT_TRUE(WIFSIGNALED(status[i]));
+               ASSERT_TRUE(WCOREDUMP(status[i]));
+       }
+
+       for (int i = 0; i < NUM_CRASHING_COREDUMPS; i++) {
+               info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP;
+               ASSERT_EQ(ioctl(pidfd[i], PIDFD_GET_INFO, &info), 0);
+               ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+               ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+       }
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
+#define MAX_EVENTS 128
+
+static void process_coredump_worker(int fd_coredump, int fd_peer_pidfd, int fd_core_file)
+{
+       int epfd = -1;
+       int exit_code = EXIT_FAILURE;
+
+       epfd = epoll_create1(0);
+       if (epfd < 0)
+               goto out;
+
+       struct epoll_event ev;
+       ev.events = EPOLLIN | EPOLLRDHUP | EPOLLET;
+       ev.data.fd = fd_coredump;
+       if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd_coredump, &ev) < 0)
+               goto out;
+
+       for (;;) {
+               struct epoll_event events[1];
+               int n = epoll_wait(epfd, events, 1, -1);
+               if (n < 0)
+                       break;
+
+               if (events[0].events & (EPOLLIN | EPOLLRDHUP)) {
+                       for (;;) {
+                               char buffer[4096];
+                               ssize_t bytes_read = read(fd_coredump, buffer, sizeof(buffer));
+                               if (bytes_read < 0) {
+                                       if (errno == EAGAIN || errno == EWOULDBLOCK)
+                                               break;
+                                       goto out;
+                               }
+                               if (bytes_read == 0)
+                                       goto done;
+                               ssize_t bytes_write = write(fd_core_file, buffer, bytes_read);
+                               if (bytes_write != bytes_read)
+                                       goto out;
+                       }
+               }
+       }
+
+done:
+       exit_code = EXIT_SUCCESS;
+out:
+       if (epfd >= 0)
+               close(epfd);
+       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);
+       _exit(exit_code);
+}
+
+TEST_F_TIMEOUT(coredump, socket_multiple_crashing_coredumps_epoll_workers, 500)
+{
+       int pidfd[NUM_CRASHING_COREDUMPS], status[NUM_CRASHING_COREDUMPS];
+       pid_t pid[NUM_CRASHING_COREDUMPS], pid_coredump_server, worker_pids[NUM_CRASHING_COREDUMPS];
+       struct pidfd_info info = {};
+       int ipc_sockets[2];
+       char c;
+
+       ASSERT_TRUE(set_core_pattern("@@/tmp/coredump.socket"));
+       ASSERT_EQ(socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ipc_sockets), 0);
+
+       pid_coredump_server = fork();
+       ASSERT_GE(pid_coredump_server, 0);
+       if (pid_coredump_server == 0) {
+               int fd_server = -1, exit_code = EXIT_FAILURE, n_conns = 0;
+               fd_server = -1;
+               exit_code = EXIT_FAILURE;
+               n_conns = 0;
+               close(ipc_sockets[0]);
+               fd_server = create_and_listen_unix_socket("/tmp/coredump.socket");
+               if (fd_server < 0)
+                       goto out;
+
+               if (write_nointr(ipc_sockets[1], "1", 1) < 0)
+                       goto out;
+               close(ipc_sockets[1]);
+
+               while (n_conns < NUM_CRASHING_COREDUMPS) {
+                       int fd_coredump = -1, fd_peer_pidfd = -1, fd_core_file = -1;
+                       struct coredump_req req = {};
+                       fd_coredump = accept4(fd_server, NULL, NULL, SOCK_CLOEXEC);
+                       if (fd_coredump < 0) {
+                               if (errno == EAGAIN || errno == EWOULDBLOCK)
+                                       continue;
+                               goto out;
+                       }
+                       fd_peer_pidfd = get_peer_pidfd(fd_coredump);
+                       if (fd_peer_pidfd < 0)
+                               goto out;
+                       if (!get_pidfd_info(fd_peer_pidfd, &info))
+                               goto out;
+                       if (!(info.mask & PIDFD_INFO_COREDUMP) || !(info.coredump_mask & PIDFD_COREDUMPED))
+                               goto out;
+                       if (!read_coredump_req(fd_coredump, &req))
+                               goto out;
+                       if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
+                                               COREDUMP_KERNEL | COREDUMP_USERSPACE |
+                                               COREDUMP_REJECT | COREDUMP_WAIT))
+                               goto out;
+                       if (!send_coredump_ack(fd_coredump, &req, COREDUMP_KERNEL | COREDUMP_WAIT, 0))
+                               goto out;
+                       if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+                               goto out;
+                       fd_core_file = open_coredump_tmpfile(self->fd_tmpfs_detached);
+                       if (fd_core_file < 0)
+                               goto out;
+                       pid_t worker = fork();
+                       if (worker == 0) {
+                               close(fd_server);
+                               process_coredump_worker(fd_coredump, fd_peer_pidfd, fd_core_file);
+                       }
+                       worker_pids[n_conns] = worker;
+                       if (fd_coredump >= 0)
+                               close(fd_coredump);
+                       if (fd_peer_pidfd >= 0)
+                               close(fd_peer_pidfd);
+                       if (fd_core_file >= 0)
+                               close(fd_core_file);
+                       n_conns++;
+               }
+               exit_code = EXIT_SUCCESS;
+out:
+               if (fd_server >= 0)
+                       close(fd_server);
+
+               // Reap all worker processes
+               for (int i = 0; i < n_conns; i++) {
+                       int wstatus;
+                       if (waitpid(worker_pids[i], &wstatus, 0) < 0) {
+                               fprintf(stderr, "Failed to wait for worker %d: %m\n", worker_pids[i]);
+                       } else if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != EXIT_SUCCESS) {
+                               fprintf(stderr, "Worker %d exited with error code %d\n", worker_pids[i], WEXITSTATUS(wstatus));
+                               exit_code = EXIT_FAILURE;
+                       }
+               }
+
+               _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);
+
+       for (int i = 0; i < NUM_CRASHING_COREDUMPS; i++) {
+               pid[i] = fork();
+               ASSERT_GE(pid[i], 0);
+               if (pid[i] == 0)
+                       crashing_child();
+               pidfd[i] = sys_pidfd_open(pid[i], 0);
+               ASSERT_GE(pidfd[i], 0);
+       }
+
+       for (int i = 0; i < NUM_CRASHING_COREDUMPS; i++) {
+               ASSERT_GE(waitpid(pid[i], &status[i], 0), 0);
+               ASSERT_TRUE(WIFSIGNALED(status[i]));
+               ASSERT_TRUE(WCOREDUMP(status[i]));
+       }
+
+       for (int i = 0; i < NUM_CRASHING_COREDUMPS; i++) {
+               info.mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP;
+               ASSERT_EQ(ioctl(pidfd[i], PIDFD_GET_INFO, &info), 0);
+               ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
+               ASSERT_GT((info.coredump_mask & PIDFD_COREDUMPED), 0);
+       }
+
+       wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+}
+
 TEST_HARNESS_MAIN