tools/testing/selftests/coredump/stackdump_test.c

// SPDX-License-Identifier: GPL-2.0

#include <assert.h>
#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>
#include <sys/un.h>
#include <unistd.h>

#include "../kselftest_harness.h"
#include "../filesystems/wrappers.h"
#include "../pidfd/pidfd.h"

#define STACKDUMP_FILE "stack_values"
#define STACKDUMP_SCRIPT "stackdump"
#define NUM_THREAD_SPAWN 128

#ifndef PAGE_SIZE
#define PAGE_SIZE 4096
#endif

static void *do_nothing(void *)
{
	while (1)
		pause();

	return NULL;
}

static void crashing_child(void)
{
	pthread_t thread;
	int i;

	for (i = 0; i < NUM_THREAD_SPAWN; ++i)
		pthread_create(&thread, NULL, do_nothing, NULL);

	/* crash on purpose */
	i = *(int *)NULL;
}

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);

	ret = fread(self->original_core_pattern, 1, sizeof(self->original_core_pattern), file);
	ASSERT_TRUE(ret || feof(file));
	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);
}

FIXTURE_TEARDOWN(coredump)
{
	const char *reason;
	FILE *file;
	int ret, status;

	unlink(STACKDUMP_FILE);

	if (self->pid_coredump_server > 0) {
		kill(self->pid_coredump_server, SIGTERM);
		waitpid(self->pid_coredump_server, &status, 0);
	}
	unlink("/tmp/coredump.file");
	unlink("/tmp/coredump.socket");

	file = fopen("/proc/sys/kernel/core_pattern", "w");
	if (!file) {
		reason = "Unable to open core_pattern";
		goto fail;
	}

	ret = fprintf(file, "%s", self->original_core_pattern);
	if (ret < 0) {
		reason = "Unable to write to core_pattern";
		goto fail;
	}

	ret = fclose(file);
	if (ret) {
		reason = "Unable to close core_pattern";
		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 */
	fprintf(stderr, "Failed to cleanup stackdump test: %s\n", reason);
}

TEST_F_TIMEOUT(coredump, stackdump, 120)
{
	unsigned long long stack;
	char *test_dir, *line;
	size_t line_length;
	char buf[PAGE_SIZE];
	int ret, i, status;
	FILE *file;
	pid_t pid;

	/*
	 * Step 1: Setup core_pattern so that the stackdump script is executed when the child
	 * process crashes
	 */
	ret = readlink("/proc/self/exe", buf, sizeof(buf));
	ASSERT_NE(-1, ret);
	ASSERT_LT(ret, sizeof(buf));
	buf[ret] = '\0';

	test_dir = dirname(buf);

	file = fopen("/proc/sys/kernel/core_pattern", "w");
	ASSERT_NE(NULL, file);

	ret = fprintf(file, "|%1$s/%2$s %%P %1$s/%3$s", test_dir, STACKDUMP_SCRIPT, STACKDUMP_FILE);
	ASSERT_LT(0, ret);

	ret = fclose(file);
	ASSERT_EQ(0, ret);

	/* Step 2: Create a process who spawns some threads then crashes */
	pid = fork();
	ASSERT_TRUE(pid >= 0);
	if (pid == 0)
		crashing_child();

	/*
	 * Step 3: Wait for the stackdump script to write the stack pointers to the stackdump file
	 */
	waitpid(pid, &status, 0);
	ASSERT_TRUE(WIFSIGNALED(status));
	ASSERT_TRUE(WCOREDUMP(status));

	for (i = 0; i < 10; ++i) {
		file = fopen(STACKDUMP_FILE, "r");
		if (file)
			break;
		sleep(1);
	}
	ASSERT_NE(file, NULL);

	/* Step 4: Make sure all stack pointer values are non-zero */
	line = NULL;
	for (i = 0; -1 != getline(&line, &line_length, file); ++i) {
		stack = strtoull(line, NULL, 10);
		ASSERT_NE(stack, 0);
	}
	free(line);

	ASSERT_EQ(i, 1 + NUM_THREAD_SPAWN);

	fclose(file);
}

static int create_and_listen_unix_socket(const char *path)
{
	struct sockaddr_un addr = {
		.sun_family = AF_UNIX,
	};
	assert(strlen(path) < sizeof(addr.sun_path) - 1);
	strncpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
	size_t addr_len =
		offsetof(struct sockaddr_un, sun_path) + strlen(path) + 1;
	int fd, ret;

	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
	if (fd < 0)
		goto out;

	ret = bind(fd, (const struct sockaddr *)&addr, addr_len);
	if (ret < 0)
		goto out;

	ret = listen(fd, 128);
	if (ret < 0)
		goto out;

	return fd;

out:
	if (fd >= 0)
		close(fd);
	return -1;
}

static bool set_core_pattern(const char *pattern)
{
	int fd;
	ssize_t ret;

	fd = open("/proc/sys/kernel/core_pattern", O_WRONLY | O_CLOEXEC);
	if (fd < 0)
		return false;

	ret = write(fd, pattern, strlen(pattern));
	close(fd);
	if (ret < 0)
		return false;

	fprintf(stderr, "Set core_pattern to '%s' | %zu == %zu\n", pattern, ret, strlen(pattern));
	return ret == strlen(pattern);
}

static int get_peer_pidfd(int fd)
{
	int fd_peer_pidfd;
	socklen_t fd_peer_pidfd_len = sizeof(fd_peer_pidfd);
	int ret = getsockopt(fd, SOL_SOCKET, SO_PEERPIDFD, &fd_peer_pidfd,
			     &fd_peer_pidfd_len);
	if (ret < 0) {
		fprintf(stderr, "%m - Failed to retrieve peer pidfd for coredump socket connection\n");
		return -1;
	}
	return fd_peer_pidfd;
}

static bool get_pidfd_info(int fd_peer_pidfd, struct pidfd_info *info)
{
	memset(info, 0, sizeof(*info));
	info->mask = PIDFD_INFO_EXIT | PIDFD_INFO_COREDUMP;
	return ioctl(fd_peer_pidfd, PIDFD_GET_INFO, info) == 0;
}

static void
wait_and_check_coredump_server(pid_t pid_coredump_server,
			       struct __test_metadata *const _metadata,
			       FIXTURE_DATA(coredump)* self)
{
	int status;
	waitpid(pid_coredump_server, &status, 0);
	self->pid_coredump_server = -ESRCH;
	ASSERT_TRUE(WIFEXITED(status));
	ASSERT_EQ(WEXITSTATUS(status), 0);
}

TEST_F(coredump, socket)
{
	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) {
		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)
			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;

		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_detect_userspace_client)
{
	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) {
		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(fd_coredump, &c, 1) < 1)
			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) {
		int fd_socket;
		ssize_t ret;
		const struct sockaddr_un coredump_sk = {
			.sun_family = AF_UNIX,
			.sun_path = "/tmp/coredump.socket",
		};
		size_t coredump_sk_len =
			offsetof(struct sockaddr_un, sun_path) +
			sizeof("/tmp/coredump.socket");

		fd_socket = socket(AF_UNIX, SOCK_STREAM, 0);
		if (fd_socket < 0)
			_exit(EXIT_FAILURE);

		ret = connect(fd_socket, (const struct sockaddr *)&coredump_sk, coredump_sk_len);
		if (ret < 0)
			_exit(EXIT_FAILURE);

		close(fd_socket);
		_exit(EXIT_SUCCESS);
	}

	pidfd = sys_pidfd_open(pid, 0);
	ASSERT_GE(pidfd, 0);

	waitpid(pid, &status, 0);
	ASSERT_TRUE(WIFEXITED(status));
	ASSERT_EQ(WEXITSTATUS(status), 0);

	ASSERT_TRUE(get_pidfd_info(pidfd, &info));
	ASSERT_GT((info.mask & PIDFD_INFO_COREDUMP), 0);
	ASSERT_EQ((info.coredump_mask & PIDFD_COREDUMPED), 0);

	wait_and_check_coredump_server(pid_coredump_server, _metadata, self);

	ASSERT_NE(stat("/tmp/coredump.file", &st), 0);
	ASSERT_EQ(errno, ENOENT);
}

TEST_F(coredump, socket_enoent)
{
	int pidfd, status;
	pid_t pid;

	ASSERT_TRUE(set_core_pattern("@/tmp/coredump.socket"));

	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));
}

TEST_F(coredump, socket_no_listener)
{
	int pidfd, ret, status;
	pid_t pid, pid_coredump_server;
	int ipc_sockets[2];
	char c;
	const struct sockaddr_un coredump_sk = {
		.sun_family = AF_UNIX,
		.sun_path = "/tmp/coredump.socket",
	};
	size_t coredump_sk_len = offsetof(struct sockaddr_un, sun_path) +
				 sizeof("/tmp/coredump.socket");

	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;
		int exit_code = EXIT_FAILURE;

		close(ipc_sockets[0]);

		fd_server = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
		if (fd_server < 0)
			goto out;

		ret = bind(fd_server, (const struct sockaddr *)&coredump_sk, coredump_sk_len);
		if (ret < 0)
			goto out;

		if (write_nointr(ipc_sockets[1], "1", 1) < 0)
			goto out;

		exit_code = EXIT_SUCCESS;
out:
		if (fd_server >= 0)
			close(fd_server);
		close(ipc_sockets[1]);
		_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));

	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_F(coredump, socket_invalid_paths)
{
	ASSERT_FALSE(set_core_pattern("@ /tmp/coredump.socket"));
	ASSERT_FALSE(set_core_pattern("@/tmp/../coredump.socket"));
	ASSERT_FALSE(set_core_pattern("@../coredump.socket"));
	ASSERT_FALSE(set_core_pattern("@/tmp/coredump.socket/.."));
	ASSERT_FALSE(set_core_pattern("@.."));

	ASSERT_FALSE(set_core_pattern("@@ /tmp/coredump.socket"));
	ASSERT_FALSE(set_core_pattern("@@/tmp/../coredump.socket"));
	ASSERT_FALSE(set_core_pattern("@@../coredump.socket"));
	ASSERT_FALSE(set_core_pattern("@@/tmp/coredump.socket/.."));
	ASSERT_FALSE(set_core_pattern("@@.."));

	ASSERT_FALSE(set_core_pattern("@@@/tmp/coredump.socket"));
}

TEST_HARNESS_MAIN