Test the new COREDUMP_RECORDS and COREDUMP_SPARSE flags.
Signed-off-by: Christian Brauner (Amutable) <[email protected]>
---
.../coredump/coredump_socket_protocol_test.c | 407 +++++++++++++++++++++
.../selftests/coredump/coredump_test_helpers.c | 236 +++++++++++-
.../selftests/coredump/coredump_test_helpers.h | 8 +
3 files changed, 650 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
b/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
index 60a357e628eb..abf6e2c4c354 100644
--- a/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
+++ b/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
@@ -1573,4 +1573,411 @@ TEST_F_TIMEOUT(coredump,
socket_multiple_crashing_coredumps_epoll_workers, 500)
wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
}
+/*
+ * Reassemble a record stream and check that what comes out is an ELF
+ * core file. The records themselves are validated by recv_coredump_records().
+ */
+TEST_F(coredump, socket_request_sparse_reassemble)
+{
+ int fd_core_file, pidfd, status;
+ pid_t pid, pid_coredump_server;
+ struct pidfd_info info = {};
+ int ipc_sockets[2];
+ char c;
+
+ ASSERT_EQ(socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0,
ipc_sockets), 0);
+ ASSERT_TRUE(set_core_pattern("@@/tmp/coredump.socket"));
+
+ 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 fd_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)
+ 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;
+
+ fd_file = creat("/tmp/coredump.file", 0644);
+ if (fd_file < 0)
+ goto out;
+
+ if (!read_coredump_req(fd_coredump, &req))
+ goto out;
+
+ if (!check_coredump_req(&req))
+ goto out;
+
+ if (!send_coredump_ack(fd_coredump, &req,
+ COREDUMP_KERNEL | COREDUMP_RECORDS |
+ COREDUMP_SPARSE | COREDUMP_WAIT, 0))
+ goto out;
+
+ if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+ goto out;
+
+ if (recv_coredump_records(fd_coredump, fd_file, NULL, NULL, -1)
< 0)
+ goto out;
+
+ exit_code = EXIT_SUCCESS;
+out:
+ if (fd_file >= 0)
+ close(fd_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);
+
+ /* What the records reassemble into has to be an ELF core file. */
+ fd_core_file = open("/tmp/coredump.file", O_RDONLY | O_CLOEXEC);
+ ASSERT_GE(fd_core_file, 0);
+ ASSERT_TRUE(is_elf_core(fd_core_file));
+ EXPECT_EQ(close(fd_core_file), 0);
+}
+
+/*
+ * Crash a child with a mostly-unpopulated mapping and reassemble its
+ * record stream, reporting what crossed the socket and the coredump
+ * size the records describe. With @kill_peer the server kills the task
+ * once the coredump is under way so the kernel has to cut it short.
+ */
+static void check_record_dump(struct __test_metadata *const _metadata,
+ FIXTURE_DATA(coredump) *self, __u64 ack_mask,
+ bool kill_peer, ssize_t *received,
+ off_t *coredump_size)
+{
+ bool truncated = false;
+ int pidfd, status;
+ pid_t pid, pid_coredump_server;
+ struct pidfd_info info = {};
+ int ipc_sockets[2];
+ int pipefds[2];
+ char c;
+
+ ASSERT_EQ(socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0,
ipc_sockets), 0);
+ ASSERT_EQ(pipe(pipefds), 0);
+ ASSERT_TRUE(set_core_pattern("@@/tmp/coredump.socket"));
+
+ 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 fd_file = -1;
+ int exit_code = EXIT_FAILURE;
+ struct coredump_req req = {};
+ bool is_truncated = false;
+ off_t size = 0;
+ ssize_t ret;
+
+ close(ipc_sockets[0]);
+ close(pipefds[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;
+
+ /*
+ * The reassembled coredump is bigger than the mapping the
+ * child made, so keep it on the detached tmpfs and sparse.
+ */
+ fd_file = open_coredump_tmpfile(self->fd_tmpfs_detached);
+ if (fd_file < 0)
+ goto out;
+
+ if (!read_coredump_req(fd_coredump, &req))
+ goto out;
+
+ if (!check_coredump_req(&req))
+ goto out;
+
+ if (!send_coredump_ack(fd_coredump, &req, ack_mask, 0))
+ goto out;
+
+ if (!read_marker(fd_coredump, COREDUMP_MARK_REQACK))
+ goto out;
+
+ ret = recv_coredump_records(fd_coredump, fd_file, &size,
&is_truncated,
+ kill_peer ? fd_peer_pidfd : -1);
+ if (ret < 0)
+ goto out;
+
+ if (write_nointr(pipefds[1], &ret, sizeof(ret)) != sizeof(ret))
+ goto out;
+ if (write_nointr(pipefds[1], &size, sizeof(size)) !=
sizeof(size))
+ goto out;
+ if (write_nointr(pipefds[1], &is_truncated,
+ sizeof(is_truncated)) != sizeof(is_truncated))
+ goto out;
+
+ exit_code = EXIT_SUCCESS;
+out:
+ close(pipefds[1]);
+ if (fd_file >= 0)
+ close(fd_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);
+ EXPECT_EQ(close(pipefds[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_sparse(SPARSE_MAPPING_SIZE);
+
+ pidfd = sys_pidfd_open(pid, 0);
+ ASSERT_GE(pidfd, 0);
+
+ waitpid(pid, &status, 0);
+ ASSERT_TRUE(WIFSIGNALED(status));
+
+ ASSERT_EQ(read_nointr(pipefds[0], received, sizeof(*received)),
+ sizeof(*received));
+ ASSERT_EQ(read_nointr(pipefds[0], coredump_size,
sizeof(*coredump_size)),
+ sizeof(*coredump_size));
+ ASSERT_EQ(read_nointr(pipefds[0], &truncated, sizeof(truncated)),
+ sizeof(truncated));
+ EXPECT_EQ(close(pipefds[0]), 0);
+
+ wait_and_check_coredump_server(pid_coredump_server, _metadata, self);
+
+ if (kill_peer) {
+ /* The kernel gave up partway, so no end record closed the
stream. */
+ ASSERT_TRUE(truncated);
+ ASSERT_FALSE(WCOREDUMP(status));
+ ASSERT_LT(*coredump_size, (off_t)SPARSE_MAPPING_SIZE);
+ return;
+ }
+
+ ASSERT_FALSE(truncated);
+ 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);
+
+ /* The mapping is in the coredump, holes included. */
+ ASSERT_GT(*coredump_size, (off_t)SPARSE_MAPPING_SIZE);
+}
+
+/*
+ * A mapping that has been written to is dumped whole, including the parts
+ * of it that were never faulted in. With COREDUMP_SPARSE the holes stay
+ * off the wire.
+ */
+TEST_F(coredump, socket_request_sparse_hole)
+{
+ off_t coredump_size = 0;
+ ssize_t received = 0;
+
+ check_record_dump(_metadata, self,
+ COREDUMP_KERNEL | COREDUMP_RECORDS |
+ COREDUMP_SPARSE | COREDUMP_WAIT,
+ false, &received, &coredump_size);
+
+ /* The holes didn't have to go over the socket. */
+ ASSERT_LT(received, coredump_size / 8);
+}
+
+/*
+ * COREDUMP_RECORDS alone splits the stream into records but elides
+ * nothing: the holes cross the socket as data records.
+ */
+TEST_F(coredump, socket_request_records_hole)
+{
+ off_t coredump_size = 0;
+ ssize_t received = 0;
+
+ check_record_dump(_metadata, self,
+ COREDUMP_KERNEL | COREDUMP_RECORDS | COREDUMP_WAIT,
+ false, &received, &coredump_size);
+
+ /* Records alone elide nothing, so everything crossed the socket. */
+ ASSERT_GT(received, coredump_size);
+}
+
+/*
+ * A coredump the kernel gives up on halfway still ends in an end record,
+ * and that record says the coredump is incomplete. COREDUMP_SPARSE is left
+ * out on purpose: the holes have to cross the socket so the coredump is
+ * far larger than the socket buffer and the kernel is still writing it
+ * when the kill lands.
+ */
+TEST_F(coredump, socket_request_records_truncated)
+{
+ off_t coredump_size = 0;
+ ssize_t received = 0;
+
+ check_record_dump(_metadata, self,
+ COREDUMP_KERNEL | COREDUMP_RECORDS | COREDUMP_WAIT,
+ true, &received, &coredump_size);
+
+ /* The end record crossed the socket even though the task was killed. */
+ ASSERT_GT(received, 0);
+}
+
+/* Ack @ack_mask, expect the kernel to refuse it as conflicting. */
+static void check_conflicting_ack(struct __test_metadata *const _metadata,
+ FIXTURE_DATA(coredump) *self, __u64 ack_mask)
+{
+ int pidfd, status;
+ pid_t pid, pid_coredump_server;
+ struct pidfd_info info = {};
+ int ipc_sockets[2];
+ char c;
+
+ ASSERT_EQ(socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0,
ipc_sockets), 0);
+ ASSERT_TRUE(set_core_pattern("@@/tmp/coredump.socket"));
+
+ 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;
+ struct coredump_req req = {};
+
+ 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 (!read_coredump_req(fd_coredump, &req))
+ goto out;
+
+ if (!check_coredump_req(&req))
+ goto out;
+
+ if (!send_coredump_ack(fd_coredump, &req, ack_mask, 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);
+}
+
+/* COREDUMP_RECORDS applies to a coredump the kernel writes, nothing else. */
+TEST_F(coredump, socket_request_records_without_kernel)
+{
+ check_conflicting_ack(_metadata, self, COREDUMP_USERSPACE |
COREDUMP_RECORDS);
+}
+
+/* A zero record can't exist outside a record stream. */
+TEST_F(coredump, socket_request_sparse_without_records)
+{
+ check_conflicting_ack(_metadata, self, COREDUMP_KERNEL |
COREDUMP_SPARSE);
+}
+
TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/coredump/coredump_test_helpers.c
b/tools/testing/selftests/coredump/coredump_test_helpers.c
index a5b9cde47239..5b2ffe17f7b7 100644
--- a/tools/testing/selftests/coredump/coredump_test_helpers.c
+++ b/tools/testing/selftests/coredump/coredump_test_helpers.c
@@ -1,9 +1,11 @@
// SPDX-License-Identifier: GPL-2.0
#include <assert.h>
+#include <elf.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
+#include <link.h>
#include <linux/coredump.h>
#include <linux/fs.h>
#include <pthread.h>
@@ -13,6 +15,7 @@
#include <string.h>
#include <sys/epoll.h>
#include <sys/ioctl.h>
+#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
@@ -23,6 +26,12 @@
#include "coredump_test_helpers.h"
+#if __ELF_NATIVE_CLASS == 64
+#define COREDUMP_ELFCLASS ELFCLASS64
+#else
+#define COREDUMP_ELFCLASS ELFCLASS32
+#endif
+
void *do_nothing(void *arg)
{
(void)arg;
@@ -44,6 +53,228 @@ void crashing_child(void)
i = *(volatile int *)NULL;
}
+void crashing_child_sparse(size_t size)
+{
+ char *p;
+
+ /*
+ * Touch the first page only. The whole mapping is dumped because
+ * it has been written to, but all of it save that one page is a
+ * hole.
+ */
+ p = mmap(NULL, size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
+ if (p != MAP_FAILED)
+ p[0] = 'x';
+
+ /* crash on purpose */
+ *(volatile int *)NULL = 0;
+}
+
+/* Read @len bytes off the socket, writing them at @offset if @fd_out >= 0. */
+static ssize_t recv_record_bytes(int fd_coredump, __u64 len, int fd_out,
+ off_t offset)
+{
+ ssize_t received = 0;
+
+ while (len) {
+ char buffer[PAGE_SIZE];
+ size_t chunk = len < sizeof(buffer) ? len : sizeof(buffer);
+ ssize_t ret;
+
+ ret = recv(fd_coredump, buffer, chunk, MSG_WAITALL);
+ if (ret <= 0) {
+ fprintf(stderr, "%s: short read %zd: %m\n",
+ __func__, ret);
+ return -1;
+ }
+
+ if (fd_out >= 0 &&
+ pwrite(fd_out, buffer, ret, offset + received) != ret) {
+ fprintf(stderr, "%s: pwrite failed: %m\n", __func__);
+ return -1;
+ }
+
+ received += ret;
+ len -= ret;
+ }
+
+ return received;
+}
+
+/*
+ * Reassemble a record stream. If @fd_peer_pidfd is valid the task behind
+ * it is killed once a data record has arrived, so the kernel has to cut
+ * the coredump short with the stream already under way.
+ */
+ssize_t recv_coredump_records(int fd_coredump, int fd_core_file,
+ off_t *coredump_size, bool *truncated,
+ int fd_peer_pidfd)
+{
+ ssize_t received = 0;
+ off_t size = 0;
+ bool is_truncated = false;
+ bool ended = false;
+ char trailing;
+
+ while (!ended) {
+ struct coredump_record_header record = {};
+ size_t known_size;
+ ssize_t ret;
+
+ /* Peek the header size the way read_coredump_req() does. */
+ ret = recv(fd_coredump, &record, sizeof(record.size),
+ MSG_PEEK | MSG_WAITALL);
+ if (ret == 0) {
+ /* Nothing closed the stream, so the coredump was cut
short. */
+ if (truncated) {
+ is_truncated = true;
+ break;
+ }
+ fprintf(stderr, "%s: stream ended without an end
record\n",
+ __func__);
+ return -1;
+ }
+ if (ret != sizeof(record.size)) {
+ fprintf(stderr, "%s: short record peek %zd: %m\n",
+ __func__, ret);
+ return -1;
+ }
+
+ if (record.size < COREDUMP_RECORD_HEADER_SIZE_VER0) {
+ fprintf(stderr, "%s: header size %u below minimum %u\n",
+ __func__, record.size,
+ COREDUMP_RECORD_HEADER_SIZE_VER0);
+ return -1;
+ }
+
+ /* Consume as much of the header as we know about. */
+ known_size = record.size < sizeof(record) ? record.size :
sizeof(record);
+ ret = recv(fd_coredump, &record, known_size, MSG_WAITALL);
+ if (ret != (ssize_t)known_size) {
+ fprintf(stderr, "%s: short record read %zd: %m\n",
+ __func__, ret);
+ return -1;
+ }
+ received += ret;
+
+ /*
+ * A flag changes what the record means, so refuse one we
+ * don't know rather than guess.
+ */
+ if (record.flags) {
+ fprintf(stderr, "%s: unknown header flags 0x%llx\n",
+ __func__, (unsigned long long)record.flags);
+ return -1;
+ }
+
+ /* Discard any part of the header we have no use for. */
+ ret = recv_record_bytes(fd_coredump, record.size - known_size,
-1, 0);
+ if (ret < 0)
+ return -1;
+ received += ret;
+
+ /* Records are sent in order and they don't leave gaps. */
+ if (record.offset != (__u64)size) {
+ fprintf(stderr, "%s: record at %llu, expected %llu\n",
+ __func__, (unsigned long long)record.offset,
+ (unsigned long long)size);
+ return -1;
+ }
+
+ switch (record.type) {
+ case COREDUMP_RECORD_ZERO:
+ /* A hole. It comes with no data and needs none. */
+ break;
+ case COREDUMP_RECORD_DATA:
+ ret = recv_record_bytes(fd_coredump, record.len,
+ fd_core_file, size);
+ if (ret < 0)
+ return -1;
+ received += ret;
+ if (fd_peer_pidfd >= 0) {
+ if (sys_pidfd_send_signal(fd_peer_pidfd,
SIGKILL,
+ NULL, 0)) {
+ fprintf(stderr, "%s: kill failed: %m\n",
+ __func__);
+ return -1;
+ }
+ fd_peer_pidfd = -1;
+ }
+ break;
+ case COREDUMP_RECORD_END:
+ /* The coredump ends here and nothing follows it. */
+ if (record.len) {
+ fprintf(stderr, "%s: end record covers %llu
bytes\n",
+ __func__,
+ (unsigned long long)record.len);
+ return -1;
+ }
+ ended = true;
+ break;
+ default:
+ fprintf(stderr, "%s: unknown record type %u\n",
+ __func__, record.type);
+ return -1;
+ }
+
+ size += record.len;
+ }
+
+ /* The end record is the last thing on the wire. */
+ if (recv(fd_coredump, &trailing, sizeof(trailing), MSG_DONTWAIT) > 0) {
+ fprintf(stderr, "%s: data after the end record\n", __func__);
+ return -1;
+ }
+
+ if (truncated)
+ *truncated = is_truncated;
+
+ /*
+ * Nothing is written for a hole, so grow the file to the size the
+ * records describe in case the coredump ended in one.
+ */
+ if (ftruncate(fd_core_file, size) < 0) {
+ fprintf(stderr, "%s: ftruncate to %llu failed: %m\n",
+ __func__, (unsigned long long)size);
+ return -1;
+ }
+
+ if (coredump_size)
+ *coredump_size = size;
+
+ fprintf(stderr, "Received %zd bytes for a %s coredump of %llu bytes\n",
+ received, is_truncated ? "truncated" : "complete",
+ (unsigned long long)size);
+ return received;
+}
+
+/* The ELF header of a native core file. */
+static bool is_core_ehdr(const ElfW(Ehdr) *ehdr)
+{
+ return !memcmp(ehdr->e_ident, ELFMAG, SELFMAG) &&
+ ehdr->e_ident[EI_CLASS] == COREDUMP_ELFCLASS &&
+ ehdr->e_type == ET_CORE;
+}
+
+/* Whatever the server ends up with has to be an ELF core file. */
+bool is_elf_core(int fd)
+{
+ ElfW(Ehdr) ehdr;
+
+ if (pread(fd, &ehdr, sizeof(ehdr), 0) != sizeof(ehdr)) {
+ fprintf(stderr, "%s: short read: %m\n", __func__);
+ return false;
+ }
+
+ if (!is_core_ehdr(&ehdr)) {
+ fprintf(stderr, "%s: not an ELF core file\n", __func__);
+ return false;
+ }
+
+ return true;
+}
+
int create_detached_tmpfs(void)
{
int fd_context, fd_tmpfs;
@@ -86,6 +317,7 @@ int create_and_listen_unix_socket(const char *path)
return fd;
out:
+ fprintf(stderr, "%s: %s: %m\n", __func__, path);
if (fd >= 0)
close(fd);
return -1;
@@ -264,8 +496,10 @@ bool send_coredump_ack(int fd, const struct coredump_req
*req,
large_ack.ack.mask = mask;
large_ack.ack.size = size_ack;
ret = send(fd, &large_ack, size_ack, MSG_NOSIGNAL);
- if (ret != size_ack)
+ if (ret != size_ack) {
+ fprintf(stderr, "%s: short send %zd: %m\n", __func__, ret);
return false;
+ }
fprintf(stderr, "Sent coredump ack with size %zu and mask 0x%llx\n",
size_ack, (unsigned long long)mask);
diff --git a/tools/testing/selftests/coredump/coredump_test_helpers.h
b/tools/testing/selftests/coredump/coredump_test_helpers.h
index 45904bd177b8..fe0a88a71b05 100644
--- a/tools/testing/selftests/coredump/coredump_test_helpers.h
+++ b/tools/testing/selftests/coredump/coredump_test_helpers.h
@@ -15,9 +15,17 @@
#define NUM_THREAD_SPAWN 128
+/* Size of the mostly unpopulated mapping the sparse coredump test maps. */
+#define SPARSE_MAPPING_SIZE (256 * 1024 * 1024)
+
/* Shared helper function declarations */
void *do_nothing(void *arg);
void crashing_child(void);
+void crashing_child_sparse(size_t size);
+ssize_t recv_coredump_records(int fd_coredump, int fd_core_file,
+ off_t *coredump_size, bool *truncated,
+ int fd_peer_pidfd);
+bool is_elf_core(int fd);
int create_detached_tmpfs(void);
int create_and_listen_unix_socket(const char *path);
bool set_core_pattern(const char *pattern);
--
2.53.0
