summaryrefslogtreecommitdiff
path: root/src/journal/coredump.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/journal/coredump.c')
-rw-r--r--src/journal/coredump.c271
1 files changed, 271 insertions, 0 deletions
diff --git a/src/journal/coredump.c b/src/journal/coredump.c
new file mode 100644
index 000000000..7dea66e6f
--- /dev/null
+++ b/src/journal/coredump.c
@@ -0,0 +1,271 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2012 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/prctl.h>
+
+#include <systemd/sd-journal.h>
+#include <systemd/sd-login.h>
+
+#include "log.h"
+#include "util.h"
+#include "special.h"
+
+#define COREDUMP_MAX (24*1024*1024)
+
+enum {
+ ARG_PID = 1,
+ ARG_UID,
+ ARG_GID,
+ ARG_SIGNAL,
+ ARG_TIMESTAMP,
+ ARG_COMM,
+ _ARG_MAX
+};
+
+static int divert_coredump(void) {
+ FILE *f;
+ int r;
+
+ log_info("Detected coredump of the journal daemon itself, diverting coredump to /var/lib/systemd/coredump/.");
+
+ mkdir_p("/var/lib/systemd/coredump", 0755);
+
+ f = fopen("/var/lib/systemd/coredump/core.systemd-journald", "we");
+ if (!f) {
+ log_error("Failed to create coredump file: %m");
+ return -errno;
+ }
+
+ for (;;) {
+ uint8_t buffer[4096];
+ size_t l, q;
+
+ l = fread(buffer, 1, sizeof(buffer), stdin);
+ if (l <= 0) {
+ if (ferror(f)) {
+ log_error("Failed to read coredump: %m");
+ r = -errno;
+ goto finish;
+ }
+
+ r = 0;
+ break;
+ }
+
+ q = fwrite(buffer, 1, l, f);
+ if (q != l) {
+ log_error("Failed to write coredump: %m");
+ r = -errno;
+ goto finish;
+ }
+ }
+
+ fflush(f);
+
+ if (ferror(f)) {
+ log_error("Failed to write coredump: %m");
+ r = -errno;
+ }
+
+finish:
+ fclose(f);
+ return r;
+}
+
+int main(int argc, char* argv[]) {
+ int r, j = 0;
+ char *p = NULL;
+ ssize_t n;
+ pid_t pid;
+ uid_t uid;
+ gid_t gid;
+ struct iovec iovec[14];
+ char *core_pid = NULL, *core_uid = NULL, *core_gid = NULL, *core_signal = NULL,
+ *core_timestamp = NULL, *core_comm = NULL, *core_exe = NULL, *core_unit = NULL,
+ *core_session = NULL, *core_message = NULL, *core_cmdline = NULL, *t;
+
+ prctl(PR_SET_DUMPABLE, 0);
+
+ if (argc != _ARG_MAX) {
+ log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
+ log_open();
+
+ log_error("Invalid number of arguments passed from kernel.");
+ r = -EINVAL;
+ goto finish;
+ }
+
+ r = parse_pid(argv[ARG_PID], &pid);
+ if (r < 0) {
+ log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
+ log_open();
+
+ log_error("Failed to parse PID.");
+ goto finish;
+ }
+
+ if (sd_pid_get_unit(pid, &t) >= 0) {
+
+ if (streq(t, SPECIAL_JOURNALD_SERVICE)) {
+ /* Make sure we don't make use of the journal,
+ * if it's the journal which is crashing */
+ log_set_target(LOG_TARGET_KMSG);
+ log_open();
+
+ r = divert_coredump();
+ goto finish;
+ }
+
+ core_unit = strappend("COREDUMP_UNIT=", t);
+ free(t);
+
+ if (core_unit)
+ IOVEC_SET_STRING(iovec[j++], core_unit);
+ }
+
+ /* OK, now we know it's not the journal, hence make use of
+ * it */
+ log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
+ log_open();
+
+ r = parse_uid(argv[ARG_UID], &uid);
+ if (r < 0) {
+ log_error("Failed to parse UID.");
+ goto finish;
+ }
+
+ r = parse_gid(argv[ARG_GID], &gid);
+ if (r < 0) {
+ log_error("Failed to parse GID.");
+ goto finish;
+ }
+
+ core_pid = strappend("COREDUMP_PID=", argv[ARG_PID]);
+ if (core_pid)
+ IOVEC_SET_STRING(iovec[j++], core_pid);
+
+ core_uid = strappend("COREDUMP_UID=", argv[ARG_UID]);
+ if (core_uid)
+ IOVEC_SET_STRING(iovec[j++], core_uid);
+
+ core_gid = strappend("COREDUMP_GID=", argv[ARG_GID]);
+ if (core_gid)
+ IOVEC_SET_STRING(iovec[j++], core_gid);
+
+ core_signal = strappend("COREDUMP_SIGNAL=", argv[ARG_SIGNAL]);
+ if (core_signal)
+ IOVEC_SET_STRING(iovec[j++], core_signal);
+
+ core_comm = strappend("COREDUMP_COMM=", argv[ARG_COMM]);
+ if (core_comm)
+ IOVEC_SET_STRING(iovec[j++], core_comm);
+
+ if (sd_pid_get_session(pid, &t) >= 0) {
+ core_session = strappend("COREDUMP_SESSION=", t);
+ free(t);
+
+ if (core_session)
+ IOVEC_SET_STRING(iovec[j++], core_session);
+ }
+
+ if (get_process_exe(pid, &t) >= 0) {
+ core_exe = strappend("COREDUMP_EXE=", t);
+ free(t);
+
+ if (core_exe)
+ IOVEC_SET_STRING(iovec[j++], core_exe);
+ }
+
+ if (get_process_cmdline(pid, LINE_MAX, false, &t) >= 0) {
+ core_cmdline = strappend("COREDUMP_CMDLINE=", t);
+ free(t);
+
+ if (core_cmdline)
+ IOVEC_SET_STRING(iovec[j++], core_cmdline);
+ }
+
+ core_timestamp = join("COREDUMP_TIMESTAMP=", argv[ARG_TIMESTAMP], "000000", NULL);
+ if (core_timestamp)
+ IOVEC_SET_STRING(iovec[j++], core_timestamp);
+
+ IOVEC_SET_STRING(iovec[j++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1");
+ IOVEC_SET_STRING(iovec[j++], "PRIORITY=2");
+
+ core_message = join("MESSAGE=Process ", argv[ARG_PID], " (", argv[ARG_COMM], ") dumped core.", NULL);
+ if (core_message)
+ IOVEC_SET_STRING(iovec[j++], core_message);
+
+ /* Now, let's drop privileges to become the user who owns the
+ * segfaulted process and allocate the coredump memory under
+ * his uid. This also ensures that the credentials journald
+ * will see are the ones of the coredumping user, thus making
+ * sure the user himself gets access to the core dump. */
+
+ if (setresgid(gid, gid, gid) < 0 ||
+ setresuid(uid, uid, uid) < 0) {
+ log_error("Failed to drop privileges: %m");
+ r = -errno;
+ goto finish;
+ }
+
+ p = malloc(9 + COREDUMP_MAX);
+ if (!p) {
+ log_error("Out of memory");
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ memcpy(p, "COREDUMP=", 9);
+
+ n = loop_read(STDIN_FILENO, p + 9, COREDUMP_MAX, false);
+ if (n < 0) {
+ log_error("Failed to read core dump data: %s", strerror(-n));
+ r = (int) n;
+ goto finish;
+ }
+
+ iovec[j].iov_base = p;
+ iovec[j].iov_len = 9 + n;
+ j++;
+
+ r = sd_journal_sendv(iovec, j);
+ if (r < 0)
+ log_error("Failed to send coredump: %s", strerror(-r));
+
+finish:
+ free(p);
+ free(core_pid);
+ free(core_uid);
+ free(core_gid);
+ free(core_signal);
+ free(core_timestamp);
+ free(core_comm);
+ free(core_exe);
+ free(core_cmdline);
+ free(core_unit);
+ free(core_session);
+ free(core_message);
+
+ return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-25 11:57:03 +0000