diff options
Diffstat (limited to 'src/journal/coredump.c')
| -rw-r--r-- | src/journal/coredump.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/src/journal/coredump.c b/src/journal/coredump.c new file mode 100644 index 0000000000..a507fc65f8 --- /dev/null +++ b/src/journal/coredump.c @@ -0,0 +1,278 @@ +/*-*- 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 Lesser General Public License as published by + the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser 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> + +#ifdef HAVE_LOGIND +#include <systemd/sd-login.h> +#endif + +#include "log.h" +#include "util.h" +#include "mkdir.h" +#include "special.h" +#include "cgroup-util.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_label("/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 (cg_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); + +#ifdef HAVE_LOGIND + 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); + } + +#endif + + 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 = strjoin("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 = strjoin("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) { + r = log_oom(); + 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; +} |