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authorLennart Poettering <lennart@poettering.net>2014-06-19 12:07:12 +0200
committerLennart Poettering <lennart@poettering.net>2014-06-19 12:38:45 +0200
commit8d4e028f1868c47864ec873d9f30c3ee961a8849 (patch)
tree8a16e81f48f49c2d5aa210d8992f0c7d4a8470c2 /src
parent8271bd16ce9327834d8580e55bb5e4e0896fd98a (diff)
coredump: include stacktrace of coredumps in the log message
elfutils' libdw is maintained, can read DWARF debug data and appears to be the library of choice for generating backtraces today.
Diffstat (limited to 'src')
-rw-r--r--src/journal/coredump.c38
-rw-r--r--src/journal/coredumpctl.c14
-rw-r--r--src/journal/stacktrace.c200
-rw-r--r--src/journal/stacktrace.h24
4 files changed, 263 insertions, 13 deletions
diff --git a/src/journal/coredump.c b/src/journal/coredump.c
index 3365f9f146..f48f4e2c89 100644
--- a/src/journal/coredump.c
+++ b/src/journal/coredump.c
@@ -38,6 +38,7 @@
#include "journald-native.h"
#include "conf-parser.h"
#include "copy.h"
+#include "stacktrace.h"
#ifdef HAVE_ACL
#include <sys/acl.h>
@@ -290,6 +291,7 @@ static int allocate_journal_field(int fd, size_t size, char **ret, size_t *ret_s
_cleanup_free_ char *field = NULL;
ssize_t n;
+ assert(fd >= 0);
assert(ret);
assert(ret_size);
@@ -346,7 +348,8 @@ int main(int argc, char* argv[]) {
_cleanup_free_ 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, *coredump_data = NULL,
- *coredump_filename = NULL, *core_slice = NULL, *core_cgroup = NULL, *core_owner_uid = NULL;
+ *coredump_filename = NULL, *core_slice = NULL, *core_cgroup = NULL, *core_owner_uid = NULL,
+ *exe = NULL;
_cleanup_close_ int coredump_fd = -1;
@@ -365,7 +368,6 @@ int main(int argc, char* argv[]) {
* crashed and it might be journald which we'd rather not log
* to then. */
log_set_target(LOG_TARGET_KMSG);
- log_set_max_level(LOG_DEBUG);
log_open();
if (argc != _ARG_MAX) {
@@ -474,10 +476,8 @@ int main(int argc, char* argv[]) {
IOVEC_SET_STRING(iovec[j++], core_slice);
}
- if (get_process_exe(pid, &t) >= 0) {
- core_exe = strappend("COREDUMP_EXE=", t);
- free(t);
-
+ if (get_process_exe(pid, &exe) >= 0) {
+ core_exe = strappend("COREDUMP_EXE=", exe);
if (core_exe)
IOVEC_SET_STRING(iovec[j++], core_exe);
}
@@ -505,17 +505,15 @@ int main(int argc, char* argv[]) {
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);
-
/* Always stream the coredump to disk, if that's possible */
r = save_external_coredump(argv, uid, &coredump_filename, &coredump_fd, &coredump_size);
if (r < 0)
goto finish;
/* If we don't want to keep the coredump on disk, remove it
- * now, as later on we will lack the privileges for it. */
+ * now, as later on we will lack the privileges for
+ * it. However, we keep the fd to it, so that we can still
+ * process it and log it. */
r = maybe_remove_external_coredump(coredump_filename, coredump_size);
if (r < 0)
goto finish;
@@ -532,6 +530,24 @@ int main(int argc, char* argv[]) {
goto finish;
}
+#ifdef HAVE_ELFUTILS
+ /* Try to get a strack trace if we can */
+ if (coredump_size <= arg_process_size_max) {
+ _cleanup_free_ char *stacktrace = NULL;
+
+ r = coredump_make_stack_trace(coredump_fd, exe, &stacktrace);
+ if (r >= 0)
+ core_message = strjoin("MESSAGE=Process ", argv[ARG_PID], " (", argv[ARG_COMM], ") of user ", argv[ARG_UID], " dumped core.\n\n", stacktrace, NULL);
+ else
+ log_warning("Failed to generate stack trace: %s", strerror(-r));
+ }
+
+ if (!core_message)
+#endif
+ core_message = strjoin("MESSAGE=Process ", argv[ARG_PID], " (", argv[ARG_COMM], ") of user ", argv[ARG_UID], " dumped core.", NULL);
+ if (core_message)
+ IOVEC_SET_STRING(iovec[j++], core_message);
+
/* Optionally store the entire coredump in the journal */
if (IN_SET(arg_storage, COREDUMP_STORAGE_JOURNAL, COREDUMP_STORAGE_BOTH) &&
coredump_size <= (off_t) arg_journal_size_max) {
diff --git a/src/journal/coredumpctl.c b/src/journal/coredumpctl.c
index ea459469ee..9eaa8979a0 100644
--- a/src/journal/coredumpctl.c
+++ b/src/journal/coredumpctl.c
@@ -403,7 +403,8 @@ static int print_info(FILE *file, sd_journal *j, bool need_space) {
*sgnl = NULL, *exe = NULL, *comm = NULL, *cmdline = NULL,
*unit = NULL, *user_unit = NULL, *session = NULL,
*boot_id = NULL, *machine_id = NULL, *hostname = NULL,
- *coredump = NULL, *slice = NULL, *cgroup = NULL, *owner_uid = NULL;
+ *coredump = NULL, *slice = NULL, *cgroup = NULL,
+ *owner_uid = NULL, *message = NULL;
const void *d;
size_t l;
@@ -427,6 +428,7 @@ static int print_info(FILE *file, sd_journal *j, bool need_space) {
retrieve(d, l, "_BOOT_ID", &boot_id);
retrieve(d, l, "_MACHINE_ID", &machine_id);
retrieve(d, l, "_HOSTNAME", &hostname);
+ retrieve(d, l, "MESSAGE", &message);
}
if (need_space)
@@ -522,6 +524,14 @@ static int print_info(FILE *file, sd_journal *j, bool need_space) {
if (access(coredump, F_OK) >= 0)
fprintf(file, " Coredump: %s\n", coredump);
+ if (message) {
+ _cleanup_free_ char *m = NULL;
+
+ m = strreplace(message, "\n", "\n ");
+
+ fprintf(file, " Message: %s\n", strstrip(m ?: message));
+ }
+
return 0;
}
@@ -696,7 +706,7 @@ static int run_gdb(sd_journal *j) {
if (errno == ENOENT)
log_error("Coredump neither in journal file nor stored externally on disk.");
else
- log_error("Failed to access coredump fiile: %s", strerror(-r));
+ log_error("Failed to access coredump file: %m");
return -errno;
}
diff --git a/src/journal/stacktrace.c b/src/journal/stacktrace.c
new file mode 100644
index 0000000000..6b9d2729f5
--- /dev/null
+++ b/src/journal/stacktrace.c
@@ -0,0 +1,200 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2014 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 <dwarf.h>
+#include <elfutils/libdwfl.h>
+
+#include "util.h"
+#include "macro.h"
+#include "stacktrace.h"
+
+#define FRAMES_MAX 64
+#define THREADS_MAX 64
+
+struct stack_context {
+ FILE *f;
+ Dwfl *dwfl;
+ Elf *elf;
+ unsigned n_thread;
+ unsigned n_frame;
+};
+
+static int frame_callback(Dwfl_Frame *frame, void *userdata) {
+ struct stack_context *c = userdata;
+ Dwarf_Addr pc, pc_adjusted, bias = 0;
+ _cleanup_free_ Dwarf_Die *scopes = NULL;
+ const char *fname = NULL, *symbol = NULL;
+ Dwfl_Module *module;
+ bool is_activation;
+
+ assert(frame);
+ assert(c);
+
+ if (c->n_frame >= FRAMES_MAX)
+ return DWARF_CB_ABORT;
+
+ if (!dwfl_frame_pc(frame, &pc, &is_activation))
+ return DWARF_CB_ABORT;
+
+ pc_adjusted = pc - (is_activation ? 0 : 1);
+
+ module = dwfl_addrmodule(c->dwfl, pc_adjusted);
+ if (module) {
+ Dwarf_Die *s, *cudie;
+ int n;
+
+ cudie = dwfl_module_addrdie(module, pc_adjusted, &bias);
+ if (cudie) {
+ n = dwarf_getscopes(cudie, pc_adjusted - bias, &scopes);
+ for (s = scopes; s < scopes + n; s++) {
+ if (IN_SET(dwarf_tag(s), DW_TAG_subprogram, DW_TAG_inlined_subroutine, DW_TAG_entry_point)) {
+ Dwarf_Attribute *a, space;
+
+ a = dwarf_attr_integrate(s, DW_AT_MIPS_linkage_name, &space);
+ if (!a)
+ a = dwarf_attr_integrate(s, DW_AT_linkage_name, &space);
+ if (a)
+ symbol = dwarf_formstring(a);
+ if (!symbol)
+ symbol = dwarf_diename(s);
+
+ if (symbol)
+ break;
+ }
+ }
+ }
+
+ if (!symbol)
+ symbol = dwfl_module_addrname(module, pc_adjusted);
+
+ fname = dwfl_module_info(module, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
+ }
+
+ fprintf(c->f, "#%-2u 0x%016" PRIx64 " %s (%s)\n", c->n_frame, (uint64_t) pc, strna(symbol), strna(fname));
+ c->n_frame ++;
+
+ return DWARF_CB_OK;
+}
+
+static int thread_callback(Dwfl_Thread *thread, void *userdata) {
+ struct stack_context *c = userdata;
+ pid_t tid;
+
+ assert(thread);
+ assert(c);
+
+ if (c->n_thread >= THREADS_MAX)
+ return DWARF_CB_ABORT;
+
+ if (c->n_thread != 0)
+ fputc('\n', c->f);
+
+ c->n_frame = 0;
+
+ tid = dwfl_thread_tid(thread);
+ fprintf(c->f, "Stack trace of thread " PID_FMT ":\n", tid);
+
+ if (dwfl_thread_getframes(thread, frame_callback, c) < 0)
+ return DWARF_CB_ABORT;
+
+ c->n_thread ++;
+
+ return DWARF_CB_OK;
+}
+
+int coredump_make_stack_trace(int fd, const char *executable, char **ret) {
+
+ static const Dwfl_Callbacks callbacks = {
+ .find_elf = dwfl_build_id_find_elf,
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ };
+
+ struct stack_context c = {};
+ char *buf = NULL;
+ size_t sz = 0;
+ int r;
+
+ assert(fd >= 0);
+ assert(ret);
+
+ if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
+ return -errno;
+
+ c.f = open_memstream(&buf, &sz);
+ if (!c.f)
+ return -ENOMEM;
+
+ elf_version(EV_CURRENT);
+
+ c.elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+ if (!c.elf) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ c.dwfl = dwfl_begin(&callbacks);
+ if (!c.dwfl) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ if (dwfl_core_file_report(c.dwfl, c.elf, executable) < 0) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ if (dwfl_report_end(c.dwfl, NULL, NULL) != 0) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ if (dwfl_core_file_attach(c.dwfl, c.elf) < 0) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ if (dwfl_getthreads(c.dwfl, thread_callback, &c) < 0) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ fclose(c.f);
+ c.f = NULL;
+
+ *ret = buf;
+ buf = NULL;
+
+ r = 0;
+
+finish:
+ if (c.dwfl)
+ dwfl_end(c.dwfl);
+
+ if (c.elf)
+ elf_end(c.elf);
+
+ if (c.f)
+ fclose(c.f);
+
+ free(buf);
+
+ return r;
+}
diff --git a/src/journal/stacktrace.h b/src/journal/stacktrace.h
new file mode 100644
index 0000000000..189e5c4597
--- /dev/null
+++ b/src/journal/stacktrace.h
@@ -0,0 +1,24 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+ This file is part of systemd.
+
+ Copyright 2014 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/>.
+***/
+
+int coredump_make_stack_trace(int fd, const char *executable, char **ret);