picnoir
/
Systemd
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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.
This commit is contained in:
Lennart Poettering 2014-06-19 12:07:12 +02:00
parent 8271bd16ce
commit 8d4e028f18
6 changed files with 311 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Makefile.am
View File

@ -3686,6 +3686,15 @@ systemd_coredump_LDADD = \
libsystemd-internal.la \
libsystemd-shared.la
if HAVE_ELFUTILS
systemd_coredump_SOURCES += \
src/journal/stacktrace.c \
src/journal/stacktrace.h
systemd_coredump_LDADD += \
$(ELFUTILS_LIBS)
endif
rootlibexec_PROGRAMS += \
systemd-coredump

39
configure.ac
View File

@ -626,6 +626,44 @@ else
fi
AC_SUBST(AUDIT_LIBS)
# ------------------------------------------------------------------------------
AC_ARG_ENABLE([elfutils],
AS_HELP_STRING([--disable-elfutils],[Disable optional ELFUTILS support]),
[case "${enableval}" in
yes) have_elfutils=yes ;;
no) have_elfutils=no ;;
*) AC_MSG_ERROR(bad value ${enableval} for --disable-elfutils) ;;
esac],
[have_elfutils=auto])
if test "x${have_elfutils}" != xno ; then
AC_CHECK_HEADERS(
[elfutils/libdwfl.h],
[have_elfutils=yes],
[if test "x$have_elfutils" = xyes ; then
AC_MSG_ERROR([*** ELFUTILS headers not found.])
fi])
AC_CHECK_LIB(
[dw],
[dwfl_begin],
[have_elfutils=yes],
[if test "x$have_elfutils" = xyes ; then
AC_MSG_ERROR([*** ELFUTILS libs not found.])
fi])
if test "x$have_elfutils" = xyes ; then
ELFUTILS_LIBS="-lelf -ldw"
AC_DEFINE(HAVE_ELFUTILS, 1, [ELFUTILS available])
else
have_elfutils=no
fi
else
ELFUTILS_LIBS=
fi
AC_SUBST(ELFUTILS_LIBS)
AM_CONDITIONAL(HAVE_ELFUTILS, [test "$have_elfutils" = "yes"])
# ------------------------------------------------------------------------------
have_libcryptsetup=no
AC_ARG_ENABLE(libcryptsetup, AS_HELP_STRING([--disable-libcryptsetup], [disable libcryptsetup tools]))
@ -1171,6 +1209,7 @@ AC_MSG_RESULT([
MICROHTTPD: ${have_microhttpd}
CHKCONFIG: ${have_chkconfig}
GNUTLS: ${have_gnutls}
ELFUTILS: ${have_elfutils}
binfmt: ${have_binfmt}
vconsole: ${have_vconsole}
readahead: ${have_readahead}

38
src/journal/coredump.c
View File

@ -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) {

14
src/journal/coredumpctl.c
View File

@ -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;
}

200
src/journal/stacktrace.c Normal file
View File

@ -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;
}

24
src/journal/stacktrace.h Normal file
View File

@ -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);