Commit 5de0409e authored by Zbigniew Jędrzejewski-Szmek's avatar Zbigniew Jędrzejewski-Szmek
Browse files

journal: add tool to extract coredumps

'systemd-coredumpctl' will list available coredumps:
   PID   UID   GID sig exe
 32452  500  500  11 /home/zbyszek/systemd/build/journalctl
 32666  500  500  11 /usr/lib64/valgrind/memcheck-amd64-linux
...

'systemd-coredumpctl dump PID' will write the coredump
to specified file or stdout.
parent accfdb7a
......@@ -482,6 +482,7 @@ MANPAGES = \
man/journald.conf.5 \
man/systemd-journald.service.8 \
man/journalctl.1 \
man/systemd-coredumpctl.1 \
man/systemd-inhibit.1 \
man/systemd-remount-fs.service.8 \
man/systemd-update-utmp-runlevel.service.8 \
......@@ -2457,6 +2458,13 @@ journalctl_LDADD += \
$(QRENCODE_LIBS)
endif
systemd_coredumpctl_SOURCES = \
src/journal/coredumpctl.c
systemd_coredumpctl_LDADD = \
libsystemd-shared.la \
libsystemd-journal.la
test_journal_SOURCES = \
src/journal/test-journal.c
......@@ -2647,6 +2655,7 @@ rootbin_PROGRAMS += \
journalctl
bin_PROGRAMS += \
systemd-coredumpctl \
systemd-cat
dist_systemunit_DATA += \
......
<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
Copyright 2012 Zbigniew Jędrzejewski-Szmek
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/>.
-->
<refentry id="systemd-coredumpctl">
<refentryinfo>
<title>systemd-coredumpctl</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Zbigniew</firstname>
<surname>Jędrzejewski-Szmek</surname>
<email>zbyszek@in.waw.pl</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>systemd-coredumpctl</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-coredumpctl</refname>
<refpurpose>Retrieve coredumps from the journal</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>systemd-coredumpctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg> <arg choice="opt" rep="repeat">PID|COMM|EXE|MATCH</arg></command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>systemd-coredumpctl</command> may be used to
retrieve coredumps from
<citerefentry><refentrytitle>systemd-journald</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>--help</option></term>
<term><option>-h</option></term>
<listitem><para>Print a short help
text and exit.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--version</option></term>
<listitem><para>Print a short version
string and exit.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--output=FILE</option></term>
<term><option>-o FILE</option></term>
<listitem><para>Write the core to
<option>FILE</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-pager</option></term>
<listitem><para>Do not pipe output of
<command>list</command> into a
pager.</para></listitem>
</varlistentry>
</variablelist>
<para>The following commands are understood:</para>
<variablelist>
<varlistentry>
<term><command>list</command></term>
<listitem><para>List coredumps captured in the journal
matching specified characteristics.</para></listitem>
</varlistentry>
<varlistentry>
<term><command>dump</command></term>
<listitem><para>Extract the last coredump
matching specified characteristics.
Coredump will be written on stdout, unless
an output file is specified with
<option>-o/--output</option>.
</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Matching</title>
<para>Match can be:</para>
<variablelist>
<varlistentry>
<term><option>PID</option></term>
<listitem><para>Process ID of the
process that dumped
core. An integer.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>COMM</option></term>
<listitem><para>Name of the executable
(matches <option>COREDUMP_COMM=</option>).
Must not contain slashes.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>EXE</option></term>
<listitem><para>Path to the executable
(matches <option>COREDUMP_EXE=</option>).
Must contain at least one slash.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>MATCH</option></term>
<listitem><para>General journalctl predicates
(see <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>).
Must contain an equals sign.
</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>On success 0 is returned, a non-zero failure
code otherwise. Not finding any mathing coredumps is treated
as failure.
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2012 Zbigniew Jędrzejewski-Szmek
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 <stdio.h>
#include <string.h>
#include <getopt.h>
#include <systemd/sd-journal.h>
#include "build.h"
#include "set.h"
#include "util.h"
#include "log.h"
#include "path-util.h"
#include "pager.h"
static enum {
ACTION_NONE,
ACTION_LIST,
ACTION_DUMP,
} arg_action = ACTION_LIST;
Set *matches;
FILE* output;
int arg_no_pager;
static Set *new_matches(void) {
Set *set;
char *tmp;
int r;
set = set_new(trivial_hash_func, trivial_compare_func);
if (!set) {
log_oom();
return NULL;
}
tmp = strdup("MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1");
if (!tmp) {
log_oom();
set_clear_free(set);
return NULL;
}
r = set_put(set, tmp);
if (r < 0) {
log_error("failed to add to set: %s", strerror(-r));
free(tmp);
set_clear_free(set);
return NULL;
}
return set;
}
static int help(void) {
printf("%s [OPTIONS...] [MATCHES...]\n\n"
"List or retrieve coredumps from the journal.\n\n"
"Flags:\n"
" -o --output=FILE Write output to FILE\n"
" --no-pager Do not pipe output into a pager\n"
"Commands:\n"
" -h --help Show this help\n"
" --version Print version string\n"
" list List available coredumps\n"
" dump PID Print coredump to stdout\n"
" dump PATH Print coredump to stdout\n"
, program_invocation_short_name);
return 0;
}
static int add_match(Set *set, const char *match) {
int r = -ENOMEM;
unsigned pid;
const char* prefix;
char *pattern = NULL;
char _cleanup_free_ *p = NULL;
if (strchr(match, '='))
prefix = "";
else if (strchr(match, '/')) {
p = path_make_absolute_cwd(match);
if (!p)
goto fail;
match = p;
prefix = "COREDUMP_EXE=";
}
else if (safe_atou(match, &pid) == 0)
prefix = "COREDUMP_PID=";
else
prefix = "COREDUMP_COMM=";
pattern = strjoin(prefix, match, NULL);
if (!pattern)
goto fail;
r = set_put(set, pattern);
if (r < 0) {
log_error("failed to add pattern '%s': %s",
pattern, strerror(-r));
goto fail;
}
log_debug("Added pattern: %s", pattern);
return 0;
fail:
free(pattern);
log_error("failed to add match: %s", strerror(-r));
return r;
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_NO_PAGER,
};
int r, c;
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "version" , no_argument, NULL, ARG_VERSION },
{ "no-pager", no_argument, NULL, ARG_NO_PAGER },
{ "output", required_argument, NULL, 'o' },
};
assert(argc >= 0);
assert(argv);
while ((c = getopt_long(argc, argv, "ho:", options, NULL)) >= 0)
switch(c) {
case 'h':
help();
arg_action = ACTION_NONE;
return 0;
case ARG_VERSION:
puts(PACKAGE_STRING);
puts(DISTRIBUTION);
puts(SYSTEMD_FEATURES);
arg_action = ACTION_NONE;
return 0;
case ARG_NO_PAGER:
arg_no_pager = true;
break;
case 'o':
if (output) {
log_error("cannot set output more than once");
return -EINVAL;
}
output = fopen(optarg, "we");
if (!output) {
log_error("writing to '%s': %m", optarg);
return -errno;
}
break;
default:
log_error("Unknown option code %c", c);
return -EINVAL;
}
if (optind < argc) {
const char *cmd = argv[optind++];
if(streq(cmd, "list"))
arg_action = ACTION_LIST;
else if (streq(cmd, "dump"))
arg_action = ACTION_DUMP;
else {
log_error("Unknown action '%s'", cmd);
return -EINVAL;
}
}
while (optind < argc) {
r = add_match(matches, argv[optind]);
if (r != 0)
return r;
optind++;
}
return 0;
}
static int retrieve(sd_journal *j, const char *name, const char **var) {
const void *data;
size_t len, field;
int r;
r = sd_journal_get_data(j, name, &data, &len);
if (r < 0) {
log_warning("Failed to retrieve %s", name);
return r;
}
field = strlen(name) + 1; // name + "="
assert(len >= field);
*var = strndup((const char*)data + field, len - field);
if (!var)
return log_oom();
return 0;
}
static void print_entry(FILE* file, sd_journal *j, int had_header) {
const char _cleanup_free_
*pid = NULL, *uid = NULL, *gid = NULL,
*sgnl = NULL, *exe = NULL;
retrieve(j, "COREDUMP_PID", &pid);
retrieve(j, "COREDUMP_UID", &uid);
retrieve(j, "COREDUMP_GID", &gid);
retrieve(j, "COREDUMP_SIGNAL", &sgnl);
retrieve(j, "COREDUMP_EXE", &exe);
if (!exe)
retrieve(j, "COREDUMP_COMM", &exe);
if (!exe)
retrieve(j, "COREDUMP_CMDLINE", &exe);
if (!pid && !uid && !gid && !sgnl && !exe) {
log_warning("empty coredump log entry");
return;
}
if (!had_header)
fprintf(file, "%*s %*s %*s %*s %s\n",
6, "PID",
5, "UID",
5, "GID",
3, "sig",
"exe");
fprintf(file, "%*s %*s %*s %*s %s\n",
6, pid,
5, uid,
5, gid,
3, sgnl,
exe);
}
static int dump_list(sd_journal *j) {
int found = 0;
assert(j);
SD_JOURNAL_FOREACH(j)
print_entry(stdout, j, found++);
if (!found) {
log_error("no coredumps found");
return -ESRCH;
}
return 0;
}
static int dump_core(sd_journal* j) {
const char *data;
size_t len, ret;
int r;
assert(j);
r = sd_journal_seek_tail(j);
if (r == 0)
r = sd_journal_previous(j);
if (r < 0) {
log_error("Failed to search journal: %s", strerror(-r));
return r;
}
if (r == 0) {
log_error("No match found");
return -ESRCH;
}
r = sd_journal_get_data(j, "COREDUMP", (const void**) &data, &len);
if (r != 0) {
log_error("retrieve COREDUMP field: %s", strerror(-r));
return r;
}
print_entry(output ? stdout : stderr, j, false);
if (on_tty() && !output) {
log_error("Refusing to dump core to tty");
return -ENOTTY;
}
assert(len >= 9);
ret = fwrite(data+9, len-9, 1, output ? output : stdout);
if (ret != 1) {
log_error("dumping coredump: %m (%zu)", ret);
return -errno;
}
r = sd_journal_previous(j);
if (r >= 0)
log_warning("More than one entry matches, ignoring rest.\n");
return 0;
}
int main(int argc, char *argv[]) {
sd_journal *j = NULL;
const char* match;
Iterator it;
int r = 0;
log_parse_environment();
log_open();
matches = new_matches();
if (!matches)
goto end;
if (parse_argv(argc, argv))
goto end;
if (arg_action == ACTION_NONE)
goto end;
r = sd_journal_open(&j, SD_JOURNAL_LOCAL_ONLY);
if (r < 0) {
log_error("Failed to open journal: %s", strerror(-r));
goto end;
}
SET_FOREACH(match, matches, it) {
log_info("Matching: %s", match);
r = sd_journal_add_match(j, match, strlen(match));
if (r != 0) {
log_error("Failed to add match '%s': %s",
match, strerror(-r));
goto end;
}
}
switch(arg_action) {
case ACTION_LIST:
if (!arg_no_pager)
pager_open();
r = dump_list(j);
break;
case ACTION_DUMP:
r = dump_core(j);
break;
case ACTION_NONE:
assert_not_reached("Shouldn't be here");
}
end:
if (j)
sd_journal_close(j);
set_free_free(matches);
pager_close();
if (output)
fclose(output);
return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
}
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