/***
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 <stdio.h>
#include <sys/prctl.h>
#include <sys/xattr.h>
#include <unistd.h>
#ifdef HAVE_ELFUTILS
#include <dwarf.h>
#include <elfutils/libdwfl.h>
#endif
#include "sd-daemon.h"
#include "sd-journal.h"
#include "sd-login.h"
#include "sd-messages.h"
#include "acl-util.h"
#include "alloc-util.h"
#include "capability-util.h"
#include "cgroup-util.h"
#include "compress.h"
#include "conf-parser.h"
#include "copy.h"
#include "coredump-vacuum.h"
#include "dirent-util.h"
#include "escape.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "io-util.h"
#include "journald-native.h"
#include "log.h"
#include "macro.h"
#include "missing.h"
#include "mkdir.h"
#include "parse-util.h"
#include "process-util.h"
#include "socket-util.h"
#include "special.h"
#include "stacktrace.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "user-util.h"
#include "util.h"
/* The maximum size up to which we process coredumps */
#define PROCESS_SIZE_MAX ((uint64_t) (2LLU*1024LLU*1024LLU*1024LLU))
/* The maximum size up to which we leave the coredump around on disk */
#define EXTERNAL_SIZE_MAX PROCESS_SIZE_MAX
/* The maximum size up to which we store the coredump in the journal */
#define JOURNAL_SIZE_MAX ((size_t) (767LU*1024LU*1024LU))
/* Make sure to not make this larger than the maximum journal entry
* size. See DATA_SIZE_MAX in journald-native.c. */
assert_cc(JOURNAL_SIZE_MAX <= DATA_SIZE_MAX);
enum {
/* We use this as array indexes for a couple of special fields we use for naming coredumping files, and
* attaching xattrs */
CONTEXT_PID,
CONTEXT_UID,
CONTEXT_GID,
CONTEXT_SIGNAL,
CONTEXT_TIMESTAMP,
CONTEXT_RLIMIT,
CONTEXT_COMM,
CONTEXT_EXE,
_CONTEXT_MAX
};
typedef enum CoredumpStorage {
COREDUMP_STORAGE_NONE,
COREDUMP_STORAGE_EXTERNAL,
COREDUMP_STORAGE_JOURNAL,
_COREDUMP_STORAGE_MAX,
_COREDUMP_STORAGE_INVALID = -1
} CoredumpStorage;
static const char* const coredump_storage_table[_COREDUMP_STORAGE_MAX] = {
[COREDUMP_STORAGE_NONE] = "none",
[COREDUMP_STORAGE_EXTERNAL] = "external",
[COREDUMP_STORAGE_JOURNAL] = "journal",
};
DEFINE_PRIVATE_STRING_TABLE_LOOKUP(coredump_storage, CoredumpStorage);
static DEFINE_CONFIG_PARSE_ENUM(config_parse_coredump_storage, coredump_storage, CoredumpStorage, "Failed to parse storage setting");
static CoredumpStorage arg_storage = COREDUMP_STORAGE_EXTERNAL;
static bool arg_compress = true;
static uint64_t arg_process_size_max = PROCESS_SIZE_MAX;
static uint64_t arg_external_size_max = EXTERNAL_SIZE_MAX;
static uint64_t arg_journal_size_max = JOURNAL_SIZE_MAX;
static uint64_t arg_keep_free = (uint64_t) -1;
static uint64_t arg_max_use = (uint64_t) -1;
static int parse_config(void) {
static const ConfigTableItem items[] = {
{ "Coredump", "Storage", config_parse_coredump_storage, 0, &arg_storage },
{ "Coredump", "Compress", config_parse_bool, 0, &arg_compress },
{ "Coredump", "ProcessSizeMax", config_parse_iec_uint64, 0, &arg_process_size_max },
{ "Coredump", "ExternalSizeMax", config_parse_iec_uint64, 0, &arg_external_size_max },
{ "Coredump", "JournalSizeMax", config_parse_iec_size, 0, &arg_journal_size_max },
{ "Coredump", "KeepFree", config_parse_iec_uint64, 0, &arg_keep_free },
{ "Coredump", "MaxUse", config_parse_iec_uint64, 0, &arg_max_use },
{}
};
return config_parse_many_nulstr(PKGSYSCONFDIR "/coredump.conf",
CONF_PATHS_NULSTR("systemd/coredump.conf.d"),
"Coredump\0",
config_item_table_lookup, items,
false, NULL);
}
static inline uint64_t storage_size_max(void) {
return arg_storage == COREDUMP_STORAGE_EXTERNAL ? arg_external_size_max : arg_journal_size_max;
}
static int fix_acl(int fd, uid_t uid) {
#ifdef HAVE_ACL
_cleanup_(acl_freep) acl_t acl = NULL;
acl_entry_t entry;
acl_permset_t permset;
int r;
assert(fd >= 0);
if (uid <= SYSTEM_UID_MAX)
return 0;
/* Make sure normal users can read (but not write or delete)
* their own coredumps */
acl = acl_get_fd(fd);
if (!acl)
return log_error_errno(errno, "Failed to get ACL: %m");
if (acl_create_entry(&acl, &entry) < 0 ||
acl_set_tag_type(entry, ACL_USER) < 0 ||
acl_set_qualifier(entry, &uid) < 0)
return log_error_errno(errno, "Failed to patch ACL: %m");
if (acl_get_permset(entry, &permset) < 0 ||
acl_add_perm(permset, ACL_READ) < 0)
return log_warning_errno(errno, "Failed to patch ACL: %m");
r = calc_acl_mask_if_needed(&acl);
if (r < 0)
return log_warning_errno(r, "Failed to patch ACL: %m");
if (acl_set_fd(fd, acl) < 0)
return log_error_errno(errno, "Failed to apply ACL: %m");
#endif
return 0;
}
static int fix_xattr(int fd, const char *context[_CONTEXT_MAX]) {
static const char * const xattrs[_CONTEXT_MAX] = {
[CONTEXT_PID] = "user.coredump.pid",
[CONTEXT_UID] = "user.coredump.uid",
[CONTEXT_GID] = "user.coredump.gid",
[CONTEXT_SIGNAL] = "user.coredump.signal",
[CONTEXT_TIMESTAMP] = "user.coredump.timestamp",
[CONTEXT_COMM] = "user.coredump.comm",
[CONTEXT_EXE] = "user.coredump.exe",
};
int r = 0;
unsigned i;
assert(fd >= 0);
/* Attach some metadata to coredumps via extended
* attributes. Just because we can. */
for (i = 0; i < _CONTEXT_MAX; i++) {
int k;
if (isempty(context[i]) || !xattrs[i])
continue;
k = fsetxattr(fd, xattrs[i], context[i], strlen(context[i]), XATTR_CREATE);
if (k < 0 && r == 0)
r = -errno;
}
return r;
}
#define filename_escape(s) xescape((s), "./ ")
static inline const char *coredump_tmpfile_name(const char *s) {
return s ? s : "(unnamed temporary file)";
}
static int fix_permissions(
int fd,
const char *filename,
const char *target,
const char *context[_CONTEXT_MAX],
uid_t uid) {
int r;
assert(fd >= 0);
assert(target);
assert(context);
/* Ignore errors on these */
(void) fchmod(fd, 0640);
(void) fix_acl(fd, uid);
(void) fix_xattr(fd, context);
if (fsync(fd) < 0)
return log_error_errno(errno, "Failed to sync coredump %s: %m", coredump_tmpfile_name(filename));
r = link_tmpfile(fd, filename, target);
if (r < 0)
return log_error_errno(r, "Failed to move coredump %s into place: %m", target);
return 0;
}
static int maybe_remove_external_coredump(const char *filename, uint64_t size) {
/* Returns 1 if might remove, 0 if will not remove, < 0 on error. */
if (arg_storage == COREDUMP_STORAGE_EXTERNAL &&
size <= arg_external_size_max)
return 0;
if (!filename)
return 1;
if (unlink(filename) < 0 && errno != ENOENT)
return log_error_errno(errno, "Failed to unlink %s: %m", filename);
return 1;
}
static int make_filename(const char *context[_CONTEXT_MAX], char **ret) {
_cleanup_free_ char *c = NULL, *u = NULL, *p = NULL, *t = NULL;
sd_id128_t boot = {};
int r;
assert(context);
c = filename_escape(context[CONTEXT_COMM]);
if (!c)
return -ENOMEM;
u = filename_escape(context[CONTEXT_UID]);
if (!u)
return -ENOMEM;
r = sd_id128_get_boot(&boot);
if (r < 0)
return r;
p = filename_escape(context[CONTEXT_PID]);
if (!p)
return -ENOMEM;
t = filename_escape(context[CONTEXT_TIMESTAMP]);
if (!t)
return -ENOMEM;
if (asprintf(ret,
"/var/lib/systemd/coredump/core.%s.%s." SD_ID128_FORMAT_STR ".%s.%s000000",
c,
u,
SD_ID128_FORMAT_VAL(boot),
p,
t) < 0)
return -ENOMEM;
return 0;
}
static int save_external_coredump(
const char *context[_CONTEXT_MAX],
int input_fd,
char **ret_filename,
int *ret_node_fd,
int *ret_data_fd,
uint64_t *ret_size) {
_cleanup_free_ char *fn = NULL, *tmp = NULL;
_cleanup_close_ int fd = -1;
uint64_t rlimit, max_size;
struct stat st;
uid_t uid;
int r;
assert(context);
assert(ret_filename);
assert(ret_node_fd);
assert(ret_data_fd);
assert(ret_size);
r = parse_uid(context[CONTEXT_UID], &uid);
if (r < 0)
return log_error_errno(r, "Failed to parse UID: %m");
r = safe_atou64(context[CONTEXT_RLIMIT], &rlimit);
if (r < 0)
return log_error_errno(r, "Failed to parse resource limit: %s", context[CONTEXT_RLIMIT]);
if (rlimit < page_size()) {
/* Is coredumping disabled? Then don't bother saving/processing the coredump.
* Anything below PAGE_SIZE cannot give a readable coredump (the kernel uses
* ELF_EXEC_PAGESIZE which is not easily accessible, but is usually the same as PAGE_SIZE. */
log_info("Resource limits disable core dumping for process %s (%s).",
context[CONTEXT_PID], context[CONTEXT_COMM]);
return -EBADSLT;
}
/* Never store more than the process configured, or than we actually shall keep or process */
max_size = MIN(rlimit, MAX(arg_process_size_max, storage_size_max()));
r = make_filename(context, &fn);
if (r < 0)
return log_error_errno(r, "Failed to determine coredump file name: %m");
mkdir_p_label("/var/lib/systemd/coredump", 0755);
fd = open_tmpfile_linkable(fn, O_RDWR|O_CLOEXEC, &tmp);
if (fd < 0)
return log_error_errno(fd, "Failed to create temporary file for coredump %s: %m", fn);
r = copy_bytes(input_fd, fd, max_size, false);
if (r < 0) {
log_error_errno(r, "Cannot store coredump of %s (%s): %m", context[CONTEXT_PID], context[CONTEXT_COMM]);
goto fail;
} else if (r == 1)
log_struct(LOG_INFO,
LOG_MESSAGE("Core file was truncated to %zu bytes.", max_size),
"SIZE_LIMIT=%zu", max_size,
LOG_MESSAGE_ID(SD_MESSAGE_TRUNCATED_CORE),
NULL);
if (fstat(fd, &st) < 0) {
log_error_errno(errno, "Failed to fstat core file %s: %m", coredump_tmpfile_name(tmp));
goto fail;
}
if (lseek(fd, 0, SEEK_SET) == (off_t) -1) {
log_error_errno(errno, "Failed to seek on %s: %m", coredump_tmpfile_name(tmp));
goto fail;
}
#if defined(HAVE_XZ) || defined(HAVE_LZ4)
/* If we will remove the coredump anyway, do not compress. */
if (arg_compress && !maybe_remove_external_coredump(NULL, st.st_size)) {
_cleanup_free_ char *fn_compressed = NULL, *tmp_compressed = NULL;
_cleanup_close_ int fd_compressed = -1;
fn_compressed = strappend(fn, COMPRESSED_EXT);
if (!fn_compressed) {
log_oom();
goto uncompressed;
}
fd_compressed = open_tmpfile_linkable(fn_compressed, O_RDWR|O_CLOEXEC, &tmp_compressed);
if (fd_compressed < 0) {
log_error_errno(fd_compressed, "Failed to create temporary file for coredump %s: %m", fn_compressed);
goto uncompressed;
}
r = compress_stream(fd, fd_compressed, -1);
if (r < 0) {
log_error_errno(r, "Failed to compress %s: %m", coredump_tmpfile_name(tmp_compressed));
goto fail_compressed;
}
r = fix_permissions(fd_compressed, tmp_compressed, fn_compressed, context, uid);
if (r < 0)
goto fail_compressed;
/* OK, this worked, we can get rid of the uncompressed version now */
if (tmp)
unlink_noerrno(tmp);
*ret_filename = fn_compressed; /* compressed */
*ret_node_fd = fd_compressed; /* compressed */
*ret_data_fd = fd; /* uncompressed */
*ret_size = (uint64_t) st.st_size; /* uncompressed */
fn_compressed = NULL;
fd = fd_compressed = -1;
return 0;
fail_compressed:
if (tmp_compressed)
(void) unlink(tmp_compressed);
}
uncompressed:
#endif
r = fix_permissions(fd, tmp, fn, context, uid);
if (r < 0)
goto fail;
*ret_filename = fn;
*ret_data_fd = fd;
*ret_node_fd = -1;
*ret_size = (uint64_t) st.st_size;
fn = NULL;
fd = -1;
return 0;
fail:
if (tmp)
(void) unlink(tmp);
return r;
}
static int allocate_journal_field(int fd, size_t size, char **ret, size_t *ret_size) {
_cleanup_free_ char *field = NULL;
ssize_t n;
assert(fd >= 0);
assert(ret);
assert(ret_size);
if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
return log_warning_errno(errno, "Failed to seek: %m");
field = malloc(9 + size);
if (!field) {
log_warning("Failed to allocate memory for coredump, coredump will not be stored.");
return -ENOMEM;
}
memcpy(field, "COREDUMP=", 9);
n = read(fd, field + 9, size);
if (n < 0)
return log_error_errno((int) n, "Failed to read core data: %m");
if ((size_t) n < size) {
log_error("Core data too short.");
return -EIO;
}
*ret = field;
*ret_size = size + 9;
field = NULL;
return 0;
}
/* Joins /proc/[pid]/fd/ and /proc/[pid]/fdinfo/ into the following lines:
* 0:/dev/pts/23
* pos: 0
* flags: 0100002
*
* 1:/dev/pts/23
* pos: 0
* flags: 0100002
*
* 2:/dev/pts/23
* pos: 0
* flags: 0100002
* EOF
*/
static int compose_open_fds(pid_t pid, char **open_fds) {
_cleanup_closedir_ DIR *proc_fd_dir = NULL;
_cleanup_close_ int proc_fdinfo_fd = -1;
_cleanup_free_ char *buffer = NULL;
_cleanup_fclose_ FILE *stream = NULL;
const char *fddelim = "", *path;
struct dirent *dent = NULL;
size_t size = 0;
int r = 0;
assert(pid >= 0);
assert(open_fds != NULL);
path = procfs_file_alloca(pid, "fd");
proc_fd_dir = opendir(path);
if (!proc_fd_dir)
return -errno;
proc_fdinfo_fd = openat(dirfd(proc_fd_dir), "../fdinfo", O_DIRECTORY|O_NOFOLLOW|O_CLOEXEC|O_PATH);
if (proc_fdinfo_fd < 0)
return -errno;
stream = open_memstream(&buffer, &size);
if (!stream)
return -ENOMEM;
FOREACH_DIRENT(dent, proc_fd_dir, return -errno) {
_cleanup_fclose_ FILE *fdinfo = NULL;
_cleanup_free_ char *fdname = NULL;
char line[LINE_MAX];
int fd;
r = readlinkat_malloc(dirfd(proc_fd_dir), dent->d_name, &fdname);
if (r < 0)
return r;
fprintf(stream, "%s%s:%s\n", fddelim, dent->d_name, fdname);
fddelim = "\n";
/* Use the directory entry from /proc/[pid]/fd with /proc/[pid]/fdinfo */
fd = openat(proc_fdinfo_fd, dent->d_name, O_NOFOLLOW|O_CLOEXEC|O_RDONLY);
if (fd < 0)
continue;
fdinfo = fdopen(fd, "re");
if (fdinfo == NULL) {
close(fd);
continue;
}
FOREACH_LINE(line, fdinfo, break) {
fputs(line, stream);
if (!endswith(line, "\n"))
fputc('\n', stream);
}
}
errno = 0;
stream = safe_fclose(stream);
if (errno > 0)
return -errno;
*open_fds = buffer;
buffer = NULL;
return 0;
}
static int get_process_ns(pid_t pid, const char *namespace, ino_t *ns) {
const char *p;
struct stat stbuf;
_cleanup_close_ int proc_ns_dir_fd;
p = procfs_file_alloca(pid, "ns");
proc_ns_dir_fd = open(p, O_DIRECTORY | O_CLOEXEC | O_RDONLY);
if (proc_ns_dir_fd < 0)
return -errno;
if (fstatat(proc_ns_dir_fd, namespace, &stbuf, /* flags */0) < 0)
return -errno;
*ns = stbuf.st_ino;
return 0;
}
static int get_mount_namespace_leader(pid_t pid, pid_t *container_pid) {
pid_t cpid = pid, ppid = 0;
ino_t proc_mntns;
int r = 0;
r = get_process_ns(pid, "mnt", &proc_mntns);
if (r < 0)
return r;
for (;;) {
ino_t parent_mntns;
r = get_process_ppid(cpid, &ppid);
if (r < 0)
return r;
r = get_process_ns(ppid, "mnt", &parent_mntns);
if (r < 0)
return r;
if (proc_mntns != parent_mntns)
break;
if (ppid == 1)
return -ENOENT;
cpid = ppid;
}
*container_pid = ppid;
return 0;
}
/* Returns 1 if the parent was found.
* Returns 0 if there is not a process we can call the pid's
* container parent (the pid's process isn't 'containerized').
* Returns a negative number on errors.
*/
static int get_process_container_parent_cmdline(pid_t pid, char** cmdline) {
int r = 0;
pid_t container_pid;
const char *proc_root_path;
struct stat root_stat, proc_root_stat;
/* To compare inodes of / and /proc/[pid]/root */
if (stat("/", &root_stat) < 0)
return -errno;
proc_root_path = procfs_file_alloca(pid, "root");
if (stat(proc_root_path, &proc_root_stat) < 0)
return -errno;
/* The process uses system root. */
if (proc_root_stat.st_ino == root_stat.st_ino) {
*cmdline = NULL;
return 0;
}
r = get_mount_namespace_leader(pid, &container_pid);
if (r < 0)
return r;
return get_process_cmdline(container_pid, 0, false, cmdline);
}
static int change_uid_gid(const char *context[]) {
uid_t uid;
gid_t gid;
int r;
r = parse_uid(context[CONTEXT_UID], &uid);
if (r < 0)
return r;
if (uid <= SYSTEM_UID_MAX) {
const char *user = "systemd-coredump";
r = get_user_creds(&user, &uid, &gid, NULL, NULL);
if (r < 0) {
log_warning_errno(r, "Cannot resolve %s user. Proceeding to dump core as root: %m", user);
uid = gid = 0;
}
} else {
r = parse_gid(context[CONTEXT_GID], &gid);
if (r < 0)
return r;
}
return drop_privileges(uid, gid, 0);
}
static int submit_coredump(
const char *context[_CONTEXT_MAX],
struct iovec *iovec,
size_t n_iovec_allocated,
size_t n_iovec,
int input_fd) {
_cleanup_close_ int coredump_fd = -1, coredump_node_fd = -1;
_cleanup_free_ char *core_message = NULL, *filename = NULL, *coredump_data = NULL;
uint64_t coredump_size = UINT64_MAX;
int r;
assert(context);
assert(iovec);
assert(n_iovec_allocated >= n_iovec + 3);
assert(input_fd >= 0);
/* Vacuum before we write anything again */
(void) coredump_vacuum(-1, arg_keep_free, arg_max_use);
/* Always stream the coredump to disk, if that's possible */
r = save_external_coredump(context, input_fd, &filename, &coredump_node_fd, &coredump_fd, &coredump_size);
if (r < 0)
/* Skip whole core dumping part */
goto log;
/* If we don't want to keep the coredump on disk, remove 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(filename, coredump_size);
if (r < 0)
return r;
if (r == 0) {
const char *coredump_filename;
coredump_filename = strjoina("COREDUMP_FILENAME=", filename);
IOVEC_SET_STRING(iovec[n_iovec++], coredump_filename);
} else if (arg_storage == COREDUMP_STORAGE_EXTERNAL)
log_info("The core will not be stored: size %"PRIu64" is greater than %"PRIu64" (the configured maximum)",
coredump_size, arg_external_size_max);
/* Vacuum again, but exclude the coredump we just created */
(void) coredump_vacuum(coredump_node_fd >= 0 ? coredump_node_fd : coredump_fd, arg_keep_free, arg_max_use);
/* Now, let's drop privileges to become the user who owns the segfaulted process and allocate the coredump
* memory under the user's uid. This also ensures that the credentials journald will see are the ones of the
* coredumping user, thus making sure the user gets access to the core dump. Let's also get rid of all
* capabilities, if we run as root, we won't need them anymore. */
r = change_uid_gid(context);
if (r < 0)
return log_error_errno(r, "Failed to drop privileges: %m");
#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, context[CONTEXT_EXE], &stacktrace);
if (r >= 0)
core_message = strjoin("MESSAGE=Process ", context[CONTEXT_PID],
" (", context[CONTEXT_COMM], ") of user ",
context[CONTEXT_UID], " dumped core.\n\n",
stacktrace);
else if (r == -EINVAL)
log_warning("Failed to generate stack trace: %s", dwfl_errmsg(dwfl_errno()));
else
log_warning_errno(r, "Failed to generate stack trace: %m");
} else
log_debug("Not generating stack trace: core size %"PRIu64" is greater than %"PRIu64" (the configured maximum)",
coredump_size, arg_process_size_max);
if (!core_message)
#endif
log:
core_message = strjoin("MESSAGE=Process ", context[CONTEXT_PID], " (",
context[CONTEXT_COMM], ") of user ",
context[CONTEXT_UID], " dumped core.");
if (core_message)
IOVEC_SET_STRING(iovec[n_iovec++], core_message);
/* Optionally store the entire coredump in the journal */
if (arg_storage == COREDUMP_STORAGE_JOURNAL) {
if (coredump_size <= arg_journal_size_max) {
size_t sz = 0;
/* Store the coredump itself in the journal */
r = allocate_journal_field(coredump_fd, (size_t) coredump_size, &coredump_data, &sz);
if (r >= 0) {
iovec[n_iovec].iov_base = coredump_data;
iovec[n_iovec].iov_len = sz;
n_iovec++;
} else
log_warning_errno(r, "Failed to attach the core to the journal entry: %m");
} else
log_info("The core will not be stored: size %"PRIu64" is greater than %"PRIu64" (the configured maximum)",
coredump_size, arg_journal_size_max);
}
assert(n_iovec <= n_iovec_allocated);
r = sd_journal_sendv(iovec, n_iovec);
if (r < 0)
return log_error_errno(r, "Failed to log coredump: %m");
return 0;
}
static void map_context_fields(const struct iovec *iovec, const char *context[]) {
static const char * const context_field_names[_CONTEXT_MAX] = {
[CONTEXT_PID] = "COREDUMP_PID=",
[CONTEXT_UID] = "COREDUMP_UID=",
[CONTEXT_GID] = "COREDUMP_GID=",
[CONTEXT_SIGNAL] = "COREDUMP_SIGNAL=",
[CONTEXT_TIMESTAMP] = "COREDUMP_TIMESTAMP=",
[CONTEXT_COMM] = "COREDUMP_COMM=",
[CONTEXT_EXE] = "COREDUMP_EXE=",
[CONTEXT_RLIMIT] = "COREDUMP_RLIMIT=",
};
unsigned i;
assert(iovec);
assert(context);
for (i = 0; i < _CONTEXT_MAX; i++) {
size_t l;
l = strlen(context_field_names[i]);
if (iovec->iov_len < l)
continue;
if (memcmp(iovec->iov_base, context_field_names[i], l) != 0)
continue;
/* Note that these strings are NUL terminated, because we made sure that a trailing NUL byte is in the
* buffer, though not included in the iov_len count. (see below) */
context[i] = (char*) iovec->iov_base + l;
break;
}
}
static int process_socket(int fd) {
_cleanup_close_ int coredump_fd = -1;
struct iovec *iovec = NULL;
size_t n_iovec = 0, n_iovec_allocated = 0, i;
const char *context[_CONTEXT_MAX] = {};
int r;
assert(fd >= 0);
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
for (;;) {
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(int))];
} control = {};
struct msghdr mh = {
.msg_control = &control,
.msg_controllen = sizeof(control),
.msg_iovlen = 1,
};
ssize_t n;
ssize_t l;
if (!GREEDY_REALLOC(iovec, n_iovec_allocated, n_iovec + 3)) {
r = log_oom();
goto finish;
}
l = next_datagram_size_fd(fd);
if (l < 0) {
r = log_error_errno(l, "Failed to determine datagram size to read: %m");
goto finish;
}
assert(l >= 0);
iovec[n_iovec].iov_len = l;
iovec[n_iovec].iov_base = malloc(l + 1);
if (!iovec[n_iovec].iov_base) {
r = log_oom();
goto finish;
}
mh.msg_iov = iovec + n_iovec;
n = recvmsg(fd, &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
if (n < 0) {
free(iovec[n_iovec].iov_base);
r = log_error_errno(errno, "Failed to receive datagram: %m");
goto finish;
}
if (n == 0) {
struct cmsghdr *cmsg, *found = NULL;
/* The final zero-length datagram carries the file descriptor and tells us that we're done. */
free(iovec[n_iovec].iov_base);
CMSG_FOREACH(cmsg, &mh) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
assert(!found);
found = cmsg;
}
}
if (!found) {
log_error("Coredump file descriptor missing.");
r = -EBADMSG;
goto finish;
}
assert(coredump_fd < 0);
coredump_fd = *(int*) CMSG_DATA(found);
break;
}
/* Add trailing NUL byte, in case these are strings */
((char*) iovec[n_iovec].iov_base)[n] = 0;
iovec[n_iovec].iov_len = (size_t) n;
cmsg_close_all(&mh);
map_context_fields(iovec + n_iovec, context);
n_iovec++;
}
if (!GREEDY_REALLOC(iovec, n_iovec_allocated, n_iovec + 3)) {
r = log_oom();
goto finish;
}
/* Make sure we got all data we really need */
assert(context[CONTEXT_PID]);
assert(context[CONTEXT_UID]);
assert(context[CONTEXT_GID]);
assert(context[CONTEXT_SIGNAL]);
assert(context[CONTEXT_TIMESTAMP]);
assert(context[CONTEXT_RLIMIT]);
assert(context[CONTEXT_COMM]);
assert(coredump_fd >= 0);
r = submit_coredump(context, iovec, n_iovec_allocated, n_iovec, coredump_fd);
finish:
for (i = 0; i < n_iovec; i++)
free(iovec[i].iov_base);
free(iovec);
return r;
}
static int send_iovec(const struct iovec iovec[], size_t n_iovec, int input_fd) {
static const union sockaddr_union sa = {
.un.sun_family = AF_UNIX,
.un.sun_path = "/run/systemd/coredump",
};
_cleanup_close_ int fd = -1;
size_t i;
int r;
assert(iovec || n_iovec <= 0);
assert(input_fd >= 0);
fd = socket(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0);
if (fd < 0)
return log_error_errno(errno, "Failed to create coredump socket: %m");
if (connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
return log_error_errno(errno, "Failed to connect to coredump service: %m");
for (i = 0; i < n_iovec; i++) {
struct msghdr mh = {
.msg_iov = (struct iovec*) iovec + i,
.msg_iovlen = 1,
};
struct iovec copy[2];
for (;;) {
if (sendmsg(fd, &mh, MSG_NOSIGNAL) >= 0)
break;
if (errno == EMSGSIZE && mh.msg_iov[0].iov_len > 0) {
/* This field didn't fit? That's a pity. Given that this is just metadata,
* let's truncate the field at half, and try again. We append three dots, in
* order to show that this is truncated. */
if (mh.msg_iov != copy) {
/* We don't want to modify the caller's iovec, hence let's create our
* own array, consisting of two new iovecs, where the first is a
* (truncated) copy of what we want to send, and the second one
* contains the trailing dots. */
copy[0] = iovec[i];
copy[1] = (struct iovec) {
.iov_base = (char[]) { '.', '.', '.' },
.iov_len = 3,
};
mh.msg_iov = copy;
mh.msg_iovlen = 2;
}
copy[0].iov_len /= 2; /* halve it, and try again */
continue;
}
return log_error_errno(errno, "Failed to send coredump datagram: %m");
}
}
r = send_one_fd(fd, input_fd, 0);
if (r < 0)
return log_error_errno(r, "Failed to send coredump fd: %m");
return 0;
}
static int process_special_crash(const char *context[], int input_fd) {
_cleanup_close_ int coredump_fd = -1, coredump_node_fd = -1;
_cleanup_free_ char *filename = NULL;
uint64_t coredump_size;
int r;
assert(context);
assert(input_fd >= 0);
/* If we are pid1 or journald, we cut things short, don't write to the journal, but still create a coredump. */
if (arg_storage != COREDUMP_STORAGE_NONE)
arg_storage = COREDUMP_STORAGE_EXTERNAL;
r = save_external_coredump(context, input_fd, &filename, &coredump_node_fd, &coredump_fd, &coredump_size);
if (r < 0)
return r;
r = maybe_remove_external_coredump(filename, coredump_size);
if (r < 0)
return r;
log_notice("Detected coredump of the journal daemon or PID 1, diverted to %s.", filename);
return 0;
}
static int process_kernel(int argc, char* argv[]) {
/* The small core field we allocate on the stack, to keep things simple */
char
*core_pid = NULL, *core_uid = NULL, *core_gid = NULL, *core_signal = NULL,
*core_session = NULL, *core_exe = NULL, *core_comm = NULL, *core_cmdline = NULL,
*core_cgroup = NULL, *core_cwd = NULL, *core_root = NULL, *core_unit = NULL,
*core_user_unit = NULL, *core_slice = NULL, *core_timestamp = NULL, *core_rlimit = NULL;
/* The larger ones we allocate on the heap */
_cleanup_free_ char
*core_owner_uid = NULL, *core_open_fds = NULL, *core_proc_status = NULL,
*core_proc_maps = NULL, *core_proc_limits = NULL, *core_proc_cgroup = NULL, *core_environ = NULL,
*core_proc_mountinfo = NULL, *core_container_cmdline = NULL;
_cleanup_free_ char *exe = NULL, *comm = NULL;
const char *context[_CONTEXT_MAX];
bool proc_self_root_is_slash;
struct iovec iovec[27];
size_t n_iovec = 0;
uid_t owner_uid;
const char *p;
pid_t pid;
char *t;
int r;
if (argc < CONTEXT_COMM + 1) {
log_error("Not enough arguments passed from kernel (%i, expected %i).", argc - 1, CONTEXT_COMM + 1 - 1);
return -EINVAL;
}
r = parse_pid(argv[CONTEXT_PID + 1], &pid);
if (r < 0)
return log_error_errno(r, "Failed to parse PID.");
r = get_process_comm(pid, &comm);
if (r < 0) {
log_warning_errno(r, "Failed to get COMM, falling back to the command line: %m");
comm = strv_join(argv + CONTEXT_COMM + 1, " ");
if (!comm)
return log_oom();
}
r = get_process_exe(pid, &exe);
if (r < 0)
log_warning_errno(r, "Failed to get EXE, ignoring: %m");
context[CONTEXT_PID] = argv[CONTEXT_PID + 1];
context[CONTEXT_UID] = argv[CONTEXT_UID + 1];
context[CONTEXT_GID] = argv[CONTEXT_GID + 1];
context[CONTEXT_SIGNAL] = argv[CONTEXT_SIGNAL + 1];
context[CONTEXT_TIMESTAMP] = argv[CONTEXT_TIMESTAMP + 1];
context[CONTEXT_RLIMIT] = argv[CONTEXT_RLIMIT + 1];
context[CONTEXT_COMM] = comm;
context[CONTEXT_EXE] = exe;
if (cg_pid_get_unit(pid, &t) >= 0) {
/* If this is PID 1 disable coredump collection, we'll unlikely be able to process it later on. */
if (streq(t, SPECIAL_INIT_SCOPE)) {
log_notice("Due to PID 1 having crashed coredump collection will now be turned off.");
(void) write_string_file("/proc/sys/kernel/core_pattern", "|/bin/false", 0);
}
/* Let's avoid dead-locks when processing journald and init crashes, as socket activation and logging
* are unlikely to work then. */
if (STR_IN_SET(t, SPECIAL_JOURNALD_SERVICE, SPECIAL_INIT_SCOPE)) {
free(t);
return process_special_crash(context, STDIN_FILENO);
}
core_unit = strjoina("COREDUMP_UNIT=", t);
free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_unit);
}
/* OK, now we know it's not the journal, hence we can make use of it now. */
log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
log_open();
if (cg_pid_get_user_unit(pid, &t) >= 0) {
core_user_unit = strjoina("COREDUMP_USER_UNIT=", t);
free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_user_unit);
}
core_pid = strjoina("COREDUMP_PID=", context[CONTEXT_PID]);
IOVEC_SET_STRING(iovec[n_iovec++], core_pid);
core_uid = strjoina("COREDUMP_UID=", context[CONTEXT_UID]);
IOVEC_SET_STRING(iovec[n_iovec++], core_uid);
core_gid = strjoina("COREDUMP_GID=", context[CONTEXT_GID]);
IOVEC_SET_STRING(iovec[n_iovec++], core_gid);
core_signal = strjoina("COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL]);
IOVEC_SET_STRING(iovec[n_iovec++], core_signal);
core_rlimit = strjoina("COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT]);
IOVEC_SET_STRING(iovec[n_iovec++], core_rlimit);
if (sd_pid_get_session(pid, &t) >= 0) {
core_session = strjoina("COREDUMP_SESSION=", t);
free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_session);
}
if (sd_pid_get_owner_uid(pid, &owner_uid) >= 0) {
r = asprintf(&core_owner_uid, "COREDUMP_OWNER_UID=" UID_FMT, owner_uid);
if (r > 0)
IOVEC_SET_STRING(iovec[n_iovec++], core_owner_uid);
}
if (sd_pid_get_slice(pid, &t) >= 0) {
core_slice = strjoina("COREDUMP_SLICE=", t);
free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_slice);
}
if (comm) {
core_comm = strjoina("COREDUMP_COMM=", comm);
IOVEC_SET_STRING(iovec[n_iovec++], core_comm);
}
if (exe) {
core_exe = strjoina("COREDUMP_EXE=", exe);
IOVEC_SET_STRING(iovec[n_iovec++], core_exe);
}
if (get_process_cmdline(pid, 0, false, &t) >= 0) {
core_cmdline = strjoina("COREDUMP_CMDLINE=", t);
free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_cmdline);
}
if (cg_pid_get_path_shifted(pid, NULL, &t) >= 0) {
core_cgroup = strjoina("COREDUMP_CGROUP=", t);
free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_cgroup);
}
if (compose_open_fds(pid, &t) >= 0) {
core_open_fds = strappend("COREDUMP_OPEN_FDS=", t);
free(t);
if (core_open_fds)
IOVEC_SET_STRING(iovec[n_iovec++], core_open_fds);
}
p = procfs_file_alloca(pid, "status");
if (read_full_file(p, &t, NULL) >= 0) {
core_proc_status = strappend("COREDUMP_PROC_STATUS=", t);
free(t);
if (core_proc_status)
IOVEC_SET_STRING(iovec[n_iovec++], core_proc_status);
}
p = procfs_file_alloca(pid, "maps");
if (read_full_file(p, &t, NULL) >= 0) {
core_proc_maps = strappend("COREDUMP_PROC_MAPS=", t);
free(t);
if (core_proc_maps)
IOVEC_SET_STRING(iovec[n_iovec++], core_proc_maps);
}
p = procfs_file_alloca(pid, "limits");
if (read_full_file(p, &t, NULL) >= 0) {
core_proc_limits = strappend("COREDUMP_PROC_LIMITS=", t);
free(t);
if (core_proc_limits)
IOVEC_SET_STRING(iovec[n_iovec++], core_proc_limits);
}
p = procfs_file_alloca(pid, "cgroup");
if (read_full_file(p, &t, NULL) >=0) {
core_proc_cgroup = strappend("COREDUMP_PROC_CGROUP=", t);
free(t);
if (core_proc_cgroup)
IOVEC_SET_STRING(iovec[n_iovec++], core_proc_cgroup);
}
p = procfs_file_alloca(pid, "mountinfo");
if (read_full_file(p, &t, NULL) >=0) {
core_proc_mountinfo = strappend("COREDUMP_PROC_MOUNTINFO=", t);
free(t);
if (core_proc_mountinfo)
IOVEC_SET_STRING(iovec[n_iovec++], core_proc_mountinfo);
}
if (get_process_cwd(pid, &t) >= 0) {
core_cwd = strjoina("COREDUMP_CWD=", t);
free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_cwd);
}
if (get_process_root(pid, &t) >= 0) {
core_root = strjoina("COREDUMP_ROOT=", t);
IOVEC_SET_STRING(iovec[n_iovec++], core_root);
/* If the process' root is "/", then there is a chance it has
* mounted own root and hence being containerized. */
proc_self_root_is_slash = strcmp(t, "/") == 0;
free(t);
if (proc_self_root_is_slash && get_process_container_parent_cmdline(pid, &t) > 0) {
core_container_cmdline = strappend("COREDUMP_CONTAINER_CMDLINE=", t);
free(t);
if (core_container_cmdline)
IOVEC_SET_STRING(iovec[n_iovec++], core_container_cmdline);
}
}
if (get_process_environ(pid, &t) >= 0) {
core_environ = strappend("COREDUMP_ENVIRON=", t);
free(t);
if (core_environ)
IOVEC_SET_STRING(iovec[n_iovec++], core_environ);
}
core_timestamp = strjoina("COREDUMP_TIMESTAMP=", context[CONTEXT_TIMESTAMP], "000000");
IOVEC_SET_STRING(iovec[n_iovec++], core_timestamp);
IOVEC_SET_STRING(iovec[n_iovec++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1");
assert_cc(2 == LOG_CRIT);
IOVEC_SET_STRING(iovec[n_iovec++], "PRIORITY=2");
assert(n_iovec <= ELEMENTSOF(iovec));
return send_iovec(iovec, n_iovec, STDIN_FILENO);
}
int main(int argc, char *argv[]) {
int r;
/* First, log to a safe place, since we don't know what crashed and it might be journald which we'd rather not
* log to then. */
log_set_target(LOG_TARGET_KMSG);
log_open();
/* Make sure we never enter a loop */
(void) prctl(PR_SET_DUMPABLE, 0);
/* Ignore all parse errors */
(void) parse_config();
log_debug("Selected storage '%s'.", coredump_storage_to_string(arg_storage));
log_debug("Selected compression %s.", yes_no(arg_compress));
r = sd_listen_fds(false);
if (r < 0) {
log_error_errno(r, "Failed to determine number of file descriptor: %m");
goto finish;
}
/* If we got an fd passed, we are running in coredumpd mode. Otherwise we are invoked from the kernel as
* coredump handler */
if (r == 0)
r = process_kernel(argc, argv);
else if (r == 1)
r = process_socket(SD_LISTEN_FDS_START);
else {
log_error("Received unexpected number of file descriptors.");
r = -EINVAL;
}
finish:
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}