tree-wide: whenever we fork off a foreign child process reset signal mask/handlers

Also, when the child is potentially long-running make sure to set a
death signal.

Also, ignore the result of the reset operations explicitly by casting
them to (void).
This commit is contained in:
Lennart Poettering 2015-05-31 23:55:55 +02:00
parent 0c2c2a3aeb
commit ce30c8dcb4
26 changed files with 98 additions and 37 deletions

View File

@ -33,6 +33,7 @@
#include "log.h"
#include "strv.h"
#include "macro.h"
#include "signal-util.h"
static char** arg_listen = NULL;
static bool arg_accept = false;
@ -192,6 +193,10 @@ static int launch1(const char* child, char** argv, char **env, int fd) {
/* In the child */
if (child_pid == 0) {
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
r = dup2(fd, STDIN_FILENO);
if (r < 0) {
log_error_errno(errno, "Failed to dup connection to stdin: %m");

View File

@ -408,8 +408,8 @@ static int busname_make_starter(BusName *n, pid_t *_pid) {
if (pid == 0) {
int ret;
default_signals(SIGNALS_CRASH_HANDLER, SIGNALS_IGNORE, -1);
ignore_signals(SIGPIPE, -1);
(void) default_signals(SIGNALS_CRASH_HANDLER, SIGNALS_IGNORE, -1);
(void) ignore_signals(SIGPIPE, -1);
log_forget_fds();
r = bus_kernel_make_starter(n->starter_fd, n->name, n->activating, n->accept_fd, n->policy, n->policy_world);

View File

@ -823,6 +823,7 @@ static int setup_pam(
/* Block SIGTERM, so that we know that it won't get lost in
* the child */
if (sigemptyset(&ss) < 0 ||
sigaddset(&ss, SIGTERM) < 0 ||
sigprocmask(SIG_BLOCK, &ss, &old_ss) < 0)
@ -857,6 +858,8 @@ static int setup_pam(
if (setresuid(uid, uid, uid) < 0)
log_error_errno(r, "Error: Failed to setresuid() in sd-pam: %m");
(void) ignore_signals(SIGPIPE, -1);
/* Wait until our parent died. This will only work if
* the above setresuid() succeeds, otherwise the kernel
* will not allow unprivileged parents kill their privileged
@ -1324,11 +1327,11 @@ static int exec_child(
* others we leave untouched because we set them to
* SIG_DFL or a valid handler initially, both of which
* will be demoted to SIG_DFL. */
default_signals(SIGNALS_CRASH_HANDLER,
SIGNALS_IGNORE, -1);
(void) default_signals(SIGNALS_CRASH_HANDLER,
SIGNALS_IGNORE, -1);
if (context->ignore_sigpipe)
ignore_signals(SIGPIPE, -1);
(void) ignore_signals(SIGPIPE, -1);
r = reset_signal_mask();
if (r < 0) {

View File

@ -1405,9 +1405,8 @@ int main(int argc, char *argv[]) {
}
/* Reset all signal handlers. */
assert_se(reset_all_signal_handlers() == 0);
ignore_signals(SIGNALS_IGNORE, -1);
(void) reset_all_signal_handlers();
(void) ignore_signals(SIGNALS_IGNORE, -1);
if (parse_config_file() < 0) {
error_message = "Failed to parse config file";
@ -1931,8 +1930,8 @@ finish:
/* Reenable any blocked signals, especially important
* if we switch from initial ramdisk to init=... */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
if (switch_root_init) {
args[0] = switch_root_init;

View File

@ -1473,8 +1473,8 @@ static int socket_chown(Socket *s, pid_t *_pid) {
gid_t gid = GID_INVALID;
int ret;
default_signals(SIGNALS_CRASH_HANDLER, SIGNALS_IGNORE, -1);
ignore_signals(SIGPIPE, -1);
(void) default_signals(SIGNALS_CRASH_HANDLER, SIGNALS_IGNORE, -1);
(void) ignore_signals(SIGPIPE, -1);
log_forget_fds();
if (!isempty(s->user)) {

View File

@ -24,6 +24,7 @@
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include <sys/prctl.h>
#include "hashmap.h"
#include "util.h"
@ -34,6 +35,7 @@
#include "strv.h"
#include "process-util.h"
#include "terminal-util.h"
#include "signal-util.h"
static const char prefixes[] =
"/etc\0"
@ -189,9 +191,14 @@ static int found_override(const char *top, const char *bottom) {
if (pid < 0)
return log_error_errno(errno, "Failed to fork off diff: %m");
else if (pid == 0) {
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
execlp("diff", "diff", "-us", "--", bottom, top, NULL);
log_error_errno(errno, "Failed to execute diff: %m");
_exit(1);
_exit(EXIT_FAILURE);
}
wait_for_terminate_and_warn("diff", pid, false);

View File

@ -394,8 +394,8 @@ int main(int argc, char *argv[]) {
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
/* Close the reading side of the progress pipe */

View File

@ -311,7 +311,7 @@ int main(int argc, char *argv[]) {
if (r <= 0)
goto finish;
ignore_signals(SIGPIPE, -1);
(void) ignore_signals(SIGPIPE, -1);
r = export_main(argc, argv);

View File

@ -97,8 +97,8 @@ int import_fork_tar_x(const char *path, pid_t *ret) {
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
pipefd[1] = safe_close(pipefd[1]);
@ -171,8 +171,8 @@ int import_fork_tar_c(const char *path, pid_t *ret) {
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
pipefd[0] = safe_close(pipefd[0]);

View File

@ -328,7 +328,7 @@ int main(int argc, char *argv[]) {
if (r <= 0)
goto finish;
ignore_signals(SIGPIPE, -1);
(void) ignore_signals(SIGPIPE, -1);
r = import_main(argc, argv);

View File

@ -390,8 +390,8 @@ static int transfer_start(Transfer *t) {
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
pipefd[0] = safe_close(pipefd[0]);

View File

@ -339,8 +339,8 @@ int pull_verify(
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
gpg_pipe[1] = safe_close(gpg_pipe[1]);

View File

@ -440,7 +440,7 @@ int main(int argc, char *argv[]) {
if (r <= 0)
goto finish;
ignore_signals(SIGPIPE, -1);
(void) ignore_signals(SIGPIPE, -1);
r = pull_main(argc, argv);

View File

@ -96,6 +96,10 @@ static int spawn_child(const char* child, char** argv) {
/* In the child */
if (child_pid == 0) {
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
r = dup2(fd[1], STDOUT_FILENO);
if (r < 0) {
log_error_errno(errno, "Failed to dup pipe to stdout: %m");

View File

@ -757,6 +757,9 @@ static int run_gdb(sd_journal *j) {
goto finish;
}
if (pid == 0) {
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
execlp("gdb", "gdb", exe, path, NULL);
log_error_errno(errno, "Failed to invoke gdb: %m");

View File

@ -738,7 +738,8 @@ int bus_socket_exec(sd_bus *b) {
if (pid == 0) {
/* Child */
reset_all_signal_handlers();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
close_all_fds(s+1, 1);

View File

@ -33,6 +33,7 @@
#include "strv.h"
#include "formats-util.h"
#include "process-util.h"
#include "signal-util.h"
static const char* arg_what = "idle:sleep:shutdown";
static const char* arg_who = NULL;
@ -274,6 +275,9 @@ int main(int argc, char *argv[]) {
if (pid == 0) {
/* Child */
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
close_all_fds(NULL, 0);
execvp(argv[optind], argv + optind);

View File

@ -3656,7 +3656,8 @@ static int spawn_getent(const char *database, const char *key, pid_t *rpid) {
if (nullfd > 2)
safe_close(nullfd);
reset_all_signal_handlers();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
close_all_fds(NULL, 0);
execle("/usr/bin/getent", "getent", database, key, NULL, &empty_env);
@ -4739,8 +4740,8 @@ int main(int argc, char *argv[]) {
rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
pid_socket_pair[0] = safe_close(pid_socket_pair[0]);
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
r = outer_child(&barrier,
arg_directory,

View File

@ -23,9 +23,11 @@
#include <stdbool.h>
#include <errno.h>
#include <unistd.h>
#include <sys/prctl.h>
#include "util.h"
#include "process-util.h"
#include "signal-util.h"
static bool arg_skip = false;
static bool arg_force = false;
@ -105,7 +107,13 @@ int main(int argc, char *argv[]) {
log_error_errno(errno, "fork(): %m");
return EXIT_FAILURE;
} else if (pid == 0) {
/* Child */
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
execv(cmdline[0], (char**) cmdline);
_exit(1); /* Operational error */
}

View File

@ -95,6 +95,9 @@ int main(int argc, char *argv[]) {
const char *arguments[5];
/* Child */
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
arguments[0] = MOUNT_PATH;
arguments[1] = me->mnt_dir;
arguments[2] = "-o";

View File

@ -109,8 +109,8 @@ static int setup_machine_raw(uint64_t size, sd_bus_error *error) {
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
fd = safe_close(fd);

View File

@ -30,6 +30,7 @@
#include "process-util.h"
#include "macro.h"
#include "terminal-util.h"
#include "signal-util.h"
static pid_t pager_pid = 0;
@ -85,6 +86,9 @@ int pager_open(bool jump_to_end) {
if (pager_pid == 0) {
const char* less_opts;
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
dup2(fd[0], STDIN_FILENO);
safe_close_pair(fd);
@ -178,6 +182,10 @@ int show_man_page(const char *desc, bool null_stdio) {
if (pid == 0) {
/* Child */
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
if (null_stdio) {
r = make_null_stdio();
if (r < 0) {

View File

@ -239,7 +239,7 @@ int pty_setup_child(Pty *pty) {
assert_return(pty_is_child(pty), -EINVAL);
assert_return(pty_is_open(pty), -EALREADY);
r = sigprocmask_many(SIG_SETMASK, -1);
r = reset_signal_mask();
if (r < 0)
return r;

View File

@ -2301,8 +2301,8 @@ static int do_execute(char **directories, usec_t timeout, char *argv[]) {
/* We fork this all off from a child process so that we can
* somewhat cleanly make use of SIGALRM to set a time limit */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
@ -3344,8 +3344,8 @@ int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *pa
/* Make sure we actually can kill the agent, if we need to, in
* case somebody invoked us from a shell script that trapped
* SIGTERM or so... */
reset_all_signal_handlers();
reset_signal_mask();
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
/* Check whether our parent died before we were able
* to set the death signal and unblock the signals */

View File

@ -5189,6 +5189,9 @@ static int enable_sysv_units(const char *verb, char **args) {
else if (pid == 0) {
/* Child */
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
execv(argv[0], (char**) argv);
log_error("Failed to execute %s: %m", argv[0]);
_exit(EXIT_FAILURE);
@ -5854,6 +5857,9 @@ static int run_editor(char **paths) {
unsigned i = 1;
size_t argc;
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
argc = strv_length(paths)/2 + 1;
args = newa(const char*, argc + 1);

View File

@ -37,6 +37,7 @@
#include "fileio.h"
#include "process-util.h"
#include "terminal-util.h"
#include "signal-util.h"
static bool is_vconsole(int fd) {
unsigned char data[1];
@ -122,6 +123,10 @@ static int keyboard_load_and_wait(const char *vc, const char *map, const char *m
if (pid < 0)
return log_error_errno(errno, "Failed to fork: %m");
else if (pid == 0) {
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
execv(args[0], (char **) args);
_exit(EXIT_FAILURE);
}
@ -160,6 +165,10 @@ static int font_load_and_wait(const char *vc, const char *font, const char *map,
if (pid < 0)
return log_error_errno(errno, "Failed to fork: %m");
else if (pid == 0) {
(void) reset_all_signal_handlers();
(void) reset_signal_mask();
execv(args[0], (char **) args);
_exit(EXIT_FAILURE);
}