rt/snapraid
1
0
Fork 0
mirror of https://github.com/amadvance/snapraid.git synced 2026-10-26 02:49:02 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Block signal delivery across fork to prevent signal forwarding race condition in main.c

Browse source
This commit is contained in:
Andrea Mazzoleni 2026-07-16 22:50:23 +02:00
parent 9621655a10
commit 821756371c
1 changed files with 19 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

20
cmdline/main.c
View file

@ -315,7 +315,7 @@ const char* get_argv0(const char* argv0)
}
/* global variable to store child PID for signal handler */
static volatile pid_t child_pid = 0;
static volatile sig_atomic_t child_pid = 0;
/* signal handler that forwards signals to child */
/* LCOV_EXCL_START */
@ -364,6 +364,18 @@ int main(int argc, char* argv[])
sigaction(SIGUSR1, &sa, NULL); /* user-defined 1 */
sigaction(SIGUSR2, &sa, NULL); /* user-defined 2 */
sigset_t set, oldset;
sigemptyset(&set);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGQUIT);
sigaddset(&set, SIGTERM);
sigaddset(&set, SIGHUP);
sigaddset(&set, SIGUSR1);
sigaddset(&set, SIGUSR2);
/* block signals to prevent signal race before child_pid is set */
sigprocmask(SIG_BLOCK, &set, &oldset);
pid_t pid = fork();
if (pid == -1) {
/* LCOV_EXCL_START */
@ -383,6 +395,9 @@ int main(int argc, char* argv[])
signal(SIGUSR1, SIG_DFL);
signal(SIGUSR2, SIG_DFL);
/* unblock signals in child */
sigprocmask(SIG_SETMASK, &oldset, NULL);
execvp(get_argv0(argv[0]), argv);
/* here it's an error */
@ -397,6 +412,9 @@ int main(int argc, char* argv[])
/* store child PID so signal handler can forward signals */
child_pid = pid;
/* unblock signals in parent */
sigprocmask(SIG_SETMASK, &oldset, NULL);
do {
ret = waitpid(pid, &status, 0);
} while (ret == -1 && errno == EINTR); /* retry if interrupted by signal */