daemon(8): handle case of waitpid() returning without exited child

PR:	277764

(cherry picked from commit 8eaa6be80d)
This commit is contained in:
Konstantin Belousov 2024-03-18 10:44:39 +02:00
parent 285f941478
commit 1d2a587ef9

View file

@ -743,18 +743,22 @@ daemon_terminate(struct daemon_state *state)
}
/*
* Returns true if SIGCHILD came from state->pid
* This function could hang if SIGCHILD was emittied for a reason other than
* child dying (e.g., ptrace attach).
* Returns true if SIGCHILD came from state->pid due to its exit.
*/
static bool
daemon_is_child_dead(struct daemon_state *state)
{
int status;
for (;;) {
int who = waitpid(-1, NULL, WNOHANG);
if (state->pid == who) {
int who = waitpid(-1, &status, WNOHANG);
if (state->pid == who && (WIFEXITED(status) ||
WIFSIGNALED(status))) {
return true;
}
if (who == 0) {
return false;
}
if (who == -1 && errno != EINTR) {
warn("waitpid");
return false;