emo/openrc
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

start-stop-daemon: use a pipe to sync parent/child processes

Browse Source 
This fixes #557.
This commit is contained in:
Mike Gilbert 2022-10-29 12:38:43 -04:00 committed by William Hubbs
parent 953172c6c6
commit 1364e6631c
1 changed files with 22 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
src/start-stop-daemon/start-stop-daemon.c
View File

@ -354,6 +354,9 @@ int main(int argc, char **argv)
#ifdef PR_SET_NO_NEW_PRIVS
bool no_new_privs = false;
#endif
int pipefd[2];
char readbuf[1];
ssize_t ss;
applet = basename_c(argv[0]);
atexit(cleanup);
@ -864,12 +867,17 @@ int main(int argc, char **argv)
if (background)
signal_setup(SIGCHLD, handle_signal);
/* Use a pipe to sync the parent/child processes. */
if (pipe2(pipefd, O_CLOEXEC) == -1)
eerrorx("%s: pipe2: %s", applet, strerror(errno));
if ((pid = fork()) == -1)
eerrorx("%s: fork: %s", applet, strerror(errno));
/* Child process - lets go! */
if (pid == 0) {
pid_t mypid = getpid();
close(pipefd[0]); /* Close the read end of the pipe. */
umask(numask);
#ifdef TIOCNOTTY
@ -1097,7 +1105,8 @@ int main(int argc, char **argv)
dup2(stderr_fd, STDERR_FILENO);
for (i = getdtablesize() - 1; i >= 3; --i)
close(i);
if (i != pipefd[1])
close(i);
if (scheduler != NULL) {
int scheduler_index;
@ -1140,6 +1149,18 @@ int main(int argc, char **argv)
}
/* Parent process */
close(pipefd[1]); /* Close the write end of the pipe. */
/* The child never writes to the pipe, so this read will block until
* the child calls exec or exits. */
while ((ss = read(pipefd[0], readbuf, 1)) == -1 && errno == EINTR);
if (ss == -1)
eerrorx("%s: failed to read from pipe: %s",
applet, strerror(errno));
close(pipefd[0]);
if (!background) {
/* As we're not backgrounding the process, wait for our pid
* to return */