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Code Issues

exec_always: fix leaks

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- child would leak in the workspace_record_pid path
 - removing malloc lets us get rid of That Comment nobody seems
to remember what it was about
 - we would leak pipe fds on first fork failling
 - we didn't return an error if second fork failed
 - the final executed process still had both pipe fds
(would show up in /proc/23560/fd in launched programs)
 - we would write twice to the pipe if execl failed for some reason
(e.g. if /bin/sh doesn't exist?!)
This commit is contained in:
Dominique Martinet 2018-07-01 00:00:15 +09:00
parent 62a7b762ac
commit ce17788533
1 changed files with 14 additions and 15 deletions
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29
sway/commands/exec_always.c
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@ -42,43 +42,42 @@ struct cmd_results *cmd_exec_always(int argc, char **argv) {
wlr_log(L_ERROR, "Unable to create pipe for fork");
}
pid_t pid;
pid_t *child = malloc(sizeof(pid_t)); // malloc'd so that Linux can avoid copying the process space
if (!child) {
return cmd_results_new(CMD_FAILURE, "exec_always", "Unable to allocate child pid");
}
pid_t pid, child;
// Fork process
if ((pid = fork()) == 0) {
// Fork child process again
setsid();
if ((*child = fork()) == 0) {
execl("/bin/sh", "/bin/sh", "-c", cmd, (void *)NULL);
// Not reached
}
close(fd[0]);
if ((child = fork()) == 0) {
close(fd[1]);
execl("/bin/sh", "/bin/sh", "-c", cmd, (void *)NULL);
_exit(0);
}
ssize_t s = 0;
while ((size_t)s < sizeof(pid_t)) {
s += write(fd[1], ((uint8_t *)child) + s, sizeof(pid_t) - s);
s += write(fd[1], ((uint8_t *)&child) + s, sizeof(pid_t) - s);
}
close(fd[1]);
_exit(0); // Close child process
} else if (pid < 0) {
free(child);
close(fd[0]);
close(fd[1]);
return cmd_results_new(CMD_FAILURE, "exec_always", "fork() failed");
}
close(fd[1]); // close write
ssize_t s = 0;
while ((size_t)s < sizeof(pid_t)) {
s += read(fd[0], ((uint8_t *)child) + s, sizeof(pid_t) - s);
s += read(fd[0], ((uint8_t *)&child) + s, sizeof(pid_t) - s);
}
close(fd[0]);
// cleanup child process
waitpid(pid, NULL, 0);
if (*child > 0) {
wlr_log(L_DEBUG, "Child process created with pid %d", *child);
if (child > 0) {
wlr_log(L_DEBUG, "Child process created with pid %d", child);
// TODO: add PID to active workspace
} else {
free(child);
return cmd_results_new(CMD_FAILURE, "exec_always",
"Second fork() failed");
}
return cmd_results_new(CMD_SUCCESS, NULL, NULL);