wait4pid: if passed with pid < 0, do not set errno - it is already set by exec!
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 11dbb24..ff2b0bc 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -61,11 +61,43 @@
pid_t xspawn(char **argv)
{
pid_t pid = spawn(argv);
- if (pid < 0) bb_perror_msg_and_die("%s", *argv);
+ if (pid < 0)
+ bb_perror_msg_and_die("%s", *argv);
return pid;
}
+// Wait for the specified child PID to exit, returning child's error return.
+int wait4pid(int pid)
+{
+ int status;
+ if (pid <= 0) {
+ /*errno = ECHILD; -- wrong. we expect errno to be set from failed exec */
+ return -1;
+ }
+ if (waitpid(pid, &status, 0) == -1)
+ return -1;
+ if (WIFEXITED(status))
+ return WEXITSTATUS(status);
+ if (WIFSIGNALED(status))
+ return WTERMSIG(status) + 10000;
+ return 0;
+}
+
+int wait_nohang(int *wstat)
+{
+ return waitpid(-1, wstat, WNOHANG);
+}
+
+int wait_pid(int *wstat, int pid)
+{
+ int r;
+
+ do
+ r = waitpid(pid, wstat, 0);
+ while ((r == -1) && (errno == EINTR));
+ return r;
+}
#if 0 //ndef BB_NOMMU
// Die with an error message if we can't daemonize.