From: Roland McGrath <roland@redhat.com>
Date: Tue, 17 Dec 2002 04:50:47 +0000 (+0000)
Subject: 2002-12-16  Roland McGrath  <roland@redhat.com>
X-Git-Tag: v4.5.18~943
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5bc05558bb9f9acd1f895ea128f3326ef4b03338;p=strace

2002-12-16  Roland McGrath  <roland@redhat.com>

	* strace.c (trace) [LINUX]: Only check errno if wait4 actually fails,
	so we don't repeat a wait and thus drop a status.  Fixes RH#62591.
---

diff --git a/strace.c b/strace.c
index ec8d7527..67e832d3 100644
--- a/strace.c
+++ b/strace.c
@@ -1679,14 +1679,14 @@ trace()
 #ifdef LINUX
 #ifdef __WALL
 		pid = wait4(-1, &status, wait4_options, cflag ? &ru : NULL);
-		if ((wait4_options & __WALL) && errno == EINVAL) {
+		if (pid < 0 && (wait4_options & __WALL) && errno == EINVAL) {
 			/* this kernel does not support __WALL */
 			wait4_options &= ~__WALL;
 			errno = 0;
 			pid = wait4(-1, &status, wait4_options,
 					cflag ? &ru : NULL);
 		}
-		if (!(wait4_options & __WALL) && errno == ECHILD) {
+		if (pid < 0 && !(wait4_options & __WALL) && errno == ECHILD) {
 			/* most likely a "cloned" process */
 			pid = wait4(-1, &status, __WCLONE,
 					cflag ? &ru : NULL);