Use waitpid()/EINTR idiom for the specific pid, rather than generic wait(),

in case the parent process was started with a dangling child.  This style
ensures any potential parent:child interlock isn't disrupted due to the
"wrong" child being waited on first.  Then the other other childs can safely
zombie.
ok millert jca brynet

6 files changed, 48 insertions, 23 deletions

diff --git a/usr.bin/calendar/io.c b/usr.bin/calendar/io.c
index 428565dfdae..8abe7996917 100644
--- a/usr.bin/calendar/io.c
+++ b/usr.bin/calendar/io.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: io.c,v 1.45 2017/08/10 14:26:31 tb Exp $	*/
+/*	$OpenBSD: io.c,v 1.46 2017/08/21 21:41:13 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993, 1994
@@ -385,6 +385,7 @@ closecal(FILE *fp)
 	struct stat sbuf;
 	int nread, pdes[2], status;
 	char buf[1024];
+	pid_t pid;
 
 	if (!doall)
 		return;
@@ -394,7 +395,7 @@ closecal(FILE *fp)
 		goto done;
 	if (pipe(pdes) < 0)
 		goto done;
-	switch (vfork()) {
+	switch ((pid = vfork())) {
 	case -1:			/* error */
 		(void)close(pdes[0]);
 		(void)close(pdes[1]);
@@ -421,8 +422,10 @@ closecal(FILE *fp)
 		(void)write(pdes[1], buf, nread);
 	(void)close(pdes[1]);
 done:	(void)fclose(fp);
-	while (wait(&status) >= 0)
-		;
+	while (waitpid(pid, &status, 0) == -1) {
+		if (errno != EINTR)
+			break;
+	}
 }
 
 
diff --git a/usr.bin/m4/gnum4.c b/usr.bin/m4/gnum4.c
index 4280cb97339..1de66f2fa1b 100644
--- a/usr.bin/m4/gnum4.c
+++ b/usr.bin/m4/gnum4.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: gnum4.c,v 1.51 2017/06/15 13:48:42 bcallah Exp $ */
+/* $OpenBSD: gnum4.c,v 1.52 2017/08/21 21:41:13 deraadt Exp $ */
 
 /*
  * Copyright (c) 1999 Marc Espie
@@ -630,7 +630,7 @@ void
 doesyscmd(const char *cmd)
 {
 	int p[2];
-	pid_t pid, cpid;
+	pid_t cpid;
 	char *argv[4];
 	int cc;
 	int status;
@@ -668,8 +668,10 @@ doesyscmd(const char *cmd)
 		} while (cc > 0 || (cc == -1 && errno == EINTR));
 
 		(void) close(p[0]);
-		while ((pid = wait(&status)) != cpid && pid >= 0)
-			continue;
+		while (waitpid(cpid, &status, 0) == -1) {
+			if (errno != EINTR)
+				break;
+		}
 		pbstr(getstring());
 	}
 }
diff --git a/usr.bin/passwd/pwd_check.c b/usr.bin/passwd/pwd_check.c
index fcb3dfdeb41..cfdd1f65ed2 100644
--- a/usr.bin/passwd/pwd_check.c
+++ b/usr.bin/passwd/pwd_check.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pwd_check.c,v 1.15 2015/12/09 19:39:10 mmcc Exp $	*/
+/*	$OpenBSD: pwd_check.c,v 1.16 2017/08/21 21:41:13 deraadt Exp $	*/
 
 /*
  * Copyright 2000 Niels Provos <provos@citi.umich.edu>
@@ -138,12 +138,14 @@ pwd_check(login_cap_t *lc, char *password)
 				err(1, "pledge");
 
 			for (i = 0; i < sizeof(patterns) / sizeof(*patterns); i++) {
+				int ret;
+
 				if (regcomp(&rgx, patterns[i].match,
 				    patterns[i].flags) != 0)
 					continue;
-				res = regexec(&rgx, password, 0, NULL, 0);
+				ret = regexec(&rgx, password, 0, NULL, 0);
 				regfree(&rgx);
-				if (res == 0) {
+				if (ret == 0) {
 					printf("%s\n", patterns[i].response);
 					exit(1);
 				}
@@ -181,8 +183,11 @@ pwd_check(login_cap_t *lc, char *password)
 	}
 
 	/* get the return value from the child */
-	wait(&child);
-	if (WIFEXITED(child) && WEXITSTATUS(child) == 0) {
+	while (waitpid(child, &res, 0) == -1) {
+		if (errno != EINTR)
+			break;
+	}
+	if (WIFEXITED(res) && WEXITSTATUS(res) == 0) {
 		free(checker);
 		return (1);
 	}
diff --git a/usr.bin/sendbug/sendbug.c b/usr.bin/sendbug/sendbug.c
index b06a823855b..cf3385b46ae 100644
--- a/usr.bin/sendbug/sendbug.c
+++ b/usr.bin/sendbug/sendbug.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sendbug.c,v 1.77 2016/10/18 20:07:35 kettenis Exp $	*/
+/*	$OpenBSD: sendbug.c,v 1.78 2017/08/21 21:41:13 deraadt Exp $	*/
 
 /*
  * Written by Ray Lai <ray@cyth.net>.
@@ -277,9 +277,10 @@ editit(const char *pathname)
 		execv(_PATH_BSHELL, argp);
 		_exit(127);
 	}
-	while (waitpid(pid, &st, 0) == -1)
+	while (waitpid(pid, &st, 0) == -1) {
 		if (errno != EINTR)
 			goto fail;
+	}
 	if (!WIFEXITED(st))
 		errno = EINTR;
 	else
@@ -317,12 +318,13 @@ int
 sendmail(const char *pathname)
 {
 	int filedes[2];
+	pid_t pid;
 
 	if (pipe(filedes) == -1) {
 		warn("pipe: unsent report in %s", pathname);
 		return (-1);
 	}
-	switch (fork()) {
+	switch ((pid = fork())) {
 	case -1:
 		warn("fork error: unsent report in %s",
 		    pathname);
@@ -349,7 +351,10 @@ sendmail(const char *pathname)
 			return (-1);
 		}
 		close(filedes[1]);
-		wait(NULL);
+		while (waitpid(pid, NULL, 0) == -1) {
+			if (errno != EINTR)
+				break;
+		}
 		break;
 	}
 	return (0);
diff --git a/usr.bin/tput/tput.c b/usr.bin/tput/tput.c
index 8289ad3d2f3..e3fa82c3812 100644
--- a/usr.bin/tput/tput.c
+++ b/usr.bin/tput/tput.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tput.c,v 1.22 2015/11/16 03:03:28 deraadt Exp $	*/
+/*	$OpenBSD: tput.c,v 1.23 2017/08/21 21:41:13 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1999 Todd C. Miller <Todd.Miller@courtesan.com>
@@ -52,6 +52,7 @@
 #include <stdlib.h>
 #include <termios.h>
 #include <unistd.h>
+#include <errno.h>
 #include <limits.h>
 #include <string.h>
 
@@ -269,9 +270,10 @@ init(void)
 	size_t len;
 	char *buf;
 	int wstatus;
+	pid_t pid;
 
 	if (init_prog && !issetugid()) {
-		switch (vfork()) {
+		switch (pid = vfork()) {
 		case -1:
 			err(4, "vfork");
 			break;
@@ -281,7 +283,10 @@ init(void)
 			_exit(127);
 			break;
 		default:
-			wait(&wstatus);
+			while (waitpid(pid, &wstatus, 0) == -1) {
+				if (errno != EINTR)
+					break;
+			}
 			/* parent */
 			break;
 		}
diff --git a/usr.bin/xinstall/xinstall.c b/usr.bin/xinstall/xinstall.c
index 949835f6bf6..9d866825107 100644
--- a/usr.bin/xinstall/xinstall.c
+++ b/usr.bin/xinstall/xinstall.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: xinstall.c,v 1.65 2016/05/13 17:51:15 jmc Exp $	*/
+/*	$OpenBSD: xinstall.c,v 1.66 2017/08/21 21:41:13 deraadt Exp $	*/
 /*	$NetBSD: xinstall.c,v 1.9 1995/12/20 10:25:17 jonathan Exp $	*/
 
 /*
@@ -558,11 +558,12 @@ strip(char *to_name)
 {
 	int serrno, status;
 	char * volatile path_strip;
+	pid_t pid;
 
 	if (issetugid() || (path_strip = getenv("STRIP")) == NULL)
 		path_strip = _PATH_STRIP;
 
-	switch (vfork()) {
+	switch ((pid = vfork())) {
 	case -1:
 		serrno = errno;
 		(void)unlink(to_name);
@@ -572,7 +573,11 @@ strip(char *to_name)
 		warn("%s", path_strip);
 		_exit(1);
 	default:
-		if (wait(&status) == -1 || !WIFEXITED(status))
+		while (waitpid(pid, &status, 0) == -1) {
+			if (errno != EINTR)
+				break;
+		}
+		if (!WIFEXITED(status))
 			(void)unlink(to_name);
 	}
 }