Replace some calls to fuword() by fueword() with proper error checking.

Sponsored by:	The FreeBSD Foundation
Tested by:	pho
MFC after:	3 weeks

1 files changed, 17 insertions, 9 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 09212c8..45d4c6f 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -1091,7 +1091,7 @@ int
 exec_copyin_args(struct image_args *args, char *fname,
     enum uio_seg segflg, char **argv, char **envv)
 {
-	char *argp, *envp;
+	u_long argp, envp;
 	int error;
 	size_t length;
 
@@ -1127,13 +1127,17 @@ exec_copyin_args(struct image_args *args, char *fname,
 	/*
 	 * extract arguments first
 	 */
-	while ((argp = (caddr_t) (intptr_t) fuword(argv++))) {
-		if (argp == (caddr_t) -1) {
+	for (;;) {
+		error = fueword(argv++, &argp);
+		if (error == -1) {
 			error = EFAULT;
 			goto err_exit;
 		}
-		if ((error = copyinstr(argp, args->endp,
-		    args->stringspace, &length))) {
+		if (argp == 0)
+			break;
+		error = copyinstr((void *)(uintptr_t)argp, args->endp,
+		    args->stringspace, &length);
+		if (error != 0) {
 			if (error == ENAMETOOLONG) 
 				error = E2BIG;
 			goto err_exit;
@@ -1149,13 +1153,17 @@ exec_copyin_args(struct image_args *args, char *fname,
 	 * extract environment strings
 	 */
 	if (envv) {
-		while ((envp = (caddr_t)(intptr_t)fuword(envv++))) {
-			if (envp == (caddr_t)-1) {
+		for (;;) {
+			error = fueword(envv++, &envp);
+			if (error == -1) {
 				error = EFAULT;
 				goto err_exit;
 			}
-			if ((error = copyinstr(envp, args->endp,
-			    args->stringspace, &length))) {
+			if (envp == 0)
+				break;
+			error = copyinstr((void *)(uintptr_t)envp,
+			    args->endp, args->stringspace, &length);
+			if (error != 0) {
 				if (error == ENAMETOOLONG)
 					error = E2BIG;
 				goto err_exit;