Fix execl[e]. Multiple execle's failed because of bogus caching of the

pointer returned by realloc().  All callers free the pointer if the
execve fails.  Nuke the caching.  This essentially restores buildargv()
to the 1.1.5 version.  Also fix a memory leak if realloc() fails.  Also
nuke similar but non-broken caching in execvp().  malloc() should be
efficient enough.

1 files changed, 14 insertions, 16 deletions

diff --git a/lib/libc/gen/exec.c b/lib/libc/gen/exec.c
index 2f7eadd..6af8868 100644
--- a/lib/libc/gen/exec.c
+++ b/lib/libc/gen/exec.c
@@ -58,19 +58,20 @@ buildargv(ap, arg, envpp)
 	const char *arg;
 	char ***envpp;
 {
-	static int memsize;
-	static char **argv;
-	register int off;
+	register char **argv, **nargv;
+	register int memsize, off;
 
 	argv = NULL;
-	for (off = 0;; ++off) {
+	for (off = memsize = 0;; ++off) {
 		if (off >= memsize) {
 			memsize += 50;	/* Starts out at 0. */
 			memsize *= 2;	/* Ramp up fast. */
-			if (!(argv = realloc(argv, memsize * sizeof(char *)))) {
-				memsize = 0;
+			nargv = realloc(argv, memsize * sizeof(char *));
+			if (nargv == NULL) {
+				free(argv);
 				return (NULL);
 			}
+			argv = nargv;
 			if (off == 0) {
 				argv[0] = (char *)arg;
 				off = 1;
@@ -183,8 +184,7 @@ execvp(name, argv)
 	const char *name;
 	char * const *argv;
 {
-	static int memsize;
-	static char **memp;
+	char **memp;
 	register int cnt, lp, ln;
 	register char *p;
 	int eacces, etxtbsy;
@@ -240,18 +240,16 @@ retry:		(void)execve(bp, argv, environ);
 		case ENOENT:
 			break;
 		case ENOEXEC:
-			for (cnt = 0; argv[cnt]; ++cnt);
-			if ((cnt + 2) * sizeof(char *) > memsize) {
-				memsize = (cnt + 2) * sizeof(char *);
-				if ((memp = realloc(memp, memsize)) == NULL) {
-					memsize = 0;
-					goto done;
-				}
-			}
+			for (cnt = 0; argv[cnt]; ++cnt)
+				;
+			memp = malloc((cnt + 2) * sizeof(char *));
+			if (memp == NULL)
+				goto done;
 			memp[0] = "sh";
 			memp[1] = bp;
 			bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
 			(void)execve(_PATH_BSHELL, memp, environ);
+			free(memp);
 			goto done;
 		case ETXTBSY:
 			if (etxtbsy < 3)