[src/trunk]: src/lib/libc/gen Use alloca() instead of malloc() and strdup(). ...

[simonb <simonb%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/92919440767f
branches:  trunk
changeset: 515166:92919440767f
user:      simonb <simonb%NetBSD.org@localhost>
date:      Tue Sep 18 05:09:37 2001 +0000

description:
Use alloca() instead of malloc() and strdup().  Proper fix for the find
problem posted to current-users%netbsd.org@localhost.  Solution suggested by a
couple of folks on that mailing list, and Art Grabowski who pointed me
at a similar change in OpenBSD.

diffstat:

 lib/libc/gen/execvp.c |  14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diffs (55 lines):

diff -r 7626147af593 -r 92919440767f lib/libc/gen/execvp.c
--- a/lib/libc/gen/execvp.c     Tue Sep 18 04:36:28 2001 +0000
+++ b/lib/libc/gen/execvp.c     Tue Sep 18 05:09:37 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: execvp.c,v 1.16 2000/01/22 22:19:09 mycroft Exp $      */
+/*     $NetBSD: execvp.c,v 1.17 2001/09/18 05:09:37 simonb Exp $       */
 
 /*-
  * Copyright (c) 1991, 1993
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)exec.c     8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: execvp.c,v 1.16 2000/01/22 22:19:09 mycroft Exp $");
+__RCSID("$NetBSD: execvp.c,v 1.17 2001/09/18 05:09:37 simonb Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -95,7 +95,9 @@
        /* Get the path we're searching. */
        if (!(path = getenv("PATH")))
                path = _PATH_DEFPATH;
-       cur = path = strdup(path);
+       cur = alloca(strlen(path) + 1);
+       strcpy(cur, path);
+       path = cur;
 
        while ((p = strsep(&cur, ":")) != NULL) {
                /*
@@ -136,7 +138,7 @@
                        break;
                case ENOEXEC:
                        for (cnt = 0; argv[cnt] != NULL; ++cnt);
-                       if ((memp = malloc((cnt + 2) * sizeof (*memp))) == NULL)
+                       if ((memp = alloca((cnt + 2) * sizeof (*memp))) == NULL)
                                goto done;
                        memp[0] = _PATH_BSHELL;
                        memp[1] = bp;
@@ -144,7 +146,6 @@
                        rwlock_rdlock(&__environ_lock);
                        (void)execve(_PATH_BSHELL, (char * const *)memp, environ);
                        rwlock_unlock(&__environ_lock);
-                       free(memp);
                        goto done;
                case ETXTBSY:
                        if (etxtbsy < 3)
@@ -158,7 +159,6 @@
                errno = EACCES;
        else if (!errno)
                errno = ENOENT;
-done:  if (path)
-               free(path);
+done:
        return (-1);
 }