Revert "Switch back to the BSD exec for now."

This reverts commit 18c31d7f4c93309a0f316412fcc6a829e41eaaae.

63615066d9f0b0b1c653c91a9b305e6c292c835a fixed the bug.

Change-Id: I1d59c4be6ad1a05b23dce0198737f0789d7e034a
diff --git a/libc/Android.bp b/libc/Android.bp
index 52006a4..4fcd83e 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -518,7 +518,6 @@
     name: "libc_openbsd_large_stack",
     defaults: ["libc_defaults"],
     srcs: [
-        "upstream-openbsd/lib/libc/gen/exec.c",
         "upstream-openbsd/lib/libc/stdio/vfprintf.c",
         "upstream-openbsd/lib/libc/stdio/vfwprintf.c",
         "upstream-openbsd/lib/libc/stdio/vfwscanf.c",
@@ -1238,6 +1237,7 @@
         "bionic/error.cpp",
         "bionic/eventfd_read.cpp",
         "bionic/eventfd_write.cpp",
+        "bionic/exec.cpp",
         "bionic/faccessat.cpp",
         "bionic/fchmod.cpp",
         "bionic/fchmodat.cpp",
diff --git a/libc/upstream-openbsd/lib/libc/gen/exec.c b/libc/upstream-openbsd/lib/libc/gen/exec.c
deleted file mode 100644
index 1e2f7d9..0000000
--- a/libc/upstream-openbsd/lib/libc/gen/exec.c
+++ /dev/null
@@ -1,251 +0,0 @@
-/*	$OpenBSD: exec.c,v 1.21 2013/09/30 12:02:33 millert Exp $ */
-/*-
- * Copyright (c) 1991, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <sys/types.h>
-#include <sys/uio.h>
-
-#include <errno.h>
-#include <limits.h>
-#include <paths.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-extern char **environ;
-
-int
-execl(const char *name, const char *arg, ...)
-{
-	va_list ap;
-	char **argv;
-	int n;
-
-	va_start(ap, arg);
-	n = 1;
-	while (va_arg(ap, char *) != NULL)
-		n++;
-	va_end(ap);
-	argv = alloca((n + 1) * sizeof(*argv));
-	if (argv == NULL) {
-		errno = ENOMEM;
-		return (-1);
-	}
-	va_start(ap, arg);
-	n = 1;
-	argv[0] = (char *)arg;
-	while ((argv[n] = va_arg(ap, char *)) != NULL)
-		n++;
-	va_end(ap);
-	return (execve(name, argv, environ));
-}
-
-int
-execle(const char *name, const char *arg, ...)
-{
-	va_list ap;
-	char **argv, **envp;
-	int n;
-
-	va_start(ap, arg);
-	n = 1;
-	while (va_arg(ap, char *) != NULL)
-		n++;
-	va_end(ap);
-	argv = alloca((n + 1) * sizeof(*argv));
-	if (argv == NULL) {
-		errno = ENOMEM;
-		return (-1);
-	}
-	va_start(ap, arg);
-	n = 1;
-	argv[0] = (char *)arg;
-	while ((argv[n] = va_arg(ap, char *)) != NULL)
-		n++;
-	envp = va_arg(ap, char **);
-	va_end(ap);
-	return (execve(name, argv, envp));
-}
-
-int
-execlp(const char *name, const char *arg, ...)
-{
-	va_list ap;
-	char **argv;
-	int n;
-
-	va_start(ap, arg);
-	n = 1;
-	while (va_arg(ap, char *) != NULL)
-		n++;
-	va_end(ap);
-	argv = alloca((n + 1) * sizeof(*argv));
-	if (argv == NULL) {
-		errno = ENOMEM;
-		return (-1);
-	}
-	va_start(ap, arg);
-	n = 1;
-	argv[0] = (char *)arg;
-	while ((argv[n] = va_arg(ap, char *)) != NULL)
-		n++;
-	va_end(ap);
-	return (execvp(name, argv));
-}
-
-int
-execv(const char *name, char *const *argv)
-{
-	(void)execve(name, argv, environ);
-	return (-1);
-}
-
-int
-execvpe(const char *name, char *const *argv, char *const *envp)
-{
-	char **memp;
-	int cnt;
-	size_t lp, ln, len;
-	char *p;
-	int eacces = 0;
-	char *bp, *cur, *path, buf[PATH_MAX];
-
-	/*
-	 * Do not allow null name
-	 */
-	if (name == NULL || *name == '\0') {
-		errno = ENOENT;
-		return (-1);
- 	}
-
-	/* If it's an absolute or relative path name, it's easy. */
-	if (strchr(name, '/')) {
-		bp = (char *)name;
-		cur = path = NULL;
-		goto retry;
-	}
-	bp = buf;
-
-	/* Get the path we're searching. */
-	if (!(path = getenv("PATH")))
-		path = _PATH_DEFPATH;
-	len = strlen(path) + 1;
-	cur = alloca(len);
-	if (cur == NULL) {
-		errno = ENOMEM;
-		return (-1);
-	}
-	strlcpy(cur, path, len);
-	path = cur;
-	while ((p = strsep(&cur, ":"))) {
-		/*
-		 * It's a SHELL path -- double, leading and trailing colons
-		 * mean the current directory.
-		 */
-		if (!*p) {
-			p = ".";
-			lp = 1;
-		} else
-			lp = strlen(p);
-		ln = strlen(name);
-
-		/*
-		 * If the path is too long complain.  This is a possible
-		 * security issue; given a way to make the path too long
-		 * the user may execute the wrong program.
-		 */
-		if (lp + ln + 2 > sizeof(buf)) {
-			struct iovec iov[3];
-
-			iov[0].iov_base = "execvp: ";
-			iov[0].iov_len = 8;
-			iov[1].iov_base = p;
-			iov[1].iov_len = lp;
-			iov[2].iov_base = ": path too long\n";
-			iov[2].iov_len = 16;
-			(void)writev(STDERR_FILENO, iov, 3);
-			continue;
-		}
-		bcopy(p, buf, lp);
-		buf[lp] = '/';
-		bcopy(name, buf + lp + 1, ln);
-		buf[lp + ln + 1] = '\0';
-
-retry:		(void)execve(bp, argv, envp);
-		switch(errno) {
-		case E2BIG:
-			goto done;
-		case EISDIR:
-		case ELOOP:
-		case ENAMETOOLONG:
-		case ENOENT:
-			break;
-		case ENOEXEC:
-			for (cnt = 0; argv[cnt]; ++cnt)
-				;
-			memp = alloca((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, envp);
-			goto done;
-		case ENOMEM:
-			goto done;
-		case ENOTDIR:
-			break;
-		case ETXTBSY:
-			/*
-			 * We used to retry here, but sh(1) doesn't.
-			 */
-			goto done;
-		case EACCES:
-			eacces = 1;
-			break;
-		default:
-			goto done;
-		}
-	}
-	if (eacces)
-		errno = EACCES;
-	else if (!errno)
-		errno = ENOENT;
-done:
-	return (-1);
-}
-
-int
-execvp(const char *name, char *const *argv)
-{
-    return execvpe(name, argv, environ);
-}
-