Rewrite the exec family.
* Removes duplication.
* Removes fixed PATH_MAX limit.
* Adds basic tests.
Bug: http://b/30032507
Change-Id: I4087a9de3e53884ac3297ebafbec4e6f8a9871b6
diff --git a/libc/Android.bp b/libc/Android.bp
index 5bfc930..589aeab 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/bionic/exec.cpp b/libc/bionic/exec.cpp
new file mode 100644
index 0000000..c1e73a5
--- /dev/null
+++ b/libc/bionic/exec.cpp
@@ -0,0 +1,163 @@
+/*-
+ * 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 "C" char** environ;
+
+enum ExecVariant { kIsExecL, kIsExecLE, kIsExecLP };
+
+static int __execl(const char* name, const char* argv0, ExecVariant variant, va_list ap) {
+ // Count the arguments.
+ va_list count_ap;
+ va_copy(count_ap, ap);
+ size_t n = 1;
+ while (va_arg(count_ap, char*) != nullptr) {
+ ++n;
+ }
+ va_end(count_ap);
+
+ // Construct the new argv.
+ char* argv[n + 1];
+ argv[0] = const_cast<char*>(argv0);
+ n = 1;
+ while ((argv[n] = va_arg(ap, char*)) != nullptr) {
+ ++n;
+ }
+
+ // Collect the argp too.
+ char** argp = (variant == kIsExecLE) ? va_arg(ap, char**) : environ;
+
+ va_end(ap);
+
+ return (variant == kIsExecLP) ? execvp(name, argv) : execve(name, argv, argp);
+}
+
+int execl(const char* name, const char* arg, ...) {
+ va_list ap;
+ va_start(ap, arg);
+ return __execl(name, arg, kIsExecL, ap);
+}
+
+int execle(const char* name, const char* arg, ...) {
+ va_list ap;
+ va_start(ap, arg);
+ return __execl(name, arg, kIsExecLE, ap);
+}
+
+int execlp(const char* name, const char* arg, ...) {
+ va_list ap;
+ va_start(ap, arg);
+ return __execl(name, arg, kIsExecLP, ap);
+}
+
+int execv(const char* name, char* const* argv) {
+ return execve(name, argv, environ);
+}
+
+int execvp(const char* name, char* const* argv) {
+ return execvpe(name, argv, environ);
+}
+
+static int __exec_as_script(char* buf, char* const* argv, char* const* envp) {
+ size_t arg_count = 0;
+ while (argv[arg_count] != nullptr) ++arg_count;
+
+ char* script_argv[arg_count + 2];
+ script_argv[0] = const_cast<char*>("sh");
+ script_argv[1] = buf;
+ bcopy(argv + 1, script_argv + 2, arg_count * sizeof(char*));
+ return execve(_PATH_BSHELL, script_argv, envp);
+}
+
+int execvpe(const char* name, char* const* argv, char* const* envp) {
+ // Do not allow null name.
+ if (name == nullptr || *name == '\0') {
+ errno = ENOENT;
+ return -1;
+ }
+
+ // If it's an absolute or relative path name, it's easy.
+ if (strchr(name, '/')) return execve(name, argv, envp);
+
+ // Get the path we're searching.
+ const char* path = getenv("PATH");
+ if (path == nullptr) path = _PATH_DEFPATH;
+
+ // Make a writable copy.
+ size_t len = strlen(path) + 1;
+ char writable_path[len];
+ memcpy(writable_path, path, len);
+
+ bool saw_EACCES = false;
+
+ // Try each element of $PATH in turn...
+ char* strsep_buf = writable_path;
+ const char* dir;
+ while ((dir = strsep(&strsep_buf, ":"))) {
+ // It's a shell path: double, leading and trailing colons
+ // mean the current directory.
+ if (*dir == '\0') dir = const_cast<char*>(".");
+
+ size_t dir_len = strlen(dir);
+ size_t name_len = strlen(name);
+
+ char buf[dir_len + 1 + name_len + 1];
+ mempcpy(mempcpy(mempcpy(buf, dir, dir_len), "/", 1), name, name_len + 1);
+
+ execve(buf, argv, envp);
+ switch (errno) {
+ case EISDIR:
+ case ELOOP:
+ case ENAMETOOLONG:
+ case ENOENT:
+ case ENOTDIR:
+ break;
+ case ENOEXEC:
+ return __exec_as_script(buf, argv, envp);
+ case EACCES:
+ saw_EACCES = true;
+ break;
+ default:
+ return -1;
+ }
+ }
+ if (saw_EACCES) errno = EACCES;
+ return -1;
+}
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);
-}
-