1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include "private/__bionic_get_shell_path.h"
30
31 #include <errno.h>
32 #include <string.h>
33 #include <sys/cdefs.h>
34 #include <unistd.h>
35
36 #define VENDOR_PREFIX "/vendor/"
37
init_sh_path()38 static const char* init_sh_path() {
39 /* If the device is not treble enabled, return the path to the system shell.
40 * Vendor code, on non-treble enabled devices could use system() / popen()
41 * with relative paths for executables on /system. Since /system will not be
42 * in $PATH for the vendor shell, simply return the system shell.
43 */
44
45 #ifdef TREBLE_LINKER_NAMESPACES
46 /* look for /system or /vendor prefix */
47 char exe_path[strlen(VENDOR_PREFIX)];
48 ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path));
49 if (len != -1 && !strncmp(exe_path, VENDOR_PREFIX, strlen(VENDOR_PREFIX))) {
50 return "/vendor/bin/sh";
51 }
52 #endif
53 return "/system/bin/sh";
54 }
55
__bionic_get_shell_path()56 const char* __bionic_get_shell_path() {
57 static const char* sh_path = init_sh_path();
58 return sh_path;
59 }
60