xref: /aosp_15_r20/external/OpenCL-ICD-Loader/loader/linux/icd_linux_envvars.c (revision 1cddb830dba8aa7c1cc1039338e56b3b9fa24952)
1 /*
2  * Copyright (c) 2016-2019 The Khronos Group Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  *
16  * OpenCL is a trademark of Apple Inc. used under license by Khronos.
17  */
18 
19 // for secure_getenv():
20 #ifndef _GNU_SOURCE
21 #define _GNU_SOURCE
22 #endif
23 
24 #include "icd_cmake_config.h"
25 
26 #include <stdlib.h>
27 #include <unistd.h>
28 
khrIcd_getenv(const char * name)29 char *khrIcd_getenv(const char *name) {
30     // No allocation of memory necessary for Linux.
31     return getenv(name);
32 }
33 
khrIcd_secure_getenv(const char * name)34 char *khrIcd_secure_getenv(const char *name) {
35 #if defined(__APPLE__)
36     // Apple does not appear to have a secure getenv implementation.
37     // The main difference between secure getenv and getenv is that secure getenv
38     // returns NULL if the process is being run with elevated privileges by a normal user.
39     // The idea is to prevent the reading of malicious environment variables by a process
40     // that can do damage.
41     // This algorithm is derived from glibc code that sets an internal
42     // variable (__libc_enable_secure) if the process is running under setuid or setgid.
43     return geteuid() != getuid() || getegid() != getgid() ? NULL : khrIcd_getenv(name);
44 #else
45 // Linux
46 #ifdef HAVE_SECURE_GETENV
47     return secure_getenv(name);
48 #elif defined(HAVE___SECURE_GETENV)
49     return __secure_getenv(name);
50 #else
51 #pragma message(                                                                       \
52     "Warning:  Falling back to non-secure getenv for environmental lookups!  Consider" \
53     " updating to a different libc.")
54     return khrIcd_getenv(name);
55 #endif
56 #endif
57 }
58 
khrIcd_free_getenv(char * val)59 void khrIcd_free_getenv(char *val) {
60     // No freeing of memory necessary for Linux, but we should at least touch
61     // val to get rid of compiler warnings.
62     (void)val;
63 }
64