1 /*
2 * Copyright (C) 2020 The Android Open Source Project
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
17 #include <fcntl.h>
18 #include <stdbool.h>
19 #include <stdlib.h>
20 #include <string.h>
21 #include <sys/stat.h>
22 #include <sys/types.h>
23 #include <unistd.h>
24
25 // This file provides a wrapper for open.
26
27 extern "C" {
28
29 int __real_open(const char* pathname, int flags, ...);
30
needs_mode(int flags)31 static bool needs_mode(int flags) {
32 return ((flags & O_CREAT) == O_CREAT) || ((flags & O_TMPFILE) == O_TMPFILE);
33 }
34
35 static const char* PROFRAW_START = "/data/misc/trace/";
is_coverage_trace(const char * pathname)36 static bool is_coverage_trace(const char* pathname) {
37 if (strncmp(pathname, PROFRAW_START, strlen(PROFRAW_START)) == 0) return true;
38 return false;
39 }
40
__wrap_open(const char * pathname,int flags,...)41 __attribute__((weak)) int __wrap_open(const char* pathname, int flags, ...) {
42 if (!needs_mode(flags)) {
43 return __real_open(pathname, flags);
44 }
45
46 va_list args;
47 va_start(args, flags);
48 mode_t mode = static_cast<mode_t>(va_arg(args, int));
49 va_end(args);
50
51 int ret = __real_open(pathname, flags, mode);
52 if (ret != -1 && is_coverage_trace(pathname)) fchmod(ret, mode);
53 return ret;
54 }
55 }
56