1 // Copyright (c) 2012 Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
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
11 // copyright notice, this list of conditions and the following disclaimer
12 // in the documentation and/or other materials provided with the
13 // distribution.
14 //     * Neither the name of Google Inc. nor the names of its
15 // contributors may be used to endorse or promote products derived from
16 // this software without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 
30 #include "client/linux/log/log.h"
31 
32 #if defined(__ANDROID__)
33 #include <android/log.h>
34 #include <dlfcn.h>
35 #else
36 #include "third_party/lss/linux_syscall_support.h"
37 #endif
38 
39 namespace logger {
40 
41 #if defined(__ANDROID__)
42 namespace {
43 
44 // __android_log_buf_write() is not exported in the NDK and is being used by
45 // dynamic runtime linking. Its declaration is taken from Android's
46 // system/core/include/log/log.h.
47 using AndroidLogBufferWriteFunc = int (*)(int bufID, int prio, const char *tag,
48                                           const char *text);
49 const int kAndroidCrashLogId = 4;  // From LOG_ID_CRASH in log.h.
50 const char kAndroidLogTag[] = "google-breakpad";
51 
52 bool g_crash_log_initialized = false;
53 AndroidLogBufferWriteFunc g_android_log_buf_write = nullptr;
54 
55 }  // namespace
56 
initializeCrashLogWriter()57 void initializeCrashLogWriter() {
58   if (g_crash_log_initialized)
59     return;
60   g_android_log_buf_write = reinterpret_cast<AndroidLogBufferWriteFunc>(
61       dlsym(RTLD_DEFAULT, "__android_log_buf_write"));
62   g_crash_log_initialized = true;
63 }
64 
writeToCrashLog(const char * buf)65 int writeToCrashLog(const char* buf) {
66   // Try writing to the crash log ring buffer. If not available, fall back to
67   // the standard log buffer.
68   if (g_android_log_buf_write) {
69     return g_android_log_buf_write(kAndroidCrashLogId, ANDROID_LOG_FATAL,
70                                    kAndroidLogTag, buf);
71   }
72   return __android_log_write(ANDROID_LOG_FATAL, kAndroidLogTag, buf);
73 }
74 #endif
75 
write(const char * buf,size_t nbytes)76 int write(const char* buf, size_t nbytes) {
77 #if defined(__ANDROID__)
78   return __android_log_write(ANDROID_LOG_WARN, kAndroidLogTag, buf);
79 #else
80   return sys_write(2, buf, nbytes);
81 #endif
82 }
83 
84 }  // namespace logger
85