1 /*
2  * Copyright (C) 2011 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 "logging.h"
18 
19 #include <iostream>
20 #include <limits>
21 #include <mutex>
22 #include <sstream>
23 
24 #include "aborting.h"
25 #include "os.h"
26 #include "unix_file/fd_file.h"
27 
28 // Headers for LogMessage::LogLine.
29 #ifdef ART_TARGET_ANDROID
30 #include <log/log.h>
31 #else
32 #include <sys/types.h>
33 #include <unistd.h>
34 #endif
35 
36 namespace art {
37 
38 LogVerbosity gLogVerbosity;
39 
40 std::atomic<unsigned int> gAborting(0);
41 
42 static std::unique_ptr<std::string> gCmdLine;
43 static std::unique_ptr<std::string> gProgramInvocationName;
44 static std::unique_ptr<std::string> gProgramInvocationShortName;
45 
GetCmdLine()46 const char* GetCmdLine() {
47   return (gCmdLine.get() != nullptr) ? gCmdLine->c_str() : nullptr;
48 }
49 
ProgramInvocationName()50 const char* ProgramInvocationName() {
51   return (gProgramInvocationName.get() != nullptr) ? gProgramInvocationName->c_str() : "art";
52 }
53 
ProgramInvocationShortName()54 const char* ProgramInvocationShortName() {
55   return (gProgramInvocationShortName.get() != nullptr) ? gProgramInvocationShortName->c_str()
56                                                         : "art";
57 }
58 
InitLogging(char * argv[],AbortFunction & abort_function)59 void InitLogging(char* argv[], AbortFunction& abort_function) {
60   if (gCmdLine.get() != nullptr) {
61     return;
62   }
63 
64   // Stash the command line for later use. We can use /proc/self/cmdline on Linux to recover this,
65   // but we don't have that luxury on the Mac, and there are a couple of argv[0] variants that are
66   // commonly used.
67   if (argv != nullptr) {
68     gCmdLine.reset(new std::string(argv[0]));
69     for (size_t i = 1; argv[i] != nullptr; ++i) {
70       gCmdLine->append(" ");
71       gCmdLine->append(argv[i]);
72     }
73     gProgramInvocationName.reset(new std::string(argv[0]));
74     const char* last_slash = strrchr(argv[0], '/');
75     gProgramInvocationShortName.reset(new std::string((last_slash != nullptr) ? last_slash + 1
76                                                                            : argv[0]));
77   } else {
78     // TODO: fall back to /proc/self/cmdline when argv is null on Linux.
79     gCmdLine.reset(new std::string("<unset>"));
80   }
81 
82 #ifdef ART_TARGET_ANDROID
83   // android::base::LogdLogger breaks messages up into line delimited 4K chunks, since that is the
84   // most that logd can handle per message.  To prevent other threads from interleaving their
85   // messages, LogdLoggerLocked uses a mutex to ensure that only one ART thread is logging at a
86   // time.
87   // Note that this lock makes logging after fork() unsafe in multi-threaded programs, which is part
88   // of the motivation that this lock is not a part of libbase logging.  Zygote guarantees that no
89   // threads are running before calling fork() via ZygoteHooks.waitUntilAllThreadsStopped().
90   class LogdLoggerLocked {
91    public:
92     LogdLoggerLocked() {}
93     void operator()(android::base::LogId id,
94                     android::base::LogSeverity severity,
95                     const char* tag,
96                     const char* file,
97                     unsigned int line,
98                     const char* message) {
99       static std::mutex* logging_lock_ = new std::mutex();
100       std::lock_guard<std::mutex> guard(*logging_lock_);
101       logd_logger_(id, severity, tag, file, line, message);
102     }
103 
104    private:
105     android::base::LogdLogger logd_logger_;
106   };
107 #define INIT_LOGGING_DEFAULT_LOGGER LogdLoggerLocked()
108 #else
109 #define INIT_LOGGING_DEFAULT_LOGGER android::base::StderrLogger
110 #endif
111   android::base::InitLogging(argv, INIT_LOGGING_DEFAULT_LOGGER,
112                              std::move<AbortFunction>(abort_function));
113 #undef INIT_LOGGING_DEFAULT_LOGGER
114 }
115 
116 #ifdef ART_TARGET_ANDROID
117 static const android_LogPriority kLogSeverityToAndroidLogPriority[] = {
118   ANDROID_LOG_VERBOSE, ANDROID_LOG_DEBUG, ANDROID_LOG_INFO, ANDROID_LOG_WARN,
119   ANDROID_LOG_ERROR, ANDROID_LOG_FATAL, ANDROID_LOG_FATAL
120 };
121 static_assert(arraysize(kLogSeverityToAndroidLogPriority) == ::android::base::FATAL + 1,
122               "Mismatch in size of kLogSeverityToAndroidLogPriority and values in LogSeverity");
123 #endif
124 
LogLineLowStack(const char * file,unsigned int line,LogSeverity log_severity,const char * message)125 void LogHelper::LogLineLowStack(const char* file,
126                                 unsigned int line,
127                                 LogSeverity log_severity,
128                                 const char* message) {
129 #ifdef ART_TARGET_ANDROID
130   // Use android_writeLog() to avoid stack-based buffers used by android_printLog().
131   const char* tag = ProgramInvocationShortName();
132   int priority = kLogSeverityToAndroidLogPriority[static_cast<size_t>(log_severity)];
133   char* buf = nullptr;
134   size_t buf_size = 0u;
135   if (priority == ANDROID_LOG_FATAL) {
136     // Allocate buffer for snprintf(buf, buf_size, "%s:%u] %s", file, line, message) below.
137     // If allocation fails, fall back to printing only the message.
138     buf_size = strlen(file) + 1 /* ':' */ + std::numeric_limits<decltype(line)>::max_digits10 +
139         2 /* "] " */ + strlen(message) + 1 /* terminating 0 */;
140     buf = reinterpret_cast<char*>(malloc(buf_size));
141   }
142   if (buf != nullptr) {
143     snprintf(buf, buf_size, "%s:%u] %s", file, line, message);
144     android_writeLog(priority, tag, buf);
145     free(buf);
146   } else {
147     android_writeLog(priority, tag, message);
148   }
149 #else
150   static constexpr char kLogCharacters[] = { 'V', 'D', 'I', 'W', 'E', 'F', 'F' };
151   static_assert(
152       arraysize(kLogCharacters) == static_cast<size_t>(::android::base::FATAL) + 1,
153       "Wrong character array size");
154 
155   const char* program_name = ProgramInvocationShortName();
156   TEMP_FAILURE_RETRY(write(STDERR_FILENO, program_name, strlen(program_name)));
157   TEMP_FAILURE_RETRY(write(STDERR_FILENO, " ", 1));
158   TEMP_FAILURE_RETRY(write(STDERR_FILENO, &kLogCharacters[static_cast<size_t>(log_severity)], 1));
159   TEMP_FAILURE_RETRY(write(STDERR_FILENO, " ", 1));
160   // TODO: pid and tid.
161   TEMP_FAILURE_RETRY(write(STDERR_FILENO, file, strlen(file)));
162   // TODO: line.
163   UNUSED(line);
164   TEMP_FAILURE_RETRY(write(STDERR_FILENO, "] ", 2));
165   TEMP_FAILURE_RETRY(write(STDERR_FILENO, message, strlen(message)));
166   TEMP_FAILURE_RETRY(write(STDERR_FILENO, "\n", 1));
167 #endif  // ART_TARGET_ANDROID
168 }
169 
PrintFileToLog(const std::string & file_name,android::base::LogSeverity level)170 bool PrintFileToLog(const std::string& file_name, android::base::LogSeverity level) {
171   File file(file_name, O_RDONLY, false);
172   if (!file.IsOpened()) {
173     return false;
174   }
175 
176   constexpr size_t kBufSize = 256;  // Small buffer. Avoid stack overflow and stack size warnings.
177   char buf[kBufSize + 1];           // +1 for terminator.
178   size_t filled_to = 0;
179   while (true) {
180     DCHECK_LT(filled_to, kBufSize);
181     int64_t n = TEMP_FAILURE_RETRY(read(file.Fd(), &buf[filled_to], kBufSize - filled_to));
182     if (n <= 0) {
183       // Print the rest of the buffer, if it exists.
184       if (filled_to > 0) {
185         buf[filled_to] = 0;
186         LOG(level) << buf;
187       }
188       return n == 0;
189     }
190     // Scan for '\n'.
191     size_t i = filled_to;
192     bool found_newline = false;
193     for (; i < filled_to + n; ++i) {
194       if (buf[i] == '\n') {
195         // Found a line break, that's something to print now.
196         buf[i] = 0;
197         LOG(level) << buf;
198         // Copy the rest to the front.
199         if (i + 1 < filled_to + n) {
200           memmove(&buf[0], &buf[i + 1], filled_to + n - i - 1);
201           filled_to = filled_to + n - i - 1;
202         } else {
203           filled_to = 0;
204         }
205         found_newline = true;
206         break;
207       }
208     }
209     if (found_newline) {
210       continue;
211     } else {
212       filled_to += n;
213       // Check if we must flush now.
214       if (filled_to == kBufSize) {
215         buf[kBufSize] = 0;
216         LOG(level) << buf;
217         filled_to = 0;
218       }
219     }
220   }
221 }
222 
223 }  // namespace art
224