[sanitizers] Log all output to CrashReport on OS X

[zaks.anna]

Summary

Log all of sanitizers' output (not just ASan bug reports) to CrashReport, which simplifies diagnosing failed checks as well as other errors. This also allows to strip the color sequences early from the printed buffer, which is more efficient than what we had perviously.

[kubamracek]

lib/sanitizer_common/sanitizer_mac.h

49 ↗

(On Diff #42344)

Don't we need a lock here? Can we optimize the strcat here (by remembering the position where to append)?

Or maybe we could unify this completely with AppendToErrorMessageBuffer (in asan_report.cc), which basically does the same thing. We could only have a single buffer to log into.

lib/sanitizer_common/sanitizer_printf.cc

283 ↗

(On Diff #42344)

This means that CallPrintfAndReportCallback is now called on a color-less string. I'm actually in favor of this change, but we should make sure everyone's okay with it.

[zaks.anna]

lib/sanitizer_common/sanitizer_mac.h

49 ↗

(On Diff #42344)

Don't we need a lock here?

Yes, we need it. Will address.

Can we optimize the strcat here (by remembering the position where to append)?

I am not convinced that increasing code complexity is worth it in this case. This is logging code...

Or maybe we could unify this completely with
AppendToErrorMessageBuffer (in asan_report.cc), which basically does > the same thing. We could only have a single buffer to log into.

Currently, AppendToErrorMessageBuffer is ASan specific. We should log output from any sanitizer.

lib/sanitizer_common/sanitizer_printf.cc

283 ↗

(On Diff #42344)

Yes, calling CallPrintfAndReportCallback on a color-less string seems to be the right thing to do, at least to me.

I can update the commit message to call this out.

[zaks.anna]

Added the lock.

[kubamracek]

LGTM with a nit.

lib/sanitizer_common/sanitizer_mac.h

52 ↗

(On Diff #42934)

Clang-format

[samsonov]

LGTM

lib/sanitizer_common/sanitizer_printf.cc

283 ↗

(On Diff #42934)

Yes, I think it's fine.

compiler-rt/trunk/lib/asan/asan_report.cc

~ScopedInErrorReport() {
     // lock that gets aquired during printing.
     InternalScopedBuffer<char> buffer_copy(kErrorMessageBufferSize);
     {
       BlockingMutexLock l(&error_message_buf_mutex);
       internal_memcpy(buffer_copy.data(),
                       error_message_buffer, kErrorMessageBufferSize);
     }
 
-    // Remove color sequences since logs cannot print them.
-    RemoveANSIEscapeSequencesFromString(buffer_copy.data());
-
     LogFullErrorReport(buffer_copy.data());
 
     if (error_report_callback) {
       error_report_callback(buffer_copy.data());
     }
     CommonSanitizerReportMutex.Unlock();
     reporting_thread_tid_ = kInvalidTid;
     lock_.Unlock();

compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h

 #if SANITIZER_MAC
 void LogFullErrorReport(const char *buffer);
 #else
 INLINE void LogFullErrorReport(const char *buffer) {}
 #endif
 
 #if SANITIZER_LINUX || SANITIZER_MAC
 void WriteOneLineToSyslog(const char *s);
+void LogMessageOnPrintf(const char *str);
 #else
 INLINE void WriteOneLineToSyslog(const char *s) {}
+INLINE void LogMessageOnPrintf(const char *str) {}
 #endif
 
 #if SANITIZER_LINUX
 // Initialize Android logging. Any writes before this are silently lost.
 void AndroidLogInit();
-bool ShouldLogAfterPrintf();
 #else
 INLINE void AndroidLogInit() {}
-INLINE bool ShouldLogAfterPrintf() { return false; }
 #endif
 
 #if SANITIZER_ANDROID
 void SanitizerInitializeUnwinder();
 AndroidApiLevel AndroidGetApiLevel();
 #else
 INLINE void AndroidLogWrite(const char *buffer_unused) {}
 INLINE void SanitizerInitializeUnwinder() {}

compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_libcdep.cc

 }
 
 void WriteToSyslog(const char *msg) {
   InternalScopedString msg_copy(kErrorMessageBufferSize);
   msg_copy.append("%s", msg);
   char *p = msg_copy.data();
   char *q;
 
-  // Remove color sequences since syslogs cannot print them.
-  RemoveANSIEscapeSequencesFromString(p);
-
   // Print one line at a time.
   // syslog, at least on Android, has an implicit message length limit.
   do {
     q = internal_strchr(p, '\n');
     if (q)
       *q = '\0';
     WriteOneLineToSyslog(p);
     if (q)

compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux_libcdep.cc

 
 #if SANITIZER_ANDROID
 static atomic_uint8_t android_log_initialized;
 
 void AndroidLogInit() {
   atomic_store(&android_log_initialized, 1, memory_order_release);
 }
 
-bool ShouldLogAfterPrintf() {
+static bool ShouldLogAfterPrintf() {
   return atomic_load(&android_log_initialized, memory_order_acquire);
 }
 #else
 void AndroidLogInit() {}
 
-bool ShouldLogAfterPrintf() { return true; }
+static bool ShouldLogAfterPrintf() { return true; }
 #endif  // SANITIZER_ANDROID
 
 void WriteOneLineToSyslog(const char *s) {
 #if SANITIZER_ANDROID &&__ANDROID_API__ < 21
   __android_log_write(ANDROID_LOG_INFO, NULL, s);
 #else
   syslog(LOG_INFO, "%s", s);
 #endif
 }
 
+void LogMessageOnPrintf(const char *str) {
+  if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
+    WriteToSyslog(str);
+}
+
 #endif // SANITIZER_LINUX
 
 } // namespace __sanitizer
 
 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX

compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.h

 }  // namespace __sanitizer
 
 extern "C" {
 static char __crashreporter_info_buff__[kErrorMessageBufferSize] = {};
 static const char *__crashreporter_info__ __attribute__((__used__)) =
   &__crashreporter_info_buff__[0];
 asm(".desc ___crashreporter_info__, 0x10");
 } // extern "C"
+static BlockingMutex crashreporter_info_mutex(LINKER_INITIALIZED);
 
-INLINE void CRSetCrashLogMessage(const char *msg) {
-  internal_strlcpy(__crashreporter_info_buff__, msg,
+INLINE void CRAppendCrashLogMessage(const char *msg) {
+  BlockingMutexLock l(&crashreporter_info_mutex);
+  internal_strlcat(__crashreporter_info_buff__, msg,
                    sizeof(__crashreporter_info_buff__)); }
 
 #endif  // SANITIZER_MAC
 #endif  // SANITIZER_MAC_H

compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc

 
 static BlockingMutex syslog_lock(LINKER_INITIALIZED);
 
 void WriteOneLineToSyslog(const char *s) {
   syslog_lock.CheckLocked();
   asl_log(nullptr, nullptr, ASL_LEVEL_ERR, "%s", s);
 }
 
+void LogMessageOnPrintf(const char *str) {
+  // Log all printf output to CrashLog.
+  if (common_flags()->abort_on_error)
+    CRAppendCrashLogMessage(str);
+}
+
 void LogFullErrorReport(const char *buffer) {
   // Log with os_trace. This will make it into the crash log.
 #if SANITIZER_OS_TRACE
   if (GetMacosVersion() >= MACOS_VERSION_YOSEMITE) {
     // os_trace requires the message (format parameter) to be a string literal.
     if (internal_strncmp(SanitizerToolName, "AddressSanitizer",
                          sizeof("AddressSanitizer") - 1) == 0)
       os_trace("Address Sanitizer reported a failure.");
#endif
   // holding the thread registry lock since that may result in a deadlock. If
   // the reporting thread holds the thread registry mutex, and asl_log waits
   // for GCD to dispatch a new thread, the process will deadlock, because the
   // pthread_create wrapper needs to acquire the lock as well.
   BlockingMutexLock l(&syslog_lock);
   if (common_flags()->log_to_syslog)
     WriteToSyslog(buffer);
 
-  // Log to CrashLog.
-  if (common_flags()->abort_on_error)
-    CRSetCrashLogMessage(buffer);
+  // The report is added to CrashLog as part of logging all of Printf output.
 }
 
 void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   ucontext_t *ucontext = (ucontext_t*)context;
 # if defined(__aarch64__)
   *pc = ucontext->uc_mcontext->__ss.__pc;
 #   if defined(__IPHONE_8_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_8_0
   *bp = ucontext->uc_mcontext->__ss.__fp;

compiler-rt/trunk/lib/sanitizer_common/sanitizer_printf.cc

#   define CHECK_NEEDED_LENGTH \
     needed_length += VSNPrintf(buffer + needed_length,
                                buffer_size - needed_length, format, args);
     CHECK_NEEDED_LENGTH
     // If the message fit into the buffer, print it and exit.
     break;
 #   undef CHECK_NEEDED_LENGTH
   }
   RawWrite(buffer);
-  if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
-    WriteToSyslog(buffer);
+
+  // Remove color sequences from the message.
+  RemoveANSIEscapeSequencesFromString(buffer);
   CallPrintfAndReportCallback(buffer);
+  LogMessageOnPrintf(buffer);
+
   // If we had mapped any memory, clean up.
   if (buffer != local_buffer)
     UnmapOrDie((void *)buffer, buffer_size);
   va_end(args2);
 }
 
 FORMAT(1, 2)
 void Printf(const char *format, ...) {