Fix buffer overflow in trace_event_android.cc

base/trace_event/trace_event_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/trace_event/trace_event_impl.h"
 
 #include <fcntl.h>
 
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/stringprintf.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/trace_event/trace_event.h"
 
 namespace base {
 namespace trace_event {
 
 namespace {
 
 int g_atrace_fd = -1;
 const char kATraceMarkerFile[] = "/sys/kernel/debug/tracing/trace_marker";
 
 void WriteToATrace(int fd, const char* buffer, size_t size) {
   size_t total_written = 0;
   while (total_written < size) {
     ssize_t written = HANDLE_EINTR(write(
-        fd, buffer + size, size - total_written));
+        fd, buffer + total_written, size - total_written));
     if (written <= 0)
       break;
     total_written += written;
   }
   if (total_written < size) {
     PLOG(WARNING) << "Failed to write buffer '" << std::string(buffer, size)
                   << "' to " << kATraceMarkerFile;
   }
 }
 
@@ skipping 164 matching lines @@
   // trace buffer.
   double now_in_seconds = (TimeTicks::Now() - TimeTicks()).InSecondsF();
   std::string marker = StringPrintf(
       "trace_event_clock_sync: parent_ts=%f\n", now_in_seconds);
   WriteToATrace(atrace_fd, marker.c_str(), marker.size());
   close(atrace_fd);
 }
 
 }  // namespace trace_event
 }  // namespace base