[tracing] Add graphics memory dump provider for Android

components/tracing/graphics_memory_dump_provider_android.cc

+// Copyright 2015 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 "components/tracing/graphics_memory_dump_provider_android.h"
+
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/un.h>
+
+#include "base/files/scoped_file.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
+#include "base/strings/string_tokenizer.h"
+#include "base/trace_event/process_memory_dump.h"
+#include "base/trace_event/process_memory_totals.h"
+
+using base::trace_event::MemoryAllocatorDump;
+
+namespace tracing {
+
+// static
+const char GraphicsMemoryDumpProvider::kDumpBaseName[] =
+    "gpu/android_memtrack/";
+
+// static
+GraphicsMemoryDumpProvider* GraphicsMemoryDumpProvider::GetInstance() {
+  return base::Singleton<
+      GraphicsMemoryDumpProvider,
+      base::LeakySingletonTraits<GraphicsMemoryDumpProvider>>::get();
+}
+
+bool GraphicsMemoryDumpProvider::OnMemoryDump(
+    const base::trace_event::MemoryDumpArgs& args,
+    base::trace_event::ProcessMemoryDump* pmd) {
+  const char kAbstractSocketName[] = "chrome_tracing_memtrack_helper";
+  struct sockaddr_un addr;
+
+  const int sock = socket(AF_UNIX, SOCK_SEQPACKET, 0);
+  if (sock == -1)
+    return false;
+  // Ensures that sock is always closed, even in case of early returns.
+  base::ScopedFD sock_closer(sock);
+
+  // Set recv() timeout to 250 ms.
+  struct timeval tv;
+  tv.tv_sec = 0;
+  tv.tv_usec = 250000;
+  setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
+
+  // Connect to the UNIX abstract (i.e. no physical filesystem link) socket.
+  memset(&addr, 0, sizeof(addr));
+  addr.sun_family = AF_UNIX;
+  strncpy(&addr.sun_path[1], kAbstractSocketName, sizeof(addr.sun_path) - 2);
+
+  if (connect(sock, reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr))) {
+    LOG(WARNING) << "Could not connect to the memtrack_helper daemon. Please "
+                    "build memtrack_helper, adb push to the device and run it "
+                    "before starting the trace to get graphics memory data.";
+    return false;
+  }
+
+  // Check that the socket is owned by root (the memtrack_helper) process and
+  // not an (untrusted) user process.
+  struct ucred cred;
+  socklen_t cred_len = sizeof(cred);
+  if (getsockopt(sock, SOL_SOCKET, SO_PEERCRED, &cred, &cred_len) < 0 ||
+      (static_cast<unsigned>(cred_len) < sizeof(cred)) ||
+      cred.uid != 0 /* root */) {
+    LOG(WARNING) << "Untrusted (!= root) memtrack_helper daemon detected.";
+    return false;
+  }
+
+  // Send the trace(PID) request.
+  char buf[4096];
+  const int buf_pid_len = snprintf(buf, sizeof(buf) - 1, "%d", getpid());
+  if (HANDLE_EINTR(send(sock, buf, buf_pid_len + 1, 0)) <= 0)
+    return false;
+
+  // The response consists of a few lines, each one with a key value pair. E.g.:
+  // graphics_total 10616832
+  // graphics_pss 10616832
+  // gl_total 17911808
+  // gl_pss 17911808
+  ssize_t rsize;
+  if ((rsize = HANDLE_EINTR(recv(sock, buf, sizeof(buf), 0))) <= 0)
+    return false;
+
+  buf[sizeof(buf) - 1] = '\0';
+  ParseResponseAndAddToDump(buf, static_cast<size_t>(rsize), pmd);
+  return true;
+}
+
+void GraphicsMemoryDumpProvider::ParseResponseAndAddToDump(
+    const char* response,
+    size_t length,
+    base::trace_event::ProcessMemoryDump* pmd) {
+  base::CStringTokenizer tokenizer(response, response + length, " \n");

[dsinclair, 2015/10/14 14:44:45]

If I have root on the device, could I setup my own daemon to respond and send
arbitrarily large amounts of text back? Should we have a max length we look at?

+  while (true) {
+    if (!tokenizer.GetNext())
+      break;
+    base::StringPiece row_name = tokenizer.token_piece();
+    if (!tokenizer.GetNext())
+      break;
+    base::StringPiece value_str = tokenizer.token_piece();
+    int64_t value;
+    if (!base::StringToInt64(value_str, &value) || value < 0)
+      continue;  // Skip invalid or negative values.
+
+    // Turn entries like graphics_total into a row named "graphics" and
+    // column named "total".
+    std::string column_name;
+    size_t key_split_point = row_name.find_last_of('_');
+    if (key_split_point > 0 && key_split_point < row_name.size() - 1) {
+      row_name.substr(key_split_point + 1).CopyToString(&column_name);
+      row_name = row_name.substr(0, key_split_point);
+    } else {
+      column_name = "unknown";
+    }
+
+    // Append a row to the memory dump.
+    std::string dump_name;
+    dump_name.reserve(arraysize(kDumpBaseName) + row_name.size() + 1);
+    dump_name.assign(kDumpBaseName);
+    row_name.AppendToString(&dump_name);
+    MemoryAllocatorDump* mad = pmd->GetOrCreateAllocatorDump(dump_name);
+    const auto& long_lived_column_name = key_names_.insert(column_name).first;
+    mad->AddScalar(long_lived_column_name->c_str(),
+                   MemoryAllocatorDump::kUnitsBytes, value);
+  }
+}
+
+GraphicsMemoryDumpProvider::GraphicsMemoryDumpProvider() {}
+
+GraphicsMemoryDumpProvider::~GraphicsMemoryDumpProvider() {}
+
+}  // namespace tracing