[tracing] Sanitize process memory dumps for background mode

base/trace_event/memory_infra_background_whitelist.cc

Index: base/trace_event/memory_infra_background_whitelist.cc
diff --git a/base/trace_event/memory_infra_background_whitelist.cc b/base/trace_event/memory_infra_background_whitelist.cc
new file mode 100644
index 0000000000000000000000000000000000000000..03dc108c076be2fa66c1b79a087ee2d419476112
--- /dev/null
+++ b/base/trace_event/memory_infra_background_whitelist.cc
@@ -0,0 +1,88 @@
+// Copyright 2016 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/memory_infra_background_whitelist.h"
+
+#include <ctype.h>
+#include <string.h>
+
+#include <string>
+
+namespace base {
+namespace trace_event {
+namespace {
+
+// The names of dump providers whitelisted for background tracing. Dump
+// providers can be added here only if the background mode dump has very
+// less performance and memory overhead.
+const char* const kDumpProviderWhitelist[] = {
+    // TODO(ssid): Fill this list with dump provider names which support
+    // background mode, crbug.com/613198.
+    nullptr  // End of list marker.
+};
+
+// A list of string names that are allowed for the memory allocator dumps in
+// background mode.
+const char* const kAllocatorDumpNameWhitelist[] = {
+    // TODO(ssid): Fill this list with dump names, crbug.com/613198.
+    nullptr  // End of list marker.
+};
+
+const char* const* g_dump_provider_whitelist = kDumpProviderWhitelist;
+const char* const* g_allocator_dump_name_whitelist =
+    kAllocatorDumpNameWhitelist;
+
+}  // namespace
+
+bool IsMemoryDumpProviderWhitelisted(const char* mdp_name) {
+  for (size_t i = 0; g_dump_provider_whitelist[i] != nullptr; ++i) {
+    if (strcmp(mdp_name, g_dump_provider_whitelist[i]) == 0)
+      return true;
+  }
+  return false;
+}
+
+bool IsMemoryAllocatorDumpNameWhitelisted(const std::string& name) {
+  // Remove special characters, numbers (including hexadecimal which are marked
+  // by '0x') from the given string.
+  const size_t length = name.size();
+  std::string stripped_str;
+  stripped_str.reserve(length);
+  bool parsing_hex = false;
+  for (size_t i = 0; i < length; ++i) {
+    if (parsing_hex) {
+      if (isxdigit(name[i])) {
+        continue;
+      } else {
+        parsing_hex = false;
+      }
+    }
+    if (i + 1 < length && name[i] == '0' && name[i + 1] == 'x') {
+      parsing_hex = true;
+      ++i;
+    } else if (isalpha(name[i]) ||
+               (name[i] == '/' && stripped_str.back() != '/')) {
+      // Do not add successive '/'(s) in |stripped_str|.
+      stripped_str.push_back(name[i]);
+    }
+  }
+
+  for (size_t i = 0; g_allocator_dump_name_whitelist[i] != nullptr; ++i) {
+    if (stripped_str == g_allocator_dump_name_whitelist[i]) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void SetDumpProviderWhitelistForTesting(const char* const* list) {
+  g_dump_provider_whitelist = list;
+}
+
+void SetAllocatorDumpNameWhitelistForTesting(const char* const* list) {
+  g_allocator_dump_name_whitelist = list;
+}
+
+}  // namespace trace_event
+}  // namespace base