gecko-dev/toolkit/components/processsingleton/ContentProcessSingleton.js
Haik Aftandilian 91677b958d Bug 1274074 - console.log()ging too much data can crash e10s via IPC call from mozilla::dom::ProcessGlobal::SendAsyncMessage; r=mconley
MozReview-Commit-ID: 6ICgsnNHFpq

--HG--
extra : transplant_source : %95%98%12%20n%AEl%E1%86%C8%8A%FF%A8%25%0D%8B%5B%C0%2A0
2016-05-28 01:15:14 -07:00

118 lines
4.6 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const Cu = Components.utils;
const Ci = Components.interfaces;
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
"@mozilla.org/childprocessmessagemanager;1",
"nsIMessageSender");
/*
* The message manager has an upper limit on message sizes that it can
* reliably forward to the parent so we limit the size of console log event
* messages that we forward here. The web console is local and receives the
* full console message, but addons subscribed to console event messages
* in the parent receive the truncated version. Due to fragmentation,
* messages as small as 1MB have resulted in IPC allocation failures on
* 32-bit platforms. To limit IPC allocation sizes, console.log messages
* with arguments with total size > MSG_MGR_CONSOLE_MAX_SIZE (bytes) have
* their arguments completely truncated. MSG_MGR_CONSOLE_VAR_SIZE is an
* approximation of how much space (in bytes) a JS non-string variable will
* require in the manager's implementation. For strings, we use 2 bytes per
* char. The console message URI and function name are limited to
* MSG_MGR_CONSOLE_INFO_MAX characters. We don't attempt to calculate
* the exact amount of space the message manager implementation will require
* for a given message so this is imperfect.
*/
const MSG_MGR_CONSOLE_MAX_SIZE = 1024 * 1024; // 1MB
const MSG_MGR_CONSOLE_VAR_SIZE = 8;
const MSG_MGR_CONSOLE_INFO_MAX = 1024;
function ContentProcessSingleton() {}
ContentProcessSingleton.prototype = {
classID: Components.ID("{ca2a8470-45c7-11e4-916c-0800200c9a66}"),
QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
Ci.nsISupportsWeakReference]),
observe: function(subject, topic, data) {
switch (topic) {
case "app-startup": {
Services.obs.addObserver(this, "console-api-log-event", false);
Services.obs.addObserver(this, "xpcom-shutdown", false);
cpmm.addMessageListener("DevTools:InitDebuggerServer", this);
break;
}
case "console-api-log-event": {
let consoleMsg = subject.wrappedJSObject;
let msgData = {
level: consoleMsg.level,
filename: consoleMsg.filename.substring(0, MSG_MGR_CONSOLE_INFO_MAX),
lineNumber: consoleMsg.lineNumber,
functionName: consoleMsg.functionName.substring(0,
MSG_MGR_CONSOLE_INFO_MAX),
timeStamp: consoleMsg.timeStamp,
arguments: [],
};
// We can't send objects over the message manager, so we sanitize
// them out, replacing those arguments with "<unavailable>".
let unavailString = "<unavailable>";
let unavailStringLength = unavailString.length * 2; // 2-bytes per char
// When the sum of argument sizes reaches MSG_MGR_CONSOLE_MAX_SIZE,
// replace all arguments with "<truncated>".
let totalArgLength = 0;
// Walk through the arguments, checking the type and size.
for (let arg of consoleMsg.arguments) {
if ((typeof arg == "object" || typeof arg == "function") &&
arg !== null) {
arg = unavailString;
totalArgLength += unavailStringLength;
} else if (typeof arg == "string") {
totalArgLength += arg.length * 2; // 2-bytes per char
} else {
totalArgLength += MSG_MGR_CONSOLE_VAR_SIZE;
}
if (totalArgLength <= MSG_MGR_CONSOLE_MAX_SIZE) {
msgData.arguments.push(arg);
} else {
// arguments take up too much space
msgData.arguments = ["<truncated>"];
break;
}
}
cpmm.sendAsyncMessage("Console:Log", msgData);
break;
}
case "xpcom-shutdown":
Services.obs.removeObserver(this, "console-api-log-event");
Services.obs.removeObserver(this, "xpcom-shutdown");
cpmm.removeMessageListener("DevTools:InitDebuggerServer", this);
break;
}
},
receiveMessage: function (message) {
// load devtools component on-demand
// Only reply if we are in a real content process
if (Services.appinfo.processType == Services.appinfo.PROCESS_TYPE_CONTENT) {
let {init} = Cu.import("resource://devtools/server/content-server.jsm", {});
init(message);
}
},
};
this.NSGetFactory = XPCOMUtils.generateNSGetFactory([ContentProcessSingleton]);