The Tor Browser / file comparison
comparison: js/xpconnect/src/XPCJSContextStack.cpp
js/xpconnect/src/XPCJSContextStack.cpp
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:27c70229eed8 |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ | |
| 2 /* vim: set ts=8 sts=4 et sw=4 tw=99: */ | |
| 3 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 /* Implement global service to track stack of JSContext. */ | |
| 8 | |
| 9 #include "xpcprivate.h" | |
| 10 #include "XPCWrapper.h" | |
| 11 #include "nsDOMJSUtils.h" | |
| 12 #include "nsNullPrincipal.h" | |
| 13 #include "mozilla/dom/BindingUtils.h" | |
| 14 | |
| 15 using namespace mozilla; | |
| 16 using namespace JS; | |
| 17 using namespace xpc; | |
| 18 using mozilla::dom::DestroyProtoAndIfaceCache; | |
| 19 | |
| 20 /***************************************************************************/ | |
| 21 | |
| 22 XPCJSContextStack::~XPCJSContextStack() | |
| 23 { | |
| 24 if (mSafeJSContext) { | |
| 25 mSafeJSContextGlobal = nullptr; | |
| 26 JS_DestroyContextNoGC(mSafeJSContext); | |
| 27 mSafeJSContext = nullptr; | |
| 28 } | |
| 29 } | |
| 30 | |
| 31 JSContext* | |
| 32 XPCJSContextStack::Pop() | |
| 33 { | |
| 34 MOZ_ASSERT(!mStack.IsEmpty()); | |
| 35 | |
| 36 uint32_t idx = mStack.Length() - 1; // The thing we're popping | |
| 37 | |
| 38 JSContext *cx = mStack[idx].cx; | |
| 39 | |
| 40 mStack.RemoveElementAt(idx); | |
| 41 if (idx == 0) { | |
| 42 js::Debug_SetActiveJSContext(mRuntime->Runtime(), nullptr); | |
| 43 return cx; | |
| 44 } | |
| 45 | |
| 46 --idx; // Advance to new top of the stack | |
| 47 | |
| 48 XPCJSContextInfo &e = mStack[idx]; | |
| 49 if (e.cx && e.savedFrameChain) { | |
| 50 // Pop() can be called outside any request for e.cx. | |
| 51 JSAutoRequest ar(e.cx); | |
| 52 JS_RestoreFrameChain(e.cx); | |
| 53 e.savedFrameChain = false; | |
| 54 } | |
| 55 js::Debug_SetActiveJSContext(mRuntime->Runtime(), e.cx); | |
| 56 return cx; | |
| 57 } | |
| 58 | |
| 59 bool | |
| 60 XPCJSContextStack::Push(JSContext *cx) | |
| 61 { | |
| 62 js::Debug_SetActiveJSContext(mRuntime->Runtime(), cx); | |
| 63 if (mStack.Length() == 0) { | |
| 64 mStack.AppendElement(cx); | |
| 65 return true; | |
| 66 } | |
| 67 | |
| 68 XPCJSContextInfo &e = mStack[mStack.Length() - 1]; | |
| 69 if (e.cx) { | |
| 70 // The cx we're pushing is also stack-top. In general we still need to | |
| 71 // call JS_SaveFrameChain here. But if that would put us in a | |
| 72 // compartment that's same-origin with the current one, we can skip it. | |
| 73 nsIScriptSecurityManager* ssm = XPCWrapper::GetSecurityManager(); | |
| 74 if ((e.cx == cx) && ssm) { | |
| 75 // DOM JSContexts don't store their default compartment object on | |
| 76 // the cx, so in those cases we need to fetch it via the scx | |
| 77 // instead. And in some cases (i.e. the SafeJSContext), we have no | |
| 78 // default compartment object at all. | |
| 79 RootedObject defaultScope(cx, GetDefaultScopeFromJSContext(cx)); | |
| 80 if (defaultScope) { | |
| 81 nsIPrincipal *currentPrincipal = | |
| 82 GetCompartmentPrincipal(js::GetContextCompartment(cx)); | |
| 83 nsIPrincipal *defaultPrincipal = GetObjectPrincipal(defaultScope); | |
| 84 if (currentPrincipal->Equals(defaultPrincipal)) { | |
| 85 mStack.AppendElement(cx); | |
| 86 return true; | |
| 87 } | |
| 88 } | |
| 89 } | |
| 90 | |
| 91 { | |
| 92 // Push() can be called outside any request for e.cx. | |
| 93 JSAutoRequest ar(e.cx); | |
| 94 if (!JS_SaveFrameChain(e.cx)) | |
| 95 return false; | |
| 96 e.savedFrameChain = true; | |
| 97 } | |
| 98 } | |
| 99 | |
| 100 mStack.AppendElement(cx); | |
| 101 return true; | |
| 102 } | |
| 103 | |
| 104 bool | |
| 105 XPCJSContextStack::HasJSContext(JSContext *cx) | |
| 106 { | |
| 107 for (uint32_t i = 0; i < mStack.Length(); i++) | |
| 108 if (cx == mStack[i].cx) | |
| 109 return true; | |
| 110 return false; | |
| 111 } | |
| 112 | |
| 113 static bool | |
| 114 SafeGlobalResolve(JSContext *cx, HandleObject obj, HandleId id) | |
| 115 { | |
| 116 bool resolved; | |
| 117 return JS_ResolveStandardClass(cx, obj, id, &resolved); | |
| 118 } | |
| 119 | |
| 120 static void | |
| 121 SafeFinalize(JSFreeOp *fop, JSObject* obj) | |
| 122 { | |
| 123 SandboxPrivate* sop = | |
| 124 static_cast<SandboxPrivate*>(xpc_GetJSPrivate(obj)); | |
| 125 sop->ForgetGlobalObject(); | |
| 126 NS_IF_RELEASE(sop); | |
| 127 DestroyProtoAndIfaceCache(obj); | |
| 128 } | |
| 129 | |
| 130 const JSClass xpc::SafeJSContextGlobalClass = { | |
| 131 "global_for_XPCJSContextStack_SafeJSContext", | |
| 132 XPCONNECT_GLOBAL_FLAGS, | |
| 133 JS_PropertyStub, JS_DeletePropertyStub, JS_PropertyStub, JS_StrictPropertyStub, | |
| 134 JS_EnumerateStub, SafeGlobalResolve, JS_ConvertStub, SafeFinalize, | |
| 135 nullptr, nullptr, nullptr, JS_GlobalObjectTraceHook | |
| 136 }; | |
| 137 | |
| 138 JSContext* | |
| 139 XPCJSContextStack::GetSafeJSContext() | |
| 140 { | |
| 141 MOZ_ASSERT(mSafeJSContext); | |
| 142 return mSafeJSContext; | |
| 143 } | |
| 144 | |
| 145 JSObject* | |
| 146 XPCJSContextStack::GetSafeJSContextGlobal() | |
| 147 { | |
| 148 MOZ_ASSERT(mSafeJSContextGlobal); | |
| 149 return mSafeJSContextGlobal; | |
| 150 } | |
| 151 | |
| 152 JSContext* | |
| 153 XPCJSContextStack::InitSafeJSContext() | |
| 154 { | |
| 155 MOZ_ASSERT(!mSafeJSContext); | |
| 156 | |
| 157 // Start by getting the principal holder and principal for this | |
| 158 // context. If we can't manage that, don't bother with the rest. | |
| 159 nsRefPtr<nsNullPrincipal> principal = new nsNullPrincipal(); | |
| 160 nsresult rv = principal->Init(); | |
| 161 if (NS_FAILED(rv)) | |
| 162 MOZ_CRASH(); | |
| 163 | |
| 164 nsXPConnect* xpc = nsXPConnect::XPConnect(); | |
| 165 JSRuntime *rt = xpc->GetRuntime()->Runtime(); | |
| 166 if (!rt) | |
| 167 MOZ_CRASH(); | |
| 168 | |
| 169 mSafeJSContext = JS_NewContext(rt, 8192); | |
| 170 if (!mSafeJSContext) | |
| 171 MOZ_CRASH(); | |
| 172 JSAutoRequest req(mSafeJSContext); | |
| 173 ContextOptionsRef(mSafeJSContext).setNoDefaultCompartmentObject(true); | |
| 174 | |
| 175 JS_SetErrorReporter(mSafeJSContext, xpc::SystemErrorReporter); | |
| 176 | |
| 177 JS::CompartmentOptions options; | |
| 178 options.setZone(JS::SystemZone) | |
| 179 .setTrace(TraceXPCGlobal); | |
| 180 mSafeJSContextGlobal = CreateGlobalObject(mSafeJSContext, | |
| 181 &SafeJSContextGlobalClass, | |
| 182 principal, options); | |
| 183 if (!mSafeJSContextGlobal) | |
| 184 MOZ_CRASH(); | |
| 185 | |
| 186 // Note: make sure to set the private before calling | |
| 187 // InitClasses | |
| 188 nsRefPtr<SandboxPrivate> sp = new SandboxPrivate(principal, mSafeJSContextGlobal); | |
| 189 JS_SetPrivate(mSafeJSContextGlobal, sp.forget().take()); | |
| 190 | |
| 191 // After this point either glob is null and the | |
| 192 // nsIScriptObjectPrincipal ownership is either handled by the | |
| 193 // nsCOMPtr or dealt with, or we'll release in the finalize | |
| 194 // hook. | |
| 195 if (NS_FAILED(xpc->InitClasses(mSafeJSContext, mSafeJSContextGlobal))) | |
| 196 MOZ_CRASH(); | |
| 197 | |
| 198 JS::RootedObject glob(mSafeJSContext, mSafeJSContextGlobal); | |
| 199 JS_FireOnNewGlobalObject(mSafeJSContext, glob); | |
| 200 | |
| 201 return mSafeJSContext; | |
| 202 } |
