Title: [183128] trunk/Source/_javascript_Core
Revision
183128
Author
[email protected]
Date
2015-04-22 13:44:32 -0700 (Wed, 22 Apr 2015)

Log Message

SparseArrayEntry's write barrier owner should be the SparseArrayValueMap.
https://bugs.webkit.org/show_bug.cgi?id=144067

Reviewed by Michael Saboff.

Currently, there are a few places where the JSObject that owns the
SparseArrayValueMap is designated as the owner of the SparseArrayEntry
write barrier.  This is a bug and can result in the GC collecting the
SparseArrayEntry even though it is being referenced by the
SparseArrayValueMap.  This patch fixes the bug.

* runtime/JSObject.cpp:
(JSC::JSObject::enterDictionaryIndexingModeWhenArrayStorageAlreadyExists):
(JSC::JSObject::putIndexedDescriptor):
* tests/stress/sparse-array-entry-update-144067.js: Added.
(useMemoryToTriggerGCs):
(foo):

Modified Paths

Added Paths

Diff

Modified: trunk/Source/_javascript_Core/ChangeLog (183127 => 183128)


--- trunk/Source/_javascript_Core/ChangeLog	2015-04-22 20:39:46 UTC (rev 183127)
+++ trunk/Source/_javascript_Core/ChangeLog	2015-04-22 20:44:32 UTC (rev 183128)
@@ -1,5 +1,25 @@
 2015-04-22  Mark Lam  <[email protected]>
 
+        SparseArrayEntry's write barrier owner should be the SparseArrayValueMap.
+        https://bugs.webkit.org/show_bug.cgi?id=144067
+
+        Reviewed by Michael Saboff.
+
+        Currently, there are a few places where the JSObject that owns the
+        SparseArrayValueMap is designated as the owner of the SparseArrayEntry
+        write barrier.  This is a bug and can result in the GC collecting the
+        SparseArrayEntry even though it is being referenced by the
+        SparseArrayValueMap.  This patch fixes the bug.
+
+        * runtime/JSObject.cpp:
+        (JSC::JSObject::enterDictionaryIndexingModeWhenArrayStorageAlreadyExists):
+        (JSC::JSObject::putIndexedDescriptor):
+        * tests/stress/sparse-array-entry-update-144067.js: Added.
+        (useMemoryToTriggerGCs):
+        (foo):
+
+2015-04-22  Mark Lam  <[email protected]>
+
         Give the heap object iterators the ability to return early.
         https://bugs.webkit.org/show_bug.cgi?id=144011
 

Modified: trunk/Source/_javascript_Core/runtime/JSObject.cpp (183127 => 183128)


--- trunk/Source/_javascript_Core/runtime/JSObject.cpp	2015-04-22 20:39:46 UTC (rev 183127)
+++ trunk/Source/_javascript_Core/runtime/JSObject.cpp	2015-04-22 20:44:32 UTC (rev 183128)
@@ -584,7 +584,7 @@
         // This will always be a new entry in the map, so no need to check we can write,
         // and attributes are default so no need to set them.
         if (value)
-            map->add(this, i).iterator->value.set(vm, this, value);
+            map->add(this, i).iterator->value.set(vm, map, value);
     }
 
     DeferGC deferGC(vm.heap);
@@ -1717,12 +1717,13 @@
 void JSObject::putIndexedDescriptor(ExecState* exec, SparseArrayEntry* entryInMap, const PropertyDescriptor& descriptor, PropertyDescriptor& oldDescriptor)
 {
     VM& vm = exec->vm();
+    auto map = m_butterfly->arrayStorage()->m_sparseMap.get();
 
     if (descriptor.isDataDescriptor()) {
         if (descriptor.value())
-            entryInMap->set(vm, this, descriptor.value());
+            entryInMap->set(vm, map, descriptor.value());
         else if (oldDescriptor.isAccessorDescriptor())
-            entryInMap->set(vm, this, jsUndefined());
+            entryInMap->set(vm, map, jsUndefined());
         entryInMap->attributes = descriptor.attributesOverridingCurrent(oldDescriptor) & ~Accessor;
         return;
     }
@@ -1745,7 +1746,7 @@
         if (setter)
             accessor->setSetter(vm, exec->lexicalGlobalObject(), setter);
 
-        entryInMap->set(vm, this, accessor);
+        entryInMap->set(vm, map, accessor);
         entryInMap->attributes = descriptor.attributesOverridingCurrent(oldDescriptor) & ~ReadOnly;
         return;
     }

Added: trunk/Source/_javascript_Core/tests/stress/sparse-array-entry-update-144067.js (0 => 183128)


--- trunk/Source/_javascript_Core/tests/stress/sparse-array-entry-update-144067.js	                        (rev 0)
+++ trunk/Source/_javascript_Core/tests/stress/sparse-array-entry-update-144067.js	2015-04-22 20:44:32 UTC (rev 183128)
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+// Regression test for https://bugs.webkit.org/show_bug.cgi?id=144067.
+// This test aims to continually override the setter in a sparse array object, and
+// trigger GCs to give it a chance to collect the newly set entry value if the bug exists. 
+// With the bug fixed, this test should not crash.
+
+var data = ""
+var sparseObj = {};
+
+for (var i = 0; i < 5; i++)
+    sparseObj[i] = i;
+
+function useMemoryToTriggerGCs() {
+    var arr = [];
+    var limit = DFGTrue() ? 10000 : 100;
+    for (var i = 0; i < limit; i++)
+        arr[i] = { a: "using" + i, b: "up" + i, c: "memory" + i };
+    return arr;
+}
+
+function foo(x) {
+    if (!x)
+        return;
+    data.textContent = sparseObj.__defineSetter__("16384", foo);
+    for (var i = 0; i < 10; i++)
+        sparseObj.__defineSetter__("" + (16384 + i), foo);
+    useMemoryToTriggerGCs();
+    sparseObj[16384] = x - 1;
+}
+
+var recursionDepthNeededToTriggerTheFailure = 100;
+foo(recursionDepthNeededToTriggerTheFailure);
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