Bug 111059 – Crash in JSC::MarkedBlock::FreeList JSC::MarkedBlock::sweepHelper

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Ryosuke Niwa]

CRASHING TEST: fast/js/regress/int-or-other-add-then-get-by-val.html

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.JavaScriptCore      	0x000000010422be86 WTF::TCMalloc_ThreadCache_FreeList::Validate(WTF::HardenedSLL, unsigned long) + 70 (FastMalloc.cpp:2626)
1   com.apple.JavaScriptCore      	0x000000010422bd11 WTF::TCMalloc_ThreadCache::Deallocate(WTF::HardenedSLL, unsigned long) + 209 (FastMalloc.cpp:3247)
2   com.apple.JavaScriptCore      	0x0000000104147345 JSC::MarkedBlock::FreeList JSC::MarkedBlock::sweepHelper<(JSC::MarkedBlock::DestructorType)2>(JSC::MarkedBlock::SweepMode) + 309 (JSCell.h:117)
3   com.apple.JavaScriptCore      	0x0000000104146f57 JSC::MarkedBlock::sweep(JSC::MarkedBlock::SweepMode) + 71 (MarkedBlock.cpp:118)
4   com.apple.JavaScriptCore      	0x000000010406864c JSC::IncrementalSweeper::doSweep(double) + 108 (IncrementalSweeper.cpp:130)
5   com.apple.JavaScriptCore      	0x0000000104066c03 JSC::HeapTimer::timerDidFire(__CFRunLoopTimer*, void*) + 179 (TimeoutChecker.h:57)
6   com.apple.CoreFoundation      	0x00007fff92ac7da4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
7   com.apple.CoreFoundation      	0x00007fff92ac78bd __CFRunLoopDoTimer + 557
8   com.apple.CoreFoundation      	0x00007fff92aad099 __CFRunLoopRun + 1513
9   com.apple.CoreFoundation      	0x00007fff92aac6b2 CFRunLoopRunSpecific + 290
10  com.apple.Foundation          	0x00007fff87a8089e -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 268
11  DumpRenderTree                	0x0000000103e33e12 runTest(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) + 1639 (DumpRenderTree.mm:1375)
12  DumpRenderTree                	0x0000000103e335a6 dumpRenderTree(int, char const**) + 1727 (DumpRenderTree.mm:832)
13  DumpRenderTree                	0x0000000103e3417b main + 86 (DumpRenderTree.mm:925)
14  libdyld.dylib                 	0x00007fff895837e1 start + 1

e.g.
http://build.webkit.org/results/Apple%20MountainLion%20Release%20WK1%20(Tests)/r144275%20(7359)/results.html

[Oliver Hunt]

So with some fiddling i can make this die fairly easily, implying a validation logic bug.  Can't work out of course, and lldb is trying hard to beat gdb for the prize of "least good at debugging optimized code" so seeing if i can make it repro in a debug build

[Oliver Hunt]

Created attachment 190776 [details]
Patch

[Filip Pizlo]

r=me too

[Oliver Hunt]

Committed r144346: <http://trac.webkit.org/changeset/144346>

[Benjamin Poulain]

Was it doing implicit conversion to bool prior to the operator?

[Ryosuke Niwa]

(In reply to comment #5)
> Was it doing implicit conversion to bool prior to the operator?

Yup :(