Bug 117139 – OOM crash in WTF::OSAllocator::reserveUncommitted.

• Status: RESOLVED
• Resolution: WORKSFORME
• Component: JavaScriptCore

[Renata Hodovan]

The for loop in the following test is unlimited and runs until it's crashing on the following check in Source/WTF/wtf/OSAllocatorPosix.cpp:

151	    if (mprotect(address, bytes, protection))
152	        CRASH();


Maybe we should add a "loopCounter mechanism" to the code?

==========================================================

The test:

function test() {
    for (var byteRate = "b"; byteRate.renderedBuffer != byteRate; byteRate += 2e3) {
    }
}

test();

==========================================================

Backtrace:

Program received signal SIGSEGV, Segmentation fault.
0x00000000007fb8e5 in WTFCrash ()
    at /home/reni/Data/REPOS/webkit_sec/Source/WTF/wtf/Assertions.cpp:339
339	    *(int *)(uintptr_t)0xbbadbeef = 0;
(gdb) bt
#0  0x00000000007fb8e5 in WTFCrash ()
    at /home/reni/Data/REPOS/webkit_sec/Source/WTF/wtf/Assertions.cpp:339
#1  0x000000000083d4c4 in WTF::OSAllocator::reserveUncommitted (bytes=126976, 
    usage=WTF::OSAllocator::UnknownUsage, writable=true, executable=false, 
    includesGuardPages=false)
    at /home/reni/Data/REPOS/webkit_sec/Source/WTF/wtf/OSAllocatorPosix.cpp:58
#2  0x000000000081ece7 in WTF::PageAllocationAligned::allocate (size=65536, 
    alignment=65536, usage=WTF::OSAllocator::UnknownUsage, writable=true)
    at /home/reni/Data/REPOS/webkit_sec/Source/WTF/wtf/PageAllocationAligned.cpp:55
#3  0x000000000050ecbe in JSC::ExcessRegion::create (blockSize=65536)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/Region.h:179
#4  0x000000000050efe4 in JSC::Region::create (superRegion=0xf31838, 
    blockSize=65536)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/Region.h:232
#5  0x000000000052e1a9 in JSC::BlockAllocator::allocate<JSC::MarkedBlock> (
    this=0xf31838)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/BlockAll0, 
    bytes=48)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/MarkedAllocator.cpp:115
#7  0x000000000052da0d in JSC::MarkedAllocator::allocateSlowCase (
    this=0xf34960, bytes=48)
---Type <return> to continue, or q <return> to quit---
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/MarkedAllocator.cpp:97
#8  0x0000000000411fc4 in JSC::MarkedAllocator::allocate (this=0xf34960, 
    bytes=48)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/MarkedAllocator.h:82
#9  0x0000000000412264 in JSC::MarkedSpace::allocateWithImmortalStructureDestructor (this=0xf31a80, bytes=48)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/MarkedSpace.h:210
#10 0x0000000000412470 in JSC::Heap::allocateWithImmortalStructureDestructor (
    this=0xf317f8, bytes=48)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/heap/Heap.h:380
#11 0x00000000005c07c3 in JSC::allocateCell<JSC::JSRopeString> (heap=..., 
    size=48)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/runtime/JSCellInlines.h:92
#12 0x00000000005bfa2d in JSC::allocateCell<JSC::JSRopeString> (heap=...)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/runtime/JSCellInlines.h:104
#13 0x00000000005bbd9e in JSC::JSRopeString::create (vm=..., 
    s1=0x7ffe9a0a0470, s2=0x7ffe9a0b4e20)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/runtime/JSString.h:300
#14 0x00000000005ba170 in JSC::DFG::operationMakeRope2 (exec=0x7fffb21c20a0, 
    left=0x7ffe9a0a0470, right=0x7ffe9a0b4e20)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/dfg/DFGOperations---Type <return> to continue, or q <return> to quit---
.cpp:1592
#15 0x00007fffb45c7b91 in ?? ()
#16 0x00007fffb21c2058 in ?? ()
#17 0x0000000000000014 in ?? ()
#18 0x00007fffb21132f0 in ?? ()
#19 0x00000000006483c7 in JSC::JSStack::installTrapsAfterFrame (this=0x0, 
    frame=0x0)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/interpreter/JSStackInlines.h:212
#20 0x0000000000647226 in JSC::JITCode::execute (this=0x7fffb217fe90, 
    stack=0xf40950, callFrame=0x7fffb21c2058, vm=0xf317e0)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/jit/JITCode.h:135
#21 0x0000000000644747 in JSC::Interpreter::execute (this=0xf40940, 
    program=0x7fffb217fe70, callFrame=0x7ffff7f5fb78, thisObj=0x7ffff7e6feb0)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/interpreter/Interpreter.cpp:976
#22 0x00000000007292c0 in JSC::evaluate (exec=0x7ffff7f5fb78, source=..., 
    thisValue=..., returnedException=0x7fffffffda10)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/runtime/Completion.cpp:83
#23 0x000000000040fdcd in runWithScripts (globalObject=0x7ffff7f5f970, 
    scripts=..., dump=false)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/jsc.cpp:587
#24 0x0000000000410b3d in jscmain (argc=2, argv=0x7fffffffdc98)
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/jsc.cpp:803
#25 0x000000000040fbcd in main (argc=2, argv=0x7fffffffdc98)
---Type <return> to continue, or q <return> to quit---
    at /home/reni/Data/REPOS/webkit_sec/Source/JavaScriptCore/jsc.cpp:550

[Renata Hodovan]

The issue isn't reproducible anymore.