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      <base href="https://bugs.webkit.org/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Overflow crash in CodeBlock::getArrayProfile under ::FixupPhase::attemptToMakeGetArrayLength running inspector tests under heavy system load"
   href="https://bugs.webkit.org/show_bug.cgi?id=147741">147741</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Overflow crash in CodeBlock::getArrayProfile under ::FixupPhase::attemptToMakeGetArrayLength running inspector tests under heavy system load
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>WebKit
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>528+ (Nightly build)
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Unspecified
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Unspecified
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>Normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P2
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>JavaScriptCore
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>webkit-unassigned&#64;lists.webkit.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>joepeck&#64;webkit.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>ap&#64;webkit.org, fpizlo&#64;apple.com, ggaren&#64;apple.com, msaboff&#64;apple.com, webkit-bug-importer&#64;group.apple.com
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=258386" name="attach_258386" title="[CRASH] Crash Report">attachment 258386</a> <a href="attachment.cgi?id=258386&amp;action=edit" title="[CRASH] Crash Report">[details]</a></span>
[CRASH] Crash Report

* SUMMARY
Overflow crash in CodeBlock::getArrayProfile under ::FixupPhase::attemptToMakeGetArrayLength running inspector tests under heavy system load.

I was at WebKit r188015.

* STEPS TO REPRODUCE
1. shell&gt; run-webkit-tests --release inspector/dom --iterations=1000 --v
  =&gt; saw this crash happen 3 out of 10000 times, presumably on the Web Inspector process, causing 3 timeout failures (each on different inspector/dom tests)

* NOTES
The only times I saw the crashes happen were when the system was under heavy load (I was compiling a debug build of WebKit while the tests were running).

* CRASH SNIPPET (full log attached)

Crashed Thread:        14  DFG Worklist Worker Thread

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x00000000bbadbeef

Thread 14 Crashed:: DFG Worklist Worker Thread
0   com.apple.JavaScriptCore          0x000000010f3e2a1e WTFCrash + 62
1   com.apple.JavaScriptCore          0x000000010edab849 WTF::CrashOnOverflow::crash() + 9
2   com.apple.JavaScriptCore          0x000000010edab839 WTF::CrashOnOverflow::overflowed() + 9
3   com.apple.JavaScriptCore          0x000000010ee0691f JSC::CodeBlock::getArrayProfile(unsigned int) + 111
4   com.apple.JavaScriptCore          0x000000010eef8c25 JSC::DFG::FixupPhase::attemptToMakeGetArrayLength(JSC::DFG::Node*) + 165
5   com.apple.JavaScriptCore          0x000000010eef22aa JSC::DFG::FixupPhase::fixupNode(JSC::DFG::Node*) + 12618
6   com.apple.JavaScriptCore          0x000000010eeeddc9 JSC::DFG::FixupPhase::run() + 121
7   com.apple.JavaScriptCore          0x000000010eeedc71 bool JSC::DFG::runPhase&lt;JSC::DFG::FixupPhase&gt;(JSC::DFG::Graph&amp;) + 113
8   com.apple.JavaScriptCore          0x000000010eeedba9 JSC::DFG::performFixup(JSC::DFG::Graph&amp;) + 9
9   com.apple.JavaScriptCore          0x000000010ef60871 JSC::DFG::Plan::compileInThreadImpl(JSC::DFG::LongLivedState&amp;) + 625
10  com.apple.JavaScriptCore          0x000000010ef602e5 JSC::DFG::Plan::compileInThread(JSC::DFG::LongLivedState&amp;, JSC::DFG::ThreadData*) + 565
11  com.apple.JavaScriptCore          0x000000010eff97c1 JSC::DFG::Worklist::runThread(JSC::DFG::ThreadData*) + 545
12  com.apple.JavaScriptCore          0x000000010f4106c3 WTF::threadEntryPoint(void*) + 179
13  com.apple.JavaScriptCore          0x000000010f410b2f WTF::wtfThreadEntryPoint(void*) + 15
14  libsystem_pthread.dylib           0x00007fff8a56405a _pthread_body + 131
15  libsystem_pthread.dylib           0x00007fff8a563fd7 _pthread_start + 176
16  libsystem_pthread.dylib           0x00007fff8a5613ed thread_start + 13</pre>
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