655505 - TI+JM: Assertion failure: checkedFreeRegs == a->freeRegs, at FrameState.cpp:1371

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jan de Mooij [:jandem]]

Mochitest-4 asserts with this and decoder posted a fuzz test case on IRC.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Patch

Comment 2

[Brian Hackett [Laid off!]]

Comment on attachment 530860 [details] [diff] [review]
Patch

Review of attachment 530860 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/methodjit/Compiler.cpp
@@ +1331,4 @@
>              for (unsigned i = 0; i < fixedDoubleEntries.length(); i++) {
>                  FrameEntry *fe = frame.getOrTrack(fixedDoubleEntries[i]);
>                  frame.ensureInteger(fe);
> +                frame.assertValidRegisterState();

Not sure about these; the assertValidRegisterState before setting jumpMap should catch these shortly, and these assertions might be expensive to run.

@@ +1343,5 @@
>                      FrameEntry *fe = frame.getOrTrack(slot);
>                      JS_ASSERT(!fe->isType(JSVAL_TYPE_DOUBLE));
>                  }
>              }
> +            frame.assertValidRegisterState();

This one shouldn't be necessary, the code above it does not mutate the FS.

Comment 3

[Jan de Mooij [:jandem]]

OK I removed the calls. Now we assert before and after the bytecode switch, I think that's most important to determine where it went wrong.

http://hg.mozilla.org/projects/jaegermonkey/rev/325744fbf7f0

Comment 4

[Jan de Mooij [:jandem]]

Attachment: Fix fixDoubleTypes

There was another bug here, we could call fixDoubleTypes twice for the same op, causing incorrect results because the same entry is converted twice. Now fixDoubleTypes is only called from generateMethod. Mochitest-4 test_transitions is green with this patch.

Comment 5

[Brian Hackett [Laid off!]]

Comment on attachment 531000 [details] [diff] [review]
Fix fixDoubleTypes

Nice factoring, this was being done in a pretty sloppy fashion.

Comment 6

[Jan de Mooij [:jandem]]

http://hg.mozilla.org/projects/jaegermonkey/rev/3d26d25a4f63