1454999 - Valgrind "Conditional jump or move depends on uninitialised value" errors in js when attempting to land javascript patch

Status: RESOLVED DUPLICATE of bug 1451198

(Core :: JavaScript Engine, defect)

Description

[Mark Banner (:standard8)]

I'm currently trying to land bug 1449317 as we'd like to uplift it to 60 if possible.

The valgrind tests are currently failing when I land, however, as it is a plain javascript patch, I don't think it is anything I am doing.

https://treeherder.mozilla.org/#/jobs?repo=try&revision=f1941a5dc4ef4ca250827bbddb959e83a0220693&selectedJob=174274082

Typical errors:

Conditional jump or move depends on uninitialised value(s) at post / init / initSlotUnchecked / js::UnboxedPlainObject::convertToNative
Conditional jump or move depends on uninitialised value(s) at DefinePropertyIsRedundant / js::NativeDefineProperty / NativeDefineDataProperty / NativeDefineDataProperty
Conditional jump or move depends on uninitialised value(s) at decltype / preBarrier / pre / set

These seem to repeat several times.

They happened when I originally landed the patch on autoland, and they also happened when I rebased on latest central and push it to try.

Comment 1

[Nicholas Nethercote [inactive]]

sfink, Valgrind says that these undefined values come from our own poison annotations:

> ==33384==  Uninitialised value was created by a client request
> ==33384==    at 0x119FD943: SetMemCheckKind (jsutil.h:303)
> ==33384==    by 0x119FD943: Poison (jsutil.h:344)
> ==33384==    by 0x119FD943: js::NurseryChunk::poisonAndInit(JSRuntime*) (Nursery.cpp:90)

Any idea what the problem might be?

Comment 2

[Jan de Mooij [:jandem]]

This is bug 1449385, a (sort of) false positive from bug 1448589. I'll fix.

Comment 3

[Jan de Mooij [:jandem]]

(In reply to Jan de Mooij [:jandem] from comment #2)
> This is bug 1449385

Er, bug 1451198.

Comment 4

[Mark Banner (:standard8)]

Thank you Jan. Do you know if FF 60 is affected as well / will it be able to be uplifted?

Comment 5

[Jan de Mooij [:jandem]]

(In reply to Mark Banner (:standard8) from comment #4)
> Thank you Jan. Do you know if FF 60 is affected as well / will it be able to
> be uplifted?

Should only affect FF 61. I'll try to get this fixed ASAP to get you unblocked.