1020370 - WebAudio: Assertion failure: skipFracNum < 2147483647 (mBeginProcessing is wrong?)

Status: RESOLVED FIXED

(Core :: Web Audio, defect, P2)

Description

[Christoph Diehl [:posidron]]

Attachment: testcase

Tested with https://hg.mozilla.org/integration/mozilla-inbound/rev/38cd6935fc19

Comment 1

[Christoph Diehl [:posidron]]

Attachment: callstack

Comment 2

[Maire Reavy [:mreavy]]

Could you retest this next time you're running an ASAN build?  Thanks - I'm hoping it's fixed

Comment 3

[Karl Tomlinson (:karlt)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 7418.7575]
0x00007ff3bb61d91a in mozilla::dom::AudioBufferSourceNodeEngine::CopyFromInputBufferWithResampling (this=0x7ff2f2b7b680, aOutput=0x7ff30508b190, 
    aChannels=1, aOffsetWithinBlock=0x7ff317ffa690, aAvailableInOutput=128, 
    aCurrentPosition=0x7ff317ffa698, aBufferMax=16)
    at /mnt/ssd1/karl/moz/dev/dom/media/webaudio/AudioBufferSourceNode.cpp:274
(gdb) p /x skipFracNum
$1 = 0xdc097ed5
(gdb) p inputLatency
$2 = 4
(gdb) p leadTicks
$3 = 13681.575461263204
(gdb) p ratioNum
$4 = 44100
(gdb) p ratioDen
$5 = 2147483647
(gdb) p /x ratioDen
$6 = 0x7fffffff

skipFracNum was 0xfffffffc before leadTicks * ratioNum was subtracted.

ratioDen is the maximum, for the very slow playbackRate.

I'll look at changing the assertion.

Comment 4

[Karl Tomlinson (:karlt)]

Attachment: adjust assert to tolerate large skipFracNum

This assertion no longer fails with this testcase, but there is still overflow
in calculating skipFracNum from large ratioDen, which I'll address separately.

Comment 5

[Karl Tomlinson (:karlt)]

Attachment: crashtest

This causes even the new assert to fail.

Comment 6

[Karl Tomlinson (:karlt)]

Attachment: use uint64_t to avoid overflow in subsample calcs

ratioDen can be large when playbackRate is low.

Subsample skipping is limited to uint32_t values supported by speex resampler.

Comment 7

[Karl Tomlinson (:karlt)]

Attachment: use int64_t to avoid overflow in subsample calcs

Correct comment and s/max/min/.

Comment 8

[Karl Tomlinson (:karlt)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=71af39e3e652

Comment 9

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/67c94e508c2e
https://hg.mozilla.org/integration/mozilla-inbound/rev/364c352a9ac9
https://hg.mozilla.org/integration/mozilla-inbound/rev/4e57a9fb9a25

Comment 10

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/67c94e508c2e
https://hg.mozilla.org/mozilla-central/rev/364c352a9ac9
https://hg.mozilla.org/mozilla-central/rev/4e57a9fb9a25