First typed array is not zero-filled (v5.10.0)

Version: v5.10.0
Platform: Darwin [...] 14.5.0 Darwin Kernel Version 14.5.0: Mon Jan 11 18:48:35 PST 2016; root:xnu-2782.50.2~1/RELEASE_X86_64 x86_64

The first typed array created during script execution may contain non-zero values. Subsequent typed arrays are zero-filled, as expected.

I began to see this behavior after installing v5.10.0 from the following source: https://nodejs.org/dist/v5.10.0/node-v5.10.0-darwin-x64.tar.gz

The previous version, 5.9.1, is not affected.

I'm pasting sample output from the attached script zerofill_bug.txt below.

zerofill_bug.txt

File contents

#!/usr/bin/env node
console.log(new Float64Array(10));
console.log(new Float64Array(10));

Sample output

Float64Array {
  '0': 0,
  '1': 0,
  '2': 2.146862934e-314,
  '3': 2.1468647947e-314,
  '4': 2.146864866e-314,
  '5': 2.1468649963e-314,
  '6': 2.146865024e-314,
  '7': 5.56270611491583e-309,
  '8': 2.3194251029888626e+242,
  '9': 9.765157996892863e+199 }
Float64Array {
  '0': 0,
  '1': 0,
  '2': 0,
  '3': 0,
  '4': 0,
  '5': 0,
  '6': 0,
  '7': 0,
  '8': 0,
  '9': 0 }

I am able to reproduce. Not sure if the labels I have applied are correct or not. I'm doing a bisect right now to see what's up

/cc @nodejs/security

Hm, I cannot reproduce it from the repl though...weird

@evanlucas

@evanlucas probably because some allocations are already made

Looks like the regression comes in from 3c02727

edit: wrong sha at first

master is affected also

@jasnell

/cc @jasnell

I'm not 100% but I'm going to guess we are doing something wrong here 3c02727#diff-cd53544f44aab2c697bcd7b6a57f23ccR949

Calling Buffer.allocUnsafe reproduces this state

Passing the --zero-fill-buffers flag definitely makes it work

@thealphanerd

@thealphanerd ... quick test on v5.x with that additional check removed still shows the problem. Master includes that exact same check also and I'm unable to reproduce there.

I just ran a test with the following on master

console.log(new Float64Array(10));
console.log(new Float64Array(10));
var a = new Buffer.allocUnsafe(200);
console.log(new Float64Array(10));
console.log(new Float64Array(10));

output is

Float64Array [
  0,
  0,
  2.5196862903032468e+180,
  2.1390944465e-314,
  0,
  1.1125369292536007e-308,
  0,
  3.105036371167128e+231,
  1.7272338147994846e-77,
  6.953355807835004e-309 ]
Float64Array [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ]
Float64Array [
  0,
  0,
  2.1345912614e-314,
  2.1346182947e-314,
  0,
  0,
  2.1345912604e-314,
  2.1346095003e-314,
  2.134609532e-314,
  2.1346095636e-314 ]
Float64Array [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ]

buffer: don't set `kNoZeroFill` flag in allocUnsafe

buffer: safeguard against accidental kNoZeroFill

buffer: don't set `kNoZeroFill` flag in allocUnsafe

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First typed array is not zero-filled (v5.10.0) #6006

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First typed array is not zero-filled (v5.10.0) #6006

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MylesBorins commented on Apr 1, 2016

evanlucas commented on Apr 1, 2016

vkurchatkin commented on Apr 1, 2016

MylesBorins commented on Apr 1, 2016

evanlucas commented on Apr 1, 2016

MylesBorins commented on Apr 1, 2016

MylesBorins commented on Apr 1, 2016

vkurchatkin commented on Apr 1, 2016

evanlucas commented on Apr 1, 2016

jasnell commented on Apr 1, 2016

MylesBorins commented on Apr 1, 2016

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