1488763 - JIT should touch stack pages on all platforms

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P2)

Description

[Ted Campbell [:tcampbell]]

Other Windows platforms have code similar to [1], but we don't have this on arm64. I believe it is still needed. Do we have test cases that cover this?

[1] https://searchfox.org/mozilla-central/source/js/src/jit/arm/Trampoline-arm.cpp#260-280

Comment 1

[Nathan Froyd [:froydnj]]

I believe https://docs.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=vs-2017#stack indicates that we need to do the necessary guard page touching on this platform as well.

Comment 2

[Ted Campbell [:tcampbell]]

After some discussion with Jan, I'm instead proposing we making the page touching of stack in EnterJit trampoline always enabled. Consistency across platforms seems to outweight saving a handful of cycles on the non-Windows platorms.

Comment 3

[Ted Campbell [:tcampbell]]

Matthew, can you take a look at this in next few weeks? It is needed for ARM64 Windows. It should be a pretty straightforward change.

Comment 4

[Matthew Gaudet (he/him) [:mgaudet]]

Attachment: Bug 1488763 - Unify stack touch logic across all platforms r?jandem

This incidentally also -adds- the stack touch logic to ARM64.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e3a9e32b069a
Unify stack touch logic across all platforms r=jandem

Comment 6

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/e3a9e32b069a