Bug 643972

Summary:	www-client/firefox option to disable JIT?
Product:	Gentoo Security	Reporter:	Fedja Beader <fedja>
Component:	Default Configs	Assignee:	The Gentoo Linux Hardened Team <hardened>
Status:	RESOLVED INVALID
Severity:	major	CC:	fedja, libor+gentoobugs, mozilla
Priority:	Normal
Version:	unspecified
Hardware:	AMD64
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---
Attachments:	firefox-52.5.2.patch

Description Fedja Beader 2018-01-09 00:41:05 UTC

What is the point of PAX when a lot of high-risk programs (which Firefox undoubtedly is) have mprotect disabled by default?

Reproducible: Always

Steps to Reproduce:
1. paxctl-ng -M /usr/lib64/firefox/firefox 
2. $ firefox

Actual Results:  
Segmentation fault

Expected Results:  
Firefox sans JIT.

I've tried putting --disable-ion into the ebuild, but the build fails after trying to precompile startup cache. IonMonkey is Firefox's JIT compiler and according to https://wiki.mozilla.org/IonMonkey

I went digging and discovered that jit could be disabled in the old ebuilds (45* era). Why was this option removed?

Comment 1 Fedja Beader 2018-01-09 00:43:36 UTC

Created attachment 513846 [details, diff]
firefox-52.5.2.patch

Attempt #1 at turning off JIT.

Comment 2 Fedja Beader 2018-01-09 00:55:37 UTC

Cannot attach build log: "The file at https://bugs.gentoo.org/attachment.cgi is not readable.".

"... IonMonkey is Firefox's JIT compiler and according to https://wiki.mozilla.org/IonMonkey" --disable-ion disables it.

Comment 3 Jory A. Pratt gentoo-dev

2019-03-31 20:06:14 UTC

Please feel free to reopen and update any bug report that can be duplicated with current esr builds, 60.x. If you feel your feature needs to be re looked at in any of these bugs reopen and update, please attach patches when appropriate. Thank you Mozilla Team