746951 - Avoid inlining js::MarkRangeConservatively with AddressSanitizer builds

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Christian Holler (:decoder)]

The function js::MarkRangeConservatively is currently the only function in the JS garbage collector that produces a false positive when not blacklisted. The reason is that this function scans (and thereby touches) the stack, including the redzones that AddressSanitizer adds between stack variables. Therefore, this function has been blacklisted from the beginning, avoiding it to be instrumented at all.

However, there is a bug in how this blacklist works together with inlining: As soon as a blacklisted function is inlined, it is still instrumented because the inlining step happens before AddressSanitizer instruments the code. The best solution I can see right now is to forbid inlining this function when building with AddressSanitizer.

Therefore, I'll add a patch adds JS_NEVER_INLINE to the function when MOZ_ASAN is defined.

Comment 1

[Christian Holler (:decoder)]

Attachment: Patch

Comment 2

[Mozilla RelEng Bot]

Autoland Patchset:
	Patches: 616531
	Branch: mozilla-central => try
	Destination: http://hg.mozilla.org/try/pushloghtml?changeset=bceb471aa567
Try run started, revision bceb471aa567. To cancel or monitor the job, see: https://tbpl.mozilla.org/?tree=Try&rev=bceb471aa567

Comment 3

[Mozilla RelEng Bot]

Try run for bceb471aa567 is complete.
Detailed breakdown of the results available here:
    https://tbpl.mozilla.org/?tree=Try&rev=bceb471aa567
Results (out of 15 total builds):
    success: 15
Builds (or logs if builds failed) available at:
http://ftp.mozilla.org/pub/mozilla.org/firefox/try-builds/[e-mail]-bceb471aa567

Comment 4

[Christian Holler (:decoder)]

Comment on attachment 616531 [details] [diff] [review]
Patch

I'd like to order one landing, please :D

Comment 5

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

(In reply to Christian Holler (:decoder) from comment #4)
> Comment on attachment 616531 [details] [diff] [review]
> Patch
> 
> I'd like to order one landing, please :D

Approval is required even for mozilla-inbound now, till April 24. I could land on Birch without approval, but that will land only after April 24.

Please request for approval-mozilla-central? flag, and leave a comment with the reasons for your request.

ref https://wiki.mozilla.org/Tree_Rules#mozilla-central_.28Nightly_channel.29

Comment 6

[Christian Holler (:decoder)]

Comment on attachment 616531 [details] [diff] [review]
Patch

This change is not part of any build (a=npotb), as they are only active when compiling with ASan (AddressSanitizer).

Comment 7

[Alex Keybl [:akeybl]]

Comment on attachment 616531 [details] [diff] [review]
Patch

Sounds good, you can just land with a=npotb but I'll approve here anyway.

Comment 8

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

http://hg.mozilla.org/integration/mozilla-inbound/rev/ba03257fab28

Comment 9

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/ba03257fab28