Geoff Brown [:gbrown] Reporter
	Description • 6 years ago

+++ This bug was initially created as a clone of Bug #1389805 +++

In bug 1389805 we saw no symbols in Android xpcshell crash reports and addressed that with 'elfhack -r'; that is no longer working.

https://treeherder.mozilla.org/logviewer.html#?job_id=206214577&repo=try&lineNumber=1756

[task 2018-10-17T20:53:21.173Z] 20:53:21     INFO -   0  libxul.so + 0x282082
[task 2018-10-17T20:53:21.174Z] 20:53:21     INFO -       r0 = 0x00000180    r1 = 0x42e6ee40    r2 = 0x00000000    r3 = 0x00000000
[task 2018-10-17T20:53:21.174Z] 20:53:21     INFO -       r4 = 0x4581d800    r5 = 0x00000000    r6 = 0x00020001    r7 = 0xbec27930
[task 2018-10-17T20:53:21.175Z] 20:53:21     INFO -       r8 = 0x00000000    r9 = 0x5103c450   r10 = 0x00000000   r12 = 0x00000000
[task 2018-10-17T20:53:21.175Z] 20:53:21     INFO -       fp = 0x458d8200    sp = 0xbec27918    lr = 0x00000000    pc = 0x40922082
[task 2018-10-17T20:53:21.176Z] 20:53:21     INFO -      Found by: given as instruction pointer in context
[task 2018-10-17T20:53:21.176Z] 20:53:21     INFO -   1  libxul.so + 0x24bba5
[task 2018-10-17T20:53:21.177Z] 20:53:21     INFO -       sp = 0xbec27938    pc = 0x408ebba7
[task 2018-10-17T20:53:21.177Z] 20:53:21     INFO -      Found by: stack scanning
[task 2018-10-17T20:53:21.178Z] 20:53:21     INFO -   2  libxul.so + 0x24bb1f
[task 2018-10-17T20:53:21.178Z] 20:53:21     INFO -       sp = 0xbec2796c    pc = 0x408ebb21
[task 2018-10-17T20:53:21.179Z] 20:53:21     INFO -      Found by: stack scanning

	Geoff Brown [:gbrown] Reporter
	Comment 1 • 6 years ago

We run elfhack just before pushing, so these "Not elfhacked" messages are likely coming from elfhack:

https://treeherder.mozilla.org/logviewer.html#?job_id=206214577&repo=try&lineNumber=1289

[task 2018-10-17T20:46:28.210Z] 20:46:28     INFO -  Pushing assets/armeabi-v7a/libfreebl3.so..
[task 2018-10-17T20:46:28.230Z] 20:46:28     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/libfreebl3.so: Not elfhacked. Skipping
[task 2018-10-17T20:46:28.536Z] 20:46:28     INFO -  Pushing assets/armeabi-v7a/liblgpllibs.so..
[task 2018-10-17T20:46:28.544Z] 20:46:28     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/liblgpllibs.so: Not elfhacked. Skipping
[task 2018-10-17T20:46:28.751Z] 20:46:28     INFO -  Pushing assets/armeabi-v7a/libmozavcodec.so..
[task 2018-10-17T20:46:28.762Z] 20:46:28     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/libmozavcodec.so: .elfhack.data.v0 and .elfhack.text.v0 not in the same segment. Skipping
[task 2018-10-17T20:46:28.969Z] 20:46:28     INFO -  Pushing assets/armeabi-v7a/libmozavutil.so..
[task 2018-10-17T20:46:28.981Z] 20:46:28     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/libmozavutil.so: Not elfhacked. Skipping
[task 2018-10-17T20:46:29.187Z] 20:46:29     INFO -  Pushing assets/armeabi-v7a/libnss3.so..
[task 2018-10-17T20:46:29.253Z] 20:46:29     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/libnss3.so: .elfhack.data.v0 and .elfhack.text.v0 not in the same segment. Skipping
[task 2018-10-17T20:46:29.860Z] 20:46:29     INFO -  Pushing assets/armeabi-v7a/libnssckbi.so..
[task 2018-10-17T20:46:29.881Z] 20:46:29     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/libnssckbi.so: Not elfhacked. Skipping
[task 2018-10-17T20:46:30.188Z] 20:46:30     INFO -  Pushing assets/armeabi-v7a/libsoftokn3.so..
[task 2018-10-17T20:46:30.201Z] 20:46:30     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/libsoftokn3.so: Not elfhacked. Skipping
[task 2018-10-17T20:46:30.407Z] 20:46:30     INFO -  Pushing assets/armeabi-v7a/libxul.so..
[task 2018-10-17T20:46:32.444Z] 20:46:32     INFO -  /tmp/tmp6Wf7nr/assets/armeabi-v7a/libxul.so: .elfhack.data.v0 and .elfhack.text.v0 not in the same segment. Skipping
[task 2018-10-17T20:46:56.902Z] 20:46:56     INFO -  Pushing lib/armeabi-v7a/libmozglue.so..
[task 2018-10-17T20:46:57.621Z] 20:46:57     INFO -  Pushing lib/armeabi-v7a/libplugin-container.so..

	Mike Hommey [:glandium] Assignee
	Comment 2 • 6 years ago

This effectively backs out bug 822584, which worked around a similar
problem to what we are facing with Android xpcshell, being that the
crash reporter doesn't handle the address space "fragmentation" induced
by elfhack. The work around worked, at the expense of some added
complexity.

It was used for B2G only, and has effectively been unused since B2G was
retired.

	Mike Hommey [:glandium] Assignee
	Comment 3 • 6 years ago

This is some sort of followup to bug 1423813, providing a minimalistic
way to undo elfhack when the elfhack sections are in separate segments,
which has been the case since bug 1385783 but didn't cause problems
on Android builds until bug 1423822.

Depends on D9622

	Mike Hommey [:glandium] Assignee
	Comment 4 • 6 years ago

Android xpcshell tests run `elfhack -r`, and do so by using an
elfhack binary from an archive downloaded via tooltool (which contains
other things).

Instead, we just put the elfhack binary in the
target.common.tests.tar.gz archive, and make the xpcshell harness
use it from there instead, allowing to pick in-tree changes to elfhack.

Depends on D9623

	Pulsebot
	Comment 5 • 6 years ago

Pushed by mh@glandium.org:
https://hg.mozilla.org/integration/autoland/rev/0988f87f6bd2
Remove support for the elfhack filler segment r=froydnj
https://hg.mozilla.org/integration/autoland/rev/550a527e90ee
Support undoing elfhack when the elfhacked sections are in separate segments r=froydnj
https://hg.mozilla.org/integration/autoland/rev/fbe393405a4a
Use elfhack from the build for Android xpcshell tests r=froydnj

	Raul Gurzau (:RaulG)
	Comment 6 • 6 years ago
bugherder

https://hg.mozilla.org/mozilla-central/rev/0988f87f6bd2
https://hg.mozilla.org/mozilla-central/rev/550a527e90ee
https://hg.mozilla.org/mozilla-central/rev/fbe393405a4a

	Ryan VanderMeulen [:RyanVM]
	Comment 7 • 6 years ago

Is this low-enough risk to consider uplifting to Beta? If so, please nominate.

	Mike Hommey [:glandium] Assignee
	Comment 8 • 6 years ago

Comment on attachment 9019583 [details]
Bug 1499915 - Remove support for the elfhack filler segment

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: Bug 1423822

User impact if declined: Automation doesn't get symbolication on xpcshell crashes

Is this code covered by automated tests?: Yes

Has the fix been verified in Nightly?: Yes

Needs manual test from QE?: No

If yes, steps to reproduce: 

List of other uplifts needed: None

Risk to taking this patch: Low

Why is the change risky/not risky? (and alternatives if risky): This patch removes support for an unused flag of elfhack.

String changes made/needed: N/A

	Mike Hommey [:glandium] Assignee
	Comment 9 • 6 years ago

Comment on attachment 9019584 [details]
Bug 1499915 - Support undoing elfhack when the elfhacked sections are in separate segments

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: Bug 1423822

User impact if declined: Automation doesn't get symbolication on xpcshell crashes

Is this code covered by automated tests?: Yes

Has the fix been verified in Nightly?: Yes

Needs manual test from QE?: No

If yes, steps to reproduce: 

List of other uplifts needed: None

Risk to taking this patch: Low

Why is the change risky/not risky? (and alternatives if risky): This changes a code path that is only exercised when running xpcshell tests.

String changes made/needed: N/A

	Mike Hommey [:glandium] Assignee
	Comment 10 • 6 years ago

Comment on attachment 9019585 [details]
Bug 1499915 - Use elfhack from the build for Android xpcshell tests

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: Bug 1423822

User impact if declined: Automation doesn't get symbolication on xpcshell crashes

Is this code covered by automated tests?: Yes

Has the fix been verified in Nightly?: Yes

Needs manual test from QE?: No

If yes, steps to reproduce: 

List of other uplifts needed: None

Risk to taking this patch: Low

Why is the change risky/not risky? (and alternatives if risky): This makes Android xcpshell tests use elfhack from the Android build rather than one that was built n months ago.

String changes made/needed:

	Ryan VanderMeulen [:RyanVM]
	Comment 11 • 6 years ago

Comment on attachment 9019583 [details]
Bug 1499915 - Remove support for the elfhack filler segment

[Triage Comment]
Allows us to get usable stacks from Android xpcshell crashes in automation. Approved for 64.0b6.

	Eliza Balazs [:ebalazs_]
	Comment 12 • 6 years ago
bugherder uplift

https://hg.mozilla.org/releases/mozilla-beta/rev/14271099afeb
https://hg.mozilla.org/releases/mozilla-beta/rev/67e9cba72b9a
https://hg.mozilla.org/releases/mozilla-beta/rev/3fcac75fdb78