1280266 - Netmonitor JS stack traces shouldn't include chrome frames

Status: NEW

(DevTools :: Netmonitor, defect, P2)

Description

[Jarda Snajdr [:jsnajdr]]

Requests JS stack traces in Netmonitor sometimes show chrome:// stack frames. This is confusing for users - they should only see the JS code from the page content.

The chrome:// frames should be shown only in browser toolbox.

Two examples of this behavior:

1) When the page is reloaded, the main document request shows stack trace from the browser calling into webNav.reload at chrome://browser/content/tab-content.js:73

2) When issuing a request from the console (i.e., type "fetch('x')"), the request stack trace contains frames like:

WCA_evalWithDebugger resource://devtools/server/actors/webconsole.js:1299

Comment 1

[Jarda Snajdr [:jsnajdr]]

One way how to implement this: when calling "components.stack", it eventually calls GetFirstSubsumedFrame at [1], which filters the frames by the current JSContext's principal. When called from network-monitor.js (at [2]), it's the system principal. It would help if we could somehow pass the content principal there instead.

Nick, do you have any advice?

[1] https://dxr.mozilla.org/mozilla-central/source/js/src/vm/SavedStacks.cpp#556
[2] https://dxr.mozilla.org/mozilla-central/source/devtools/shared/webconsole/network-monitor.js#220

Comment 2

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

https://github.com/fitzgen/gecko-dev/blob/master/js/src/doc/SavedFrame/SavedFrame.md has the documentation you're looking for.

Basically, Cu.waiveXrays(stack) will give you the content's view of the stack.

Comment 3

[Emma Humphries ☕️🎸🧞‍♀️✨ (she/they) [:emceeaich] (Pacific Time) use needinfo]

This is an assigned P1 bug without activity in two weeks. 

If you intend to continue working on this bug for the current release/iteration/sprint, remove the 'stale-bug' keyword.

Otherwise we'll reset the priority of the bug back to '--' on Monday, August 28th.

Comment 4

[:Harald Kirschner :digitarald]

This seems to be fixed, probably by bug 1392411. Re-open if chrome stacks still appear.

Comment 5

[Sebastian Zartner [:sebo]]

Sorry, not fixed yet!

STR:

1. Open the Network panel on this page
2. Reload the page
3. Click the request for the document
4. Switch to the Stack Trace tab

You'll see something like this:

receiveMessage/< resource:///actors/BrowserTabChild.jsm:98:26
wrapHandlingUserInput resource://gre/modules/E10SUtils.jsm:837:7
receiveMessage resource:///actors/BrowserTabChild.jsm:95:21

I've tested this in Nightly 72.0a1 (2019-11-04).

In the case of a user initiated request or one only containing stack frames of chrome scripts, I would expect the Stack Trace tab not to be displayed at all.
Having said that, in the Browser Toolbox this info might still be useful.

Sebastian

Comment 6

[Jan Honza Odvarko [:Honza] (always need-info? me)]

I can reproduce the problem on my machine too (Win10, Nightly).

@Brian, could you please look at this.

Thanks,
Honza

Comment 7

[:Harald Kirschner :digitarald]

Honza, Initiator column will put this front and center. For the non-browser-toolbox case, could we test if a stack looks internal and discard it if it does?

Comment 8

[Jan Honza Odvarko [:Honza] (always need-info? me)]

I am no longer able to reproduce the problem using STR from comment #5 (there is no Stack Trace tab).
Sebastian, can you?

Honza

Comment 9

[:Harald Kirschner :digitarald]

Still occurs for me.

Load https://platform-status.mozilla.org/. For https://platform-status.mozilla.org/images/favicon.ico I get:

load
resource:///modules/FaviconLoader.jsm:165:20
load
resource:///modules/FaviconLoader.jsm:557:70
loadIcons
resource:///modules/FaviconLoader.jsm:633:26
onPageShow
resource:///modules/FaviconLoader.jsm:670:12
onHeadParsed
resource:///actors/LinkHandlerChild.jsm:60:24
handleEvent
resource:///actors/LinkHandlerChild.jsm:175:21

Comment 10

[Sebastian Zartner [:sebo]]

For reference, the Stack Trace tab is not shown for the main document request anymore since bug 1595637 got fixed (according to moz-regression).

But, as Harald already pointed out, the issue can still be reproduced on other requests.

In the case of a user initiated request or one only containing stack frames of chrome scripts, I would expect the Stack Trace tab not to be displayed at all.
Having said that, in the Browser Toolbox this info might still be useful.

Actually, I believe displaying chrome frames should depend on the option Show Gecko platform data, which obviously got introduced for the JS Profiler, though also fits for this case, in my opinion.

Sebastian

Comment 11

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Thanks!

Some pointers to the code base:

1. The Stack Trace panel is rendered here:
   https://searchfox.org/mozilla-central/rev/96f1457323cc598a36f5701f8e67aedaf97acfcf/devtools/client/netmonitor/src/components/StackTracePanel.js#67

2. It's using StackTrace component that is implemented here
   https://searchfox.org/mozilla-central/rev/96f1457323cc598a36f5701f8e67aedaf97acfcf/devtools/client/shared/components/StackTrace.js#37

3. The stack-trace is collected on the backend here
   https://searchfox.org/mozilla-central/rev/96f1457323cc598a36f5701f8e67aedaf97acfcf/devtools/server/actors/network-monitor/stack-trace-collector.js#114

4. We could peel off the chrome frame on the backend to safe a bit on RDP traffic but, also depends whether we want to support that Show Gecko platform data pref.

Here is an existing helper implemented for the Console panel. It isn't handling all of the chrome frames but, could be adapted:
https://searchfox.org/mozilla-central/rev/96f1457323cc598a36f5701f8e67aedaf97acfcf/devtools/server/actors/webconsole/utils.js#173-214

@Nicolas: can you provide some info about how the helper could be improved?

Honza

Comment 12

[Nicolas Chevobbe [:nchevobbe]]

I think we could have another helper, which would do a similar job, but that would filter out all the frames that starts with resource:// or chrome:// ? (maybe we should be more thoughtful on this for webextension? not sure

Comment 13

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Thanks Nicolas!
Honza

Comment 14

[manas]

Should the helper function be implemented in the StackTrace class or in StackTraceCollector itself?

Comment 15

[Jan Honza Odvarko [:Honza] (always need-info? me)]

We should peel off the chrome frames directly in the StackTraceCollector (and send to the client only what's needed) but, want tot keep these frames within the Browser Toolbox Network panel. Nicolas, do we have a way to check out whether the Network panel (and it's backend) is instantiated in the regular or Browser Toolbox?

Honza

Comment 16

[Maria Ortiz [ :marylicious ]]

Is someone working on this bug? I want to try it

Comment 17

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Assigned to you, thanks for the help!

Honza

Comment 18

[Nicolas Chevobbe [:nchevobbe]]

(In reply to Jan Honza Odvarko [:Honza] (always need-info? me) from comment #15)

We should peel off the chrome frames directly in the StackTraceCollector (and send to the client only what's needed) but, want tot keep these frames within the Browser Toolbox Network panel. Nicolas, do we have a way to check out whether the Network panel (and it's backend) is instantiated in the regular or Browser Toolbox?

We have this function on the toolbox devtools/client/framework/toolbox.js#606-608

Comment 19

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Hi Maria, are you still interested in fixing this bug?
Is there anything we can help with?

Honza

Comment 20

[Maria Ortiz [ :marylicious ]]

Attachment: Bug 1280266 - adding a filter for chrome frames on stacktrace panel

Comment 21

[Jan Honza Odvarko [:Honza] (always need-info? me)]

See also bug 1640371, should we fix both by one patch?

Honza

Comment 22

[Maria Ortiz [ :marylicious ]]

ok, I will check it out

Comment 24

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Another nice test case that shows the problem if HTTP request for fav-icon. It's done by the browser (not by the page) and the stack trace points to resource:// modules.

Honza

Comment 25

[BugBot [:suhaib / :marco/ :calixte]]

This good-first-bug hasn't had any activity for 6 months, it is automatically unassigned.
For more information, please visit auto_nag documentation.

Comment 26

[Riz]

Hi, I can reproduce this problem when looking at the stack trace of an HTTP request to https://www.google.com/favicon.ico .

My User-Agent when reproducing this bug is: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Firefox/138.0

Can you assign this bug to me please?

Comment 27

[Riz]

Hi, I've started looking in to this. I can't find an identifier called StackTraceCollector in the codebase (as per comment #15).

I can see how this helper could be repurposed to filter out the frames that start with resource://, chrome:// and webextension:// (should we filter out webextension:// too?) , and am trying to figure out how to ensure that it does so for the Network panel in the regular browser, but not in the Browser Toolbox.

Do I need to find the StackTraceCollector identifier and then peel the chrome frames directly in StackTraceCollector (as per comment #15)?

I think the codebase has changed significantly since the above comments were posted, so this insight might now be out of date.

Thanks

Comment 28

[Hubert Boma Manilla (:bomsy)]

Thanks Riz for the interest in working on this.
I'll assign to you.

The stacktraces are created and sent for network panel in https://searchfox.org/mozilla-central/rev/578d9c83f046d8c361ac6b98b297c27990d468fd/devtools/server/actors/resources/network-events-stacktraces.js#192-199. I think you might be able to filter out the chrome requests before this.onStackTraceAvailable is called.

For distinguishing the browser toolbox you could probably use this.watcherActor.sessionContext.type == "all" as in https://searchfox.org/mozilla-central/rev/578d9c83f046d8c361ac6b98b297c27990d468fd/devtools/server/actors/resources/network-events.js#255

Hope this helps!

Comment 29

[Riz]

Thank you Hubert

Comment 30

[Riz]

Hi Hubert, I added a console.log() statement to the first line of this method for my testing and local development, and it is barely ever invoked when I run my test case in the Nightly browser. My test case for this patch is to navigate to google.com and then look at the stacktrace of the favicon request in the Network tab of the browser inspector.

But despite the chrome frames always appearing in the stacktrace of the request, in the Network tab (and so the stacktrace always being generated), the console.log('stacktrace: ', stacktrace); call that I added, on the first line of _setStackTrace(), isn't always invoked when I navigate to google.com. In fact it is hardly ever invoked.

I could be missing something here about when/how it is invoked, and if so then this is likely because I am new to the codebase.

For me to write a helper function that successfully filters out the chrome frames from the stacktrace, I need to verify that it works by logging output. And that doesn't seem to be possible because this method doesn't seem to be called.

Comment 31

[Hubert Boma Manilla (:bomsy)]

(In reply to Riz from comment #30)

Hi Hubert, I added a console.log() statement to the first line of this method for my testing and local development, and it is barely ever invoked when I run my test case in the Nightly browser. My test case for this patch is to navigate to google.com and then look at the stacktrace of the favicon request in the Network tab of the browser inspector.

But despite the chrome frames always appearing in the stacktrace of the request, in the Network tab (and so the stacktrace always being generated), the console.log('stacktrace: ', stacktrace); call that I added, on the first line of _setStackTrace(), isn't always invoked when I navigate to google.com. In fact it is hardly ever invoked.

I could be missing something here about when/how it is invoked, and if so then this is likely because I am new to the codebase.

For me to write a helper function that successfully filters out the chrome frames from the stacktrace, I need to verify that it works by logging output. And that doesn't seem to be possible because this method doesn't seem to be called.

console.log won't work as this is devtools server code. Try using dump instead like this dump("the msg to log \n"). Also see https://searchfox.org/mozilla-central/search?q=dump%28&path=&case=false&regexp=false

Comment 32

[Riz]

Hi, that doesn't work either. I can't see any output as a result of invoking dump() on the first line of _setStackTrace.

I have recorded a demo and uploaded it to YouTube so you can take a look at the output in the console as I navigate to google.com in Nightly: https://www.youtube.com/watch?v=s7fd0_oaGgs

Comment 33

[Hubert Boma Manilla (:bomsy)]

(In reply to Riz from comment #32)

Hi, that doesn't work either. I can't see any output as a result of invoking dump() on the first line of _setStackTrace.

I have recorded a demo and uploaded it to YouTube so you can take a look at the output in the console as I navigate to google.com in Nightly: https://www.youtube.com/watch?v=s7fd0_oaGgs

Thanks for the video.

That's odd! Did you build i.e ./mach build after adding the dump statement?

Comment 34

[Riz]

Hi, I did build (i.e ./mach build) after adding the dump statement, but didn't record myself doing so because I didn't want the video to be longer than it needed to be.

I can record the video again in doing so record the ./mach build process in Powershell if you want.

Comment 35

[Riz]

I can record the video again** and, in doing so,** record the ./mach build process in Powershell if you want. *