638204 - Expose frame trust in stacks

Status: RESOLVED FIXED

(Socorro :: General, task)

Description

[Jeff Muizelaar [:jrmuizel]]

The breakpad stack walking code has the concept of how confident it is with the  current stack frame. It would be helpful when interpreting stacks if this was exposed on Socorro.

I expect that this should be done after bug 573100 is fixed.

Comment 1

[(no longer active)]

Does it also have alternate suggestions with less degrees of confidence?

Comment 2

[Jeff Muizelaar [:jrmuizel]]

(In reply to comment #1)
> Does it also have alternate suggestions with less degrees of confidence?

No, but that would be neat functionality to add. Currently we just unwalk each frame by trying the different methods in order of their reliability. It would be interesting to try a more global approach to avoid getting stuck on the wrong path and ending up in the weeds.

Comment 3

[(not currently active) Ted Mielczarek]

This will be trivial to add once bug 573100 is fixed. (In fact, this was one of the main things I wanted to expose by fixing that.)

Comment 4

[Benjamin Smedberg]

Ted said he'd take this soon. I asked not only for the stackwalk reason, but also whether, for each frame, we have the symbols for that frame or not. This will help with the reporting I'd like in bug 907312.

Comment 5

[(not currently active) Ted Mielczarek]

I'd like to split the symbol information out separately since that's a slightly different issue.

Comment 6

[(not currently active) Ted Mielczarek]

I have a patch, it will produce output like so:
         "frames" : [
            {
               "frame" : 0,
               "module" : "ntdll.dll",
               "module_offset" : "0xe514",
               "offset" : "0x7c90e514",
               "trust" : "context"
            },
            {
               "frame" : 1,
               "offset" : "0x4d9ffff",
               "trust" : "frame_pointer"
            },
            {
               "frame" : 2,
               "module" : "kernel32.dll",
               "module_offset" : "0xb9d6",
               "offset" : "0x7c80b9d6",
               "trust" : "scan"
            },

The possible values are "context", "cfi", "frame_pointer", "cfi_scan", "scan", "none".

Pull request coming up soon.

Comment 7

[(not currently active) Ted Mielczarek]

https://github.com/luser/socorro/commit/d7345d2a9335ef8da9c37aa88c8f1187f38ab028

Comment 8

[(not currently active) Ted Mielczarek]

Attachment: expose frame trust in stacks

Comment 9

[(not currently active) Ted Mielczarek]

I'll fix the symbol stuff in bug 431514.

Comment 10

[[github robot]]

Commit pushed to master at https://github.com/mozilla/socorro

https://github.com/mozilla/socorro/commit/d7345d2a9335ef8da9c37aa88c8f1187f38ab028
bug 638204 - expose frame trust in stacks

Comment 11

[(not currently active) Ted Mielczarek]

I'll file a followup on exposing this in the UI.

Comment 12

[(not currently active) Ted Mielczarek]

Filed bug 929095 on the UI.