687672 - [SkipList]Add fastcopy_I to prefix skiplist

Status: RESOLVED FIXED

(Socorro :: Infra, task)

Description

[Gregory Szorc [:gps]]

'fastcopy_I' is part of the implementation of memcpy, realloc, etc in msvcrXX.dll on Windows. It doesn't really add any value to stack traces since it isn't a public API, so it should probably be skipped from the frame list entirely.

The callers of fastcopy_I should be preserved in the frame list, however, as errors could be the result of a heap corruption that the calling frame has nothing to do with.

An example crash report with fastcopy_I at the top of the stack is https://crash-stats.mozilla.com/report/index/5c3c3f81-23fb-4a6e-a032-ba6b22110919.

Comment 1

[Laura Thomson :laura]

All of the memcpy type functions are right now in the prefix list rather than the irrelevant list - just want to confirm which of those you want, since it sounds like you want to add this one to the irrelevant list.

See definitions here:
https://wiki.mozilla.org/Breakpad/Skip_List_How_To

Comment 2

[Gregory Szorc [:gps]]

fastcopy_I is a private function in Microsoft's implementation of memory allocation functions. It will always be called by a public API, like memcpy, realloc, memmove, etc. I would think it would be safe to hide. But, being able to search on this symbol might be a good way to aggregate all the memory-related/heap-corruption bugs on Windows. So maybe it is best to move to the prefix list.


I'll defer to people with more experience.

Comment 3

[Laura Thomson :laura]

Waiting on info to implement.

Comment 4

[Laura Thomson :laura]

Kairo asked me to do this today, so without more input from anyone, I'm adding it to the prefix list.

Comment 5

[Laura Thomson :laura]

In https://github.com/mozilla/socorro/pull/377

Comment 6

[[github robot]]

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

https://github.com/mozilla/socorro/commit/6d551c0a63f04f58e7212a451d0fab2495426e60
Fixes bug 687672, add fastcopy_I to the prefix skiplist