runtime: occasional "exit status 0xc0000005" on windows-386-2012 builder

[dmitshur]

#!watchflakes
post <- pkg == "runtime" && goos == "windows" && goarch == "386" && `exit status 0xc0000005`

Observed once in a TryBot run on CL 420675:

exit status 0xc0000005
FAIL	runtime	18.548s

(https://storage.googleapis.com/go-build-log/1d5e997e/windows-386-2012_858cca10.log)

Searching around doesn't find this particular exit code, though there are similar ones like in issue #41450. That exit code seems to be a pretty generic "Application Error" failure, so given the rare occurrence maybe there's not much that can be done.

CC @golang/runtime.

[mknyszek]

I think that error code is specifically a segfault, likely an unrecoverable one (maybe in the win32 libraries or something). We should look into this. How rare is the failure? Is this the only one?

[dmitshur]

It's the only one I've seen so far; we can try greplogs or similar tools to look if there've been more.

[prattmic]

2022-04-25T22:33:21-22a00f2/windows-amd64-longtest

This is a failure similar to #52647. I'm not sure if it is related to this.

[mvdan]

Also on https://storage.googleapis.com/go-build-log/4f5c3361/windows-386-2012_1b7a5237.log for https://go-review.googlesource.com/c/go/+/412555, a small change in go/printer:

            > go list -deps -f '{{.Module}}' ./subpkg
            [exit status 0xc0000005]
            FAIL: testdata\script\mod_symlink.txt:10: unexpected command failure

[prattmic]

Got on https://go.dev/cl/470875

https://storage.googleapis.com/go-build-log/57637523/windows-386-2012_0426fd63.log

ok  	reflect	0.220s
ok  	regexp	0.550s
ok  	regexp/syntax	0.887s
exit status 0xc0000005
FAIL	runtime	23.620s
FAIL
go tool dist: Failed: exit status 1

[gopherbot]

Change https://go.dev/cl/510755 mentions this issue: runtime: ensure stack is aligned in _rt0_amd64_windows_lib

[qmuntal]

I've submitted CL 510755 to fix a failure more which I'm pretty sure is very related to this issue. I just fix crashes in Go DLLs, haven't had time to investigate if the stack alignment issue also happens in Go PIE binaries.

The SEH and frame pointer passing work done in Go 1.21 might cause this issue to happen more frequently. IMO we should merge CL 510755 into Go 1.21.