runtime: segmentation violation while adjusting stack pointer

[WAY29]

What version of Go are you using (go version)?

$ go version
go version go1.20.6 linux/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/root/.cache/go-build"
GOENV="/root/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/root/coding/golang/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/root/coding/golang"
GOPRIVATE=""
GOPROXY="https://goproxy.cn,direct"
GOROOT="/root/.go/go1.20.6"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/root/.go/go1.20.6/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.20.6"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/dev/null"
GOWORK=""
CGO_CFLAGS="-O2 -g"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-O2 -g"
CGO_FFLAGS="-O2 -g"
CGO_LDFLAGS="-O2 -g"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build649550129=/tmp/go-build -gno-record-gcc-switches"

What did you do?

When I attempt to debug my project in VS Code by connecting to WSL2 using remote-wsl, I encounter a fatal error. The error occurs with a high probability, but it is not guaranteed to happen every time.

What did you expect to see?

Debug normally

What did you see instead?

"unexpected signal during runtime execution"
Stack:
	0  0x0000000000448720 in runtime.throw
	    at /root/.go/go1.20.6/src/runtime/panic.go:1040
	1  0x0000000000460865 in runtime.sigpanic
	    at /root/.go/go1.20.6/src/runtime/signal_unix.go:825
	2  0x000000000042c010 in runtime.scanstack
	    at /root/.go/go1.20.6/src/runtime/mgcmark.go:810
	3  0x000000000042acc5 in runtime.markroot.func1
	    at /root/.go/go1.20.6/src/runtime/mgcmark.go:239
	4  0x000000000042a979 in runtime.markroot
	    at /root/.go/go1.20.6/src/runtime/mgcmark.go:213
	5  0x000000000042cab8 in runtime.gcDrain
	    at /root/.go/go1.20.6/src/runtime/mgcmark.go:1069
	6  0x0000000000428aed in runtime.gcBgMarkWorker.func2
	    at /root/.go/go1.20.6/src/runtime/mgc.go:1367
	7  0x000000000047e409 in runtime.systemstack
	    at /root/.go/go1.20.6/src/runtime/asm_amd64.s:496
	8  0x00007f6b2bffe9ff in ???
	    at ?:-1
	    error: input/output error
	(truncated)

[dr2chase]

@golang/tools-team

Pinging @qmuntal in case this rings any Windows bells.

[qmuntal]

I'll need more information to reproduce this issue. Are you using Delve? If so, which version? Can you share a reproducer and some instructions to get to the fatal error?

Thanks.

[WAY29]

I'll need more information to reproduce this issue. Are you using Delve? If so, which version? Can you share a reproducer and some instructions to get to the fatal error?

Thanks.

❯ dlv version
Delve Debugger
Version: 1.21.0
Build: $Id: fec0d226b2c2cce1567d5f59169660cf61dc1efe $

I just debug program in vscode use debug test button, and fatal error occurs randomly, the command vscode run is:dlv dap --listen=127.0.0.1:41301 --log-dest=3 from /src/yaklang/common/yak/yaktest/mustpass

[qmuntal]

Thanks @WAY29.

I manage to reproduce the unexpected signal during runtime execution, although with a different call stack (see below).

It looks like an issue in the Go runtime, I don't see how it can be related to running on WSL, and definitely not a Delve remote debugging issue, as running the test by hand also throws.

More info:

• It also fails with go1.20rc4.
• It fails when running go test -gcflags="all=-N -l" -v ./common/yak/yaktest/mustpass, rooted at https://github.com/yaklang/yaklang.
• It doesn't fail if -gcflags is not set.

[signal SIGSEGV: segmentation violation code=0x80 addr=0x0 pc=0x462be0]

runtime stack:
runtime.throw({0x31cf13d?, 0x416f99?})
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/panic.go:1047 +0x5d fp=0x7f226cad9850 sp=0x7f226cad9820 pc=0x44869d
runtime.sigpanic()
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/signal_unix.go:825 +0x285 fp=0x7f226cad9880 sp=0x7f226cad9850 pc=0x460785
runtime.adjustpointer(0x463245?, 0x12f?)
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/stack.go:573 fp=0x7f226cad9888 sp=0x7f226cad9880 pc=0x462be0
runtime.adjustdefers(0xc0000061a0, 0xc08?)
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/stack.go:765 +0x58 fp=0x7f226cad98b8 sp=0x7f226cad9888 pc=0x4632d8
runtime.copystack(0xc0000061a0, 0x10000)
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/stack.go:921 +0x209 fp=0x7f226cad9a70 sp=0x7f226cad98b8 pc=0x463829
runtime.shrinkstack(0xc0000061a0)
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/stack.go:1216 +0x134 fp=0x7f226cad9a98 sp=0x7f226cad9a70 pc=0x464814
runtime.scanstack(0xc0000061a0, 0xc00006d238)
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/mgcmark.go:775 +0x10b fp=0x7f226cad9cb8 sp=0x7f226cad9a98 pc=0x42bd4b
runtime.markroot.func1()
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/mgcmark.go:239 +0xc5 fp=0x7f226cad9d08 sp=0x7f226cad9cb8 pc=0x42abe5
runtime.markroot(0xc00006d238, 0x3a, 0x1)
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/mgcmark.go:213 +0x199 fp=0x7f226cad9da8 sp=0x7f226cad9d08 pc=0x42a899
runtime.gcDrain(0xc00006d238, 0x3)
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/mgcmark.go:1069 +0x378 fp=0x7f226cad9e00 sp=0x7f226cad9da8 pc=0x42c9d8
runtime.gcBgMarkWorker.func2()
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/mgc.go:1348 +0xa5 fp=0x7f226cad9e50 sp=0x7f226cad9e00 pc=0x428a45
runtime.systemstack()
	/home/qmuntaldiaz/sdk/go1.20.7/src/runtime/asm_amd64.s:496 +0x49 fp=0x7f226cad9e58 sp=0x7f226cad9e50 pc=0x47e1e9

@golang/runtime

[dr2chase]

There's a lot of what I'd call gratuitous unsafe code in there.

If it were me, I would take all the little unsafe-using functions, write less-efficient safe versions of the same, and put them under a build tag to allow testing with all the unsafe code avoided. Otherwise, my default assumption is you accidentally broke a runtime rule (they can be subtle) in unsafe code.

The sort of short functions I'd expect to see from this would all inline trivially, and thus cost nothing.