Steps to build and get the core dump. CGO_CFLAGS="-g" go build -gcflags=all="-N -l" . ulimit -c unlimited echo "core" > /proc/sys/kernel/core_pattern export GOTRACEBACK=crash
test_cgo_panic-main# /root/go/bin/dlv core ./test core.1106319
(dlv) bt
0 0x0000000000460ec1 in runtime.raise
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/sys_linux_amd64.s:154
1 0x0000000000449865 in runtime.dieFromSignal
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/signal_unix.go:879
2 0x0000000000449e45 in runtime.sigfwdgo
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/signal_unix.go:1092
3 0x00000000004487c7 in runtime.sigtrampgo
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/signal_unix.go:432
4 0x0000000000461186 in runtime.sigtramp
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/sys_linux_amd64.s:352
5 0x0000153219292520 in ???
at ?:-1
6 0x0000000000449a78 in runtime.crash
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/signal_unix.go:971
7 0x0000000000434da5 in runtime.fatalpanic
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/panic.go:1168
8 0x00000000004344ec in runtime.gopanic
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/panic.go:987
9 0x00000000004642a7 in main.Test4
at ./export.go:8
10 0x000000000046431c in _cgoexp_209e16473f08_Test4
at _cgo_gotypes.go:61
11 0x000000000040535b in runtime.cgocallbackg1
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/cgocall.go:315
12 0x0000000000405079 in runtime.cgocallbackg
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/cgocall.go:234
13 0x0000000000461b0f in runtime.cgocallbackg
at <autogenerated>:1
14 0x000000000045f3f4 in runtime.cgocallback
at /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/asm_amd64.s:998
15 0x0000000000000001 in ???
15 0x0000000000000001 in ???
at ?:-1
16 0x000000c00003e000 in ???
at ?:-1
error: error while reading spliced memory at 0x8: EOF
(truncated)
Line which is causing the issue is clear from the following runtime debugging using dlv.
test_cgo_panic-main# /root/go/bin/dlv exec ./test
(dlv) break runtime.unwindm
Breakpoint 1 set at 0x4054e6 for runtime.unwindm() /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/cgocall.go:326
(dlv) c
> runtime.unwindm() /home/soomohan/mbalraj/GO/go1.20.2/go/src/runtime/cgocall.go:326 (hits goroutine(1):1 total:1) (PC: 0x4054e6)
Warning: debugging optimized function
321: // Do not unwind m->g0->sched.sp.
322: // Our caller, cgocallback, will do that.
323: restore = false
324: }
325:
=> 326: func unwindm(restore *bool) {
327: if *restore {
328: // Restore sp saved by cgocallback during
329: // unwind of g's stack (see comment at top of file).
330: mp := acquirem()
331: sched := &mp.g0.sched
(dlv) n
(dlv) n
(dlv) n
(dlv) p %x mp.g0.sched.sp
7ffcc23bda48
(dlv) n
(dlv) p %x mp.g0.sched.sp
7ffcc23bdbb8
Go environment
root@soomohan:/home/soomohan/mbalraj/test_hb2# go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/root/.cache/go-build"
GOENV="/root/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/root/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/root/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/soomohan/mbalraj/GO/go1.20.2/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/soomohan/mbalraj/GO/go1.20.2/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.20.2"
GCCGO="/usr/bin/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-build3821222181=/tmp/go-build -gno-record-gcc"