runtime: darwin using -buildmode=c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a #40131

wangzz719 · 2020-07-09T09:51:50Z

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

$ go version
go version go1.14.4 darwin/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=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/wangzhizhao/Library/Caches/go-build"
GOENV="/Users/wangzhizhao/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GONOPROXY="*.byted.org,*.everphoto.cn"
GONOSUMDB="*.byted.org,*.everphoto.cn"
GOOS="darwin"
GOPATH="/Users/wangzhizhao/go"
GOPRIVATE="*.byted.org,*.everphoto.cn"
GOPROXY="https://go-mod-proxy.byted.org,https://goproxy.cn,https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.google.cn"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/wangzhizhao/go/src/goscripts/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/c5/gc9h916j1578f82zvg1hgxf40000gp/T/go-build852002820=/tmp/go-build -gno-record-gcc-switches -fno-common"

uname -a Output

$uname -a
Darwin wangzhizhaodeMacBook-Pro.local 18.7.0 Darwin Kernel Version 18.7.0: Mon Apr 27 20:09:39 PDT 2020; root:xnu-4903.278.35~1/RELEASE_X86_64 x86_64

What did you do?

source code is the following two files:
verify.go

package main

// #include <stdlib.h>
import "C"

import (
	"encoding/hex"
	"strings"

	"verify/sec"
)

//export Verify
func Verify(serviceNameC *C.char, keyC *C.char) *C.char {
	serviceName := C.GoString(serviceNameC)

	key := []byte(C.GoString(keyC))
	sec.InitWithKey(key)

	res := "res"
	return C.CString(strings.Join([]string{serviceName, res, hex.EncodeToString(key)}, "-"))
}

func main() {

}

sec/key.go

package sec

import (
	"encoding/hex"
	"fmt"
)

var CryptoKey []byte

func InitWithKey(key []byte) {
	CryptoKey = key
	fmt.Println(hex.EncodeToString(key))
}

go build genrate c-shared .so
go build -buildmode=c-shared -a -o libverify.so verify.go
using libverify.so

package main

// #cgo LDFLAGS: -lverify
// #include </usr/local/lib/verify.h>
import "C"
import (
	"fmt"
	"unsafe"
)

func freeCString(cString *C.char) {
	C.free(unsafe.Pointer(cString))
}

func Init(serviceName string) {
	cServiceName := C.CString(serviceName)
	defer freeCString(cServiceName)
	key := C.CString("test")
	defer freeCString(key)

	cRes := C.Verify(cServiceName, key)
	defer freeCString(cRes)

	fmt.Println(C.GoString(cRes))
}

func main() {
	Init("my-service")
}

What did you expect to see?

no panic, and print out a string.

What did you see instead?

fatal error: unexpected signal during runtime execution
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x41e745a]

goroutine 1 [running, locked to thread]:
runtime.throw(0x40d653d, 0x2a)
	/usr/local/go/src/runtime/panic.go:1116 +0x72 fp=0xc0000439b0 sp=0xc000043980 pc=0x4030dd2
runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a
stack: frame={sp:0xc0000439b0, fp:0xc0000439e0} stack=[0xc000043000,0xc000044000)
000000c0000438b0:  0000000000000000  0000000000000000
000000c0000438c0:  0000000000000000  0000000000000000
000000c0000438d0:  0000000000000000  0000000000000000
000000c0000438e0:  0000000000000000  0000000000000000
000000c0000438f0:  0000000000000000  0000000000000000
000000c000043900:  0000000000000000  0000000000000000
000000c000043910:  0000000000000000  0000000000000000
000000c000043920:  0000000000000000  0000000000000000
000000c000043930:  0000000000000000  0000000000000000
000000c000043940:  0000000004030f97 <runtime.fatalthrow+87>  000000c000043950
000000c000043950:  000000000405a860 <runtime.fatalthrow.func1+0>  000000c000000180
000000c000043960:  0000000004030dd2 <runtime.throw+114>  000000c000043980
000000c000043970:  000000c0000439a0  0000000004030dd2 <runtime.throw+114>
000000c000043980:  000000c000043988  000000000405a7e0 <runtime.throw.func1+0>
000000c000043990:  00000000040d653d  000000000000002a
000000c0000439a0:  000000c0000439d0  0000000004044f2a <runtime.sigpanic+1130>
000000c0000439b0: <00000000040d653d  000000000000002a
000000c0000439c0:  0000000000000000  0000000000000000
000000c0000439d0:  000000c000043aa8 !00000000041e745a
000000c0000439e0: >0000000000000000  0000000000000000
000000c0000439f0:  0000000000000000  0000000000000000
000000c000043a00:  0000000000000000  0000000000000000
000000c000043a10:  0000000000000000  0000000000000000
000000c000043a20:  000802aaaa00aaaa  0000000000000034
000000c000043a30:  0000000000000020  0000000000000000
000000c000043a40:  0000000000000000  0000000000000000
000000c000043a50:  0000000000000000  0000000000203000
000000c000043a60:  0000000000203000  0000000000203000
000000c000043a70:  0000000000000000  0000000000000000
000000c000043a80:  0000000000000008  0000000000000000
000000c000043a90:  0000000000000000  000000c000043b38
000000c000043aa0:  000000000400d726 <runtime.mallocgc+790>  000000c000043b48
000000c000043ab0:  00000000041df53e  000000c000012200
000000c000043ac0:  0000000000000010  0000000000000010
000000c000043ad0:  0000000004281340  0000000000000680
runtime.sigpanic()
	/usr/local/go/src/runtime/signal_unix.go:679 +0x46a fp=0xc0000439e0 sp=0xc0000439b0 pc=0x4044f2a

goroutine 2 [force gc (idle)]:
runtime.gopark(0x40d7b98, 0x417f670, 0x1411, 0x1)
	/usr/local/go/src/runtime/proc.go:304 +0xe0 fp=0xc000030fb0 sp=0xc000030f90 pc=0x40337f0
runtime.goparkunlock(...)
	/usr/local/go/src/runtime/proc.go:310
runtime.forcegchelper()
	/usr/local/go/src/runtime/proc.go:253 +0xb7 fp=0xc000030fe0 sp=0xc000030fb0 pc=0x40336a7
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1373 +0x1 fp=0xc000030fe8 sp=0xc000030fe0 pc=0x405da91
created by runtime.init.6
	/usr/local/go/src/runtime/proc.go:242 +0x35

goroutine 18 [GC sweep wait]:
runtime.gopark(0x40d7b98, 0x417f7a0, 0x140c, 0x1)
	/usr/local/go/src/runtime/proc.go:304 +0xe0 fp=0xc00002c7a8 sp=0xc00002c788 pc=0x40337f0
runtime.goparkunlock(...)
	/usr/local/go/src/runtime/proc.go:310
runtime.bgsweep(0xc00008e000)
	/usr/local/go/src/runtime/mgcsweep.go:70 +0x9c fp=0xc00002c7d8 sp=0xc00002c7a8 pc=0x4021a4c
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1373 +0x1 fp=0xc00002c7e0 sp=0xc00002c7d8 pc=0x405da91
created by runtime.gcenable
	/usr/local/go/src/runtime/mgc.go:214 +0x5c

goroutine 19 [GC scavenge wait]:
runtime.gopark(0x40d7b98, 0x417f760, 0x140d, 0x1)
	/usr/local/go/src/runtime/proc.go:304 +0xe0 fp=0xc00002cf78 sp=0xc00002cf58 pc=0x40337f0
runtime.goparkunlock(...)
	/usr/local/go/src/runtime/proc.go:310
runtime.bgscavenge(0xc00008e000)
	/usr/local/go/src/runtime/mgcscavenge.go:237 +0xd0 fp=0xc00002cfd8 sp=0xc00002cf78 pc=0x401ffa0
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1373 +0x1 fp=0xc00002cfe0 sp=0xc00002cfd8 pc=0x405da91
created by runtime.gcenable
	/usr/local/go/src/runtime/mgc.go:215 +0x7e

goroutine 3 [finalizer wait]:
runtime.gopark(0x40d7b98, 0x41a8ca8, 0x1410, 0x1)
	/usr/local/go/src/runtime/proc.go:304 +0xe0 fp=0xc000030758 sp=0xc000030738 pc=0x40337f0
runtime.goparkunlock(...)
	/usr/local/go/src/runtime/proc.go:310
runtime.runfinq()
	/usr/local/go/src/runtime/mfinal.go:175 +0xa3 fp=0xc0000307e0 sp=0xc000030758 pc=0x4017773
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:1373 +0x1 fp=0xc0000307e8 sp=0xc0000307e0 pc=0x405da91
created by runtime.createfing
	/usr/local/go/src/runtime/mfinal.go:156 +0x61
exit status 2

The text was updated successfully, but these errors were encountered:

odeke-em · 2020-07-10T07:45:52Z

Thank you for this report @wangzhione and welcome to the Go project!

I can reproduce this even for Go1.13.12, Go1.12.17, but for Go1.11.13 there are CGO errors.

Kindly paging @ianlancetaylor @cherrymui

luchsh · 2020-07-21T13:10:54Z

I tried to debug this problem, it crashed at method runtime.heapBitsSetType.
After digging into the assembly,

(lldb) di -f -m
libverify.so`runtime.heapBitsSetType:
....
    0x4327139 <+2361>: cmpl   $0x20, %edi
    0x432713c <+2364>: sbbl   %eax, %eax
    0x432713e <+2366>: sbbl   %edx, %edx
    0x4327140 <+2368>: movzbl (%r10), %ebx
    0x4327144 <+2372>: andl   $0x3, %ebx
    0x4327147 <+2375>: orl    $0x10, %ebx
->  0x432714a <+2378>: movzbl (%rsi), %r8d
    0x432714e <+2382>: movl   %edi, %ecx
    0x4327150 <+2384>: movl   $0x33, %r9d
    0x4327156 <+2390>: shll   %cl, %r9d
    0x4327159 <+2393>: andl   %eax, %r9d

It looks like the heapAreana.bitmap corresponding to this newly allocated memory p is NULL.

I could not find an efficient debugger on Catalina to further dig into this problem;
lldb cannot set breakpoints; dlv and gdb cannot display symbols; Pls let me know if you have a working debugger on Catalina.

Then I tried to add many print statements to the Go runtime and found:

the initialization code of the shared library got executed.
but the shared library code was trying to access runtime.mheap_ from the main executable's Go runtime.
And it could not find any records in mheap_.arenas[0][*] corresponding the memory p allocated via the shared library's runtime.mheap_.

But I still do not know why the shared library was accessing the wrong runtime.mheap_.
I've tried to rewrite the executable and the shared library in C language, and the following scenarios all work well:

C-calls-Go
Go-calls-C
C-calls-C

any thoughts?

ianlancetaylor · 2020-07-22T03:16:24Z

A shared library built with -buildmode=c-shared is intended to be used with a C program, not a Go program.

I don't know whether the Mach-O symbol visibility rules can support using -buildmode=c-shared with a Go program.

networkimprov · 2020-07-22T04:11:19Z

Emmanual @odeke-em found that Go 1.11 gave a CGO error, not a segfault.

anshuman-mor · 2022-07-21T08:32:00Z

@networkimprov - Did you get this working by any chance?

@ianlancetaylor - IMHO, If golang is providing a way to build native shared library, then it does not matter, whether caller is written in Go, C, C++ or any other language, as long as caller follow the rules.

ianlancetaylor · 2022-07-21T19:57:54Z

Unless we have strict symbol visibility control, it matters what language the caller is written, because a Go program and a Go shared library will define many symbols with the same names. Those symbols must be distinct, and not combined by the dynamic linker.

Linkangyis · 2022-08-31T07:16:40Z

这个问题，你在dll的代码里面只要用到了接口，必报错

Linkangyis · 2022-08-31T07:18:40Z

这个问题在go任何一个支持cgo的版本都会出现，包括最新的1.19

jiftle · 2023-12-15T14:10:16Z

go version: go1.20.5 darwin/amd64
os: uname -a Darwin macbookdeMacBook-Pro.local 20.6.0 Darwin Kernel Version 20.6.0: Thu Jul 6 22:12:47 PDT 2023; root:xnu-7195.141.49.702.12~1/RELEASE_X86_64 x86_64
golang call *.dylib from golang code.
this is *.dylib is been golang generate.

this is Makefile

CGO_ENABLED=1 \
GOOS=darwin \
GOARCH=amd64 \
go build \
-buildmode=c-shared \
-o bin/darwin/*.dylib

error

fatal error: bad sweepgen in refill

goroutine 1 [running]:
runtime.throw({0x14ae9f7?, 0xc000666de0?})
	/usr/local/go/src/runtime/panic.go:1047 +0x5d fp=0xc000666d80 sp=0xc000666d50 pc=0x1035b3d
runtime.(*mcache).refill(0x9c005b8, 0x0?)
	/usr/local/go/src/runtime/mcache.go:157 +0x216 fp=0xc000666dc0 sp=0xc000666d80 pc=0x10167d6
runtime.(*mcache).nextFree(0x9c005b8, 0x5)
	/usr/local/go/src/runtime/malloc.go:855 +0x85 fp=0xc000666e08 sp=0xc000666dc0 pc=0x100d3a5
runtime.mallocgc(0x4, 0x140b3e0, 0x1)
	/usr/local/go/src/runtime/malloc.go:1017 +0x2c5 fp=0xc000666e70 sp=0xc000666e08 pc=0x100d805
reflect.unsafe_New(0xc0001c2840?)
	/usr/local/go/src/runtime/malloc.go:1259 +0x27 fp=0xc000666e98 sp=0xc000666e70 pc=0x1064807
reflect.New({0x15546e8?, 0x140b3e0})
	/usr/local/go/src/reflect/value.go:3194 +0x5f fp=0xc000666ec8 sp=0xc000666e98 pc=0x109b79f
github.com/ebitengine/purego.RegisterFunc.func1({0xc0001123f0?, 0x2?, 0x2?})
	/Users/mac/wsp/gowork/pkg/mod/github.com/ebitengine/purego@v0.5.0/func.go:259 +0xada fp=0xc000667238 sp=0xc000666ec8 pc=0x13777ba
reflect.callReflect(0xc00053fc50, 0xc0006677a0, 0xc000667678, 0xc000667680)
	/usr/local/go/src/reflect/value.go:772 +0x56d fp=0xc000667628 sp=0xc000667238 pc=0x109558d
reflect.callReflect(0xc00053fc50, 0xc0006677a0, 0xc000667678, 0xc000667680)
	<autogenerated>:1 +0x4b fp=0xc000667658 sp=0xc000667628 pc=0x10a012b
reflect.makeFuncStub()
	/usr/local/go/src/reflect/asm_amd64.s:47 +0x7a fp=0xc0006677a0 sp=0xc000667658 pc=0x109e79a

wangzz719 changed the title ~~Darwin using c-shared so got fatal error: bad sweepgen in refill~~ Darwin using c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a Jul 9, 2020

odeke-em changed the title ~~Darwin using c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a~~ runtime: darwin using -buildmode=c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a Jul 10, 2020

odeke-em added NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one. OS-Darwin labels Jul 10, 2020

royari mentioned this issue Jul 21, 2020

macOS kapitan release proposal kapicorp/kapitan#568

Closed

gopherbot added the compiler/runtime Issues related to the Go compiler and/or runtime. label Jul 7, 2022

seankhliao added this to the Unplanned milestone Aug 27, 2022

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runtime: darwin using -buildmode=c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a #40131

runtime: darwin using -buildmode=c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a #40131

wangzz719 commented Jul 9, 2020 •

edited

odeke-em commented Jul 10, 2020

luchsh commented Jul 21, 2020

ianlancetaylor commented Jul 22, 2020

networkimprov commented Jul 22, 2020

anshuman-mor commented Jul 21, 2022

ianlancetaylor commented Jul 21, 2022

Linkangyis commented Aug 31, 2022

Linkangyis commented Aug 31, 2022

jiftle commented Dec 15, 2023 •

edited

runtime: darwin using -buildmode=c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a #40131

runtime: darwin using -buildmode=c-shared so got runtime: unexpected return pc for runtime.sigpanic called from 0x41e745a #40131

Comments

wangzz719 commented Jul 9, 2020 • edited

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

Does this issue reproduce with the latest release?

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

What did you do?

What did you expect to see?

What did you see instead?

odeke-em commented Jul 10, 2020

luchsh commented Jul 21, 2020

ianlancetaylor commented Jul 22, 2020

networkimprov commented Jul 22, 2020

anshuman-mor commented Jul 21, 2022

ianlancetaylor commented Jul 21, 2022

Linkangyis commented Aug 31, 2022

Linkangyis commented Aug 31, 2022

jiftle commented Dec 15, 2023 • edited

error

wangzz719 commented Jul 9, 2020 •

edited

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

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

jiftle commented Dec 15, 2023 •

edited