runtime: ARM uClinux crash with -buildmode=c-archive

[ooepay]

Please answer these questions before submitting your issue. Thanks!

What did you do?

main.go
package main
/*
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
*/
import "C"

//export TestAdd
func TestAdd(a C.int32_t, b C.int32_t) C.int32_t {
return a + b
}

func main() {}

build:
CGO_ENABLED=1 GOOS=linux GOARCH=arm GOARM=5 CC=arm-hisiv500-linux-uclibcgnueabi-gcc CXX=arm-hisiv500-linux-uclibcgnueabi-g++ go build -buildmode=c-archive

output dlltest.a

test.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <inttypes.h>

extern "C" {
int32_t TestAdd(int32_t a, int32_t b);
}

int main(int argc, char* argv[])
{
int ret = TestAdd(10, 11);
printf("TestAdd, ret=%d", ret);
}

build:
export CC=arm-hisiv500-linux-uclibcgnueabi-gcc
export CXX=arm-hisiv500-linux-uclibcgnueabi-g++
$CXX -g test.c -o test dlltest.a -lpthread

output test exe file.
file test
test: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, with debug_info, not stripped

copy test to ARM board, run it.

What did you expect to see?

output TestAdd, ret=21

What did you see instead?

Segmentation fault

System details

gdb debug output
Program received signal SIGSEGV, Segmentation fault.
[Switching to LWP 427]
runtime.sysargs (argc=0, argv=0x0) at /usr/local/go-linux-arm-bootstrap/src/runtime/os_linux.go:206

go version go1.12.3 linux/amd64
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/csw/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/csw/work/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/work/dlltest/go.mod"
GOROOT/bin/go version: go version go1.12.3 linux/amd64
GOROOT/bin/go tool compile -V: compile version go1.12.3
uname -sr: Linux 4.19.0-041900-generic
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04.2 LTS
Release:	18.04
Codename:	bionic
/lib/x86_64-linux-gnu/libc.so.6: GNU C Library (Ubuntu GLIBC 2.27-3ubuntu1) stable release version 2.27.
gdb --version: GNU gdb (Ubuntu 8.1-0ubuntu3) 8.1.0.20180409-git

[ianlancetaylor]

The Go runtime on GNU/Linux systems currently expects that entries in the DT_INIT_ARRAY section are invoked with the C argc and argv values. The glibc library does this, but perhaps the uClinux library does not.

This could likely be fixed by changing the runtime package to read /proc/self/cmdline when the arguments are not passed in when running in c-archive mode.

[ooepay]

Thanks, the same problem in when running in c-shared mode.

[ooepay]

how to fix this problem, have patch?
i do not how to change argv, it is **byte

func args(c int32, v **byte) {
argc = c
argv = v
sysargs(c, v)
}

[gopherbot]

Change https://golang.org/cl/334991 mentions this issue: runtime: add check before using arguments with -buildmode=c-archive and -buildmode=c-shared on non glibc systems such as musl/uclinux