[go-nuts] Segmentation fault when linking with Go library from a C++ program

[inetic]

I have a C++ application from which I need to call Go functions. I noticed 
that the application crashes
on exit from the `main` function (with only a "Segmentation fault" message, 
no core dump and neither
did gdb show anything useful) about once in three runs. Then I added the 
`-fsanitize=address` flag to
the build and started to see messages such as these:

=================================================================
==8006==ERROR: LeakSanitizer: detected memory leaks


Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f9ef4571602 in malloc 
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x40421d in x_cgo_thread_start 
/usr/local/go/src/runtime/cgo/gcc_util.c:15
    #2 0x42bcff in runtime.startm /usr/local/go/src/runtime/proc.go:1698
    #3 0x42c059 in runtime.wakep /usr/local/go/src/runtime/proc.go:1779
    #4 0x42f179 in runtime.newproc1 /usr/local/go/src/runtime/proc.go:2958
    #5 0x4490d2 in runtime.newproc.func1 
/usr/local/go/src/runtime/proc.go:2845
    #6 0x4498d1 in runtime.systemstack 
/usr/local/go/src/runtime/asm_amd64.s:327


Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f9ef4571602 in malloc 
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x40421d in x_cgo_thread_start 
/usr/local/go/src/runtime/cgo/gcc_util.c:15
    #2 0x4488a7 in runtime.main.func1 /usr/local/go/src/runtime/proc.go:126
    #3 0x4498d1 in runtime.systemstack 
/usr/local/go/src/runtime/asm_amd64.s:327


Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f9ef4571602 in malloc 
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x40421d in x_cgo_thread_start 
/usr/local/go/src/runtime/cgo/gcc_util.c:15
    #2 0x42bcff in runtime.startm /usr/local/go/src/runtime/proc.go:1698
    #3 0x42bdd6 in runtime.handoffp /usr/local/go/src/runtime/proc.go:1725
    #4 0x42c1f4 in runtime.stoplockedm 
/usr/local/go/src/runtime/proc.go:1793
    #5 0x42d5da in runtime.schedule /usr/local/go/src/runtime/proc.go:2180
    #6 0x42d730 in runtime.park_m /usr/local/go/src/runtime/proc.go:2285
    #7 0x449842 in runtime.mcall /usr/local/go/src/runtime/asm_amd64.s:269


SUMMARY: AddressSanitizer: 72 byte(s) leaked in 3 allocation(s).

or

=================================================================
==28395==ERROR: LeakSanitizer: detected memory leaks


Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f562b171602 in malloc 
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x403a0d in x_cgo_thread_start 
/usr/local/go/src/runtime/cgo/gcc_util.c:15
    #2 0x42b4ef in runtime.startm /usr/local/go/src/runtime/proc.go:1698
    #3 0x42b5c6 in runtime.handoffp /usr/local/go/src/runtime/proc.go:1725
    #4 0x42b9e4 in runtime.stoplockedm 
/usr/local/go/src/runtime/proc.go:1793
    #5 0x42cdca in runtime.schedule /usr/local/go/src/runtime/proc.go:2180
    #6 0x42cf20 in runtime.park_m /usr/local/go/src/runtime/proc.go:2285
    #7 0x449032 in runtime.mcall /usr/local/go/src/runtime/asm_amd64.s:269


Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f562b171602 in malloc 
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x403a0d in x_cgo_thread_start 
/usr/local/go/src/runtime/cgo/gcc_util.c:15
    #2 0x42b4ef in runtime.startm /usr/local/go/src/runtime/proc.go:1698
    #3 0x42b849 in runtime.wakep /usr/local/go/src/runtime/proc.go:1779
    #4 0x42c8b4 in runtime.resetspinning 
/usr/local/go/src/runtime/proc.go:2141
    #5 0x42cc09 in runtime.schedule /usr/local/go/src/runtime/proc.go:2229
    #6 0x42a2db in runtime.mstart1 /usr/local/go/src/runtime/proc.go:1189
    #7 0x42a1f5 in runtime.mstart /usr/local/go/src/runtime/proc.go:1149
    #8 0x403a62  (/home/peter/work/tmp/minimal-cgo/a.out+0x403a62)


SUMMARY: AddressSanitizer: 48 byte(s) leaked in 2 allocation(s).

but most often just this one:

=================================================================
==17138==ERROR: LeakSanitizer: detected memory leaks


Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f15bfe0e602 in malloc 
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98602)
    #1 0x403eed in x_cgo_thread_start 
/usr/local/go/src/runtime/cgo/gcc_util.c:15
    #2 0x448577 in runtime.main.func1 /usr/local/go/src/runtime/proc.go:126
    #3 0x4495a1 in runtime.systemstack 
/usr/local/go/src/runtime/asm_amd64.s:327


SUMMARY: AddressSanitizer: 24 byte(s) leaked in 1 allocation(s).

I reduced the code which can reproduce these to the three attached files. 
With this reduced code I can see the failures
a lot less often though. Sometimes I can see the error quite quickly, but 
sometimes I need to let the `run.sh` script run
for more than a minute.

I have tested with go1.8, go1.8.3 and go1.9rc2 (linux amd64) with the same 
results.

~ > g++ --version
g++ (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609

Do I need to call some cgo function to properly de-initialize go when 
exiting the main function?

Regards,

Peter


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go_code.go
Description: Binary data

#include "go_code.h"
#include <vector>
#include <assert.h>

struct Options {
    Options() : ff(10000) { ff.push_back(32); }
    std::vector<int> ff;
};

int main(int argc, const char** argv)
{
    Options options;

    assert(argc > 0);
    if (argc > 0) return 0;

    // This is never called.
    go_start((char*) "");

    return 0;
}

#!/bin/sh

set -e

if [ "$1" = "clean" ]; then
    rm a.out go_code.h go_code.a 2>/dev/null || true
    exit
fi

export ASAN_OPTIONS=strict_string_checks=1:detect_stack_use_after_return=1:check_initialization_order=1:strict_init_order=1
go build --buildmode=c-archive ./go_code.go
g++ ./main.cpp -pthread -I./ ./go_code.a -fsanitize=address
echo start
while true; do ./a.out; done