[Libguestfs] libnbd golang failure on RISC-V

[Richard W.M. Jones]

On Thu, Jun 09, 2022 at 09:23:50PM +0300, Nir Soffer wrote:
> On Thu, Jun 9, 2022 at 6:24 PM Richard W.M. Jones <rjones at redhat.com> wrote:
> > $ emacs -nw run.in    # comment out GODEBUG line
...
> > $ make -C golang check
> > ...
> > PASS: run-tests.sh
> 
> So when skipping libnbd_020_aio_buffer_test.go we don't get the warning about
> Go pointer in C memory?

No, I commented out the GODEBUG line.

Enabling the GODEBUG line (ie. the normal case) gives:

$ uname -m
riscv64
$ git restore run.in
$ make
...
/home/rjones/d/libnbd/run go build
write of Go pointer 0x3fbc028000 to non-Go memory 0x3fe899bb20
fatal error: Go pointer stored into non-Go memory

runtime stack:
runtime.dopanic_m
	../../../libgo/go/runtime/panic.go:1211
runtime.fatalthrow
	../../../libgo/go/runtime/panic.go:1071
runtime.throw
	../../../libgo/go/runtime/panic.go:1042
runtime.cgoCheckWriteBarrier..func1
	../../../libgo/go/runtime/cgocheck.go:55
runtime.systemstack..func1
	../../../libgo/go/runtime/stubs.go:63
runtime_mstart
	../../../libgo/runtime/proc.c:593

goroutine 1 [running, locked to thread]:
runtime.mcall
	../../../libgo/runtime/proc.c:343
runtime.systemstack
	../../../libgo/go/runtime/stubs.go:66
runtime.cgoCheckWriteBarrier
	../../../libgo/go/runtime/cgocheck.go:53
runtime.wbBufFlush
	../../../libgo/go/runtime/mwbbuf.go:196
runtime.gcWriteBarrier
	../../../libgo/go/runtime/mgc_gccgo.go:168
runtime.main
	../../../libgo/go/runtime/proc.go:209
make[2]: *** [Makefile:1089: all-local] Aborted (core dumped)


The stack trace is not very interesting:

Thread 2 (Thread 0x3fbbfff150 (LWP 269087)):
#0  0x0000003fe72f9a60 in syscall () from /lib64/lp64d/libc.so.6
#1  0x0000003fe7e72f88 in __go_syscall6 (flag=<optimized out>, a1=<optimized out>, a2=<optimized out>, a3=<optimized out>, a4=<optimized out>, a5=<optimized out>, a6=<optimized out>) at ../../../libgo/runtime/go-varargs.c:109
#2  0x0000003fe814b05c in runtime.futex (val3=<optimized out>, addr2=<optimized out>, ts=<optimized out>, val=<optimized out>, op=<optimized out>, addr=<optimized out>) at ../../../libgo/go/runtime/os_linux.go:17
#3  runtime.futexsleep (addr=0x3fe899a878 <runtime.sched+240>, val=<optimized out>, ns=<optimized out>) at ../../../libgo/go/runtime/os_linux.go:59
#4  0x0000003fe815970c in runtime.notetsleep_internal (n=n at entry=0x3fe899a878 <runtime.sched+240>, ns=ns at entry=60000000000) at ../../../libgo/go/runtime/lock_futex.go:204
#5  0x0000003fe81598ce in runtime.notetsleep (n=n at entry=0x3fe899a878 <runtime.sched+240>, ns=60000000000) at ../../../libgo/go/runtime/lock_futex.go:227
#6  0x0000003fe8179e9c in runtime.sysmon () at ../../../libgo/go/runtime/proc.go:4210
#7  0x0000003fe817c1a6 in runtime.mstart1 () at ../../../libgo/go/runtime/proc.go:1074
#8  0x0000003fe7e7379e in runtime_mstart (arg=<optimized out>) at ../../../libgo/runtime/proc.c:611
#9  0x0000003fe723f606 in start_thread () from /lib64/lp64d/libpthread.so.0
#10 0x0000003fe72fc28e in __thread_start () from /lib64/lp64d/libc.so.6

Thread 1 (Thread 0x3fe7221630 (LWP 269040)):
#0  0x0000003fe7287084 in raise () from /lib64/lp64d/libc.so.6
#1  0x0000003fe8150cca in runtime.dieFromSignal (sig=sig at entry=6) at ../../../libgo/go/runtime/signal_unix.go:668
#2  0x0000003fe816ebdc in runtime.sigfwdgo (ctx=0x3fc059fc40, info=0x3fc059fbc0, sig=<optimized out>) at ../../../libgo/go/runtime/signal_unix.go:883
#3  runtime.sigtrampgo (sig=<optimized out>, info=0x3fc059fbc0, ctx=0x3fc059fc40) at ../../../libgo/go/runtime/signal_unix.go:392
#4  <signal handler called>
#5  0x0000003fe7287084 in raise () from /lib64/lp64d/libc.so.6
#6  0x0000003fe8150cca in runtime.dieFromSignal (sig=sig at entry=6) at ../../../libgo/go/runtime/signal_unix.go:668
#7  0x0000003fe8150d42 in runtime.crash () at ../../../libgo/go/runtime/signal_unix.go:763
#8  0x0000003fe8155132 in runtime.fatalthrow () at ../../../libgo/go/runtime/panic.go:1072
#9  runtime.throw (s=...) at ../../../libgo/go/runtime/panic.go:1042
#10 0x0000003fe81551c4 in runtime.cgoCheckWriteBarrier..func1 () at ../../../libgo/go/runtime/cgocheck.go:55
#11 0x0000003fe814bf3e in runtime.systemstack..func1 (origg=0x3fbc000a80) at ../../../libgo/go/runtime/stubs.go:63
#12 0x0000003fe7e7376e in runtime_mstart (arg=<optimized out>) at ../../../libgo/runtime/proc.c:593
#13 0x0000000000035abe in main (argc=<optimized out>, argv=<optimized out>) at ../../../libgo/runtime/go-main.c:58
#14 0x0000003fe7277956 in __libc_start_main () from /lib64/lp64d/libc.so.6
#15 0x0000000000035afc in _start ()


My money is still on a buggy golang runtime.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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