[Bug go/79281] New: gccgo: Binaries using goroutines crash on m68k

["glaubitz at physik dot fu-berlin.de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79281

            Bug ID: 79281
           Summary: gccgo: Binaries using goroutines crash on m68k
           Product: gcc
           Version: 6.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: glaubitz at physik dot fu-berlin.de
                CC: cmang at google dot com, doko at gcc dot gnu.org,
                    gcc-bugzilla at mkarcher dot dialup.fu-berlin.de,
                    ian at airs dot com, jrtc27 at jrtc27 dot com, schwab at gcc dot gnu.org
  Target Milestone: ---

After fixing #79037, I can compile and run Go programs on m68k now. However,
there is still a problem when using Go routines:

(sid-m68k-sbuild)root@ikarus:/# cat routines.go
package main

import (
        "fmt"
        "time"
)

func say(s string) {
        for i := 0; i < 5; i++ {
                time.Sleep(100 * time.Millisecond)
                fmt.Println(s)
        }
}

func main() {
        go say("World")
        go say("Alice")
        go say("Bob")
        say("Hello")
}

(sid-m68k-sbuild)root@ikarus:/# gccgo-6 routines.go -o routines
(sid-m68k-sbuild)root@ikarus:/# ./routines
futexwakeup addr=0x90416c5e returned -1
fatal error: unexpected signal during runtime execution
[signal 0xb code=0x1 addr=0x1006]

goroutine 22 [syscall]:
runtime_dopanic
        ../../../src/libgo/runtime/panic.c:131
runtime_throw
        ../../../src/libgo/runtime/panic.c:193
sig_panic_leadin
        ../../../src/libgo/runtime/go-signal.c:249
sig_panic_info_handler
        ../../../src/libgo/runtime/go-signal.c:283

        :0
runtime_futexwakeup
        ../../../src/libgo/runtime/thread-linux.c:70
runtime_notewakeup
        ../../../src/libgo/runtime/lock_futex.c:121
handoffp
        ../../../src/libgo/runtime/proc.c:1518
runtime_entersyscallblock
        ../../../src/libgo/runtime/proc.c:2081
runtime_notetsleepg
        ../../../src/libgo/runtime/lock_futex.c:200
timerproc
        ../../../src/libgo/runtime/time.goc:263
kickoff
        ../../../src/libgo/runtime/proc.c:235
created by addtimer
        ../../../src/libgo/runtime/time.goc:147

goroutine 16 [running]:
        goroutine running on other thread; stack unavailable

goroutine 17 [syscall]:
        goroutine in C code; stack unavailable
created by runtime_main
        ../../../src/libgo/runtime/proc.c:598

goroutine 18 [finalizer wait]:
Hello
runtime_mcall
        ../../../src/libgo/runtime/proc.c:295
runtime_parkunlock
        ../../../src/libgo/runtime/proc.c:1887
runfinq
        ../../../src/libgo/runtime/mgc0.c:2512
kickoff
        ../../../src/libgo/runtime/proc.c:235
created by runtime_createfing
        ../../../src/libgo/runtime/mgc0.c:2577

goroutine 19 [sleep]:
runtime_mcall
        ../../../src/libgo/runtime/proc.c:295
runtime_parkunlock
        ../../../src/libgo/runtime/proc.c:1887
runtime_tsleep
        ../../../src/libgo/runtime/time.goc:97
time.Sleep
        ../../../src/libgo/runtime/time.goc:39
main.say
        //routines.go:10
kickoff
        ../../../src/libgo/runtime/proc.c:235
created by main.main
        //routines.go:16

goroutine 20 [sleep]:
runtime_mcall
        ../../../src/libgo/runtime/proc.c:295
runtime_parkunlock
        ../../../src/libgo/runtime/proc.c:1887
runtime_tsleep
        ../../../src/libgo/runtime/time.goc:97
time.Sleep
        ../../../src/libgo/runtime/time.goc:39
main.say
        //routines.go:10
kickoff
        ../../../src/libgo/runtime/proc.c:235
created by main.main
        //routines.go:17

goroutine 21 [sleep]:
runtime_mcall
        ../../../src/libgo/runtime/proc.c:295
runtime_parkunlock
        ../../../src/libgo/runtime/proc.c:1887
runtime_tsleep
        ../../../src/libgo/runtime/time.goc:97
time.Sleep
        ../../../src/libgo/runtime/time.goc:39
main.say
        //routines.go:10
kickoff
        ../../../src/libgo/runtime/proc.c:235
created by main.main
        //routines.go:18

goroutine 23 [GC sweep wait]:
runtime_mcall
        ../../../src/libgo/runtime/proc.c:295
runtime_parkunlock
        ../../../src/libgo/runtime/proc.c:1887
bgsweep
        ../../../src/libgo/runtime/mgc0.c:1844
kickoff
        ../../../src/libgo/runtime/proc.c:235
created by mgc
        ../../../src/libgo/runtime/mgc0.c:2215
(sid-m68k-sbuild)root@ikarus:/#

I have not looked into the problem in detail yet, but I assume it's either the
16-bit alignment striking again or maybe a missing syscall definition.

Let me know if there is something I can try to address the issue.