runtime: Fault when allocating byte slice in anonymous goroutine function

[kisielk]

Go version:

What steps will reproduce the problem?
If possible, include a link to a program on play.golang.org.
1. go get github.com/kisielk/vigo
2. cd $GOPATH/github.com/kisielk/vigo
3. go build
4. ./vigo 2> trace

The stack trace is here:

unexpected fault address 0xc1c46c1668
fatal error: fault
[signal 0xb code=0x1 addr=0xc1c46c1668 pc=0x40c590]
 
goroutine 4 [running]:
[fp=0xc200059ed0] runtime.throw(0x596d97)
        /home/kamil/go/src/pkg/runtime/panic.c:473 +0x67
[fp=0xc200059ee8] runtime.sigpanic()
        /home/kamil/go/src/pkg/runtime/os_linux.c:239 +0xe7
[fp=0xc20005a288] scanblock(0x7f27611d9000, 0x7f27611d9048, 0x2, 0x1)
        /home/kamil/go/src/pkg/runtime/mgc0.c:800 +0xa00
[fp=0xc20005a3b8] gc(0x7f27612e7e04)
        /home/kamil/go/src/pkg/runtime/mgc0.c:2001 +0x2c5
----- stack segment boundary -----
[fp=0x7f27612e7e18] runtime.gc(0xc200000000)
        /home/kamil/go/src/pkg/runtime/mgc0.c:1927 +0x11b
[fp=0x7f27612e7e70] runtime.mallocgc(0x80, 0x100000001, 0x1)
        /home/kamil/go/src/pkg/runtime/zmalloc_linux_amd64.c:101 +0x1e4
[fp=0x7f27612e7ea8] makeslice1(0x4afc40, 0x80, 0x80, 0x7f27612e7ef0)
        /home/kamil/go/src/pkg/runtime/slice.c:61 +0x89
[fp=0x7f27612e7ed8] runtime.makeslice(0x4afc40, 0x80, 0x80, 0x0, 0x80, ...)
        /home/kamil/go/src/pkg/runtime/slice.c:34 +0x9a
[fp=0x7f27612e7fb8] github.com/nsf/termbox-go.func·001()
        /home/kamil/src/github.com/nsf/termbox-go/api.go:84 +0x3e
[fp=0x7f27612e7fc0] runtime.goexit()
        /home/kamil/go/src/pkg/runtime/proc.c:1223
created by github.com/nsf/termbox-go.Init
        /home/kamil/src/github.com/nsf/termbox-go/api.go:101 +0x66f
 
goroutine 1 [chan receive]:
github.com/kisielk/vigo/editor.(*editor).Loop(0xc20009f000, 0xc2000472d0, 0x0)
        /home/kamil/src/github.com/kisielk/vigo/editor/editor.go:435 +0x61
main.main()
        /home/kamil/src/github.com/kisielk/vigo/main.go:26 +0x18c
 
goroutine 3 [syscall]:
os/signal.loop()
        /home/kamil/go/src/pkg/os/signal/signal_unix.go:21 +0x1c
created by os/signal.init·1
        /home/kamil/go/src/pkg/os/signal/signal_unix.go:27 +0x2f
 
goroutine 5 [runnable]:
main.func·001()
        /home/kamil/src/github.com/kisielk/vigo/main.go:21
created by main.main
        /home/kamil/src/github.com/kisielk/vigo/main.go:25 +0x179

The relevant part of termbox-go/api.go:
   
   83     go func() {
   84         buf := make([]byte, 128)
   85         for {
   86             select {
   87             case <-sigio:
   88                 for {
   89                     n, err := syscall.Read(in, buf)
   90                     if err == syscall.EAGAIN || err == syscall.EWOULDBLOCK {
   91                         break
   92                     }
   93                     input_comm <- input_event{buf[:n], err}
   94                     ie := <-input_comm
   95                     buf = ie.data[:128]
   96                 }
   97             case <-quit:
   98                 return
   99             }
  100         }
  101     }()

The program depends on termbox-go, for which the code is at github.com/nsf/termbox-go
Note that it uses unsafe in a few places to make some syscalls to determine terminal
size.

There is no crash with GOGC=off. Also if I check out theprevious revision of the vigo
project, before I moved things from package main to a subpackage, there is no crash
either. The code runs fine when compiled with go1.0.2 on the same machine.

Sorry I couldn't provide a smaller test case at this point, but let me know if I can do
anything to narrow it down.

Which compiler are you using (5g, 6g, 8g, gccgo)?
8g

Which operating system are you using?
Ubuntu 12.10 64-bit, Mac OS X 10.8

Which version are you using?  (run 'go version')

go version devel +0c16e97c7587 Thu Apr 25 13:23:24 2013 +0900 linux/amd64

[kisielk]

Comment 2:

I guess the title is a bit misleading. I tried changing the termbox code so that the
function is not anonymous any more but still get the same error.

[dvyukov]

Comment 3:

The bad gcinfo is generated for io.ioutil/blackHoleBuf
https://golang.org/cl/8929044 turns it into compilation error.
https://golang.org/cl/8663052 seems to fix the crash.

Owner changed to @dvyukov.

Status changed to Duplicate.

Merged into issue #5291.