Kernel Helpers segmentation fault

[Sateesh K]

Hi,
  My setup is as follows:
  l4linux 4.19.0-l4
  Fiasco.OC
  Raspberry Pi 3 Model B

  I am running a helloworld.go program which is causing the following stack
trace.

(gdb) bt full
#0  0xffff0f60 in ?? ()
No symbol table info available.
#1  0x0001143c in kernelCAS64 ()
    at /usr/local/go/src/sync/atomic/asm_linux_arm.s:112
No locals.
#2  0x0001103c in sync/atomic.loadUint64 (addr=0x10442080, val=48)
    at /usr/local/go/src/sync/atomic/64bit_arm.go:10
No locals.
#3  0x00071f44 in internal/poll.(*fdMutex).rwlock (mu=0x10442080,
read=false,
    ~r1=160) at /usr/local/go/src/internal/poll/fd_mutex.go:130
        mutexBit.lo = 4
        mutexMask.hi = 2147481600
        mutexMask.lo = 0
        mutexSema = 0x1044208c
        mutexWait.hi = 2048
        mutexWait.lo = 0
#4  0x00072314 in internal/poll.(*FD).writeLock (fd=0x10442080, ~r0=...)
    at /usr/local/go/src/internal/poll/fd_mutex.go:237
No locals.
#5  0x00072a94 in internal/poll.(*FD).Write (fd=0x10442080, p=..., ~r1=0,
    ~r2=...) at /usr/local/go/src/internal/poll/fd_unix.go:243
        n = -1212420096
        nn = 118
--Type <RET> for more, q to quit, c to continue without paging--c
#6  0x00073958 in os.(*File).write (b=..., err=..., f=0x1040c0f0, n=2729821
44) at /usr/local/go/src/os/file_unix.go:243
No locals.
#7  0x00072ffc in os.(*File).Write (b=..., err=..., f=0x1040c0f0, n=0) at
/usr/local/go/src/os/file.go:144
        err.data = 0x12c0e8 <fmt.ppFree> ""
        err.itab = 0x8b7a8 <fmt.Fprintln+20> "\004"
        ~r2.data = 0x10456014 ""
        ~r2.itab = 0x0
#8  0x0008b7fc in fmt.Fprintln (a=..., err=..., n=233960, w=...) at
/usr/local/go/src/fmt/print.go:255
        p = 0x10456080
#9  0x0008b888 in fmt.Println (a=..., err=..., n=0) at
/usr/local/go/src/fmt/print.go:264
No locals.
#10 0x000916c0 in main.main () at /home/pi/hello.go:6
No locals.

 On further analysis, I find that segmentation fault is at

__kuser_cmpxchg64.

I have enabled CONFIG_KUSER_HELPERS=y when building the linux kernel.

Any hint please on how to proceed.


Best Regards,
Sateesh Kalidas
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://os.inf.tu-dresden.de/pipermail/l4-hackers/attachments/20191113/9cafe539/attachment.html>