Re: rump core on module load

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

On Sat, May 06, 2017 at 04:29:04PM +0800, Paul Goyette wrote:
> On Sat, 6 May 2017, Patrick Welche wrote:
> > > > dumps core. The odd thing is that modload is happy!
> > > > 
> > > > #0  0x00000000e5405e57 in ?? ()
> > > > #1  0x00007f7fe48b0efb in module_do_load (name=0x7f7ff7bccc00 "/module.mod",
> > > >    isdep=false, flags=0, props=0x0, modp=0x0, modclass=MODULE_CLASS_ANY,
> > > >    autoload=false)
> > > >    at /usr/src/lib/librump/../../sys/rump/../kern/kern_module.c:1127

> (Note that that address is not in the 0x07f7xxxxxx range that you would
> expect for "kernel stuff" such as the other stack frames.  This is one part
> of the "rump is different than real kernel" I mentioned!)

The only mention of that address I can find is the rip register:

rax            0x0      0
rbx            0x0      0
rcx            0x1      1
rdx            0x7ffff000       2147479552
rsi            0x7fffb160       2147463520
rdi            0x7fffb1b0       2147463600
rbp            0x7f7fffffdf60   0x7f7fffffdf60
rsp            0x7f7fffffde88   0x7f7fffffde88
rip            0xe5405e57       0xe5405e57


   0x00007f7fe48b0ee8 <+2541>:  jmp    0x7f7fe48b0ef1 <module_do_load+2550>
   0x00007f7fe48b0eea <+2543>:  mov    -0xa8(%rbp),%rax
   0x00007f7fe48b0ef1 <+2550>:  mov    %rax,%rsi
   0x00007f7fe48b0ef4 <+2553>:  mov    $0x0,%edi
   0x00007f7fe48b0ef9 <+2558>:  callq  *%rdx
   0x00007f7fe48b0efb <+2560>:  mov    %eax,-0x84(%rbp)
   0x00007f7fe48b0f01 <+2566>:  mov    -0x40(%rbp),%rax
   0x00007f7fe48b0f05 <+2570>:  mov    %rax,0x26df7c(%rip)        # 0x7f7fe4b1ee88
   0x00007f7fe48b0f0c <+2577>:  mov    -0x78(%rbp),%rax
   0x00007f7fe48b0f10 <+2581>:  test   %rax,%rax
   0x00007f7fe48b0f13 <+2584>:  je     0x7f7fe48b0f29 <module_do_load+2606>


I'll return to more traditional debugging ;-)

Cheers,

Patrick