Re: [Xen-devel] Re: 2.6.28.7 domU: 32-bit emulation seems to be broken

["Sven Köhler" <sven.koehler@gmail.com>]

Jeremy Fitzhardinge schrieb:
> Hm.  How about "x/30i __kernel_vsyscall"?

# export LANG=C
# ulimit -c unlimited
# ./a.out
Segmentation fault (core dumped)
# dmesg|grep "ip:"
a.out[18031] general protection ip:f7f4642f sp:ff943d74 error:0
a.out[18038] general protection ip:f7f0042f sp:ff8fd534 error:0
# gdb ./a.out core
GNU gdb 6.8
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-pc-linux-gnu"...
Core was generated by `./a.out'.
Program terminated with signal 11, Segmentation fault.
[New process 18038]
#0  0xf7f0042f in __kernel_vsyscall ()
(gdb) x/i f7f0042f
No symbol "f7f0042f" in current context.
(gdb) x/i $eip-2
0xf7f0042d <__kernel_vsyscall+13>:	jmp    0x25f0c78f
(gdb) x/30i __kernel_vsyscall
0xf7f00420 <__kernel_vsyscall>:	push   %ebp
0xf7f00421 <__kernel_vsyscall+1>:	mov    %ecx,%ebp
0xf7f00423 <__kernel_vsyscall+3>:	syscall
0xf7f00425 <__kernel_vsyscall+5>:	mov    $0x2b,%ecx
0xf7f0042a <__kernel_vsyscall+10>:	mov    %ecx,%ss
0xf7f0042c <__kernel_vsyscall+12>:	mov    %ebp,%ecx
0xf7f0042e <__kernel_vsyscall+14>:	pop    %ebp
0xf7f0042f <__kernel_vsyscall+15>:	ret
0xf7f00430:	add    %ch,(%esi)
0xf7f00432:	jae    0xf7f0049c
0xf7f00434:	jae    0xf7f004aa
0xf7f00436:	jb     0xf7f004ac
0xf7f00438:	popa
0xf7f00439:	bound  %eax,(%eax)
0xf7f0043b:	cs
0xf7f0043c:	push   $0x687361
0xf7f00441:	cs
0xf7f00442:	fs
0xf7f00443:	jns    0xf7f004b3
0xf7f00445:	jae    0xf7f004c0
0xf7f00447:	insl   (%dx),%es:(%edi)
0xf7f00448:	add    %ch,(%esi)
0xf7f0044a:	fs
---Type <return> to continue, or q <return> to quit---
0xf7f0044b:	jns    0xf7f004bb
0xf7f0044d:	jae    0xf7f004c3
0xf7f0044f:	jb     0xf7f00451
0xf7f00451:	addr16 outsb %cs:(%si),(%dx)
0xf7f00454:	jne    0xf7f00484
0xf7f00456:	jbe    0xf7f004bd
0xf7f00458:	jb     0xf7f004cd
(gdb)