Re: [Qemu-devel] Insta-segfault! i386-linux-user

[Alexander Graf]

On Sep 18, 2007, at 11:49 PM, Thayne Harbaugh wrote:

> On Tue, 2007-09-18 at 21:11 +0200, Alexander Graf wrote:
> > On Sep 18, 2007, at 8:25 PM, Thayne Harbaugh wrote:
> >
> > > On Tue, 2007-09-18 at 15:53 +0200, Ronald wrote:
> > > > Thayne Harbaugh schreef:
>
> <SNIP>
>
> > > > > ./i386-linux-user/qemu-i386 --help
> > > > > Segmentation fault
> > > > >
> > > > > > From GDB:
> > > > >
> > > > > Program received signal SIGSEGV, Segmentation fault.
> > > > > 0x0000000000000000 in ?? ()
> > > > > (gdb) bt
> > > > > #0  0x0000000000000000 in ?? ()
> > > > > #1  0x00000000600575ed in __libc_csu_init ()
> > > > > #2  0x00002b826c660ade in __libc_start_main () from /lib/libc.so.6
> > > > > #3  0x00000000600050e9 in _start ()
>
> <SNIP>
>
> > We had this on the list some months ago.
>
> I'll dig for that.
>
> > As far as I recall this
> > correctly the problem is the linker script. Just take a look at the
> > suse source rpm where we replace that one, so it works with x86_64.
>
> Thanks for the guidance.
>
> > Be prepared for breakage though, as linux-user on 64-Bit hosts does
> > not work properly.
>
> What about it doesn't work properly?  Do you have some links for the
> list archives?

Mostly syscalls that return 64-bit pointers. So for example mmap is  
broken. You can find a patch for x86_64 for that in the rpm or on the  
list as well, which does not fix the issue on ppc64 or ia64 though.  
Additionally there is an IPC call that does an mmap in the end, where  
you can not force it to return 32-bit values, so this can not be  
easily fixed. The IA64-IA32 emulator actually does have an approach  
for this, but I did not have the time to take a deeper look into that.

Good luck,

Alex