[Qemu-devel] RE: [PATCH 0/5]

[Liu Yu-B13201]

> -----Original Message-----
> From: Nathan Froyd [mailto:address@hidden 
> Sent: Monday, July 27, 2009 9:14 PM
> To: Liu Yu-B13201
> Cc: address@hidden; address@hidden; 
> address@hidden; address@hidden
> Subject: Re: [PATCH 0/5]
> 
> On Sat, Jul 25, 2009 at 04:40:12PM +0800, Liu Yu wrote:
> > For example booke has a code template for
> > jumping to and returning from interrupt handlers:
> >
> >     bl transfer
> >     .long handler_addr
> >     .long ret_addr
> >
> > when call transfer, it never return but
> > in transfer assembly code it will read the handler_addr
> > and ultimately call the handler.
> > Gdb doesn't know that and treat it as a normal function call.
> > so gdb put a software breakpoint instruction at handler_addr,
> > in order to get trap there when return from transfer.
> >
> > Then guest will read software breakpoint as handler_addr 
> and jump to there..
> >
> > I'm not sure if x86 suffer this kind of issue.
> > Is there any way to avoid this?
> 
> You would need to modify GDB to recognize this sort of case with the
> skip_trampoline_code gdbarch method.
> 

Hmm.. I am not a gdb expert.
But even gdb can recognize this pattern, is it safe to skip it?