Re: [PATCH] Remove mfinfo[64] used by get_wchan()

[Atsushi Nemoto <anemo@mba.ocn.ne.jp>]

On Fri, 18 Aug 2006 14:17:29 +0200, Franck Bui-Huu <vagabon.xyz@gmail.com> 
wrote:
> > Why get_frame_info() will be called with info->func_size != 0 ?  The
> > offset of a _first_ instruction is 0, so "ofs" of this line in
> > unwind_stack() will be 0.
> > 
> >     info.func_size = ofs;   /* analyze from start to ofs */
> > 
> 
> because in unwind_stack(), before the line you showed, we do:
> 
>       if (!kallsyms_lookup(pc, &size, &ofs, &modname, namebuf))
>               return 0;
>       if (ofs == 0)
>               return 0;

Oh I missed it.

> Maybe we should do instead:
> 
>       if (!kallsyms_lookup(pc, &size, &ofs, &modname, namebuf))
>               return 0;
>       /* return ra if an exception occured at the first instruction */
>       if (ofs == 0)
>               return ra;

Sure.  I should be a right fix.  This part must be fixed anyway.

> And in any cases, if we pass info->func_size = 0 to get_frame_info(),
> then it will consider the function size as unknown.

I see.  You're right.

---
Atsushi Nemoto