ftrace introduces instability into kernel 2.6.27(-rc2,-rc3)

[Benjamin Herrenschmidt]

On Mon, 2008-08-18 at 14:27 -0400, Steven Rostedt wrote:
> 
> On Mon, 18 Aug 2008, Scott Wood wrote:
> 
> > Mathieu Desnoyers wrote:
> > >         asm volatile (
> > >                 "1: lwz         %1, 0(%2)\n"
> > >                 "   cmpw        %1, %5\n"
> > >                 "   bne         2f\n"
> > >                 "   stwu        %3, 0(%2)\n"
> > >                 "2:\n"
> > >                 ".section .fixup, \"ax\"\n"
> > >                 "3:     li %0, 1\n"
> > >                 "       b 2b\n"
> > >                 ".previous\n"
> > >                 ".section __ex_table,\"a\"\n"
> > >                 _ASM_ALIGN "\n"
> > >                 _ASM_PTR "1b, 3b\n"
> > >                 ".previous"
> > >                 : "=r"(faulted), "=r"(replaced)
> > >                 : "r"(ip), "r"(new),
> > >                   "0"(faulted), "r"(old)
> > >                 : "memory");
> > 
> > Some (most likely unrelated) nits in the above inline asm:


Why not use __get_user/__put_user ?

Cheers,
Ben.