Re: [git-pull -tip V2] x86: cpu architecture debug code

Jaswinder Singh Rajput
2009-03-11T11:26:21Z

On Wed, 2009-03-11 at 11:53 +0100, Ingo Molnar wrote:
> * Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
>
> > On Tue, 2009-03-10 at 18:45 +0100, Ingo Molnar wrote:
> > > Thanks - picked it up into tip:x86/debug. (Note that i
> > > rearranged the Makefile details a bit so that it does not
> > > conflict with tip:perfcounters)
> > >
> > > Not yet in tip:master, because it triggers this build failure:
> > >
> > > arch/x86/kernel/cpu/cpu_debug.c: In function ‘print_dt’:
> > > arch/x86/kernel/cpu/cpu_debug.c:475: error: implicit declaration of function ‘store_ldt’
> > >
> >
> > Here is the fix.
> >
> > The following changes since commit 259ef6fcea4046fe24495b1e3631c1b905c531c1:
> > Jaswinder Singh Rajput (1):
> > x86: cpu architecture debug code
> >
> > are available in the git repository at:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/jaswinder/linux-2.6-tip-cpu.git master
> >
> > Jaswinder Singh Rajput (1):
> > x86: cpu_debug.c remove some dependency
> >
> > arch/x86/kernel/cpu/cpu_debug.c | 8 ++++----
> > 1 files changed, 4 insertions(+), 4 deletions(-)
> >
> > Complete diff:
> > diff --git a/arch/x86/kernel/cpu/cpu_debug.c b/arch/x86/kernel/cpu/cpu_debug.c
> > index 0bdf4da..08c365a 100755
> > --- a/arch/x86/kernel/cpu/cpu_debug.c
> > +++ b/arch/x86/kernel/cpu/cpu_debug.c
> > @@ -464,19 +464,19 @@ static void print_dt(void *seq)
> > unsigned long ldt;
> >
> > /* IDT */
> > - store_idt((struct desc_ptr *)&dt);
> > + native_store_idt((struct desc_ptr *)&dt);
>
> hm, this wont work on Xen then.
>

Strange it should work for Xen, Are you getting any error.

Xen also uses native_store_idt:
arch/x86/xen/enlighten.c: .store_idt = native_store_idt,

> > print_desc_ptr("IDT", seq, dt);
> >
> > /* GDT */
> > - store_gdt((struct desc_ptr *)&dt);
> > + native_store_gdt((struct desc_ptr *)&dt);
> > print_desc_ptr("GDT", seq, dt);
> >
> > /* LDT */
> > - store_ldt(ldt);
> > + asm volatile("sldt %0" : "=m" (ldt));
> > seq_printf(seq, " LDT\t: %016lx\n", ldt);
> >
> > /* TR */
> > - store_tr(ldt);
> > + asm volatile("str %0" : "=r" (ldt));
> > seq_printf(seq, " TR\t: %016lx\n", ldt);
>
> we do have a store_tr() primitive - why open code the assembly?
>

It is a single line code to avoid further conflicts, so i moved it here.

Can you please test are these works on your boxes.

Thanks,

--
JSR