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

Ingo Molnar
2009-03-11T10:53:48Z

* 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.

> 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?

The real fix (if it's not just a missing include line) would be
to make sure these primitives are generally available.

Ingo