On Wed, 2009-03-11 at 14:13 +0100, Ingo Molnar wrote:This shouldn't be necessary. asm/desc.h should pull it in if it needs it.
* Ingo Molnar <mingo@xxxxxxx> wrote:
* Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx> wrote:As i pointed it out before, we should not open-code an assembly primitive - especially since store_ldt() is available in arch/x86/include/asm/desc.h.
@@ -472,7 +473,7 @@ static void print_dt(void *seq)this is still wrong.
print_desc_ptr("GDT", seq, dt);
/* LDT */
- store_ldt(ldt);
+ asm volatile("sldt %0" : "=m" (ldt));
True, that primitive is not available on CONFIG_PARAVIRT, but that is a bug: the fix is to move the store_ldt() definition outside the CONFIG_PARAVIRT section in desc.h, not to hack around the problem by open-coding assembly code.
I.e. dont let an uncleanliness and incomplete primitive spread to other code. Fix the primitive and remove the uncleanliness that way.
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 (2):
x86: cpu_debug.c cleanup
x86: move store_ldt outside the CONFIG_PARAVIRT section
arch/x86/include/asm/desc.h | 3 ++-
arch/x86/kernel/cpu/cpu_debug.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
Complete diff:
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index dc27705..ceb17cc 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -91,7 +91,6 @@ static inline int desc_empty(const void *ptr)
#define store_gdt(dtr) native_store_gdt(dtr)
#define store_idt(dtr) native_store_idt(dtr)
#define store_tr(tr) (tr = native_store_tr())
-#define store_ldt(ldt) asm("sldt %0":"=m" (ldt))
#define load_TLS(t, cpu) native_load_tls(t, cpu)
#define set_ldt native_set_ldt
@@ -112,6 +111,8 @@ static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
}
#endif /* CONFIG_PARAVIRT */
+#define store_ldt(ldt) asm("sldt %0":"=m" (ldt))
+
static inline void native_write_idt_entry(gate_desc *idt, int entry,
const gate_desc *gate)
{
diff --git a/arch/x86/kernel/cpu/cpu_debug.c b/arch/x86/kernel/cpu/cpu_debug.c
index 0bdf4da..9abbcbd 100755
--- a/arch/x86/kernel/cpu/cpu_debug.c
+++ b/arch/x86/kernel/cpu/cpu_debug.c
@@ -23,6 +23,7 @@
#include <linux/smp.h>
#include <asm/cpu_debug.h>
+#include <asm/paravirt.h>