[PATCH] f00f workaround update, TLS, 2.5.28

This updates the F00F bug workaround code to the IDT changes in the TLS
patch.

Tested it on a non-Pentium box on which i triggered the workaround
artificially.

arch/i386/kernel/head.S

@@ -348,6 +348,7 @@ ignore_int:
 .globl cpu_gdt_descr
 
 	ALIGN
+	.word 0				# 32-bit align idt_desc.address
 idt_descr:
 	.word IDT_ENTRIES*8-1		# idt contains 256 entries
 	.long idt_table

arch/i386/kernel/traps.c

@@ -784,11 +784,10 @@ void __init trap_init_f00f_bug(void)
 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
 
 	/*
-	 * "idt" is magic - it overlaps the idt_descr
-	 * variable so that updating idt will automatically
-	 * update the idt descriptor..
+	 * Update the IDT descriptor and reload the IDT so that
+	 * it uses the read-only mapped virtual address.
 	 */
-	idt = (struct desc_struct *) fix_to_virt(FIX_F00F_IDT);
+	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
 	__asm__ __volatile__("lidt %0": "=m" (idt_descr));
 }
 #endif

arch/i386/mm/fault.c

@@ -24,6 +24,7 @@
 #include <asm/uaccess.h>
 #include <asm/pgalloc.h>
 #include <asm/hardirq.h>
+#include <asm/desc.h>
 
 extern void die(const char *,struct pt_regs *,long);
 
@@ -129,7 +130,6 @@ void bust_spinlocks(int yes)
 }
 
 asmlinkage void do_invalid_op(struct pt_regs *, unsigned long);
-extern unsigned long idt;
 
 /*
  * This routine handles page faults.  It determines the address,
@@ -293,7 +293,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code)
 	if (boot_cpu_data.f00f_bug) {
 		unsigned long nr;
 		
-		nr = (address - idt) >> 3;
+		nr = (address - idt_descr.address) >> 3;
 
 		if (nr == 6) {
 			do_invalid_op(regs, 0);