x86: add is_f00f_bug helper to fault_32|64.c

Further towards unifying these files, add another helper
in same spirit as is_errata93.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c
index dd26e680a431..df13487aa83a 100644
--- a/arch/x86/mm/fault_64.c
+++ b/arch/x86/mm/fault_64.c
@@ -256,6 +256,27 @@ static int is_errata93(struct pt_regs *regs, unsigned long address)
         return 0;
 }
 
+void do_invalid_op(struct pt_regs *, unsigned long);
+
+static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
+{
+#ifdef CONFIG_X86_F00F_BUG
+        unsigned long nr;
+        /*
+         * Pentium F0 0F C7 C8 bug workaround.
+         */
+        if (boot_cpu_data.f00f_bug) {
+                nr = (address - idt_descr.address) >> 3;
+
+                if (nr == 6) {
+                        do_invalid_op(regs, 0);
+                        return 1;
+                }
+        }
+#endif
+        return 0;
+}
+
 static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
                                  unsigned long error_code)
 {
@@ -581,6 +602,9 @@ bad_area_nosemaphore:
                 return;
         }
 
+        if (is_f00f_bug(regs, address))
+                return;
+
 no_context:
         /* Are we prepared to handle this kernel fault?  */
         if (fixup_exception(regs))