x86: prefetch fix #2

Linus noticed a second bug and an uncleanliness:

 - we'd return on any instruction fetch fault

 - we'd use both the value of 16 and the PF_INSTR symbol which are
   the same and make no sense

the cleanup nicely unifies this piece of logic.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 7 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index c0c82bc143c9..ec08d8389850 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -91,13 +91,10 @@ static int is_prefetch(struct pt_regs *regs, unsigned long addr,
         int prefetch = 0;
         unsigned char *max_instr;
 
-#ifdef CONFIG_X86_32
-        /* Catch an obscure case of prefetch inside an NX page: */
-        if ((__supported_pte_mask & _PAGE_NX) && (error_code & 16))
-                return 0;
-#endif
-
-        /* If it was a exec fault on NX page, ignore */
+        /*
+         * If it was a exec (instruction fetch) fault on NX page, then
+         * do not ignore the fault:
+         */
         if (error_code & PF_INSTR)
                 return 0;