[PATCH] x86_64: Adjust page fault handling

Adjust page fault protection error check before considering it to be
a vmalloc synchronization candidate.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/x86_64/mm/fault.c b/arch/x86_64/mm/fault.c
index 21d1596946d6..fd07b86c062d 100644
--- a/arch/x86_64/mm/fault.c
+++ b/arch/x86_64/mm/fault.c
@@ -299,7 +299,8 @@ int exception_trace = 1;
  *      bit 0 == 0 means no page found, 1 means protection fault
  *      bit 1 == 0 means read, 1 means write
  *      bit 2 == 0 means kernel, 1 means user-mode
- *      bit 3 == 1 means fault was an instruction fetch
+ *      bit 3 == 1 means use of reserved bit detected
+ *      bit 4 == 1 means fault was an instruction fetch
  */
 asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
                                         unsigned long error_code)
@@ -342,10 +343,10 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
          *
          * This verifies that the fault happens in kernel space
          * (error_code & 4) == 0, and that the fault was not a
-         * protection error (error_code & 1) == 0.
+         * protection error (error_code & 9) == 0.
          */
         if (unlikely(address >= TASK_SIZE64)) {
-                if (!(error_code & 5) &&
+                if (!(error_code & 0xd) &&
                       ((address >= VMALLOC_START && address < VMALLOC_END) ||
                        (address >= MODULES_VADDR && address < MODULES_END))) {
                         if (vmalloc_fault(address) < 0)