Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/mm/fault.c | 31 +++++++++----------------------
1 files changed, 9 insertions(+), 22 deletions(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index e28cc52..2737493 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -508,6 +508,10 @@ static int vmalloc_fault(unsigned long address)
pmd_t *pmd, *pmd_ref;
pte_t *pte, *pte_ref;
+ /* Make sure we are in vmalloc area */
+ if (!(address >= VMALLOC_START && address < VMALLOC_END))
+ return -1;
+
/* Copy kernel mappings over when needed. This can also
happen within a race in page table update. In the later
case just flush. */
@@ -603,6 +607,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
*/
#ifdef CONFIG_X86_32
if (unlikely(address >= TASK_SIZE)) {
+#else
+ if (unlikely(address >= TASK_SIZE64)) {
+#endif
if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
vmalloc_fault(address) >= 0)
return;
@@ -618,6 +625,8 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
goto bad_area_nosemaphore;
}
+
+#ifdef CONFIG_X86_32
/* It's safe to allow irq's after cr2 has been saved and the vmalloc
fault has been handled. */
if (regs->flags & (X86_EFLAGS_IF|VM_MASK))
@@ -630,28 +639,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
if (in_atomic() || !mm)
goto bad_area_nosemaphore;
#else /* CONFIG_X86_64 */
- if (unlikely(address >= TASK_SIZE64)) {
- /*
- * Don't check for the module range here: its PML4
- * is always initialized because it's shared with the main
- * kernel text. Only vmalloc may need PML4 syncups.
- */
- if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
- ((address >= VMALLOC_START && address < VMALLOC_END))) {
- if (vmalloc_fault(address) >= 0)
- return;
- }
-
- /* Can handle a stale RO->RW TLB */
- if (spurious_fault(address, error_code))
- return;
-
- /*
- * Don't take the mm semaphore here. If we fixup a prefetch
- * fault we could otherwise deadlock.
- */
- goto bad_area_nosemaphore;
- }
if (likely(regs->flags & X86_EFLAGS_IF))
local_irq_enable();
--
1.5.4.rc4.1142.gf5a97
--
