Merge git://git.kernel.org/pub/scm/linux/kernel/git/perex/alsa

[powerpc.git] / arch / powerpc / mm / fault.c

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index ec4adcb..fdbba42 100644 (file)
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -177,15 +177,15 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
 
        /* When running in the kernel we expect faults to occur only to
         * addresses in user space.  All other faults represent errors in the
-        * kernel and should generate an OOPS.  Unfortunatly, in the case of an
-        * erroneous fault occuring in a code path which already holds mmap_sem
+        * kernel and should generate an OOPS.  Unfortunately, in the case of an
+        * erroneous fault occurring in a code path which already holds mmap_sem
         * we will deadlock attempting to validate the fault against the
         * address space.  Luckily the kernel only validly references user
         * space from well defined areas of code, which are listed in the
         * exceptions table.
         *
         * As the vast majority of faults will be valid we will only perform
-        * the source reference check when there is a possibilty of a deadlock.
+        * the source reference check when there is a possibility of a deadlock.
         * Attempt to lock the address space, if we cannot we then validate the
         * source.  If this is invalid we can skip the address space check,
         * thus avoiding the deadlock.
@@ -267,25 +267,29 @@ good_area:
 #endif
 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
                pte_t *ptep;
+               pmd_t *pmdp;
 
                /* Since 4xx/Book-E supports per-page execute permission,
                 * we lazily flush dcache to icache. */
                ptep = NULL;
-               if (get_pteptr(mm, address, &ptep) && pte_present(*ptep)) {
-                       struct page *page = pte_page(*ptep);
-
-                       if (! test_bit(PG_arch_1, &page->flags)) {
-                               flush_dcache_icache_page(page);
-                               set_bit(PG_arch_1, &page->flags);
+               if (get_pteptr(mm, address, &ptep, &pmdp)) {
+                       spinlock_t *ptl = pte_lockptr(mm, pmdp);
+                       spin_lock(ptl);
+                       if (pte_present(*ptep)) {
+                               struct page *page = pte_page(*ptep);
+
+                               if (!test_bit(PG_arch_1, &page->flags)) {
+                                       flush_dcache_icache_page(page);
+                                       set_bit(PG_arch_1, &page->flags);
+                               }
+                               pte_update(ptep, 0, _PAGE_HWEXEC);
+                               _tlbie(address);
+                               pte_unmap_unlock(ptep, ptl);
+                               up_read(&mm->mmap_sem);
+                               return 0;
                        }
-                       pte_update(ptep, 0, _PAGE_HWEXEC);
-                       _tlbie(address);
-                       pte_unmap(ptep);
-                       up_read(&mm->mmap_sem);
-                       return 0;
+                       pte_unmap_unlock(ptep, ptl);
                }
-               if (ptep != NULL)
-                       pte_unmap(ptep);
 #endif
        /* a write */
        } else if (is_write) {