Merge branch 'core/urgent' into locking/urgent, to collect all pending locking fixes

[pandora-kernel.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index d8aebc5..d7e497e 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2378,12 +2378,12 @@ void unmap_mapping_range(struct address_space *mapping,
                details.last_index = ULONG_MAX;
 
 
-       i_mmap_lock_read(mapping);
+       i_mmap_lock_write(mapping);
        if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap)))
                unmap_mapping_range_tree(&mapping->i_mmap, &details);
        if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
                unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
-       i_mmap_unlock_read(mapping);
+       i_mmap_unlock_write(mapping);
 }
 EXPORT_SYMBOL(unmap_mapping_range);
 
@@ -2593,7 +2593,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
                if (prev && prev->vm_end == address)
                        return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
 
-               expand_downwards(vma, address - PAGE_SIZE);
+               return expand_downwards(vma, address - PAGE_SIZE);
        }
        if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) {
                struct vm_area_struct *next = vma->vm_next;
@@ -2602,7 +2602,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
                if (next && next->vm_start == address + PAGE_SIZE)
                        return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM;
 
-               expand_upwards(vma, address + PAGE_SIZE);
+               return expand_upwards(vma, address + PAGE_SIZE);
        }
        return 0;
 }
@@ -3195,7 +3195,16 @@ static int handle_pte_fault(struct mm_struct *mm,
        pte_t entry;
        spinlock_t *ptl;
 
-       entry = ACCESS_ONCE(*pte);
+       /*
+        * some architectures can have larger ptes than wordsize,
+        * e.g.ppc44x-defconfig has CONFIG_PTE_64BIT=y and CONFIG_32BIT=y,
+        * so READ_ONCE or ACCESS_ONCE cannot guarantee atomic accesses.
+        * The code below just needs a consistent view for the ifs and
+        * we later double check anyway with the ptl lock held. So here
+        * a barrier will do.
+        */
+       entry = *pte;
+       barrier();
        if (!pte_present(entry)) {
                if (pte_none(entry)) {
                        if (vma->vm_ops) {