[PATCH] uml: locking commentary in the random driver

[firefly-linux-kernel-4.4.55.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index af227d26e104674e324f99c5f135f3f34e8b4d22..0e6a402d86bee7edf968b1ef97f8b46a42f37a52 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -678,7 +678,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
                                if (pte_dirty(ptent))
                                        set_page_dirty(page);
                                if (pte_young(ptent))
-                                       mark_page_accessed(page);
+                                       SetPageReferenced(page);
                                file_rss--;
                        }
                        page_remove_rmap(page, vma);
@@ -1531,8 +1531,6 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                        if (vma->vm_ops->page_mkwrite(vma, old_page) < 0)
                                goto unwritable_page;
 
-                       page_cache_release(old_page);
-
                        /*
                         * Since we dropped the lock we need to revalidate
                         * the PTE as someone else may have changed it.  If
@@ -1541,6 +1539,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                         */
                        page_table = pte_offset_map_lock(mm, pmd, address,
                                                         &ptl);
+                       page_cache_release(old_page);
                        if (!pte_same(*page_table, orig_pte))
                                goto unlock;
                }
@@ -2606,8 +2605,15 @@ static int __init gate_vma_init(void)
        gate_vma.vm_mm = NULL;
        gate_vma.vm_start = FIXADDR_USER_START;
        gate_vma.vm_end = FIXADDR_USER_END;
-       gate_vma.vm_page_prot = PAGE_READONLY;
-       gate_vma.vm_flags = 0;
+       gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
+       gate_vma.vm_page_prot = __P101;
+       /*
+        * Make sure the vDSO gets into every core dump.
+        * Dumping its contents makes post-mortem fully interpretable later
+        * without matching up the same kernel and hardware config to see
+        * what PC values meant.
+        */
+       gate_vma.vm_flags |= VM_ALWAYSDUMP;
        return 0;
 }
 __initcall(gate_vma_init);