[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 bf6100236e6270336651229acbb2056021a68991..0e6a402d86bee7edf968b1ef97f8b46a42f37a52 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -678,10 +678,10 @@ 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);
+                       page_remove_rmap(page, vma);
                        tlb_remove_page(tlb, page);
                        continue;
                }
@@ -1091,7 +1091,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                        if (pages) {
                                pages[i] = page;
 
-                               flush_anon_page(page, start);
+                               flush_anon_page(vma, page, start);
                                flush_dcache_page(page);
                        }
                        if (vmas)
@@ -1441,7 +1441,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
        return pte;
 }
 
-static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va)
+static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)
 {
        /*
         * If the source page was a PFN mapping, we don't have
@@ -1464,9 +1464,9 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
                kunmap_atomic(kaddr, KM_USER0);
                flush_dcache_page(dst);
                return;
-               
+
        }
-       copy_user_highpage(dst, src, va);
+       copy_user_highpage(dst, src, va, 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;
                }
@@ -1577,7 +1576,7 @@ gotten:
                new_page = alloc_page_vma(GFP_HIGHUSER, vma, address);
                if (!new_page)
                        goto oom;
-               cow_user_page(new_page, old_page, address);
+               cow_user_page(new_page, old_page, address, vma);
        }
 
        /*
@@ -1586,7 +1585,7 @@ gotten:
        page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
        if (likely(pte_same(*page_table, orig_pte))) {
                if (old_page) {
-                       page_remove_rmap(old_page);
+                       page_remove_rmap(old_page, vma);
                        if (!PageAnon(old_page)) {
                                dec_mm_counter(mm, file_rss);
                                inc_mm_counter(mm, anon_rss);
@@ -2200,7 +2199,7 @@ retry:
                        page = alloc_page_vma(GFP_HIGHUSER, vma, address);
                        if (!page)
                                goto oom;
-                       copy_user_highpage(page, new_page, address);
+                       copy_user_highpage(page, new_page, address, vma);
                        page_cache_release(new_page);
                        new_page = page;
                        anon = 1;
@@ -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);