1 files changed, 49 insertions, 7 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 71cdefd1ef14..9fef7272fb9e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -64,6 +64,8 @@
 
 #include "internal.h"
 
+#include "internal.h"
+
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 /* use the per-pgdat data instead for discontigmem - mbligh */
 unsigned long max_mapnr;
@@ -1129,12 +1131,17 @@ static inline int use_zero_page(struct vm_area_struct *vma)
         return !vma->vm_ops || !vma->vm_ops->fault;
 }
 
-int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-                unsigned long start, int len, int write, int force,
+
+
+int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+                     unsigned long start, int len, int flags,
                 struct page **pages, struct vm_area_struct **vmas)
 {
         int i;
-        unsigned int vm_flags;
+        unsigned int vm_flags = 0;
+        int write = !!(flags & GUP_FLAGS_WRITE);
+        int force = !!(flags & GUP_FLAGS_FORCE);
+        int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
 
         if (len <= 0)
                 return 0;
@@ -1158,7 +1165,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         pud_t *pud;
                         pmd_t *pmd;
                         pte_t *pte;
-                        if (write) /* user gate pages are read-only */
+
+                        /* user gate pages are read-only */
+                        if (!ignore && write)
                                 return i ? : -EFAULT;
                         if (pg > TASK_SIZE)
                                 pgd = pgd_offset_k(pg);
@@ -1190,8 +1199,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         continue;
                 }
 
-                if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP))
-                                || !(vm_flags & vma->vm_flags))
+                if (!vma ||
+                    (vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+                    (!ignore && !(vm_flags & vma->vm_flags)))
                         return i ? : -EFAULT;
 
                 if (is_vm_hugetlb_page(vma)) {
@@ -1266,6 +1276,23 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
         } while (len);
         return i;
 }
+
+int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+                unsigned long start, int len, int write, int force,
+                struct page **pages, struct vm_area_struct **vmas)
+{
+        int flags = 0;
+
+        if (write)
+                flags |= GUP_FLAGS_WRITE;
+        if (force)
+                flags |= GUP_FLAGS_FORCE;
+
+        return __get_user_pages(tsk, mm,
+                                start, len, flags,
+                                pages, vmas);
+}
+
 EXPORT_SYMBOL(get_user_pages);
 
 pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
@@ -1858,6 +1885,15 @@ gotten:
         new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
         if (!new_page)
                 goto oom;
+        /*
+         * Don't let another task, with possibly unlocked vma,
+         * keep the mlocked page.
+         */
+        if (vma->vm_flags & VM_LOCKED) {
+                lock_page(old_page);    /* for LRU manipulation */
+                clear_page_mlock(old_page);
+                unlock_page(old_page);
+        }
         cow_user_page(new_page, old_page, address, vma);
         __SetPageUptodate(new_page);
 
@@ -2325,7 +2361,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
         page_add_anon_rmap(page, vma, address);
 
         swap_free(entry);
-        if (vm_swap_full())
+        if (vm_swap_full() || (vma->vm_flags & VM_LOCKED) || PageMlocked(page))
                 remove_exclusive_swap_page(page);
         unlock_page(page);
 
@@ -2465,6 +2501,12 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                                 ret = VM_FAULT_OOM;
                                 goto out;
                         }
+                        /*
+                         * Don't let another task, with possibly unlocked vma,
+                         * keep the mlocked page.
+                         */
+                        if (vma->vm_flags & VM_LOCKED)
+                                clear_page_mlock(vmf.page);
                         copy_user_highpage(page, vmf.page, address, vma);
                         __SetPageUptodate(page);
                 } else {