Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

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

diff --git a/mm/gup.c b/mm/gup.c
index a798293fc6486bac215ecb58ed071263a5f775f0..deafa2c91b362206b7ef56aec918509a9cc24dd2 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -129,7 +129,7 @@ retry:
                 */
                mark_page_accessed(page);
        }
-       if ((flags & FOLL_POPULATE) && (vma->vm_flags & VM_LOCKED)) {
+       if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
                /*
                 * The preliminary mapping check is mainly to avoid the
                 * pointless overhead of lock_page on the ZERO_PAGE
@@ -299,6 +299,9 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma,
        unsigned int fault_flags = 0;
        int ret;
 
+       /* mlock all present pages, but do not fault in new pages */
+       if ((*flags & (FOLL_POPULATE | FOLL_MLOCK)) == FOLL_MLOCK)
+               return -ENOENT;
        /* For mm_populate(), just skip the stack guard page. */
        if ((*flags & FOLL_POPULATE) &&
                        (stack_guard_page_start(vma, address) ||
@@ -890,7 +893,10 @@ long populate_vma_page_range(struct vm_area_struct *vma,
        VM_BUG_ON_VMA(end   > vma->vm_end, vma);
        VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);
 
-       gup_flags = FOLL_TOUCH | FOLL_POPULATE;
+       gup_flags = FOLL_TOUCH | FOLL_POPULATE | FOLL_MLOCK;
+       if (vma->vm_flags & VM_LOCKONFAULT)
+               gup_flags &= ~FOLL_POPULATE;
+
        /*
         * We want to touch writable mappings with a write fault in order
         * to break COW, except for shared mappings because these don't COW