mm: use mm_populate() when adjusting brk with MCL_FUTURE in effect

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 4 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 9b12e3047a86..a23e30f9719c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -256,6 +256,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
         unsigned long newbrk, oldbrk;
         struct mm_struct *mm = current->mm;
         unsigned long min_brk;
+        bool populate;
 
         down_write(&mm->mmap_sem);
 
@@ -305,8 +306,15 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
         /* Ok, looks good - let it rip. */
         if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
                 goto out;
+
 set_brk:
         mm->brk = brk;
+        populate = newbrk > oldbrk && (mm->def_flags & VM_LOCKED) != 0;
+        up_write(&mm->mmap_sem);
+        if (populate)
+                mm_populate(oldbrk, newbrk - oldbrk);
+        return brk;
+
 out:
         retval = mm->brk;
         up_write(&mm->mmap_sem);
@@ -2600,10 +2608,8 @@ static unsigned long do_brk(unsigned long addr, unsigned long len)
 out:
         perf_event_mmap(vma);
         mm->total_vm += len >> PAGE_SHIFT;
-        if (flags & VM_LOCKED) {
-                if (!mlock_vma_pages_range(vma, addr, addr + len))
-                        mm->locked_vm += (len >> PAGE_SHIFT);
-        }
+        if (flags & VM_LOCKED)
+                mm->locked_vm += (len >> PAGE_SHIFT);
         return addr;
 }
 
@@ -2611,10 +2617,14 @@ unsigned long vm_brk(unsigned long addr, unsigned long len)
 {
         struct mm_struct *mm = current->mm;
         unsigned long ret;
+        bool populate;
 
         down_write(&mm->mmap_sem);
         ret = do_brk(addr, len);
+        populate = ((mm->def_flags & VM_LOCKED) != 0);
         up_write(&mm->mmap_sem);
+        if (populate)
+                mm_populate(addr, len);
         return ret;
 }
 EXPORT_SYMBOL(vm_brk);