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>

diff --git a/mm/mmap.c b/mm/mmap.c
index 9b12e30..a23e30f 100644 (file)
--- 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);