mm: make do_mmap_pgoff return populate as a size in bytes, not as a bool

do_mmap_pgoff() rounds up the desired size to the next PAGE_SIZE
multiple, however there was no equivalent code in mm_populate(), which
caused issues.

This could be fixed by introduced the same rounding in mm_populate(),
however I think it's preferable to make do_mmap_pgoff() return populate
as a size rather than as a boolean, so we don't have to duplicate the
size rounding logic in mm_populate().

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, 3 insertions, 3 deletions

diff --git a/mm/util.c b/mm/util.c
index 13467e043e9e..3704bf1bef94 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -355,7 +355,7 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
 {
         unsigned long ret;
         struct mm_struct *mm = current->mm;
-        bool populate;
+        unsigned long populate;
 
         ret = security_mmap_file(file, prot, flag);
         if (!ret) {
@@ -363,8 +363,8 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
                 ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
                                     &populate);
                 up_write(&mm->mmap_sem);
-                if (!IS_ERR_VALUE(ret) && populate)
-                        mm_populate(ret, len);
+                if (populate)
+                        mm_populate(ret, populate);
         }
         return ret;
 }