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;
 }