From 4e7e5697243c985136ea08167a04ffd8312c33da Mon Sep 17 00:00:00 2001
From: Todd Poynor <toddpoynor@google.com>
Date: Thu, 19 Jul 2018 20:49:13 -0700
Subject: [PATCH] staging: gasket: gasket_mmap use PAGE_MASK

gasket_mmap use PAGE_MASK, instead of performing math on PAGE_SIZE, for
simplicity and clarity.

Reported-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Simon Que <sque@chromium.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 gasket_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gasket_core.c b/gasket_core.c
index 43c63da..610d035 100644
--- a/gasket_core.c
+++ b/gasket_core.c
@@ -1601,7 +1601,7 @@ static int gasket_mmap(struct file *filp, struct vm_area_struct *vma)
 	}
 	driver_desc = gasket_dev->internal_desc->driver_desc;
 
-	if (vma->vm_start & (PAGE_SIZE - 1)) {
+	if (vma->vm_start & ~PAGE_MASK) {
 		gasket_log_error(
 			gasket_dev, "Base address not page-aligned: 0x%p\n",
 			(void *)vma->vm_start);