[PATCH v1 10/10] mm/usercopy.c: Update comment in check_page_span() regarding ZONE_DEVICE

[David Hildenbrand]

ZONE_DEVICE (a.k.a. device memory) is no longer marked PG_reserved. Update
the comment.

While at it, make it match what the code is acutally doing (reject vs.
accept).

Cc: Kees Cook <keescook at chromium.org>
Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: "Isaac J. Manjarres" <isaacm at codeaurora.org>
Cc: "Matthew Wilcox (Oracle)" <willy at infradead.org>
Cc: Qian Cai <cai at lca.pw>
Cc: Thomas Gleixner <tglx at linutronix.de>
Signed-off-by: David Hildenbrand <david at redhat.com>
---
 mm/usercopy.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/usercopy.c b/mm/usercopy.c
index 660717a1ea5c..80f254024c97 100644
--- a/mm/usercopy.c
+++ b/mm/usercopy.c
@@ -199,9 +199,9 @@ static inline void check_page_span(const void *ptr, unsigned long n,
 		return;
 
 	/*
-	 * Reject if range is entirely either Reserved (i.e. special or
-	 * device memory), or CMA. Otherwise, reject since the object spans
-	 * several independently allocated pages.
+	 * Accept if the range is entirely either Reserved ("special") or
+	 * CMA. Otherwise, reject since the object spans several independently
+	 * allocated pages.
 	 */
 	is_reserved = PageReserved(page);
 	is_cma = is_migrate_cma_page(page);
-- 
2.21.0