From d538c164fc018bdb79f07f904fa9d48acf18bb0a Mon Sep 17 00:00:00 2001
From: Wei Yang <richard.weiyang@gmail.com>
Date: Thu, 7 Jun 2018 17:06:39 -0700
Subject: [PATCH] mm/sparse.c: check __highest_present_section_nr only for a
 present section

When searching a present section, there are two boundaries:

    * __highest_present_section_nr
    * NR_MEM_SECTIONS

And it is known, __highest_present_section_nr is a more strict boundary
than NR_MEM_SECTIONS.  This means it would be necessary to check
__highest_present_section_nr only.

Link: http://lkml.kernel.org/r/20180326081956.75275-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/sparse.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/sparse.c b/mm/sparse.c
index 73dc2fcc0eab2..3570ff294ab1c 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -190,15 +190,13 @@ static inline int next_present_section_nr(int section_nr)
 		section_nr++;
 		if (present_section_nr(section_nr))
 			return section_nr;
-	} while ((section_nr < NR_MEM_SECTIONS) &&
-		 (section_nr <= __highest_present_section_nr));
+	} while ((section_nr <= __highest_present_section_nr));
 
 	return -1;
 }
 #define for_each_present_section_nr(start, section_nr)		\
 	for (section_nr = next_present_section_nr(start-1);	\
 	     ((section_nr >= 0) &&				\
-	      (section_nr < NR_MEM_SECTIONS) &&			\
 	      (section_nr <= __highest_present_section_nr));	\
 	     section_nr = next_present_section_nr(section_nr))
 
-- 
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