From:   sxwjean@me.com
To:     akpm@linux-foundation.org, linux-mm@kvack.org
Cc:     linux-kernel@vger.kernel.org, Xiongwei Song <sxwjean@gmail.com>,
        Arthur Marsh <arthur.marsh@internode.on.net>
Subject: [PATCH] mm: page_alloc: Fix building error on -Werror=array-compare
Date:   Thu, 25 Nov 2021 21:09:28 +0800
Message-Id: <20211125130928.32465-1-sxwjean@me.com>
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From: Xiongwei Song <sxwjean@gmail.com>

Arthur Marsh reported we would hit the error below when building kernel
with gcc-12:
CC      mm/page_alloc.o
mm/page_alloc.c: In function ‘mem_init_print_info’:
mm/page_alloc.c:8173:27: error: comparison between two arrays [-Werror=array-compare]
 8173 |                 if (start <= pos && pos < end && size > adj) \
      |

In C++20, the comparision between arrays should be warned.

Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
---
 mm/page_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c5952749ad40..8f304c3d0e19 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8170,7 +8170,7 @@ void __init mem_init_print_info(void)
 	 */
 #define adj_init_size(start, end, size, pos, adj) \
 	do { \
-		if (start <= pos && pos < end && size > adj) \
+		if (&start[0] <= &pos[0] && &pos[0] < &end[0] && size > adj) \
 			size -= adj; \
 	} while (0)
 
-- 
2.30.2