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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Xiongwei Song <sxwjean@gmail.com>,
        Arthur Marsh <arthur.marsh@internode.on.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Khem Raj <raj.khem@gmail.com>
Subject: [PATCH 4.9 02/24] mm: page_alloc: fix building error on -Werror=array-compare
Date:   Tue, 26 Apr 2022 10:20:56 +0200
Message-Id: <20220426081731.445639121@linuxfoundation.org>
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From: Xiongwei Song <sxwjean@gmail.com>

commit ca831f29f8f25c97182e726429b38c0802200c8f upstream.

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.

Link: https://lkml.kernel.org/r/20211125130928.32465-1-sxwjean@me.com
Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 mm/page_alloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6504,7 +6504,7 @@ void __init mem_init_print_info(const ch
 	 */
 #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)