mm: page_alloc: fix building error on -Werror=array-compare

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>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 25c21aa398f8cfc91bbdc54644820368c83f2a25..a6e682569e5b980b8c57d872fb2d7d41f07c6ce2 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6504,7 +6504,7 @@ void __init mem_init_print_info(const char *str)
         */
 #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)