[PATCH 5.15.y 6/8] minmax: allow comparisons of 'int' against 'unsigned char/short'

[SeongJae Park <sj@kernel.org>]

From: David Laight <David.Laight@ACULAB.COM>

commit 4ead534fba42fc4fd41163297528d2aa731cd121 upstream.

Since 'unsigned char/short' get promoted to 'signed int' it is safe to
compare them against an 'int' value.

Link: https://lkml.kernel.org/r/8732ef5f809c47c28a7be47c938b28d4@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 4ead534fba42fc4fd41163297528d2aa731cd121)
Signed-off-by: SeongJae Park <sj@kernel.org>
---
 include/linux/minmax.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/minmax.h b/include/linux/minmax.h
index 501fab582d68..f76b7145fc11 100644
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -25,8 +25,9 @@
 	__builtin_choose_expr(__is_constexpr(is_signed_type(typeof(x))),	\
 		is_signed_type(typeof(x)), 0)
 
-#define __types_ok(x, y) \
-	(__is_signed(x) == __is_signed(y))
+#define __types_ok(x, y) 			\
+	(__is_signed(x) == __is_signed(y) ||	\
+		__is_signed((x) + 0) == __is_signed((y) + 0))
 
 #define __cmp_op_min <
 #define __cmp_op_max >
-- 
2.39.2