[PATCH v2 11/27 5.10.y] minmax: allow comparisons of 'int' against 'unsigned char/short'

Eliav Farber
2025-10-17T09:09:03Z

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

[ Upstream commit 4ead534fba42fc4fd41163297528d2aa731cd121 ]

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>
Signed-off-by: Eliav Farber <farbere@amazon.com>
---
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 c0e738eacefa..842c1db62ffe 100644
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -26,8 +26,9 @@
__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 >
--
2.47.3