Patch "minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()" has been added to the 6.1-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From stable+bounces-183179-greg=kroah.com at vger.kernel.org Fri Oct  3 14:27:07 2025
From: Eliav Farber <farbere at amazon.com>
Date: Fri, 3 Oct 2025 12:15:17 +0000
Subject: minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
To: <gregkh at linuxfoundation.org>, <kenneth.feng at amd.com>, <alexander.deucher at amd.com>, <christian.koenig at amd.com>, <airlied at gmail.com>, <simona at ffwll.ch>, <linus.walleij at linaro.org>, <dmitry.torokhov at gmail.com>, <tglx at linutronix.de>, <wens at csie.org>, <jernej.skrabec at gmail.com>, <samuel at sholland.org>, <agk at redhat.com>, <snitzer at kernel.org>, <mpatocka at redhat.com>, <clm at fb.com>, <dsterba at suse.com>, <luc.vanoostenryck at gmail.com>, <pmladek at suse.com>, <rostedt at goodmis.org>, <andriy.shevchenko at linux.intel.com>, <linux at rasmusvillemoes.dk>, <senozhatsky at chromium.org>, <akpm at linux-foundation.org>, <lijo.lazar at amd.com>, <asad.kamal at amd.com>, <kevinyang.wang at amd.com>, <David.Laight at ACULAB.COM>, <amd-gfx at lists.freedesktop.org>, <dri-devel at lists.freedesktop.org>, <linux-kernel at vger.kernel.org>, <linux-input at vger.kernel.org>, <linux-arm-kernel at lists.infradead.org>, <linux-sunxi at lists.linux.dev>, <dm-devel at lists.linux.dev>, <linux-btrfs at vger.kernel.org>, <linux-sparse at vger.kernel.org>, <stable at vger.
 kernel.org>, <farbere at amazon.com>
Cc: Arnd Bergmann <arnd at kernel.org>, Christoph Hellwig <hch at infradead.org>, Dan Carpenter <dan.carpenter at linaro.org>, "Jason A. Donenfeld" <Jason at zx2c4.com>, Jens Axboe <axboe at kernel.dk>, Lorenzo Stoakes <lorenzo.stoakes at oracle.com>, Mateusz Guzik <mjguzik at gmail.com>, "Matthew Wilcox" <willy at infradead.org>, Pedro Falcato <pedro.falcato at gmail.com>
Message-ID: <20251003121520.8176-9-farbere at amazon.com>

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

[ Upstream commit a5743f32baec4728711bbc01d6ac2b33d4c67040 ]

Use BUILD_BUG_ON_MSG(statically_true(ulo > uhi), ...) for the sanity check
of the bounds in clamp().  Gives better error coverage and one less
expansion of the arguments.

Link: https://lkml.kernel.org/r/34d53778977747f19cce2abb287bb3e6@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight at aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Cc: Arnd Bergmann <arnd at kernel.org>
Cc: Christoph Hellwig <hch at infradead.org>
Cc: Dan Carpenter <dan.carpenter at linaro.org>
Cc: Jason A. Donenfeld <Jason at zx2c4.com>
Cc: Jens Axboe <axboe at kernel.dk>
Cc: Lorenzo Stoakes <lorenzo.stoakes at oracle.com>
Cc: Mateusz Guzik <mjguzik at gmail.com>
Cc: Matthew Wilcox <willy at infradead.org>
Cc: Pedro Falcato <pedro.falcato at gmail.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Eliav Farber <farbere at amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 include/linux/minmax.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -106,8 +106,7 @@
 	__auto_type uval = (val);						\
 	__auto_type ulo = (lo);							\
 	__auto_type uhi = (hi);							\
-	static_assert(__builtin_choose_expr(__is_constexpr((lo) > (hi)), 	\
-			(lo) <= (hi), true),					\
+	BUILD_BUG_ON_MSG(statically_true(ulo > uhi),				\
 		"clamp() low limit " #lo " greater than high limit " #hi);	\
 	BUILD_BUG_ON_MSG(!__types_ok3(uval, ulo, uhi),				\
 		"clamp("#val", "#lo", "#hi") signedness error");		\


Patches currently in stable-queue which might be from farbere at amazon.com are

queue-6.1/minmax-improve-macro-expansion-and-type-checking.patch
queue-6.1/minmax.h-simplify-the-variants-of-clamp.patch
queue-6.1/minmax.h-move-all-the-clamp-definitions-after-the-min-max-ones.patch
queue-6.1/minmax-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch
queue-6.1/minmax.h-remove-some-defines-that-are-only-expanded-once.patch
queue-6.1/minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch
queue-6.1/minmax-simplify-min-max-clamp-implementation.patch
queue-6.1/minmax.h-add-whitespace-around-operators-and-after-commas.patch
queue-6.1/minmax-fix-up-min3-and-max3-too.patch
queue-6.1/minmax.h-reduce-the-define-expansion-of-min-max-and-clamp.patch
queue-6.1/minmax.h-update-some-comments.patch