Patch "minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()" has been added to the 5.15-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 5.15-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-5.15 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 prvs=36971892a=farbere at amazon.com Wed Oct  8 17:34:59 2025
From: Eliav Farber <farbere at amazon.com>
Date: Wed, 8 Oct 2025 15:29:41 +0000
Subject: minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
To: <gregkh at linuxfoundation.org>, <jdike at addtoit.com>, <richard at nod.at>, <anton.ivanov at cambridgegreys.com>, <dave.hansen at linux.intel.com>, <luto at kernel.org>, <peterz at infradead.org>, <tglx at linutronix.de>, <mingo at redhat.com>, <bp at alien8.de>, <x86 at kernel.org>, <hpa at zytor.com>, <tony.luck at intel.com>, <qiuxu.zhuo at intel.com>, <james.morse at arm.com>, <rric at kernel.org>, <airlied at linux.ie>, <daniel at ffwll.ch>, <maarten.lankhorst at linux.intel.com>, <mripard at kernel.org>, <tzimmermann at suse.de>, <robdclark at gmail.com>, <sean at poorly.run>, <jdelvare at suse.com>, <linux at roeck-us.net>, <linus.walleij at linaro.org>, <dmitry.torokhov at gmail.com>, <maz at kernel.org>, <wens at csie.org>, <jernej.skrabec at gmail.com>, <agk at redhat.com>, <snitzer at redhat.com>, <dm-devel at redhat.com>, <davem at davemloft.net>, <kuba at kernel.org>, <mcoquelin.stm32 at gmail.com>, <krzysztof.kozlowski at canonical.com>, <malattia at linux.it>, <hdegoede at redhat.com>, <mgross at linux.intel.com>, <jejb at linux.ibm.com>, <martin.petersen at oracle.com>, <sakari.ailus at l
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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>, "Pedro Falcato" <pedro.falcato at gmail.com>
Message-ID: <20251008152946.29285-17-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-5.15/minmax-add-a-few-more-min_t-max_t-users.patch
queue-5.15/minmax-improve-macro-expansion-and-type-checking.patch
queue-5.15/minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch
queue-5.15/minmax.h-simplify-the-variants-of-clamp.patch
queue-5.15/minmax-add-in_range-macro.patch
queue-5.15/minmax.h-move-all-the-clamp-definitions-after-the-min-max-ones.patch
queue-5.15/minmax-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch
queue-5.15/minmax.h-remove-some-defines-that-are-only-expanded-once.patch
queue-5.15/minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch
queue-5.15/minmax-simplify-min-max-clamp-implementation.patch
queue-5.15/minmax-deduplicate-__unconst_integer_typeof.patch
queue-5.15/minmax-simplify-and-clarify-min_t-max_t-implementation.patch
queue-5.15/minmax.h-add-whitespace-around-operators-and-after-commas.patch
queue-5.15/minmax-avoid-overly-complicated-constant-expressions-in-vm-code.patch
queue-5.15/minmax-make-generic-min-and-max-macros-available-everywhere.patch
queue-5.15/minmax-fix-up-min3-and-max3-too.patch
queue-5.15/minmax.h-reduce-the-define-expansion-of-min-max-and-clamp.patch
queue-5.15/minmax-introduce-min-max-_array.patch
queue-5.15/minmax.h-update-some-comments.patch