The patch titled
Subject: minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
minmaxh-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/minmaxh-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: David Laight <David.Laight@xxxxxxxxxx>
Subject: minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
Date: Mon, 18 Nov 2024 19:13:31 +0000
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@xxxxxxxxxxxxxxxx
Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Jason A. Donenfeld <Jason@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Mateusz Guzik <mjguzik@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Pedro Falcato <pedro.falcato@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/minmax.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/include/linux/minmax.h~minmaxh-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp
+++ a/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 -mm which might be from David.Laight@xxxxxxxxxx are
minmaxh-add-whitespace-around-operators-and-after-commas.patch
minmaxh-update-some-comments.patch
minmaxh-reduce-the-define-expansion-of-min-max-and-clamp.patch
minmaxh-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch
minmaxh-move-all-the-clamp-definitions-after-the-min-max-ones.patch
minmaxh-simplify-the-variants-of-clamp.patch
minmaxh-remove-some-defines-that-are-only-expanded-once.patch
