Patch "minmax: don't use max() in situations that want a C constant expression" has been added to the 5.10-stable tree

gregkh
2025-10-17T13:49:01Z

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

minmax: don't use max() in situations that want a C constant expression

to the 5.10-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-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch
and it can be found in the queue-5.10 subdirectory.

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

From prvs=378230090=farbere@amazon.com Fri Oct 17 11:11:06 2025
From: Eliav Farber <farbere@amazon.com>
Date: Fri, 17 Oct 2025 09:05:09 +0000
Subject: minmax: don't use max() in situations that want a C constant expression
To: <gregkh@linuxfoundation.org>, <stable@vger.kernel.org>, <linux@armlinux.org.uk>, <jdike@addtoit.com>, <richard@nod.at>, <anton.ivanov@cambridgegreys.com>, <dave.hansen@linux.intel.com>, <luto@kernel.org>, <peterz@infradead.org>, <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>, <x86@kernel.org>, <hpa@zytor.com>, <tony.luck@intel.com>, <qiuxu.zhuo@intel.com>, <mchehab@kernel.org>, <james.morse@arm.com>, <rric@kernel.org>, <harry.wentland@amd.com>, <sunpeng.li@amd.com>, <alexander.deucher@amd.com>, <christian.koenig@amd.com>, <airlied@linux.ie>, <daniel@ffwll.ch>, <evan.quan@amd.com>, <james.qian.wang@arm.com>, <liviu.dudau@arm.com>, <mihail.atanassov@arm.com>, <brian.starkey@arm.com>, <maarten.lankhorst@linux.intel.com>, <mripard@kernel.org>, <tzimmermann@suse.de>, <robdclark@gmail.com>, <sean@poorly.run>, <jdelvare@suse.com>, <linux@roeck-us.net>, <fery@cypress.com>, <dmitry.torokhov@gmail.com>, <agk@redhat.com>, <snitzer@redhat.com>, <dm-devel@redhat.com>, <rajur
@chelsio
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on.com>,
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cussion@
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Cc: Linus Torvalds <torvalds@linux-foundation.org>, David Laight <David.Laight@aculab.com>, Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Message-ID: <20251017090519.46992-18-farbere@amazon.com>

From: Linus Torvalds <torvalds@linux-foundation.org>

[ Upstream commit cb04e8b1d2f24c4c2c92f7b7529031fc35a16fed ]

We only had a couple of array[] declarations, and changing them to just
use 'MAX()' instead of 'max()' fixes the issue.

This will allow us to simplify our min/max macros enormously, since they
can now unconditionally use temporary variables to avoid using the
argument values multiple times.

Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/input/touchscreen/cyttsp4_core.c | 2 +-
drivers/md/dm-integrity.c | 4 ++--
fs/btrfs/tree-checker.c | 2 +-
lib/vsprintf.c | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/input/touchscreen/cyttsp4_core.c
+++ b/drivers/input/touchscreen/cyttsp4_core.c
@@ -857,7 +857,7 @@ static void cyttsp4_get_mt_touches(struc
struct cyttsp4_touch tch;
int sig;
int i, j, t = 0;
- int ids[max(CY_TMA1036_MAX_TCH, CY_TMA4XX_MAX_TCH)];
+ int ids[MAX(CY_TMA1036_MAX_TCH, CY_TMA4XX_MAX_TCH)];

memset(ids, 0, si->si_ofs.tch_abs[CY_TCH_T].max * sizeof(int));
for (i = 0; i < num_cur_tch; i++) {
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1600,7 +1600,7 @@ static void integrity_metadata(struct wo
struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
char *checksums;
unsigned extra_space = unlikely(digest_size > ic->tag_size) ? digest_size - ic->tag_size : 0;
- char checksums_onstack[max((size_t)HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
+ char checksums_onstack[MAX(HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
sector_t sector;
unsigned sectors_to_process;

@@ -1882,7 +1882,7 @@ retry_kmap:
} while (++s < ic->sectors_per_block);
#ifdef INTERNAL_VERIFY
if (ic->internal_hash) {
- char checksums_onstack[max((size_t)HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
+ char checksums_onstack[MAX(HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];

integrity_sector_checksum(ic, logical_sector, mem + bv.bv_offset, checksums_onstack);
if (unlikely(memcmp(checksums_onstack, journal_entry_tag(ic, je), ic->tag_size))) {
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -587,7 +587,7 @@ static int check_dir_item(struct extent_
*/
if (key->type == BTRFS_DIR_ITEM_KEY ||
key->type == BTRFS_XATTR_ITEM_KEY) {
- char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)];
+ char namebuf[MAX(BTRFS_NAME_LEN, XATTR_NAME_MAX)];

read_extent_buffer(leaf, namebuf,
(unsigned long)(di + 1), name_len);
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1078,7 +1078,7 @@ char *resource_string(char *buf, char *e
#define FLAG_BUF_SIZE (2 * sizeof(res->flags))
#define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
#define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
- char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
+ char sym[MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];

char *p = sym, *pend = sym + sizeof(sym);

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

queue-5.10/minmax-allow-comparisons-of-int-against-unsigned-char-short.patch
queue-5.10/minmax-add-a-few-more-min_t-max_t-users.patch
queue-5.10/minmax-improve-macro-expansion-and-type-checking.patch
queue-5.10/minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch
queue-5.10/minmax.h-simplify-the-variants-of-clamp.patch
queue-5.10/minmax-add-in_range-macro.patch
queue-5.10/minmax.h-move-all-the-clamp-definitions-after-the-min-max-ones.patch
queue-5.10/minmax-allow-min-max-clamp-if-the-arguments-have-the-same-signedness.patch
queue-5.10/minmax-don-t-use-max-in-situations-that-want-a-c-constant-expression.patch
queue-5.10/minmax.h-remove-some-defines-that-are-only-expanded-once.patch
queue-5.10/minmax.h-use-build_bug_on_msg-for-the-lo-hi-test-in-clamp.patch
queue-5.10/minmax-simplify-min-max-clamp-implementation.patch
queue-5.10/minmax-deduplicate-__unconst_integer_typeof.patch
queue-5.10/minmax-simplify-and-clarify-min_t-max_t-implementation.patch
queue-5.10/minmax.h-add-whitespace-around-operators-and-after-commas.patch
queue-5.10/minmax-sanity-check-constant-bounds-when-clamping.patch
queue-5.10/minmax-avoid-overly-complicated-constant-expressions-in-vm-code.patch
queue-5.10/minmax-make-generic-min-and-max-macros-available-everywhere.patch
queue-5.10/minmax-fix-up-min3-and-max3-too.patch
queue-5.10/minmax.h-reduce-the-define-expansion-of-min-max-and-clamp.patch
queue-5.10/minmax-fix-header-inclusions.patch
queue-5.10/minmax-introduce-min-max-_array.patch
queue-5.10/btrfs-remove-duplicated-in_range-macro.patch
queue-5.10/overflow-tracing-define-the-is_signed_type-macro-once.patch
queue-5.10/minmax-relax-check-to-allow-comparison-between-unsigned-arguments-and-signed-constants.patch
queue-5.10/minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch
queue-5.10/minmax.h-update-some-comments.patch