From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E4420CCD193 for ; Sat, 18 Oct 2025 08:51:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A474810ED01; Sat, 18 Oct 2025 08:50:59 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GdFnBKLq"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1B8D010EBF7; Fri, 17 Oct 2025 13:49:59 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 70BC46439D; Fri, 17 Oct 2025 13:49:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 133B9C4CEF9; Fri, 17 Oct 2025 13:49:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760708998; bh=JbeTxONLotsoUmGtlE2ZrdbmSRZbe9l8UZPkeUV3olA=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=GdFnBKLqHQxvvfCRS1tGiWNmdF45QR+5n7uf4kfPOU5GYBP/qILxzCeToRALQL8MS m+zYFVkpdBHkUgOXssgxOUwGkkVGfNVpBKtqameWvt5NQbO7qWrkuza+nSukckry2b JX2ay7ftEAMBlmpMnwVBHOKhgC3CpPNVh9CZd9Xo= Subject: Patch "minmax.h: update some comments" has been added to the 5.10-stable tree To: David.Laight@ACULAB.COM, Jason@zx2c4.com, adilger.kernel@dilger.ca, agk@redhat.com, airlied@linux.ie, akpm@linux-foundation.org, alexander.deucher@amd.com, alexandre.torgue@st.com, amd-gfx@lists.freedesktop.org, andriy.shevchenko@linux.intel.com, anton.ivanov@cambridgegreys.com, arnd@kernel.org, artur.paszkiewicz@intel.com, axboe@kernel.dk, bp@alien8.de, brian.starkey@arm.com, bvanassche@acm.org, chao@kernel.org, christian.koenig@amd.com, clm@fb.com, coreteam@netfilter.org, dan.carpenter@linaro.org, daniel@ffwll.ch, dave.hansen@linux.intel.com, davem@davemloft.net, david.laight@aculab.com, dm-devel@redhat.com, dmitry.torokhov@gmail.com, dri-devel@lists.freedesktop.org, dsterba@suse.com, dushistov@mail.ru, evan.quan@amd.com, farbere@amazon.com, fery@cypress.com, freedreno@lists.freedesktop.org, fw@strlen.de, gregkh@linuxfoundation.org, harry.wentland@amd.com, hch@infradead.org, hdegoede@redhat.com, herve.codina@bootlin.com, hpa@zytor.com, intel-linux-scu@intel.com, jack@suse.com, james.morse@arm.com, james.qian.wang@arm.com, jdelvare@suse.com, jdike@addtoit.com, jejb@linux.ibm.com, jmaloy@redhat.com, joabreu@synopsys.com, josef@toxicpanda.com, kadlec@netfilter.org, kbusch@kernel.org, keescook@chromium.org, kuba@kernel.org, kuznet@ms2.inr.ac.ru, linux-arm-kernel@lists.infradead.org, linux-erofs@lists.ozlabs.org, linux-mm@kvack.org, linux-staging@lists.linux.dev, linux-stm32@st-md-mailman.stormreply.com, linux-um@lists.infradead.org, linux@armlinux.org.uk, linux@rasmusvillemoes.dk, linux@roeck-us.net, liviu.dudau@arm.com, lorenzo.stoakes@oracle.com, luc.vanoostenryck@gmail.com, luto@kernel.org, maarten.lankhorst@linux.intel.com, malattia@linux.it, martin.petersen@oracle.com, mchehab@kernel.org, mcoquelin.stm32@gmail.com, mgross@linux.intel.com, mihail.atanassov@arm.com, minchan@kernel.org, mingo@redhat.com, mjguzik@gmail.com, mripard@kernel.org, nathan@kernel.org, ndesaulniers@google.com, ngupta@vflare.org, pablo@netfilter.org, pedro.falcato@gmail.com, peppe.cavallaro@st.com, peterz@infradead.org, pmladek@suse.com, qiuxu.zhuo@intel.com, rajur@chels, io.com@freedesktop.org, richard@nod.at, robdclark@gmail.com, rostedt@goodmis.org, rric@kernel.org, ruanjinjie@huawei.com, sakari.ailus@linux.intel.com, sashal@kernel.org, sean@poorly.run, sergey.senozhatsky@gmail.com, snitzer@redhat.com, sunpeng.li@amd.com, tglx@linutronix.de, tipc-discussion@lists.sourceforge.net, tony.luck@intel.com, tytso@mit.edu, tzimmermann@suse.de, willy@infradead.org, x86@kernel.org, xiang@kernel.org, ying.xue@windriver.com, yoshfuji@linux-ipv6.org Cc: From: Date: Fri, 17 Oct 2025 15:48:33 +0200 In-Reply-To: <20251017090519.46992-23-farbere@amazon.com> Message-ID: <2025101733-emission-backed-1098@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore X-Mailman-Approved-At: Sat, 18 Oct 2025 08:50:54 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" This is a note to let you know that I've just added the patch titled minmax.h: update some comments 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.h-update-some-comments.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 know about it. >From prvs=378230090=farbere@amazon.com Fri Oct 17 11:12:31 2025 From: Eliav Farber Date: Fri, 17 Oct 2025 09:05:14 +0000 Subject: minmax.h: update some comments To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Cc: Arnd Bergmann , Christoph Hellwig , Dan Carpenter , Jens Axboe , Lorenzo Stoakes , Mateusz Guzik , Pedro Falcato Message-ID: <20251017090519.46992-23-farbere@amazon.com> From: David Laight [ Upstream commit 10666e99204818ef45c702469488353b5bb09ec7 ] - Change three to several. - Remove the comment about retaining constant expressions, no longer true. - Realign to nearer 80 columns and break on major punctiation. - Add a leading comment to the block before __signed_type() and __is_nonneg() Otherwise the block explaining the cast is a bit 'floating'. Reword the rest of that comment to improve readability. Link: https://lkml.kernel.org/r/85b050c81c1d4076aeb91a6cded45fee@AcuMS.aculab.com Signed-off-by: David Laight Cc: Andy Shevchenko Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: Dan Carpenter Cc: Jason A. Donenfeld Cc: Jens Axboe Cc: Lorenzo Stoakes Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Pedro Falcato Signed-off-by: Andrew Morton Signed-off-by: Eliav Farber Signed-off-by: Greg Kroah-Hartman --- include/linux/minmax.h | 61 ++++++++++++++++++++++--------------------------- 1 file changed, 28 insertions(+), 33 deletions(-) --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -8,13 +8,10 @@ #include /* - * min()/max()/clamp() macros must accomplish three things: + * min()/max()/clamp() macros must accomplish several things: * * - Avoid multiple evaluations of the arguments (so side-effects like * "x++" happen only once) when non-constant. - * - Retain result as a constant expressions when called with only - * constant expressions (to avoid tripping VLA warnings in stack - * allocation usage). * - Perform signed v unsigned type-checking (to generate compile * errors instead of nasty runtime surprises). * - Unsigned char/short are always promoted to signed int and can be @@ -31,25 +28,23 @@ * bit #0 set if ok for unsigned comparisons * bit #1 set if ok for signed comparisons * - * In particular, statically non-negative signed integer - * expressions are ok for both. + * In particular, statically non-negative signed integer expressions + * are ok for both. * - * NOTE! Unsigned types smaller than 'int' are implicitly - * converted to 'int' in expressions, and are accepted for - * signed conversions for now. This is debatable. - * - * Note that 'x' is the original expression, and 'ux' is - * the unique variable that contains the value. - * - * We use 'ux' for pure type checking, and 'x' for when - * we need to look at the value (but without evaluating - * it for side effects! Careful to only ever evaluate it - * with sizeof() or __builtin_constant_p() etc). - * - * Pointers end up being checked by the normal C type - * rules at the actual comparison, and these expressions - * only need to be careful to not cause warnings for - * pointer use. + * NOTE! Unsigned types smaller than 'int' are implicitly converted to 'int' + * in expressions, and are accepted for signed conversions for now. + * This is debatable. + * + * Note that 'x' is the original expression, and 'ux' is the unique variable + * that contains the value. + * + * We use 'ux' for pure type checking, and 'x' for when we need to look at the + * value (but without evaluating it for side effects! + * Careful to only ever evaluate it with sizeof() or __builtin_constant_p() etc). + * + * Pointers end up being checked by the normal C type rules at the actual + * comparison, and these expressions only need to be careful to not cause + * warnings for pointer use. */ #define __signed_type_use(x, ux) (2 + __is_nonneg(x, ux)) #define __unsigned_type_use(x, ux) (1 + 2 * (sizeof(ux) < 4)) @@ -57,19 +52,19 @@ __signed_type_use(x, ux) : __unsigned_type_use(x, ux)) /* - * To avoid warnings about casting pointers to integers - * of different sizes, we need that special sign type. + * Check whether a signed value is always non-negative. * - * On 64-bit we can just always use 'long', since any - * integer or pointer type can just be cast to that. + * A cast is needed to avoid any warnings from values that aren't signed + * integer types (in which case the result doesn't matter). * - * This does not work for 128-bit signed integers since - * the cast would truncate them, but we do not use s128 - * types in the kernel (we do use 'u128', but they will - * be handled by the !is_signed_type() case). - * - * NOTE! The cast is there only to avoid any warnings - * from when values that aren't signed integer types. + * On 64-bit any integer or pointer type can safely be cast to 'long'. + * But on 32-bit we need to avoid warnings about casting pointers to integers + * of different sizes without truncating 64-bit values so 'long' or 'long long' + * must be used depending on the size of the value. + * + * This does not work for 128-bit signed integers since the cast would truncate + * them, but we do not use s128 types in the kernel (we do use 'u128', + * but they are handled by the !is_signed_type() case). */ #ifdef CONFIG_64BIT #define __signed_type(ux) long 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