From patchwork Thu Sep 5 07:56:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 13791864 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 41133193422 for ; Thu, 5 Sep 2024 07:57:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725523032; cv=none; b=Uanp1ed7OwbUBMOvUijsgKHlHmlHGE7x+g2GAHMOHiPzjBPkmQJAk4WvATmuJ1BgnHT8Ykoy6u8k6+wZ3JSs7y3hGJZwYr1fZ81cAe7V98WYgcB4FlOTJMu1KvGSCZlqcVIXd/We+w2/Pm9Y1FZDZHdR4AGa1TTueYoOmVc+REI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725523032; c=relaxed/simple; bh=YrF0YLTWmhzO7ohK2/AAEF++N1Zrk2GGMPwzT5f/roQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=MV4zB1H9mkPk0Ox4VOJkPtnktDW8zu1y+eWpI3t43bWZlrO+sYoymWBhoqy1aZ2RBmNRbP9WjPzvMq2BunjKKtAGV9dGWnSCaZfbN4lOPjVFNLYIktIbV3BW1oBVrJEdeH3ZOlFHww9oXkIBtxUI+AdBXXe9EAekQp84hZmkFsQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RlCvUk1a; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RlCvUk1a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 639DFC4CEC6; Thu, 5 Sep 2024 07:57:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725523031; bh=YrF0YLTWmhzO7ohK2/AAEF++N1Zrk2GGMPwzT5f/roQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=RlCvUk1aAW1A2PTD5pA5BLm8yKdG5h9Nt+M5LC6cKKQZe2I8dRntcu8FyPewu3x5J bPbBpiEdveTRgdl2rDXE02u69/PKcGxp4H2uFl4dCWQx0k4W96+0wwJ7e2MpqqErjU jiLHLqE0gCi9Iivb/u2ycl8NEWOIb4HS+0v/dgFWitb1THmhvyhD6XJXIOa/u9H+tv oLqtkwQfqy4mhDvTn2hhvtXkhRKGd4M5lIJIBbRIB7cH1wYLawsCDoihg623L76PHv 0ze59QHEhOpVT6y4uckiaW2M9CYoVqFlWcG1cYyb/+yuXiGNA2MakauPnqCJhQ3vg9 v/eKzN6tnn1Xw== From: Christian Brauner Date: Thu, 05 Sep 2024 09:56:45 +0200 Subject: [PATCH v4 02/17] slab: add struct kmem_cache_args Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240905-work-kmem_cache_args-v4-2-ed45d5380679@kernel.org> References: <20240905-work-kmem_cache_args-v4-0-ed45d5380679@kernel.org> In-Reply-To: <20240905-work-kmem_cache_args-v4-0-ed45d5380679@kernel.org> To: Vlastimil Babka , Jens Axboe , Jann Horn , Linus Torvalds , Mike Rapoport Cc: Kees Cook , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Christian Brauner X-Mailer: b4 0.15-dev-37811 X-Developer-Signature: v=1; a=openpgp-sha256; l=5895; i=brauner@kernel.org; h=from:subject:message-id; bh=YrF0YLTWmhzO7ohK2/AAEF++N1Zrk2GGMPwzT5f/roQ=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMaTdTPFSL7jxYpd08eYXgeIGe5bWCPKWVF16ZvHq2XwLa 363/g6djlIWBjEuBlkxRRaHdpNwueU8FZuNMjVg5rAygQxh4OIUgIlozWb4zbI7r2Llq6MVPNum sxuH8z9azFfQ4R4//xLr78mf5jW9s2Vk+LRC82SZM8PUuc8EzDzOe63d90G9/pLulPkctmbFkdN 7+QE= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Currently we have multiple kmem_cache_create*() variants that take up to seven separate parameters with one of the functions having to grow an eigth parameter in the future to handle both usercopy and a custom freelist pointer. Add a struct kmem_cache_args structure and move less common parameters into it. Core parameters such as name, object size, and flags continue to be passed separately. Add a new function __kmem_cache_create_args() that takes a struct kmem_cache_args pointer and port do_kmem_cache_create_usercopy() over to it. In follow-up patches we will port the other kmem_cache_create*() variants over to it as well. Reviewed-by: Kees Cook Reviewed-by: Jens Axboe Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Vlastimil Babka Signed-off-by: Christian Brauner Reviewed-by: Roman Gushchin --- include/linux/slab.h | 21 ++++++++++++++++ mm/slab_common.c | 67 +++++++++++++++++++++++++++++++++++++++------------- 2 files changed, 72 insertions(+), 16 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index 5b2da2cf31a8..79d8c8bca4a4 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -240,6 +240,27 @@ struct mem_cgroup; */ bool slab_is_available(void); +/** + * @align: The required alignment for the objects. + * @useroffset: Usercopy region offset + * @usersize: Usercopy region size + * @freeptr_offset: Custom offset for the free pointer in RCU caches + * @use_freeptr_offset: Whether a @freeptr_offset is used + * @ctor: A constructor for the objects. + */ +struct kmem_cache_args { + unsigned int align; + unsigned int useroffset; + unsigned int usersize; + unsigned int freeptr_offset; + bool use_freeptr_offset; + void (*ctor)(void *); +}; + +struct kmem_cache *__kmem_cache_create_args(const char *name, + unsigned int object_size, + struct kmem_cache_args *args, + slab_flags_t flags); struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, unsigned int align, slab_flags_t flags, void (*ctor)(void *)); diff --git a/mm/slab_common.c b/mm/slab_common.c index 91e0e36e4379..0f13c045b8d1 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -248,14 +248,24 @@ static struct kmem_cache *create_cache(const char *name, return ERR_PTR(err); } -static struct kmem_cache * -do_kmem_cache_create_usercopy(const char *name, - unsigned int size, unsigned int freeptr_offset, - unsigned int align, slab_flags_t flags, - unsigned int useroffset, unsigned int usersize, - void (*ctor)(void *)) +/** + * __kmem_cache_create_args - Create a kmem cache + * @name: A string which is used in /proc/slabinfo to identify this cache. + * @object_size: The size of objects to be created in this cache. + * @args: Arguments for the cache creation (see struct kmem_cache_args). + * @flags: See %SLAB_* flags for an explanation of individual @flags. + * + * Cannot be called within a interrupt, but can be interrupted. + * + * Return: a pointer to the cache on success, NULL on failure. + */ +struct kmem_cache *__kmem_cache_create_args(const char *name, + unsigned int object_size, + struct kmem_cache_args *args, + slab_flags_t flags) { struct kmem_cache *s = NULL; + unsigned int freeptr_offset = UINT_MAX; const char *cache_name; int err; @@ -275,7 +285,7 @@ do_kmem_cache_create_usercopy(const char *name, mutex_lock(&slab_mutex); - err = kmem_cache_sanity_check(name, size); + err = kmem_cache_sanity_check(name, object_size); if (err) { goto out_unlock; } @@ -296,12 +306,14 @@ do_kmem_cache_create_usercopy(const char *name, /* Fail closed on bad usersize of useroffset values. */ if (!IS_ENABLED(CONFIG_HARDENED_USERCOPY) || - WARN_ON(!usersize && useroffset) || - WARN_ON(size < usersize || size - usersize < useroffset)) - usersize = useroffset = 0; - - if (!usersize) - s = __kmem_cache_alias(name, size, align, flags, ctor); + WARN_ON(!args->usersize && args->useroffset) || + WARN_ON(object_size < args->usersize || + object_size - args->usersize < args->useroffset)) + args->usersize = args->useroffset = 0; + + if (!args->usersize) + s = __kmem_cache_alias(name, object_size, args->align, flags, + args->ctor); if (s) goto out_unlock; @@ -311,9 +323,11 @@ do_kmem_cache_create_usercopy(const char *name, goto out_unlock; } - s = create_cache(cache_name, size, freeptr_offset, - calculate_alignment(flags, align, size), - flags, useroffset, usersize, ctor); + if (args->use_freeptr_offset) + freeptr_offset = args->freeptr_offset; + s = create_cache(cache_name, object_size, freeptr_offset, + calculate_alignment(flags, args->align, object_size), + flags, args->useroffset, args->usersize, args->ctor); if (IS_ERR(s)) { err = PTR_ERR(s); kfree_const(cache_name); @@ -335,6 +349,27 @@ do_kmem_cache_create_usercopy(const char *name, } return s; } +EXPORT_SYMBOL(__kmem_cache_create_args); + +static struct kmem_cache * +do_kmem_cache_create_usercopy(const char *name, + unsigned int size, unsigned int freeptr_offset, + unsigned int align, slab_flags_t flags, + unsigned int useroffset, unsigned int usersize, + void (*ctor)(void *)) +{ + struct kmem_cache_args kmem_args = { + .align = align, + .use_freeptr_offset = freeptr_offset != UINT_MAX, + .freeptr_offset = freeptr_offset, + .useroffset = useroffset, + .usersize = usersize, + .ctor = ctor, + }; + + return __kmem_cache_create_args(name, size, &kmem_args, flags); +} + /** * kmem_cache_create_usercopy - Create a cache with a region suitable