From patchwork Thu Sep 5 07:56:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 13791871 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 D9A12194123 for ; Thu, 5 Sep 2024 07:57:39 +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=1725523059; cv=none; b=SIeAahyWWP3mO5IfwosioiggKZAV27v4s8h5TyXbdR313NQyCCAAicEwqLYs03sMmGsGrvt+nPVM2QFTFTcB+amIuC2UoZDaP5qlif9gr+ggO/GzH685bLPJrdtzvm+CPLvUjsnJoFHmo0REMeOEnZjrF7eSMGd0spHcH7pCVs8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725523059; c=relaxed/simple; bh=Zf6O0R24GKVW0QtPgh/qra6wApA/id2hJZ9TPx/ME9U=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=h38/Hwh//3ZqLiqLCUuTvyp8u8Yh9pdUO7nqxzmOTqQ+aQFJ2DJRSYHOikD6cOPo+v8CBR1cMPfnu4eJdFDIPbMKOJc0hLNEtA+e6n7gH5krTSssB+S0aq4lJ9ynqsi2NgBrDV1f9WP7VNSuYzPTPjO9vYwYsU8sfalhLaD6lcI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pT0XIJG5; 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="pT0XIJG5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E0B0C4CEC3; Thu, 5 Sep 2024 07:57:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725523059; bh=Zf6O0R24GKVW0QtPgh/qra6wApA/id2hJZ9TPx/ME9U=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=pT0XIJG5jf6UweHnX3PnusUh7KGghRnwnSRbHnn3xA4ShIU+NmamAtaK6vBrYk2mi H6So88w+HbyvPAA6PDRnnFNIX0mSLfAAN1ytfggZbn5Czz9MLNbo0wEr/26NW+zctS NbjwmB9y12/NwWbSHwQ95npLdiS3NL9NjuEc79Da+qVyQ3KrGqzzXIuDfMpyu6Z60L 90wpyQFvLYUI15pVE3ZdqZtstQx6165hHWkrJaTTk9Y1v70sc8xzly8D/iwtpDHXlq FrL8ueGzjJSOMor9BAJg0BpmFwFpTKugigsDRLEcIUjr0aax7uYvEm1co7kpgV+KT8 qFafnPFKwZwwQ== From: Christian Brauner Date: Thu, 05 Sep 2024 09:56:52 +0200 Subject: [PATCH v4 09/17] slab: remove rcu_freeptr_offset from struct kmem_cache 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-v4-9-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=3996; i=brauner@kernel.org; h=from:subject:message-id; bh=Zf6O0R24GKVW0QtPgh/qra6wApA/id2hJZ9TPx/ME9U=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMaTdTPG+VWf2/MDpjftOT9Dq6BX8s4SRRaTC3vkMS+kit vQu1Ze/OkpZGMS4GGTFFFkc2k3C5ZbzVGw2ytSAmcPKBDKEgYtTACbCEsjwh2d513G2xGq1PKvE d3ETuZ0Wbma+rL342ZUPPB2sn12X2jD8L0n7/Zo7ePHZ5tUKqYdmx3dnZx0WiJ1mnrW6d0fuGlM dbgA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Pass down struct kmem_cache_args to calculate_sizes() so we can use args->{use}_freeptr_offset directly. This allows us to remove ->rcu_freeptr_offset from struct kmem_cache. 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 --- mm/slab.h | 2 -- mm/slub.c | 25 +++++++------------------ 2 files changed, 7 insertions(+), 20 deletions(-) diff --git a/mm/slab.h b/mm/slab.h index c7a4e0fc3cf1..36ac38e21fcb 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -261,8 +261,6 @@ struct kmem_cache { unsigned int object_size; /* Object size without metadata */ struct reciprocal_value reciprocal_size; unsigned int offset; /* Free pointer offset */ - /* Specific free pointer requested (if not UINT_MAX) */ - unsigned int rcu_freeptr_offset; #ifdef CONFIG_SLUB_CPU_PARTIAL /* Number of per cpu partial objects to keep around */ unsigned int cpu_partial; diff --git a/mm/slub.c b/mm/slub.c index 4719b60215b8..a23c7036cd61 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3916,8 +3916,7 @@ static void *__slab_alloc_node(struct kmem_cache *s, * If the object has been wiped upon free, make sure it's fully initialized by * zeroing out freelist pointer. * - * Note that we also wipe custom freelist pointers specified via - * s->rcu_freeptr_offset. + * Note that we also wipe custom freelist pointers. */ static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s, void *obj) @@ -5141,17 +5140,11 @@ static void set_cpu_partial(struct kmem_cache *s) #endif } -/* Was a valid freeptr offset requested? */ -static inline bool has_freeptr_offset(const struct kmem_cache *s) -{ - return s->rcu_freeptr_offset != UINT_MAX; -} - /* * calculate_sizes() determines the order and the distribution of data within * a slab object. */ -static int calculate_sizes(struct kmem_cache *s) +static int calculate_sizes(struct kmem_cache_args *args, struct kmem_cache *s) { slab_flags_t flags = s->flags; unsigned int size = s->object_size; @@ -5192,7 +5185,7 @@ static int calculate_sizes(struct kmem_cache *s) */ s->inuse = size; - if (((flags & SLAB_TYPESAFE_BY_RCU) && !has_freeptr_offset(s)) || + if (((flags & SLAB_TYPESAFE_BY_RCU) && !args->use_freeptr_offset) || (flags & SLAB_POISON) || s->ctor || ((flags & SLAB_RED_ZONE) && (s->object_size < sizeof(void *) || slub_debug_orig_size(s)))) { @@ -5214,8 +5207,8 @@ static int calculate_sizes(struct kmem_cache *s) */ s->offset = size; size += sizeof(void *); - } else if ((flags & SLAB_TYPESAFE_BY_RCU) && has_freeptr_offset(s)) { - s->offset = s->rcu_freeptr_offset; + } else if ((flags & SLAB_TYPESAFE_BY_RCU) && args->use_freeptr_offset) { + s->offset = args->freeptr_offset; } else { /* * Store freelist pointer near middle of object to keep @@ -5856,10 +5849,6 @@ int do_kmem_cache_create(struct kmem_cache *s, const char *name, #ifdef CONFIG_SLAB_FREELIST_HARDENED s->random = get_random_long(); #endif - if (args->use_freeptr_offset) - s->rcu_freeptr_offset = args->freeptr_offset; - else - s->rcu_freeptr_offset = UINT_MAX; s->align = args->align; s->ctor = args->ctor; #ifdef CONFIG_HARDENED_USERCOPY @@ -5867,7 +5856,7 @@ int do_kmem_cache_create(struct kmem_cache *s, const char *name, s->usersize = args->usersize; #endif - if (!calculate_sizes(s)) + if (!calculate_sizes(args, s)) goto out; if (disable_higher_order_debug) { /* @@ -5877,7 +5866,7 @@ int do_kmem_cache_create(struct kmem_cache *s, const char *name, if (get_order(s->size) > get_order(s->object_size)) { s->flags &= ~DEBUG_METADATA_FLAGS; s->offset = 0; - if (!calculate_sizes(s)) + if (!calculate_sizes(args, s)) goto out; } }