From patchwork Wed May 17 09:03:50 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 9732095 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5529B6022E for ; Wed, 17 May 2017 23:38:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EDBEC287D6 for ; Wed, 17 May 2017 23:38:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E28C9287F4; Wed, 17 May 2017 23:38:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 72CE7287D6 for ; Wed, 17 May 2017 23:38:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4FEA96E4DD; Wed, 17 May 2017 23:36:25 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 396FC6E3D3 for ; Wed, 17 May 2017 09:03:55 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 98CD4AAB4; Wed, 17 May 2017 09:03:52 +0000 (UTC) Date: Wed, 17 May 2017 11:03:50 +0200 From: Michal Hocko To: Chris Wilson Subject: Re: [PATCH 1/2] drm: replace drm_[cm]alloc* by kvmalloc alternatives Message-ID: <20170517090350.GG18247@dhcp22.suse.cz> References: <20170517065509.18659-1-mhocko@kernel.org> <20170517073809.GJ26693@nuc-i3427.alporthouse.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170517073809.GJ26693@nuc-i3427.alporthouse.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Mailman-Approved-At: Wed, 17 May 2017 23:35:44 +0000 Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, dri-devel@lists.freedesktop.org, Daniel Vetter X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP On Wed 17-05-17 08:38:09, Chris Wilson wrote: > On Wed, May 17, 2017 at 08:55:08AM +0200, Michal Hocko wrote: > > From: Michal Hocko > > > > drm_[cm]alloc* has grown their own kvmalloc with vmalloc fallback > > implementations. MM has grown kvmalloc* helpers in the meantime. Let's > > use those because it a) reduces the code and b) MM has a better idea > > how to implement fallbacks (e.g. do not vmalloc before kmalloc is tried > > with __GFP_NORETRY). > > > > drm_calloc_large needs to get __GFP_ZERO explicitly but it is the same > > thing as kvmalloc_array in principle. > > > > Signed-off-by: Michal Hocko > > Just a little surprised that calloc_large users still exist. > > Reviewed-by: Chris Wilson Thanks! > One more feature request from mm, can we have the > if (size != 0 && n > SIZE_MAX / size) > check exported by itself. What do you exactly mean by exporting? Something like the following? I haven't compile tested it outside of mm with different config options. Sticking alloc_array_check into mm_types.h is kind of gross but I do not have a great idea where to put it. A new header doesn't seem nice. diff --git a/include/linux/mm.h b/include/linux/mm.h index 7cb17c6b97de..f908b14ffc4c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -534,7 +534,7 @@ static inline void *kvzalloc(size_t size, gfp_t flags) static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags) { - if (size != 0 && n > SIZE_MAX / size) + if (!alloc_array_check(n, size)) return NULL; return kvmalloc(n * size, flags); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 45cdb27791a3..d7154b43a0d1 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -601,4 +601,10 @@ typedef struct { unsigned long val; } swp_entry_t; +static inline bool alloc_array_check(size_t n, size_t size) +{ + if (size != 0 && n > SIZE_MAX / size) + return false; + return true; +} #endif /* _LINUX_MM_TYPES_H */ diff --git a/include/linux/slab.h b/include/linux/slab.h index 3c37a8c51921..e936ca7c55a1 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -602,7 +602,7 @@ int memcg_update_all_caches(int num_memcgs); */ static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) { - if (size != 0 && n > SIZE_MAX / size) + if (!alloc_array_check(n, size)) return NULL; if (__builtin_constant_p(n) && __builtin_constant_p(size)) return kmalloc(n * size, flags);