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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C60EC10F1B for ; Wed, 21 Dec 2022 09:00:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234437AbiLUJAx (ORCPT ); Wed, 21 Dec 2022 04:00:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229696AbiLUJAu (ORCPT ); Wed, 21 Dec 2022 04:00:50 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 93B85F18 for ; Wed, 21 Dec 2022 01:00:48 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 040462F4; Wed, 21 Dec 2022 01:01:29 -0800 (PST) Received: from [10.57.44.6] (unknown [10.57.44.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5BC293F71A; Wed, 21 Dec 2022 01:00:46 -0800 (PST) Message-ID: <9cfb3356-3e3b-e9f3-1e16-ff02790e5829@arm.com> Date: Wed, 21 Dec 2022 10:00:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 From: Pierre Gondois Subject: Re: [PATCH v2 1/1] drivers: base: cacheinfo: fix shared_cpu_map To: Yong-Xuan Wang Cc: Sudeep Holla , Vincent Chen , Greentime Hu , linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Greg Kroah-Hartman References: <20221219105132.27690-1-yongxuan.wang@sifive.com> <20221219105132.27690-2-yongxuan.wang@sifive.com> Content-Language: en-US In-Reply-To: <20221219105132.27690-2-yongxuan.wang@sifive.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Yong-Xuan, Except for the nit below, I tried the patch and everything seemed ok, so with that: Reviewed-by: Pierre Gondois Regards, Pierre On 12/19/22 11:51, Yong-Xuan Wang wrote: > The cacheinfo sets up the shared_cpu_map by checking whether the caches > with the same index are shared between CPUs. However, this will trigger > slab-out-of-bounds access if the CPUs do not have the same cache hierarchy. > Another problem is the mismatched shared_cpu_map when the shared cache does > not have the same index between CPUs. > > CPU0 I D L3 > index 0 1 2 x > ^ ^ ^ ^ > index 0 1 2 3 > CPU1 I D L2 L3 > > This patch checks each cache is shared with all caches on other CPUs. > > Signed-off-by: Yong-Xuan Wang > --- > drivers/base/cacheinfo.c | 25 +++++++++++++++---------- > 1 file changed, 15 insertions(+), 10 deletions(-) > > diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c > index 950b22cdb5f7..d38f80f6fff1 100644 > --- a/drivers/base/cacheinfo.c > +++ b/drivers/base/cacheinfo.c > @@ -256,7 +256,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu) > { > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > struct cacheinfo *this_leaf, *sib_leaf; > - unsigned int index; > + unsigned int index, sib_index; > int ret = 0; > > if (this_cpu_ci->cpu_map_populated) > @@ -284,11 +284,12 @@ static int cache_shared_cpu_map_setup(unsigned int cpu) > > if (i == cpu || !sib_cpu_ci->info_list) > continue;/* skip if itself or no cacheinfo */ > - > - sib_leaf = per_cpu_cacheinfo_idx(i, index); > - if (cache_leaves_are_shared(this_leaf, sib_leaf)) { > - cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); > - cpumask_set_cpu(i, &this_leaf->shared_cpu_map); > + for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) { > + sib_leaf = per_cpu_cacheinfo_idx(i, sib_index);; It seems there are 2 ';' above (same in the block below). > + if (cache_leaves_are_shared(this_leaf, sib_leaf)) { > + cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); > + cpumask_set_cpu(i, &this_leaf->shared_cpu_map); > + } > } > } > /* record the maximum cache line size */ > @@ -302,7 +303,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu) > static void cache_shared_cpu_map_remove(unsigned int cpu) > { > struct cacheinfo *this_leaf, *sib_leaf; > - unsigned int sibling, index; > + unsigned int sibling, index, sib_index; > > for (index = 0; index < cache_leaves(cpu); index++) { > this_leaf = per_cpu_cacheinfo_idx(cpu, index); > @@ -313,9 +314,13 @@ static void cache_shared_cpu_map_remove(unsigned int cpu) > if (sibling == cpu || !sib_cpu_ci->info_list) > continue;/* skip if itself or no cacheinfo */ > > - sib_leaf = per_cpu_cacheinfo_idx(sibling, index); > - cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); > - cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); > + for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) { > + sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);; > + if (cache_leaves_are_shared(this_leaf, sib_leaf)) { > + cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); > + cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); > + } > + } > } > } > }