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 B9D15C001DC for ; Fri, 21 Jul 2023 19:02:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231564AbjGUTCe (ORCPT ); Fri, 21 Jul 2023 15:02:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231560AbjGUTCd (ORCPT ); Fri, 21 Jul 2023 15:02:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7467130CA for ; Fri, 21 Jul 2023 12:02:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 067E361D85 for ; Fri, 21 Jul 2023 19:02:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16376C433C8; Fri, 21 Jul 2023 19:02:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689966151; bh=FYU0MNpM/rgyRv+42rM3FhUGN3zMHK1k5paAcndi6SM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r2EzffK149DWhLy/zGm5L9NWgAQAB1kIeHiLM7nuqioQ1Ed35C7eS8tCguyY/r/yb 4pWp/qUCO8WrrZQ6WzMQdhliItYnlPs8N45XO36/lW0JIaLgb19TfB/B9ll1BhV3oI BPU8Hwf8InLGCX4jC9KEdlFfPrTG9FAK8CKODvfw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tarun Sahu , Vishal Verma , Sasha Levin Subject: [PATCH 5.15 242/532] dax/kmem: Pass valid argument to memory_group_register_static Date: Fri, 21 Jul 2023 18:02:26 +0200 Message-ID: <20230721160627.482116933@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160614.695323302@linuxfoundation.org> References: <20230721160614.695323302@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tarun Sahu [ Upstream commit 46e66dab8565f742374e9cc4ff7d35f344d774e2 ] memory_group_register_static takes maximum number of pages as the argument while dev_dax_kmem_probe passes total_len (in bytes) as the argument. IIUC, I don't see any crash/panic impact as such. As, memory_group_register_static just set the max_pages limit which is used in auto_movable_zone_for_pfn to determine the zone. which might cause these condition to behave differently, This will be true always so jump will happen to kernel_zone ... if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) goto kernel_zone; ... kernel_zone: return default_kernel_zone_for_pfn(nid, pfn, nr_pages); Here, In below, zone_intersects compare range will be larger as nr_pages will be higher (derived from total_len passed in dev_dax_kmem_probe). ... static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, unsigned long nr_pages) { struct pglist_data *pgdat = NODE_DATA(nid); int zid; for (zid = 0; zid < ZONE_NORMAL; zid++) { struct zone *zone = &pgdat->node_zones[zid]; if (zone_intersects(zone, start_pfn, nr_pages)) return zone; } return &pgdat->node_zones[ZONE_NORMAL]; } Incorrect zone will be returned here, which in later time might cause bigger problem. Fixes: eedf634aac3b ("dax/kmem: use a single static memory group for a single probed unit") Signed-off-by: Tarun Sahu Link: https://lore.kernel.org/r/20230621155025.370672-1-tsahu@linux.ibm.com Reviewed-by: Vishal Verma Signed-off-by: Vishal Verma Signed-off-by: Sasha Levin --- drivers/dax/kmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 04f85f16720c8..97723ee15bc68 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -88,7 +88,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) if (!data->res_name) goto err_res_name; - rc = memory_group_register_static(numa_node, total_len); + rc = memory_group_register_static(numa_node, PFN_UP(total_len)); if (rc < 0) goto err_reg_mgid; data->mgid = rc; -- 2.39.2