From mboxrd@z Thu Jan 1 00:00:00 1970 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 C42218F74 for ; Sun, 16 Jul 2023 20:17:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8111C433C7; Sun, 16 Jul 2023 20:17:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689538624; bh=+fHDIzySRnnHmFJzKNYfD4czu+DrzCi+Gq8FpGBTcOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HfZ/pTNZY3EpwqE5G5r5uy6i8dPhVgMzhPmAAgGeSrUvvLZEyIxEq34zqZA7KP6YZ nVqNqZvtHGKnSHLcQsAf1iPgJWoQkm4q40wf0LkGzrmZwoOfXmHFR0pW8/LN1Gz0N9 wcs51RKdFg8hYw1mN8EepXW3kIO8fTQpmR/91tt4= 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 6.4 517/800] dax/kmem: Pass valid argument to memory_group_register_static Date: Sun, 16 Jul 2023 21:46:10 +0200 Message-ID: <20230716195001.098269234@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194949.099592437@linuxfoundation.org> References: <20230716194949.099592437@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 7b36db6f1cbdc..898ca95057547 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -99,7 +99,7 @@ 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