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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D93AEC433FF for ; Tue, 6 Aug 2019 09:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B302B208C3 for ; Tue, 6 Aug 2019 09:01:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732379AbfHFJBs (ORCPT ); Tue, 6 Aug 2019 05:01:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59812 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728056AbfHFJBr (ORCPT ); Tue, 6 Aug 2019 05:01:47 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5DEB13082B15; Tue, 6 Aug 2019 09:01:47 +0000 (UTC) Received: from t460s.redhat.com (ovpn-117-71.ams2.redhat.com [10.36.117.71]) by smtp.corp.redhat.com (Postfix) with ESMTP id 039DE1A269; Tue, 6 Aug 2019 09:01:42 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, David Hildenbrand , Greg Kroah-Hartman , "Rafael J. Wysocki" , Andrew Morton , Pavel Tatashin , Michal Hocko , Dan Williams Subject: [PATCH v1] driver/base/memory.c: Validate memory block size early Date: Tue, 6 Aug 2019 11:01:42 +0200 Message-Id: <20190806090142.22709-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Tue, 06 Aug 2019 09:01:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let's validate the memory block size early, when initializing the memory device infrastructure. Fail hard in case the value is not suitable. As nobody checks the return value of memory_dev_init(), turn it into a void function and fail with a panic in all scenarios instead. Otherwise, we'll crash later during boot when core/drivers expect that the memory device infrastructure (including memory_block_size_bytes()) works as expected. Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Andrew Morton Cc: Pavel Tatashin Cc: Michal Hocko Cc: Dan Williams Signed-off-by: David Hildenbrand --- drivers/base/memory.c | 31 +++++++++---------------------- include/linux/memory.h | 6 +++--- 2 files changed, 12 insertions(+), 25 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 790b3bcd63a6..6bea4f3f8040 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -100,21 +100,6 @@ unsigned long __weak memory_block_size_bytes(void) } EXPORT_SYMBOL_GPL(memory_block_size_bytes); -static unsigned long get_memory_block_size(void) -{ - unsigned long block_sz; - - block_sz = memory_block_size_bytes(); - - /* Validate blk_sz is a power of 2 and not less than section size */ - if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) { - WARN_ON(1); - block_sz = MIN_MEMORY_BLOCK_SIZE; - } - - return block_sz; -} - /* * Show the first physical section index (number) of this memory block. */ @@ -461,7 +446,7 @@ static DEVICE_ATTR_RO(removable); static ssize_t block_size_bytes_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sprintf(buf, "%lx\n", get_memory_block_size()); + return sprintf(buf, "%lx\n", memory_block_size_bytes()); } static DEVICE_ATTR_RO(block_size_bytes); @@ -811,19 +796,22 @@ static const struct attribute_group *memory_root_attr_groups[] = { /* * Initialize the sysfs support for memory devices... */ -int __init memory_dev_init(void) +void __init memory_dev_init(void) { int ret; int err; unsigned long block_sz, nr; + /* Validate the configured memory block size */ + block_sz = memory_block_size_bytes(); + if (!is_power_of_2(block_sz) || block_sz < MIN_MEMORY_BLOCK_SIZE) + panic("Memory block size not suitable: 0x%lx\n", block_sz); + sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; + ret = subsys_system_register(&memory_subsys, memory_root_attr_groups); if (ret) goto out; - block_sz = get_memory_block_size(); - sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; - /* * Create entries for memory sections that were found * during boot and have been initialized @@ -839,8 +827,7 @@ int __init memory_dev_init(void) out: if (ret) - printk(KERN_ERR "%s() failed: %d\n", __func__, ret); - return ret; + panic("%s() failed: %d\n", __func__, ret); } /** diff --git a/include/linux/memory.h b/include/linux/memory.h index 704215d7258a..0ebb105eb261 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -79,9 +79,9 @@ struct mem_section; #define IPC_CALLBACK_PRI 10 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE -static inline int memory_dev_init(void) +static inline void memory_dev_init(void) { - return 0; + return; } static inline int register_memory_notifier(struct notifier_block *nb) { @@ -112,7 +112,7 @@ extern int register_memory_isolate_notifier(struct notifier_block *nb); extern void unregister_memory_isolate_notifier(struct notifier_block *nb); int create_memory_block_devices(unsigned long start, unsigned long size); void remove_memory_block_devices(unsigned long start, unsigned long size); -extern int memory_dev_init(void); +extern void memory_dev_init(void); extern int memory_notify(unsigned long val, void *v); extern int memory_isolate_notify(unsigned long val, void *v); extern struct memory_block *find_memory_block(struct mem_section *); -- 2.21.0