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 68849C433F5 for ; Tue, 31 May 2022 18:14:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346923AbiEaSOA (ORCPT ); Tue, 31 May 2022 14:14:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346882AbiEaSNv (ORCPT ); Tue, 31 May 2022 14:13:51 -0400 Received: from mail.cybernetics.com (mail.cybernetics.com [173.71.130.66]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B1469CC99 for ; Tue, 31 May 2022 11:13:34 -0700 (PDT) X-ASG-Debug-ID: 1654020812-1cf43917f334afe0001-xx1T2L Received: from cybernetics.com ([10.10.4.126]) by mail.cybernetics.com with ESMTP id nHifSkbHIxrhwGDp; Tue, 31 May 2022 14:13:32 -0400 (EDT) X-Barracuda-Envelope-From: tonyb@cybernetics.com X-ASG-Whitelist: Client DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=cybernetics.com; s=mail; bh=FrnayQTLRg3bImjySCMn4AK6vTiCgnyfnm+pKLSvhx0=; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:References:Cc:To:From: Content-Language:Subject:MIME-Version:Date:Message-ID; b=G9I1y0Cm5SI5a20B9p45 Ch/vtXr3T2oFr+6ys40VeK3ubfORXd8KFUN5jCE/6JUWAIy1cBsSzzxHDqoXYj3XE0YBtRWEEJxSV VLobdcVMmmCaDWU+U0KnUIuyfrTSUdqRMkNdomm+YVy9APQXHE5/7HR7dEPHZYkExGOv45asZE= Received: from [10.157.2.224] (HELO [192.168.200.1]) by cybernetics.com (CommuniGate Pro SMTP 7.1.1) with ESMTPS id 11829190; Tue, 31 May 2022 14:13:32 -0400 Message-ID: <81004e69-d91f-9fbb-2b94-217b48a064c3@cybernetics.com> Date: Tue, 31 May 2022 14:13:32 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: [PATCH 02/10] dmapool: cleanup integer types Content-Language: en-US X-ASG-Orig-Subj: [PATCH 02/10] dmapool: cleanup integer types From: Tony Battersby To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: iommu@lists.linux-foundation.org, kernel-team@fb.com, Matthew Wilcox , Keith Busch , Andy Shevchenko , Robin Murphy , Tony Lindgren References: <9b08ab7c-b80b-527d-9adf-7716b0868fbc@cybernetics.com> In-Reply-To: <9b08ab7c-b80b-527d-9adf-7716b0868fbc@cybernetics.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Barracuda-Connect: UNKNOWN[10.10.4.126] X-Barracuda-Start-Time: 1654020812 X-Barracuda-URL: https://10.10.4.122:443/cgi-mod/mark.cgi X-Barracuda-BRTS-Status: 1 X-Virus-Scanned: by bsmtpd at cybernetics.com X-Barracuda-Scan-Msg-Size: 3356 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To represent the size of a single allocation, dmapool currently uses 'unsigned int' in some places and 'size_t' in other places. Standardize on 'unsigned int' to reduce overhead, but use 'size_t' when counting all the blocks in the entire pool. Signed-off-by: Tony Battersby --- This puts an upper bound on 'size' of INT_MAX to avoid overflowing the following comparison in pool_initialise_page(): unsigned int offset = 0; unsigned int next = offset + pool->size; if (unlikely((next + pool->size) > ... 'boundary' is passed in as a size_t but gets stored as an unsigned int. 'boundary' values >= 'allocation' do not have any effect, so clipping 'boundary' to 'allocation' keeps it within the range of unsigned int without affecting anything else. A few lines above (not in the diff) you can see that if 'boundary' is passed in as 0 then it is set to 'allocation', so it is nothing new. For reference, here is the relevant code after being patched: if (!boundary) boundary = allocation; else if ((boundary < size) || (boundary & (boundary - 1))) return NULL; boundary = min(boundary, allocation); mm/dmapool.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/mm/dmapool.c b/mm/dmapool.c index 0f89de408cbe..d7b372248111 100644 --- a/mm/dmapool.c +++ b/mm/dmapool.c @@ -43,10 +43,10 @@ struct dma_pool { /* the pool */ struct list_head page_list; spinlock_t lock; - size_t size; + unsigned int size; struct device *dev; - size_t allocation; - size_t boundary; + unsigned int allocation; + unsigned int boundary; char name[32]; struct list_head pools; }; @@ -80,7 +80,7 @@ static ssize_t pools_show(struct device *dev, struct device_attribute *attr, cha mutex_lock(&pools_lock); list_for_each_entry(pool, &dev->dma_pools, pools) { unsigned pages = 0; - unsigned blocks = 0; + size_t blocks = 0; spin_lock_irq(&pool->lock); list_for_each_entry(page, &pool->page_list, page_list) { @@ -90,9 +90,10 @@ static ssize_t pools_show(struct device *dev, struct device_attribute *attr, cha spin_unlock_irq(&pool->lock); /* per-pool info, no real statistics yet */ - temp = scnprintf(next, size, "%-16s %4u %4zu %4zu %2u\n", + temp = scnprintf(next, size, "%-16s %4zu %4zu %4u %2u\n", pool->name, blocks, - pages * (pool->allocation / pool->size), + (size_t) pages * + (pool->allocation / pool->size), pool->size, pages); size -= temp; next += temp; @@ -139,7 +140,7 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev, else if (align & (align - 1)) return NULL; - if (size == 0) + if (size == 0 || size > INT_MAX) return NULL; else if (size < 4) size = 4; @@ -152,6 +153,8 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev, else if ((boundary < size) || (boundary & (boundary - 1))) return NULL; + boundary = min(boundary, allocation); + retval = kmalloc(sizeof(*retval), GFP_KERNEL); if (!retval) return retval; @@ -312,7 +315,7 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, { unsigned long flags; struct dma_page *page; - size_t offset; + unsigned int offset; void *retval; might_alloc(mem_flags); -- 2.25.1