From patchwork Mon Jun 17 13:28:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 10999269 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B399214C0 for ; Mon, 17 Jun 2019 13:31:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A3B96286AA for ; Mon, 17 Jun 2019 13:31:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A14BA28775; Mon, 17 Jun 2019 13:31:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2E2B228898 for ; Mon, 17 Jun 2019 13:31:43 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hcrhw-0004uv-Cb; Mon, 17 Jun 2019 13:30:00 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hcrhu-0004ul-Nh for xen-devel@lists.xenproject.org; Mon, 17 Jun 2019 13:29:58 +0000 X-Inumbo-ID: fd83f180-9103-11e9-84ae-c7f5df6ae246 Received: from mout.kundenserver.de (unknown [212.227.126.131]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id fd83f180-9103-11e9-84ae-c7f5df6ae246; Mon, 17 Jun 2019 13:29:54 +0000 (UTC) Received: from threadripper.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue011 [212.227.15.129]) with ESMTPA (Nemesis) id 1Mnq8Y-1iQnn21uzS-00pKbB; Mon, 17 Jun 2019 15:29:50 +0200 From: Arnd Bergmann To: Christoph Hellwig , Marek Szyprowski Date: Mon, 17 Jun 2019 15:28:43 +0200 Message-Id: <20190617132946.2817440-1-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 X-Provags-ID: V03:K1:WxAlzhRk05Boo+/YM4l5i3GHyI9GeBc8OiWCfJusR6LAoI1zMkq mI5T09W/WmD7J75VlpcbwtZqQ0SrDUbM08mliK9OyOpw5VGdZN1zx6lKdkmnejKI2IWefXV gD87Cuo+tKgxk+8DVFi5MULUIVmtKYjNbQ/mH9PLbLfMO/vz0NadJP8Sg5EQz6l4Rygh/yT LeEipTLCyl1mG60QYU9LA== X-UI-Out-Filterresults: notjunk:1;V03:K0:pjHS7vU6GCo=:oYrDoKB2+KgIcpoaYs8GlG uTtBiYh+a9NRCMSK/VAmJBtr3OyY50oWkyFrAONPZtPHVNpiF2a8CHfvo5FAn9V1TMPmHj5jF NHxQxqMxS1V9M23uTBejYpfbDSjtIH/c0sAcPnkGEJkybimAEup6/oze7uWb2eQBnfEFQoWUQ aJy4HSSAKT+4gw0ktzsx3iM6TPn57cocJrG/3j5ZCD/oAdErbgrysiAhEeIY9GWvEVkvjDLUI ONy9C26roR2C6uw20//9hHKteelpqgKuxODx/J/UPtPgIMywqCsDLHqOreyPZIamuMa1y+w5G VfTKrnXuklvNm0PX7w7uJIDUmjaHUOra43Y5OxASS35FYFrpJFZvxfUiVc8eRpYhueBJoiqeA aAO7vgmS0K7aJcv4XsT7yAuXgRNjzO7c8G4uCtniGqhvkCj6f0V3UlfvkLvAEw1olB/EoBZGI 3UqpKNY5rjoEdLlVgcSXpS2IAI4cwApvlzIwjAAoBu4rrtqwv/aK0yvzchZRHvCzAFXGe8bRe +bm04PWiu6yyPZ/yOlveC8euUHfYhoJOdzudhIanL205wpbYyqs+QeylkyGFUUOg3X6Qs5qsa RMJUfD0XDSpuNei092sg7J/xfBCHQmIWZmyPvHOtDnOWOGKcu2l7SMGW+i1PFzF9/LL4Vrn18 3KHw4A+YxFrMfGY9xxypp+kyL9UCU3Vi3s/DYWqc7KuDLjYVMLmoUjW3hGoYprONHKuxNyhn/ ltfrC74ikaZMsbUQaH/Ka2jk6kCcG4leKkdP+w== Subject: [Xen-devel] [PATCH] swiotlb: fix phys_addr_t overflow warning X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Stefano Stabellini , Arnd Bergmann , Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, Mike Rapoport , iommu@lists.linux-foundation.org, Joerg Roedel , Jesper Dangaard Brouer , xen-devel@lists.xenproject.org, Boris Ostrovsky , Robin Murphy , Andrew Morton Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP On architectures that have a larger dma_addr_t than phys_addr_t, the swiotlb_tbl_map_single() function truncates its return code in the failure path, making it impossible to identify the error later, as we compare to the original value: kernel/dma/swiotlb.c:551:9: error: implicit conversion from 'dma_addr_t' (aka 'unsigned long long') to 'phys_addr_t' (aka 'unsigned int') changes value from 18446744073709551615 to 4294967295 [-Werror,-Wconstant-conversion] return DMA_MAPPING_ERROR; Use an explicit typecast here to convert it to the narrower type, and use the same expression in the error handling later. Fixes: b907e20508d0 ("swiotlb: remove SWIOTLB_MAP_ERROR") Signed-off-by: Arnd Bergmann Acked-by: Stefano Stabellini --- I still think that reverting the original commit would have provided clearer semantics for this corner case, but at least this patch restores the correct behavior. --- drivers/xen/swiotlb-xen.c | 2 +- kernel/dma/swiotlb.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index d53f3493a6b9..cfbe46785a3b 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -402,7 +402,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir, attrs); - if (map == DMA_MAPPING_ERROR) + if (map == (phys_addr_t)DMA_MAPPING_ERROR) return DMA_MAPPING_ERROR; dev_addr = xen_phys_to_bus(map); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index e906ef2e6315..a3be651973ad 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -548,7 +548,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", size, io_tlb_nslabs, tmp_io_tlb_used); - return DMA_MAPPING_ERROR; + return (phys_addr_t)DMA_MAPPING_ERROR; found: io_tlb_used += nslots; spin_unlock_irqrestore(&io_tlb_lock, flags); @@ -666,7 +666,7 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr, /* Oh well, have to allocate and map a bounce buffer. */ *phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start), *phys, size, dir, attrs); - if (*phys == DMA_MAPPING_ERROR) + if (*phys == (phys_addr_t)DMA_MAPPING_ERROR) return false; /* Ensure that the address returned is DMA'ble */