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=-8.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 6F75AC31E58 for ; Mon, 17 Jun 2019 13:36:34 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 51E5B20657 for ; Mon, 17 Jun 2019 13:36:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 51E5B20657 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 1E4D0D1A; Mon, 17 Jun 2019 13:36:34 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id D7822CD1 for ; Mon, 17 Jun 2019 13:36:32 +0000 (UTC) X-Greylist: delayed 00:05:38 by SQLgrey-1.7.6 Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.134]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id EA4DF822 for ; Mon, 17 Jun 2019 13:36:31 +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 Subject: [PATCH] swiotlb: fix phys_addr_t overflow warning 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:EzVBvm4Eeto=:HRETReHTnJ8QFSk4hEn1qQ krBULTtSEsRA+SKfHiPAXB12Zs69NRs0bPjQGoTcievwJnntyFT3O24n7nfWasqk9oCcIPIbq 8+ub1689HW7yvCboXuImPFTSlh2tCL0NLL7Bcoix/CBAyqNw3Fi9G6HeFavkYC+F1zWwgeru+ J12wYgm9/hNAHPURyds0+ZcnPMuiXNsJUTjX38YiCC3jYWEwDu6xPDeBBEHoP9OcVGriBUDWx nOtpS/DXsQQd+AfDKT6V9MlZKf6oYAzTUGT9C6k2rM/ribM2s5yRUCIzrSxhHhcXMDrt8nIdG QffskYVm5eCdyxQAD9mhkvA6fi3d+AZdyUtGBFzT1+XJWRyKQMf1TF6sSqPK7AytRi+IRwx7Y 3rb29jaADxJKPd4GvDST7YSFTPove1KdKtNJo3c8gfvPfQjpPQS79o/SQKKi4p9gInDRS3zkP 84iLKTn4IoIztZmlEVRaBsoyGXi/JuB10WGEascz18nsRl0CJDr7p4IFPhIl7rqsKO5lVyGIT JcUAfPeH2Hp61ihPdVXkAc8a0tYdfKI9Zdq5LcLB+9Hvcf4bYyzbdLeOcsoHD0fE7hRnLW/g6 MXQnltmz0Y0jzkKjcvyGJ91jeVoEMhXhIPAjHhltucQCT8il67h1/F7BIWNZaWbRmC2/fzPGA 5clNyY5Oy0AMXYtToCeUcnEUfnDkQxd5TWThoKjDGXT+p+UaSGc+DU299OuWrcBhv7ClOU4Zu PEGu0P+KUJrEzvcWvrRXDjgnWaQ4ZOCrNDfRcA== 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 X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org 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 --- 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 */ -- 2.20.0 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu