From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 649E32517A5; Fri, 25 Jul 2025 20:04:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753473902; cv=none; b=fAnStYIsQotAQDZay/rQUO+LMYfitS8NJBye+ebnGlpHP4fazLxfwMFF6Y9G/DgXhyr8QZKGUvqtP6GS3agi6SVblOuSJ8StpNtjPu2wdneJ1EvFBhJNnuAG/gsAX7GMyI0miRdfuIv9iZ7YspWyDh6ilmyyy4h9Cery0rWfCjM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753473902; c=relaxed/simple; bh=8+OH0jpnYCxLHJivUXbltpTlvIRJChdCd+Jh3a0RZJA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sHOUCpOo9WPF/HbKlJCxU6O58ubw1bo6u/eVbbc68JLiqCX6bBBtyPntLRGzmuJDir8unMFdvboKe34nSW1eCl3jGTKgbf4becPY8rfMY5RVdBPmcXXdm+cHi6MWE+FBri+dnkpybeFCY+gWmMLMzz6L28DUEfANnO+ljmHn6o4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8E344176C; Fri, 25 Jul 2025 13:04:51 -0700 (PDT) Received: from [10.57.4.83] (unknown [10.57.4.83]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 167FB3F6A8; Fri, 25 Jul 2025 13:04:52 -0700 (PDT) Message-ID: <02240cf7-c4d4-4296-9b1e-87b4231874a1@arm.com> Date: Fri, 25 Jul 2025 21:04:50 +0100 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 6/8] dma-mapping: fail early if physical address is mapped through platform callback To: Leon Romanovsky , Marek Szyprowski Cc: Leon Romanovsky , Christoph Hellwig , Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Joerg Roedel , Will Deacon , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Masami Hiramatsu , Mathieu Desnoyers , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, iommu@lists.linux.dev, virtualization@lists.linux.dev, kasan-dev@googlegroups.com, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org References: <5fc1f0ca52a85834b3e978c5d6a3171d7dd3c194.1750854543.git.leon@kernel.org> From: Robin Murphy Content-Language: en-GB In-Reply-To: <5fc1f0ca52a85834b3e978c5d6a3171d7dd3c194.1750854543.git.leon@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025-06-25 2:19 pm, Leon Romanovsky wrote: > From: Leon Romanovsky > > All platforms which implement map_page interface don't support physical > addresses without real struct page. Add condition to check it. As-is, the condition also needs to cover iommu-dma, because that also still doesn't support non-page-backed addresses. You can't just do a simple s/page/phys/ rename and hope it's OK because you happen to get away with it for coherent, 64-bit, trusted devices. Thanks, Robin. > Signed-off-by: Leon Romanovsky > --- > kernel/dma/mapping.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c > index 709405d46b2b..74efb6909103 100644 > --- a/kernel/dma/mapping.c > +++ b/kernel/dma/mapping.c > @@ -158,6 +158,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, > { > const struct dma_map_ops *ops = get_dma_ops(dev); > phys_addr_t phys = page_to_phys(page) + offset; > + bool is_pfn_valid = true; > dma_addr_t addr; > > BUG_ON(!valid_dma_direction(dir)); > @@ -170,8 +171,20 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, > addr = dma_direct_map_phys(dev, phys, size, dir, attrs); > else if (use_dma_iommu(dev)) > addr = iommu_dma_map_phys(dev, phys, size, dir, attrs); > - else > + else { > + if (IS_ENABLED(CONFIG_DMA_API_DEBUG)) > + is_pfn_valid = pfn_valid(PHYS_PFN(phys)); > + > + if (unlikely(!is_pfn_valid)) > + return DMA_MAPPING_ERROR; > + > + /* > + * All platforms which implement .map_page() don't support > + * non-struct page backed addresses. > + */ > addr = ops->map_page(dev, page, offset, size, dir, attrs); > + } > + > kmsan_handle_dma(phys, size, dir); > trace_dma_map_phys(dev, phys, addr, size, dir, attrs); > debug_dma_map_phys(dev, phys, size, dir, addr, attrs);