From: Christoph Hellwig <hch@lst.de>
To: Mike Rapoport <rppt@kernel.org>
Cc: Will Deacon <will@kernel.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
David Hildenbrand <david@redhat.com>,
Alex Bee <knaerzche@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
iommu@lists.linux-foundation.org,
Andrew Morton <akpm@linux-foundation.org>,
Mike Rapoport <rppt@linux.ibm.com>,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/2] dma-mapping: remove bogus test for pfn_valid from dma_map_resource
Date: Thu, 30 Sep 2021 07:46:37 +0200 [thread overview]
Message-ID: <20210930054637.GA22287@lst.de> (raw)
In-Reply-To: <20210930013039.11260-2-rppt@kernel.org>
On Thu, Sep 30, 2021 at 04:30:38AM +0300, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> dma_map_resource() uses pfn_valid() to ensure the range is not RAM.
> However, pfn_valid() only checks for availability of the memory map for a
> PFN but it does not ensure that the PFN is actually backed by RAM.
>
> As dma_map_resource() is the only method in DMA mapping APIs that has this
> check, simply drop the pfn_valid() test from dma_map_resource().
>
> Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
We'll lose a bit of a sanity check with this, but given the problems it
caused:
Reviewed-by: Christoph Hellwig <hch@lst.de>
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Mike Rapoport <rppt@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
Alex Bee <knaerzche@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Christoph Hellwig <hch@lst.de>,
David Hildenbrand <david@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Robin Murphy <robin.murphy@arm.com>,
Will Deacon <will@kernel.org>,
iommu@lists.linux-foundation.org
Subject: Re: [PATCH 1/2] dma-mapping: remove bogus test for pfn_valid from dma_map_resource
Date: Thu, 30 Sep 2021 07:46:37 +0200 [thread overview]
Message-ID: <20210930054637.GA22287@lst.de> (raw)
In-Reply-To: <20210930013039.11260-2-rppt@kernel.org>
On Thu, Sep 30, 2021 at 04:30:38AM +0300, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> dma_map_resource() uses pfn_valid() to ensure the range is not RAM.
> However, pfn_valid() only checks for availability of the memory map for a
> PFN but it does not ensure that the PFN is actually backed by RAM.
>
> As dma_map_resource() is the only method in DMA mapping APIs that has this
> check, simply drop the pfn_valid() test from dma_map_resource().
>
> Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
We'll lose a bit of a sanity check with this, but given the problems it
caused:
Reviewed-by: Christoph Hellwig <hch@lst.de>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Mike Rapoport <rppt@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
Alex Bee <knaerzche@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Christoph Hellwig <hch@lst.de>,
David Hildenbrand <david@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Robin Murphy <robin.murphy@arm.com>,
Will Deacon <will@kernel.org>,
iommu@lists.linux-foundation.org
Subject: Re: [PATCH 1/2] dma-mapping: remove bogus test for pfn_valid from dma_map_resource
Date: Thu, 30 Sep 2021 07:46:37 +0200 [thread overview]
Message-ID: <20210930054637.GA22287@lst.de> (raw)
In-Reply-To: <20210930013039.11260-2-rppt@kernel.org>
On Thu, Sep 30, 2021 at 04:30:38AM +0300, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> dma_map_resource() uses pfn_valid() to ensure the range is not RAM.
> However, pfn_valid() only checks for availability of the memory map for a
> PFN but it does not ensure that the PFN is actually backed by RAM.
>
> As dma_map_resource() is the only method in DMA mapping APIs that has this
> check, simply drop the pfn_valid() test from dma_map_resource().
>
> Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
We'll lose a bit of a sanity check with this, but given the problems it
caused:
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2021-09-30 5:46 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-30 1:30 [PATCH 0/2] arm64: retry dropping HAVE_ARCH_PFN_VALID Mike Rapoport
2021-09-30 1:30 ` Mike Rapoport
2021-09-30 1:30 ` Mike Rapoport
2021-09-30 1:30 ` [PATCH 1/2] dma-mapping: remove bogus test for pfn_valid from dma_map_resource Mike Rapoport
2021-09-30 1:30 ` Mike Rapoport
2021-09-30 1:30 ` Mike Rapoport
2021-09-30 5:46 ` Christoph Hellwig [this message]
2021-09-30 5:46 ` Christoph Hellwig
2021-09-30 5:46 ` Christoph Hellwig
2021-09-30 7:27 ` David Hildenbrand
2021-09-30 7:27 ` David Hildenbrand
2021-09-30 7:27 ` David Hildenbrand
2021-09-30 1:30 ` [PATCH 2/2] arm64/mm: drop HAVE_ARCH_PFN_VALID Mike Rapoport
2021-09-30 1:30 ` Mike Rapoport
2021-09-30 1:30 ` Mike Rapoport
2021-10-01 14:01 ` [PATCH 0/2] arm64: retry dropping HAVE_ARCH_PFN_VALID Will Deacon
2021-10-01 14:01 ` Will Deacon
2021-10-01 14:01 ` Will Deacon
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