linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Joerg Roedel <joro@8bytes.org>, Will Deacon <will.deacon@arm.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	Christoph Hellwig <hch@lst.de>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 02/21] arm64/iommu: improve mmap bounds checking
Date: Tue, 9 Apr 2019 19:09:13 +0200	[thread overview]
Message-ID: <20190409170913.GA14679@lst.de> (raw)
In-Reply-To: <45672f18-c741-601d-6bb2-92f50b77e981@arm.com>

On Tue, Apr 09, 2019 at 04:12:51PM +0100, Robin Murphy wrote:
> On 07/04/2019 07:59, Christoph Hellwig wrote:
>> On Fri, Apr 05, 2019 at 06:30:52PM +0100, Robin Murphy wrote:
>>> On 27/03/2019 08:04, Christoph Hellwig wrote:
>>>> The nr_pages checks should be done for all mmap requests, not just those
>>>> using remap_pfn_range.
>>>
>>> Hmm, the logic in iommu_dma_mmap() inherently returns an error for the "off
>>>> = nr_pages" case already. It's also supposed to be robust against the
>>> "vma_pages(vma) > nr_pages - off" condition, although by making the partial
>>> mapping and treating it as a success, rather than doing nothing and
>>> returning an error. What's the exact motivation here?
>>
>> Have one error check at the front of the function that is identical
>> to the mmap checks in the other dma_map_ops instances so that:
>>
>>   a) we get the same error behavior for partial requests everywhere
>>   b) we can lift these checks into common code in the next round.
>>
>
> Fair enough, but in that case why isn't the dma_mmap_from_coherent() path 
> also covered?

dma_mmap_from_coherent currently duplicates those checks itself, and
because of that the other callers also don't include it in their
checks.  I don't actually like that situation and have patches to
refactor and clean up that whole mess by also moving the dma coherent
mmap to common code, and share the checks that I plan to also lift.

But for now I'm holding these back as they would conflict with this
series and I'm not sure if it will go in and if yes if that is through
the dma-mapping or iommu tree.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2019-04-09 17:09 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-27  8:04 implement generic dma_map_ops for IOMMUs v2 [rebase + resend] Christoph Hellwig
2019-03-27  8:04 ` [PATCH 01/21] arm64/iommu: handle non-remapped addresses in ->mmap and ->get_sgtable Christoph Hellwig
2019-04-05 17:16   ` Robin Murphy
2019-03-27  8:04 ` [PATCH 02/21] arm64/iommu: improve mmap bounds checking Christoph Hellwig
2019-04-05 17:30   ` Robin Murphy
2019-04-07  6:59     ` Christoph Hellwig
2019-04-09 15:12       ` Robin Murphy
2019-04-09 17:09         ` Christoph Hellwig [this message]
2019-03-27  8:04 ` [PATCH 03/21] dma-mapping: add a Kconfig symbol to indicated arch_dma_prep_coherent presence Christoph Hellwig
2019-04-05 17:41   ` Robin Murphy
2019-03-27  8:04 ` [PATCH 04/21] dma-iommu: cleanup dma-iommu.h Christoph Hellwig
2019-04-05 17:42   ` Robin Murphy
2019-04-09 17:10     ` Christoph Hellwig
2019-03-27  8:04 ` [PATCH 05/21] dma-iommu: remove the flush_page callback Christoph Hellwig
2019-04-05 17:46   ` Robin Murphy
2019-03-27  8:04 ` [PATCH 06/21] dma-iommu: use for_each_sg in iommu_dma_alloc Christoph Hellwig
2019-04-05 18:08   ` Robin Murphy
2019-03-27  8:04 ` [PATCH 07/21] dma-iommu: move the arm64 wrappers to common code Christoph Hellwig
2019-04-09 15:07   ` Robin Murphy
2019-04-09 17:15     ` Christoph Hellwig
2019-04-09 17:23     ` Christoph Hellwig
2019-04-09 17:33       ` Robin Murphy
2019-03-27  8:04 ` [PATCH 08/21] dma-iommu: refactor iommu_dma_mmap Christoph Hellwig
2019-04-09 15:29   ` Robin Murphy
2019-04-09 17:25     ` Christoph Hellwig
2019-03-27  8:04 ` [PATCH 09/21] dma-iommu: refactor iommu_dma_get_sgtable Christoph Hellwig
2019-04-09 15:49   ` Robin Murphy
2019-04-09 17:26     ` Christoph Hellwig
2019-03-27  8:04 ` [PATCH 10/21] dma-iommu: move __iommu_dma_map Christoph Hellwig
2019-04-09 15:54   ` Robin Murphy
2019-03-27  8:04 ` [PATCH 11/21] dma-iommu: refactor page array remap helpers Christoph Hellwig
2019-04-09 16:38   ` Robin Murphy
2019-03-27  8:04 ` [PATCH 12/21] dma-iommu: factor atomic pool allocations into helpers Christoph Hellwig
2019-04-09 17:59   ` Robin Murphy
2019-04-10  6:11     ` Christoph Hellwig
2019-04-17  6:33       ` Christoph Hellwig
2019-04-17 11:54         ` Robin Murphy
2019-04-18 15:06         ` Robin Murphy
2019-04-18 16:35           ` Christoph Hellwig
2019-04-18 16:41             ` Robin Murphy
2019-04-19  9:07               ` Christoph Hellwig
2019-04-23  9:48                 ` Robin Murphy
2019-04-18 18:15             ` Robin Murphy
2019-04-19  8:23               ` Christoph Hellwig
2019-04-23 10:01                 ` Robin Murphy
2019-04-23 14:52                   ` Christoph Hellwig
2019-04-29 11:49                   ` Christoph Hellwig
2019-04-29 12:02                     ` Robin Murphy
2019-04-22 18:03               ` Christoph Hellwig
2019-03-27  8:04 ` [PATCH 13/21] dma-iommu: factor contiguous " Christoph Hellwig
2019-03-27  8:04 ` [PATCH 14/21] dma-iommu: refactor iommu_dma_free Christoph Hellwig
2019-03-27  8:04 ` [PATCH 15/21] dma-iommu: don't remap contiguous allocations for coherent devices Christoph Hellwig
2019-03-27  8:04 ` [PATCH 16/21] dma-iommu: factor contiguous remapped allocations into helpers Christoph Hellwig
2019-03-27  8:04 ` [PATCH 17/21] dma-iommu: refactor iommu_dma_alloc Christoph Hellwig
2019-03-27  8:04 ` [PATCH 18/21] dma-iommu: don't depend on CONFIG_DMA_DIRECT_REMAP Christoph Hellwig
2019-03-27  8:04 ` [PATCH 19/21] dma-iommu: switch copyright boilerplace to SPDX Christoph Hellwig
2019-03-27  8:04 ` [PATCH 20/21] arm64: switch copyright boilerplace to SPDX in dma-mapping.c Christoph Hellwig
2019-04-01  6:28   ` Mukesh Ojha
2019-04-01  9:39     ` Robin Murphy
2019-03-27  8:04 ` [PATCH 21/21] arm64: trim includes " Christoph Hellwig
  -- strict thread matches above, loose matches on Subject: below --
2019-02-13 18:28 implement generic dma_map_ops for IOMMUs v2 Christoph Hellwig
2019-02-13 18:29 ` [PATCH 02/21] arm64/iommu: improve mmap bounds checking Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190409170913.GA14679@lst.de \
    --to=hch@lst.de \
    --cc=catalin.marinas@arm.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=joro@8bytes.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=thomas.lendacky@amd.com \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).