From: Souptick Joarder <jrdr.linux@gmail.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: robin.murphy@arm.com, Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>,
joro@8bytes.org, Linux-MM <linux-mm@kvack.org>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/9] iommu/dma-iommu.c: Convert to use vm_insert_range
Date: Sat, 24 Nov 2018 10:31:20 +0530 [thread overview]
Message-ID: <CAFqt6zawenCGGhLoVzCrjzdHH4rV1RqpWGswDGjGE-VqJETFBA@mail.gmail.com> (raw)
In-Reply-To: <20181123213448.GW3065@bombadil.infradead.org>
On Sat, Nov 24, 2018 at 3:04 AM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Fri, Nov 23, 2018 at 05:23:06PM +0000, Robin Murphy wrote:
> > On 15/11/2018 15:49, Souptick Joarder wrote:
> > > Convert to use vm_insert_range() to map range of kernel
> > > memory to user vma.
> > >
> > > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > > Reviewed-by: Matthew Wilcox <willy@infradead.org>
> > > ---
> > > drivers/iommu/dma-iommu.c | 12 ++----------
> > > 1 file changed, 2 insertions(+), 10 deletions(-)
> > >
> > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > > index d1b0475..69c66b1 100644
> > > --- a/drivers/iommu/dma-iommu.c
> > > +++ b/drivers/iommu/dma-iommu.c
> > > @@ -622,17 +622,9 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
> > > int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma)
> > > {
> > > - unsigned long uaddr = vma->vm_start;
> > > - unsigned int i, count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> > > - int ret = -ENXIO;
> > > + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> > > - for (i = vma->vm_pgoff; i < count && uaddr < vma->vm_end; i++) {
> > > - ret = vm_insert_page(vma, uaddr, pages[i]);
> > > - if (ret)
> > > - break;
> > > - uaddr += PAGE_SIZE;
> > > - }
> > > - return ret;
> > > + return vm_insert_range(vma, vma->vm_start, pages, count);
> >
> > AFIACS, vm_insert_range() doesn't respect vma->vm_pgoff, so doesn't this
> > break partial mmap()s of a large buffer? (which I believe can be a thing)
>
> Whoops. That should have been:
>
> return vm_insert_range(vma, vma->vm_start, pages + vma->vm_pgoff, count);
>
> I suppose.
Matthew, patch "drm/rockchip/rockchip_drm_gem.c: Convert to use vm_insert_range"
also need to address the same issue ?
>
> Although arguably we should respect vm_pgoff inside vm_insert_region()
> and then callers automatically get support for vm_pgoff without having
> to think about it ... although we should then also pass in the length
> of the pages array to avoid pages being mapped in which aren't part of
> the allocated array.
>
> Hm. More thought required.
next prev parent reply other threads:[~2018-11-24 5:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-15 15:49 [PATCH 6/9] iommu/dma-iommu.c: Convert to use vm_insert_range Souptick Joarder
2018-11-23 17:23 ` Robin Murphy
2018-11-23 21:34 ` Matthew Wilcox
2018-11-24 5:01 ` Souptick Joarder [this message]
2018-11-26 6:44 ` Souptick Joarder
2018-11-26 13:18 ` Robin Murphy
2019-01-11 15:11 Souptick Joarder
2019-01-28 6:31 ` Souptick Joarder
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=CAFqt6zawenCGGhLoVzCrjzdHH4rV1RqpWGswDGjGE-VqJETFBA@mail.gmail.com \
--to=jrdr.linux@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=iommu@lists.linux-foundation.org \
--cc=joro@8bytes.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=robin.murphy@arm.com \
--cc=willy@infradead.org \
/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).