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From: Christoph Hellwig <hch@infradead.org>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Alan Mikhak <alan.mikhak@sifive.com>,
	linux-kernel@vger.kernel.org, martin.petersen@oracle.com,
	alexios.zavras@intel.com, ming.lei@redhat.com,
	gregkh@linuxfoundation.org, tglx@linutronix.de,
	christophe.leroy@c-s.fr, palmer@sifive.com,
	paul.walmsley@sifive.com
Subject: Re: [PATCH] scatterlist: Validate page before calling PageSlab()
Date: Sun, 6 Oct 2019 23:12:12 -0700	[thread overview]
Message-ID: <20191007061212.GA17978@infradead.org> (raw)
In-Reply-To: <20191001121623.GA22532@ziepe.ca>

On Tue, Oct 01, 2019 at 09:16:23AM -0300, Jason Gunthorpe wrote:
> > If the virtual address obtained from ioremap() is not
> > backed by a page struct, virt_to_page() returns an
> > invalid page pointer. However, sg_copy_buffer() can
> > correctly recover the original virtual address. Such
> > addresses can successfully be assigned to scatterlist
> > segments to transfer data across the PCI bus with
> > sg_copy_buffer() if it were not for the crash in
> > PageSlab() when called by sg_miter_stop().
> 
> I thought we already agreed in general that putting things that don't
> have struct page into the scatter list was not allowed?

Yes, that absolutely is the case.

  parent reply	other threads:[~2019-10-07  6:12 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-30 23:22 Alan Mikhak
2019-10-01 12:16 ` Jason Gunthorpe
2019-10-01 17:09   ` Alan Mikhak
2019-10-01 17:12     ` Jason Gunthorpe
2019-10-01 17:26       ` Alan Mikhak
2019-10-01 17:43         ` Jason Gunthorpe
2019-10-01 17:46           ` Alan Mikhak
2019-10-07  6:12   ` Christoph Hellwig [this message]
2019-10-07  6:13 ` Christoph Hellwig
2019-10-07 16:44   ` Alan Mikhak
2019-10-07 21:13     ` Alan Mikhak
2019-10-15  9:55       ` Christoph Hellwig
2019-10-15 16:12         ` Logan Gunthorpe
2019-10-15 19:02           ` Alan Mikhak
2019-10-15 17:40         ` Alan Mikhak
2019-10-15 17:45           ` Logan Gunthorpe
2019-10-15 18:11             ` Alan Mikhak

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