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From: Daniel Vetter <daniel@ffwll.ch>
To: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: "DRI Development" <dri-devel@lists.freedesktop.org>,
	LKML <linux-kernel@vger.kernel.org>,
	kvm@vger.kernel.org, linux-mm@kvack.org,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org,
	linux-s390@vger.kernel.org,
	"Gerald Schaefer" <gerald.schaefer@linux.ibm.com>,
	"Daniel Vetter" <daniel.vetter@intel.com>,
	"Jason Gunthorpe" <jgg@ziepe.ca>,
	"Dan Williams" <dan.j.williams@intel.com>,
	"Kees Cook" <keescook@chromium.org>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"John Hubbard" <jhubbard@nvidia.com>,
	"Jérôme Glisse" <jglisse@redhat.com>, "Jan Kara" <jack@suse.cz>
Subject: Re: [PATCH v2 08/17] s390/pci: Remove races against pte updates
Date: Thu, 22 Oct 2020 09:39:43 +0200
Message-ID: <20201022073943.GS401619@phenom.ffwll.local> (raw)
In-Reply-To: <3594c115-541f-806a-ee33-e99a2d1d31e8@linux.ibm.com>

On Wed, Oct 21, 2020 at 09:55:57AM +0200, Niklas Schnelle wrote:
> Hi Daniel,
> 
> friendly ping. I haven't seen a new version of this patch series,
> as I said I think your change for s390/pci is generally useful so
> I'm curious, are you planning on sending a new version soon?
> If you want you can also just sent this patch with the last few
> nitpicks (primarily the mail address) fixed and I'll happily apply.

(I think this was stuck somewhere in moderation, only showed up just now)

I was waiting for the testing result for the habana driver from Oded, but
I guess Oded was waiting for v3. Hence the delay.

Cheers, Daniel

> 
> Best regards,
> Niklas Schnelle
> 
> On 10/12/20 4:19 PM, Daniel Vetter wrote:
> > On Mon, Oct 12, 2020 at 04:03:28PM +0200, Niklas Schnelle wrote:
> ... snip ....
> >>> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> >>> Cc: Dan Williams <dan.j.williams@intel.com>
> >>> Cc: Kees Cook <keescook@chromium.org>
> >>> Cc: Andrew Morton <akpm@linux-foundation.org>
> >>> Cc: John Hubbard <jhubbard@nvidia.com>
> >>> Cc: Jérôme Glisse <jglisse@redhat.com>
> >>> Cc: Jan Kara <jack@suse.cz>
> >>> Cc: Dan Williams <dan.j.williams@intel.com>
> >>
> >> The above Cc: line for Dan Williams is a duplicate
> >>
> >>> Cc: linux-mm@kvack.org
> >>> Cc: linux-arm-kernel@lists.infradead.org
> >>> Cc: linux-samsung-soc@vger.kernel.org
> >>> Cc: linux-media@vger.kernel.org
> >>> Cc: Niklas Schnelle <schnelle@linux.ibm.com>
> >>> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> >>> Cc: linux-s390@vger.kernel.org
> >>> --
> >>> v2: Move VM_IO | VM_PFNMAP checks around so they keep returning EINVAL
> >>> like before (Gerard)
> >>
> >> I think the above should go before the CC/Signed-off/Reviewev block.
> > 
> > This is a per-subsystem bikeshed :-) drivers/gpu definitely wants it
> > above, but most core subsystems want it below. I'll move it.
> > 
> >>> ---
> >>>  arch/s390/pci/pci_mmio.c | 98 +++++++++++++++++++++++-----------------
> >>>  1 file changed, 57 insertions(+), 41 deletions(-)
> >>>
> >>> diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c
> >>> index 401cf670a243..1a6adbc68ee8 100644
> >>> --- a/arch/s390/pci/pci_mmio.c
> >>> +++ b/arch/s390/pci/pci_mmio.c
> >>> @@ -119,33 +119,15 @@ static inline int __memcpy_toio_inuser(void __iomem *dst,
> >>>  	return rc;
> >>>  }
> >>>  
> >>> -static long get_pfn(unsigned long user_addr, unsigned long access,
> >>> -		    unsigned long *pfn)
> >>> -{
> >>> -	struct vm_area_struct *vma;
> >>> -	long ret;
> >>> -
> >>> -	mmap_read_lock(current->mm);
> >>> -	ret = -EINVAL;
> >>> -	vma = find_vma(current->mm, user_addr);
> >>> -	if (!vma)
> >>> -		goto out;
> >>> -	ret = -EACCES;
> >>> -	if (!(vma->vm_flags & access))
> >>> -		goto out;
> >>> -	ret = follow_pfn(vma, user_addr, pfn);
> >>> -out:
> >>> -	mmap_read_unlock(current->mm);
> >>> -	return ret;
> >>> -}
> >>> -
> >>>  SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
> >>>  		const void __user *, user_buffer, size_t, length)
> >>>  {
> >>>  	u8 local_buf[64];
> >>>  	void __iomem *io_addr;
> >>>  	void *buf;
> >>> -	unsigned long pfn;
> >>> +	struct vm_area_struct *vma;
> >>> +	pte_t *ptep;
> >>> +	spinlock_t *ptl;
> >>
> >> With checkpatch.pl --strict the above yields a complained
> >> "CHECK: spinlock_t definition without comment" but I think
> >> that's really okay since your commit description is very clear.
> >> Same oin line 277.
> > 
> > I think this is a falls positive, checkpatch doesn't realize that
> > SYSCALL_DEFINE3 is a function, not a structure. And in a structure I'd
> > have added the kerneldoc or comment.
> > 
> > I'll fix up all the nits you've found for the next round. Thanks for
> > taking a look.
> > -Daniel
> > 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

  reply index

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-09  7:59 [PATCH v2 00/17] follow_pfn and other iomap races Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 01/17] drm/exynos: Stop using frame_vector helpers Daniel Vetter
2020-10-16  7:42   ` John Hubbard
2020-10-09  7:59 ` [PATCH v2 02/17] drm/exynos: Use FOLL_LONGTERM for g2d cmdlists Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 03/17] misc/habana: Stop using frame_vector helpers Daniel Vetter
2020-10-10 20:26   ` Oded Gabbay
2020-10-10 21:32     ` Daniel Vetter
2020-10-10 21:41       ` Daniel Vetter
2020-10-10 21:47         ` Oded Gabbay
2020-10-16  7:45   ` John Hubbard
2020-10-09  7:59 ` [PATCH v2 04/17] misc/habana: Use FOLL_LONGTERM for userptr Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 05/17] mm/frame-vector: Use FOLL_LONGTERM Daniel Vetter
2020-10-16  7:54   ` John Hubbard
2020-10-16  8:03     ` Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 06/17] media: videobuf2: Move frame_vector into media subsystem Daniel Vetter
2020-10-09 10:14   ` Mauro Carvalho Chehab
2020-10-09 16:57     ` Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 07/17] mm: Close race in generic_access_phys Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 08/17] s390/pci: Remove races against pte updates Daniel Vetter
2020-10-12 14:03   ` Niklas Schnelle
2020-10-12 14:19     ` Daniel Vetter
2020-10-12 14:39       ` Niklas Schnelle
2020-10-21  7:55       ` Niklas Schnelle
2020-10-22  7:39         ` Daniel Vetter [this message]
2020-10-09  7:59 ` [PATCH v2 09/17] mm: Add unsafe_follow_pfn Daniel Vetter
2020-10-09 10:34   ` Mauro Carvalho Chehab
2020-10-09 12:21     ` Jason Gunthorpe
2020-10-09 12:37       ` Mauro Carvalho Chehab
2020-10-09 12:39         ` Mauro Carvalho Chehab
2020-10-09 12:48         ` Jason Gunthorpe
2020-10-09 17:52           ` Daniel Vetter
2020-10-09 18:01             ` Jason Gunthorpe
2020-10-09 19:31               ` Daniel Vetter
2020-10-10  9:21             ` Mauro Carvalho Chehab
2020-10-10 10:53               ` Daniel Vetter
2020-10-10 11:39                 ` Mauro Carvalho Chehab
2020-10-10 11:56                   ` Daniel Vetter
2020-10-10 17:22             ` Tomasz Figa
2020-10-10 21:35               ` Laurent Pinchart
2020-10-10 21:50                 ` Daniel Vetter
2020-10-11  6:27                   ` Mauro Carvalho Chehab
2020-10-11  6:36                     ` Mauro Carvalho Chehab
2020-10-10 21:11             ` Laurent Pinchart
2020-10-12 10:46           ` Marek Szyprowski
2020-10-12 13:49             ` Daniel Vetter
2020-10-10 17:30         ` Tomasz Figa
2020-10-09  7:59 ` [PATCH v2 10/17] media/videbuf1|2: Mark follow_pfn usage as unsafe Daniel Vetter
2020-10-10  9:24   ` Mauro Carvalho Chehab
2020-10-09  7:59 ` [PATCH v2 11/17] vfio/type1: Mark follow_pfn " Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 12/17] PCI: Obey iomem restrictions for procfs mmap Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 13/17] /dev/mem: Only set filp->f_mapping Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 14/17] resource: Move devmem revoke code to resource framework Daniel Vetter
2020-10-09 10:59   ` Greg Kroah-Hartman
2020-10-09 12:31   ` Jason Gunthorpe
2020-10-09 14:24     ` Daniel Vetter
2020-10-09 14:32       ` Jason Gunthorpe
2020-10-09 18:28         ` Dan Williams
2020-10-15  0:09           ` Jason Gunthorpe
2020-10-15  7:52             ` Daniel Vetter
2020-10-15  7:55               ` Daniel Vetter
2020-10-15 15:29             ` Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 15/17] sysfs: Support zapping of binary attr mmaps Daniel Vetter
2020-10-09 10:58   ` Greg Kroah-Hartman
2020-10-09  7:59 ` [PATCH v2 16/17] PCI: Revoke mappings like devmem Daniel Vetter
2020-10-09  7:59 ` [PATCH v2 17/17] drm/i915: Properly request PCI BARs Daniel Vetter
2020-10-09  9:47   ` Ville Syrjälä
2020-10-09 10:01     ` Daniel Vetter
2020-10-09 10:41       ` Ville Syrjälä
2020-10-09 14:18         ` Daniel Vetter

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