From: Niklas Schnelle <schnelle@linux.ibm.com>
To: "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: Mon, 12 Oct 2020 16:39:30 +0200 [thread overview]
Message-ID: <3c28a96a-6bb5-f581-4671-5c87161238f7@linux.ibm.com> (raw)
In-Reply-To: <20201012141906.GX438822@phenom.ffwll.local>
... snip ...
>>> 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.
Today I learned, thanks! That said I think most of the time I've
actually not seen version change information in the commit message itself
only in the cover letters. I really don't care just looked odd to me.
>
>>> ---
>>> 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.
Interesting, your theory sounds convincing, I too thought this
was a bit too pedantic.
>
> I'll fix up all the nits you've found for the next round. Thanks for
> taking a look.
You're welcome hope I didn't sound pedantic. I think you've a lot
more experience actually and this can indeed turn into bikeshedding
but since I was answering anyway and most of this was checkpatch…
> -Daniel
>
next prev parent reply other threads:[~2020-10-12 14:41 UTC|newest]
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 [this message]
2020-10-21 7:55 ` Niklas Schnelle
2020-10-22 7:39 ` Daniel Vetter
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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