From: Jason Gunthorpe <jgg@ziepe.ca>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
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,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Kees Cook" <keescook@chromium.org>,
"Dan Williams" <dan.j.williams@intel.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"John Hubbard" <jhubbard@nvidia.com>,
"Jérôme Glisse" <jglisse@redhat.com>, "Jan Kara" <jack@suse.cz>,
"Arnd Bergmann" <arnd@arndb.de>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"David Hildenbrand" <david@redhat.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: [PATCH v2 14/17] resource: Move devmem revoke code to resource framework
Date: Fri, 9 Oct 2020 09:31:09 -0300 [thread overview]
Message-ID: <20201009123109.GO5177@ziepe.ca> (raw)
In-Reply-To: <20201009075934.3509076-15-daniel.vetter@ffwll.ch>
On Fri, Oct 09, 2020 at 09:59:31AM +0200, Daniel Vetter wrote:
> +struct address_space *iomem_get_mapping(void)
> +{
> + return iomem_inode->i_mapping;
This should pair an acquire with the release below
> + /*
> + * Publish /dev/mem initialized.
> + * Pairs with smp_load_acquire() in revoke_iomem().
> + */
> + smp_store_release(&iomem_inode, inode);
However, this seems abnormal, initcalls rarely do this kind of stuff
with global data..
The kernel crashes if this fs_initcall is raced with
iomem_get_mapping() due to the unconditional dereference, so I think
it can be safely switched to a simple assignment.
Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
"Jan Kara" <jack@suse.cz>, "Kees Cook" <keescook@chromium.org>,
kvm@vger.kernel.org, "David Hildenbrand" <david@redhat.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
LKML <linux-kernel@vger.kernel.org>,
"DRI Development" <dri-devel@lists.freedesktop.org>,
linux-mm@kvack.org, "Jérôme Glisse" <jglisse@redhat.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: Re: [PATCH v2 14/17] resource: Move devmem revoke code to resource framework
Date: Fri, 9 Oct 2020 09:31:09 -0300 [thread overview]
Message-ID: <20201009123109.GO5177@ziepe.ca> (raw)
In-Reply-To: <20201009075934.3509076-15-daniel.vetter@ffwll.ch>
On Fri, Oct 09, 2020 at 09:59:31AM +0200, Daniel Vetter wrote:
> +struct address_space *iomem_get_mapping(void)
> +{
> + return iomem_inode->i_mapping;
This should pair an acquire with the release below
> + /*
> + * Publish /dev/mem initialized.
> + * Pairs with smp_load_acquire() in revoke_iomem().
> + */
> + smp_store_release(&iomem_inode, inode);
However, this seems abnormal, initcalls rarely do this kind of stuff
with global data..
The kernel crashes if this fs_initcall is raced with
iomem_get_mapping() due to the unconditional dereference, so I think
it can be safely switched to a simple assignment.
Jason
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
"Jan Kara" <jack@suse.cz>, "Kees Cook" <keescook@chromium.org>,
kvm@vger.kernel.org, "David Hildenbrand" <david@redhat.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
LKML <linux-kernel@vger.kernel.org>,
"DRI Development" <dri-devel@lists.freedesktop.org>,
linux-mm@kvack.org, "Jérôme Glisse" <jglisse@redhat.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: Re: [PATCH v2 14/17] resource: Move devmem revoke code to resource framework
Date: Fri, 9 Oct 2020 09:31:09 -0300 [thread overview]
Message-ID: <20201009123109.GO5177@ziepe.ca> (raw)
In-Reply-To: <20201009075934.3509076-15-daniel.vetter@ffwll.ch>
On Fri, Oct 09, 2020 at 09:59:31AM +0200, Daniel Vetter wrote:
> +struct address_space *iomem_get_mapping(void)
> +{
> + return iomem_inode->i_mapping;
This should pair an acquire with the release below
> + /*
> + * Publish /dev/mem initialized.
> + * Pairs with smp_load_acquire() in revoke_iomem().
> + */
> + smp_store_release(&iomem_inode, inode);
However, this seems abnormal, initcalls rarely do this kind of stuff
with global data..
The kernel crashes if this fs_initcall is raced with
iomem_get_mapping() due to the unconditional dereference, so I think
it can be safely switched to a simple assignment.
Jason
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2020-10-09 12:31 UTC|newest]
Thread overview: 214+ 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 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` [PATCH v2 01/17] drm/exynos: Stop using frame_vector helpers Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-16 7:42 ` John Hubbard
2020-10-16 7:42 ` John Hubbard
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 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` [PATCH v2 03/17] misc/habana: Stop using frame_vector helpers Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-10 20:26 ` Oded Gabbay
2020-10-10 20:26 ` Oded Gabbay
2020-10-10 20:26 ` Oded Gabbay
2020-10-10 21:32 ` Daniel Vetter
2020-10-10 21:32 ` Daniel Vetter
2020-10-10 21:32 ` Daniel Vetter
2020-10-10 21:41 ` Daniel Vetter
2020-10-10 21:41 ` Daniel Vetter
2020-10-10 21:41 ` Daniel Vetter
2020-10-10 21:47 ` Oded Gabbay
2020-10-10 21:47 ` Oded Gabbay
2020-10-10 21:47 ` Oded Gabbay
2020-10-16 7:45 ` John Hubbard
2020-10-16 7:45 ` John Hubbard
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 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` [PATCH v2 05/17] mm/frame-vector: Use FOLL_LONGTERM Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-16 7:54 ` John Hubbard
2020-10-16 7:54 ` John Hubbard
2020-10-16 7:54 ` John Hubbard
2020-10-16 8:03 ` Daniel Vetter
2020-10-16 8:03 ` Daniel Vetter
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 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 10:14 ` Mauro Carvalho Chehab
2020-10-09 10:14 ` Mauro Carvalho Chehab
2020-10-09 10:14 ` Mauro Carvalho Chehab
2020-10-09 16:57 ` Daniel Vetter
2020-10-09 16:57 ` Daniel Vetter
2020-10-09 16:57 ` Daniel Vetter
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 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` [PATCH v2 08/17] s390/pci: Remove races against pte updates Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-12 14:03 ` Niklas Schnelle
2020-10-12 14:03 ` Niklas Schnelle
2020-10-12 14:03 ` Niklas Schnelle
2020-10-12 14:19 ` Daniel Vetter
2020-10-12 14:19 ` Daniel Vetter
2020-10-12 14:19 ` Daniel Vetter
2020-10-12 14:19 ` Daniel Vetter
2020-10-12 14:39 ` Niklas Schnelle
2020-10-12 14:39 ` Niklas Schnelle
2020-10-12 14:39 ` Niklas Schnelle
2020-10-21 7:55 ` Niklas Schnelle
2020-10-21 7:55 ` Niklas Schnelle
2020-10-21 7:55 ` Niklas Schnelle
2020-10-22 7:39 ` Daniel Vetter
2020-10-22 7:39 ` Daniel Vetter
2020-10-22 7:39 ` Daniel Vetter
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 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 10:34 ` Mauro Carvalho Chehab
2020-10-09 10:34 ` Mauro Carvalho Chehab
2020-10-09 10:34 ` Mauro Carvalho Chehab
2020-10-09 12:21 ` Jason Gunthorpe
2020-10-09 12:21 ` Jason Gunthorpe
2020-10-09 12:21 ` Jason Gunthorpe
2020-10-09 12:37 ` Mauro Carvalho Chehab
2020-10-09 12:37 ` Mauro Carvalho Chehab
2020-10-09 12:37 ` Mauro Carvalho Chehab
2020-10-09 12:39 ` Mauro Carvalho Chehab
2020-10-09 12:39 ` Mauro Carvalho Chehab
2020-10-09 12:39 ` Mauro Carvalho Chehab
2020-10-09 12:48 ` Jason Gunthorpe
2020-10-09 12:48 ` Jason Gunthorpe
2020-10-09 12:48 ` Jason Gunthorpe
2020-10-09 17:52 ` Daniel Vetter
2020-10-09 17:52 ` Daniel Vetter
2020-10-09 17:52 ` Daniel Vetter
2020-10-09 18:01 ` Jason Gunthorpe
2020-10-09 18:01 ` Jason Gunthorpe
2020-10-09 18:01 ` Jason Gunthorpe
2020-10-09 19:31 ` Daniel Vetter
2020-10-09 19:31 ` Daniel Vetter
2020-10-09 19:31 ` Daniel Vetter
2020-10-10 9:21 ` Mauro Carvalho Chehab
2020-10-10 9:21 ` Mauro Carvalho Chehab
2020-10-10 9:21 ` Mauro Carvalho Chehab
2020-10-10 10:53 ` Daniel Vetter
2020-10-10 10:53 ` Daniel Vetter
2020-10-10 10:53 ` Daniel Vetter
2020-10-10 11:39 ` Mauro Carvalho Chehab
2020-10-10 11:39 ` Mauro Carvalho Chehab
2020-10-10 11:39 ` Mauro Carvalho Chehab
2020-10-10 11:56 ` Daniel Vetter
2020-10-10 11:56 ` Daniel Vetter
2020-10-10 11:56 ` Daniel Vetter
2020-10-10 17:22 ` Tomasz Figa
2020-10-10 17:22 ` Tomasz Figa
2020-10-10 17:22 ` Tomasz Figa
2020-10-10 21:35 ` Laurent Pinchart
2020-10-10 21:35 ` Laurent Pinchart
2020-10-10 21:35 ` Laurent Pinchart
2020-10-10 21:50 ` Daniel Vetter
2020-10-10 21:50 ` Daniel Vetter
2020-10-10 21:50 ` Daniel Vetter
2020-10-11 6:27 ` Mauro Carvalho Chehab
2020-10-11 6:27 ` Mauro Carvalho Chehab
2020-10-11 6:27 ` Mauro Carvalho Chehab
2020-10-11 6:36 ` Mauro Carvalho Chehab
2020-10-11 6:36 ` Mauro Carvalho Chehab
2020-10-11 6:36 ` Mauro Carvalho Chehab
2020-10-10 21:11 ` Laurent Pinchart
2020-10-10 21:11 ` Laurent Pinchart
2020-10-10 21:11 ` Laurent Pinchart
2020-10-12 10:46 ` Marek Szyprowski
2020-10-12 10:46 ` Marek Szyprowski
2020-10-12 10:46 ` Marek Szyprowski
2020-10-12 13:49 ` Daniel Vetter
2020-10-12 13:49 ` Daniel Vetter
2020-10-12 13:49 ` Daniel Vetter
2020-10-10 17:30 ` Tomasz Figa
2020-10-10 17:30 ` Tomasz Figa
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
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-10 9:24 ` Mauro Carvalho Chehab
2020-10-10 9:24 ` Mauro Carvalho Chehab
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 ` Daniel Vetter
2020-10-09 7:59 ` 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 ` Daniel Vetter
2020-10-09 7:59 ` 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 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` [PATCH v2 14/17] resource: Move devmem revoke code to resource framework Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 10:59 ` Greg Kroah-Hartman
2020-10-09 10:59 ` Greg Kroah-Hartman
2020-10-09 10:59 ` Greg Kroah-Hartman
2020-10-09 10:59 ` Greg Kroah-Hartman
2020-10-09 12:31 ` Jason Gunthorpe [this message]
2020-10-09 12:31 ` Jason Gunthorpe
2020-10-09 12:31 ` Jason Gunthorpe
2020-10-09 14:24 ` Daniel Vetter
2020-10-09 14:24 ` Daniel Vetter
2020-10-09 14:24 ` Daniel Vetter
2020-10-09 14:32 ` Jason Gunthorpe
2020-10-09 14:32 ` Jason Gunthorpe
2020-10-09 14:32 ` Jason Gunthorpe
2020-10-09 18:28 ` Dan Williams
2020-10-09 18:28 ` Dan Williams
2020-10-09 18:28 ` Dan Williams
2020-10-15 0:09 ` Jason Gunthorpe
2020-10-15 0:09 ` Jason Gunthorpe
2020-10-15 0:09 ` Jason Gunthorpe
2020-10-15 7:52 ` Daniel Vetter
2020-10-15 7:52 ` Daniel Vetter
2020-10-15 7:52 ` Daniel Vetter
2020-10-15 7:55 ` Daniel Vetter
2020-10-15 7:55 ` Daniel Vetter
2020-10-15 7:55 ` Daniel Vetter
2020-10-15 15:29 ` Daniel Vetter
2020-10-15 15:29 ` 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 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 10:58 ` Greg Kroah-Hartman
2020-10-09 10:58 ` Greg Kroah-Hartman
2020-10-09 10:58 ` Greg Kroah-Hartman
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 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` [PATCH v2 17/17] drm/i915: Properly request PCI BARs Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 7:59 ` Daniel Vetter
2020-10-09 9:47 ` Ville Syrjälä
2020-10-09 9:47 ` Ville Syrjälä
2020-10-09 9:47 ` Ville Syrjälä
2020-10-09 9:47 ` Ville Syrjälä
2020-10-09 10:01 ` Daniel Vetter
2020-10-09 10:01 ` Daniel Vetter
2020-10-09 10:01 ` Daniel Vetter
2020-10-09 10:41 ` Ville Syrjälä
2020-10-09 10:41 ` Ville Syrjälä
2020-10-09 10:41 ` Ville Syrjälä
2020-10-09 10:41 ` Ville Syrjälä
2020-10-09 14:18 ` Daniel Vetter
2020-10-09 14:18 ` Daniel Vetter
2020-10-09 14:18 ` Daniel Vetter
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