From: Daniel Vetter <hidden> Date: 2021-02-06 00:05:59
We are already doing this for all the regular sysfs files on PCI
devices, but not yet on the legacy io files on the PCI buses. Thus far
no problem, but in the next patch I want to wire up iomem revoke
support. That needs the vfs up and running already to make sure that
iomem_get_mapping() works.
Wire it up exactly like the existing code in
pci_create_sysfs_dev_files(). Note that pci_remove_legacy_files()
doesn't need a check since the one for pci_bus->legacy_io is
sufficient.
An alternative solution would be to implement a callback in sysfs to
set up the address space from iomem_get_mapping() when userspace calls
mmap(). This also works, but Greg didn't really like that just to work
around an ordering issue when the kernel loads initially.
v2: Improve commit message (Bjorn)
Signed-off-by: Daniel Vetter <redacted>
Cc: Stephen Rothwell <redacted>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <redacted>
Cc: Dan Williams <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <redacted>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
---
drivers/pci/pci-sysfs.c | 7 +++++++
1 file changed, 7 insertions(+)
From: Daniel Vetter <hidden> Date: 2021-02-10 17:44:51
Hi Bjorn,
Can you ack this for merging through my topic branch with the other
follow_pfn/iomem revoke fixes for 5.12?
If not, what's the plan for getting this (or equivalent functionality)
in for 5.13? I have more of these follow_pfn/iomem revoke patches on
top, so I'd like to get the first cut merged sooner than later if
possible. And the other prep work has been in -next since -rc1.
Thanks, Daniel
On Fri, Feb 5, 2021 at 2:36 PM Daniel Vetter [off-list ref] wrote:
quoted hunk
We are already doing this for all the regular sysfs files on PCI
devices, but not yet on the legacy io files on the PCI buses. Thus far
no problem, but in the next patch I want to wire up iomem revoke
support. That needs the vfs up and running already to make sure that
iomem_get_mapping() works.
Wire it up exactly like the existing code in
pci_create_sysfs_dev_files(). Note that pci_remove_legacy_files()
doesn't need a check since the one for pci_bus->legacy_io is
sufficient.
An alternative solution would be to implement a callback in sysfs to
set up the address space from iomem_get_mapping() when userspace calls
mmap(). This also works, but Greg didn't really like that just to work
around an ordering issue when the kernel loads initially.
v2: Improve commit message (Bjorn)
Signed-off-by: Daniel Vetter <redacted>
Cc: Stephen Rothwell <redacted>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <redacted>
Cc: Dan Williams <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <redacted>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
---
drivers/pci/pci-sysfs.c | 7 +++++++
1 file changed, 7 insertions(+)
On Fri, Feb 05, 2021 at 02:36:32PM +0100, Daniel Vetter wrote:
We are already doing this for all the regular sysfs files on PCI
devices, but not yet on the legacy io files on the PCI buses. Thus far
no problem, but in the next patch I want to wire up iomem revoke
support. That needs the vfs up and running already to make sure that
iomem_get_mapping() works.
Wire it up exactly like the existing code in
pci_create_sysfs_dev_files(). Note that pci_remove_legacy_files()
doesn't need a check since the one for pci_bus->legacy_io is
sufficient.
An alternative solution would be to implement a callback in sysfs to
set up the address space from iomem_get_mapping() when userspace calls
mmap(). This also works, but Greg didn't really like that just to work
around an ordering issue when the kernel loads initially.
v2: Improve commit message (Bjorn)
Signed-off-by: Daniel Vetter <redacted>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
I wish we weren't extending a known-racy mechanism to do this, but at
least we're not *adding* a brand new race.
quoted hunk
Cc: Stephen Rothwell <redacted>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <redacted>
Cc: Dan Williams <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <redacted>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
---
drivers/pci/pci-sysfs.c | 7 +++++++
1 file changed, 7 insertions(+)
From: Daniel Vetter <hidden> Date: 2021-02-11 15:26:18
On Wed, Feb 10, 2021 at 10:40 PM Bjorn Helgaas [off-list ref] wrote:
On Fri, Feb 05, 2021 at 02:36:32PM +0100, Daniel Vetter wrote:
quoted
We are already doing this for all the regular sysfs files on PCI
devices, but not yet on the legacy io files on the PCI buses. Thus far
no problem, but in the next patch I want to wire up iomem revoke
support. That needs the vfs up and running already to make sure that
iomem_get_mapping() works.
Wire it up exactly like the existing code in
pci_create_sysfs_dev_files(). Note that pci_remove_legacy_files()
doesn't need a check since the one for pci_bus->legacy_io is
sufficient.
An alternative solution would be to implement a callback in sysfs to
set up the address space from iomem_get_mapping() when userspace calls
mmap(). This also works, but Greg didn't really like that just to work
around an ordering issue when the kernel loads initially.
v2: Improve commit message (Bjorn)
Signed-off-by: Daniel Vetter <redacted>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
I wish we weren't extending a known-racy mechanism to do this, but at
least we're not *adding* a brand new race.
Yeah it's not great. Thanks for looking at both again, I'll fix up the
typos on the 2nd one and merge them both.
Cheers, Daniel
quoted
Cc: Stephen Rothwell <redacted>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <redacted>
Cc: Dan Williams <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <redacted>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
---
drivers/pci/pci-sysfs.c | 7 +++++++
1 file changed, 7 insertions(+)