From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>,
LKML <linux-kernel@vger.kernel.org>
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, "Jason Gunthorpe" <jgg@ziepe.ca>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
linux-pci@vger.kernel.org, linux-mm@kvack.org,
"Jérôme Glisse" <jglisse@redhat.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"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: [PATCH 10/13] PCI: revoke mappings like devmem
Date: Wed, 7 Oct 2020 18:44:23 +0200 [thread overview]
Message-ID: <20201007164426.1812530-11-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <20201007164426.1812530-1-daniel.vetter@ffwll.ch>
Since 3234ac664a87 ("/dev/mem: Revoke mappings when a driver claims
the region") /dev/kmem zaps ptes when the kernel requests exclusive
acccess to an iomem region. And with CONFIG_IO_STRICT_DEVMEM, this is
the default for all driver uses.
Except there's two more ways to access pci bars: sysfs and proc mmap
support. Let's plug that hole.
For revoke_devmem() to work we need to link our vma into the same
address_space, with consistent vma->vm_pgoff. ->pgoff is already
adjusted, because that's how (io_)remap_pfn_range works, but for the
mapping we need to adjust vma->vm_file->f_mapping. Usually that's done
at ->open time, but that's a bit tricky here with all the entry points
and arch code. So instead create a fake file and adjust vma->vm_file.
Note this only works for ARCH_GENERIC_PCI_MMAP_RESOURCE. But that
seems to be a subset of architectures support STRICT_DEVMEM, so we
should be good.
The only difference in access checks left is that sysfs pci mmap does
not check for CAP_RAWIO. But I think that makes some sense compared to
/dev/mem and proc, where one file gives you access to everything and
no ownership applies.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dan Williams <dan.j.williams@intel.com>
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>
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/char/mem.c | 16 +++++++++++++++-
drivers/pci/mmap.c | 3 +++
include/linux/ioport.h | 2 ++
3 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index abd4ffdc8cde..5e58a326d4ee 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -810,6 +810,7 @@ static loff_t memory_lseek(struct file *file, loff_t offset, int orig)
}
static struct inode *devmem_inode;
+static struct vfsmount *devmem_vfs_mount;
#ifdef CONFIG_IO_STRICT_DEVMEM
void revoke_devmem(struct resource *res)
@@ -843,6 +844,20 @@ void revoke_devmem(struct resource *res)
unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
}
+
+struct file *devmem_getfile(void)
+{
+ struct file *file;
+
+ file = alloc_file_pseudo(devmem_inode, devmem_vfs_mount, "devmem",
+ O_RDWR, &kmem_fops);
+ if (IS_ERR(file))
+ return NULL;
+
+ file->f_mapping = devmem_indoe->i_mapping;
+
+ return file;
+}
#endif
static int open_port(struct inode *inode, struct file *filp)
@@ -1010,7 +1025,6 @@ static struct file_system_type devmem_fs_type = {
static int devmem_init_inode(void)
{
- static struct vfsmount *devmem_vfs_mount;
static int devmem_fs_cnt;
struct inode *inode;
int rc;
diff --git a/drivers/pci/mmap.c b/drivers/pci/mmap.c
index b8c9011987f4..63786cc9c746 100644
--- a/drivers/pci/mmap.c
+++ b/drivers/pci/mmap.c
@@ -7,6 +7,7 @@
* Author: David Woodhouse <dwmw2@infradead.org>
*/
+#include <linux/file.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/pci.h>
@@ -64,6 +65,8 @@ int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
vma->vm_ops = &pci_phys_vm_ops;
+ fput(vma->vm_file);
+ vma->vm_file = devmem_getfile();
return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 6c2b06fe8beb..83238cba19fe 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -304,8 +304,10 @@ struct resource *request_free_mem_region(struct resource *base,
#ifdef CONFIG_IO_STRICT_DEVMEM
void revoke_devmem(struct resource *res);
+struct file *devm_getfile(void);
#else
static inline void revoke_devmem(struct resource *res) { };
+static inline struct file *devmem_getfile(void) { return NULL; };
#endif
#endif /* __ASSEMBLY__ */
--
2.28.0
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2020-10-07 16:44 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 16:44 [PATCH 00/13] follow_pfn and other iomap races Daniel Vetter
2020-10-07 16:44 ` [PATCH 01/13] drm/exynos: Stop using frame_vector helpers Daniel Vetter
2020-10-07 20:32 ` John Hubbard
2020-10-07 21:32 ` Daniel Vetter
2020-10-07 21:36 ` John Hubbard
2020-10-07 21:50 ` Daniel Vetter
2020-10-07 16:44 ` [PATCH 02/13] drm/exynos: Use FOLL_LONGTERM for g2d cmdlists Daniel Vetter
2020-10-07 20:43 ` John Hubbard
2020-10-07 16:44 ` [PATCH 03/13] misc/habana: Stop using frame_vector helpers Daniel Vetter
2020-10-07 20:38 ` John Hubbard
2020-10-07 16:44 ` [PATCH 04/13] misc/habana: Use FOLL_LONGTERM for userptr Daniel Vetter
2020-10-07 20:46 ` John Hubbard
2020-10-07 16:44 ` [PATCH 05/13] mm/frame-vector: Use FOLL_LONGTERM Daniel Vetter
2020-10-07 16:53 ` Jason Gunthorpe
2020-10-07 17:12 ` Daniel Vetter
2020-10-07 17:33 ` Jason Gunthorpe
2020-10-07 21:13 ` John Hubbard
2020-10-07 21:30 ` Daniel Vetter
2020-10-07 16:44 ` [PATCH 06/13] media: videobuf2: Move frame_vector into media subsystem Daniel Vetter
2020-10-07 22:18 ` John Hubbard
2020-10-07 16:44 ` [PATCH 07/13] mm: close race in generic_access_phys Daniel Vetter
2020-10-07 17:27 ` Jason Gunthorpe
2020-10-07 18:01 ` Daniel Vetter
2020-10-07 23:21 ` Jason Gunthorpe
2020-10-08 0:44 ` John Hubbard
2020-10-08 7:23 ` Daniel Vetter
2020-10-07 16:44 ` [PATCH 08/13] s390/pci: Remove races against pte updates Daniel Vetter
2020-10-08 16:44 ` Gerald Schaefer
2020-10-08 17:16 ` Daniel Vetter
2020-10-07 16:44 ` [PATCH 09/13] PCI: obey iomem restrictions for procfs mmap Daniel Vetter
2020-10-07 18:46 ` Bjorn Helgaas
2020-10-07 16:44 ` Daniel Vetter [this message]
2020-10-07 18:41 ` [PATCH 10/13] PCI: revoke mappings like devmem Bjorn Helgaas
2020-10-07 19:24 ` Daniel Vetter
2020-10-07 19:33 ` Dan Williams
2020-10-07 19:47 ` Daniel Vetter
2020-10-07 22:23 ` Dan Williams
2020-10-07 22:29 ` Dan Williams
2020-10-08 8:09 ` Daniel Vetter
2020-10-07 23:24 ` Jason Gunthorpe
2020-10-08 7:31 ` Daniel Vetter
2020-10-08 7:49 ` Dan Williams
2020-10-08 8:13 ` Daniel Vetter
2020-10-08 8:35 ` Dan Williams
2020-10-08 12:41 ` Jason Gunthorpe
2020-10-07 16:44 ` [PATCH 11/13] mm: add unsafe_follow_pfn Daniel Vetter
2020-10-07 17:36 ` Jason Gunthorpe
2020-10-07 18:10 ` Daniel Vetter
2020-10-07 19:00 ` Jason Gunthorpe
2020-10-07 19:38 ` Daniel Vetter
2020-10-07 16:44 ` [PATCH 12/13] media/videbuf1|2: Mark follow_pfn usage as unsafe Daniel Vetter
2020-10-07 16:44 ` [PATCH 13/13] vfio/type1: Mark follow_pfn " Daniel Vetter
2020-10-07 17:39 ` Jason Gunthorpe
2020-10-07 18:14 ` Daniel Vetter
2020-10-07 18:47 ` Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201007164426.1812530-11-daniel.vetter@ffwll.ch \
--to=daniel.vetter@ffwll.ch \
--cc=akpm@linux-foundation.org \
--cc=bhelgaas@google.com \
--cc=dan.j.williams@intel.com \
--cc=daniel.vetter@intel.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=jack@suse.cz \
--cc=jgg@ziepe.ca \
--cc=jglisse@redhat.com \
--cc=jhubbard@nvidia.com \
--cc=keescook@chromium.org \
--cc=kvm@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).