This effectively reverts commit 16c243e99d ("udmabuf: Add support for
mapping hugepages (v4)"). Recently, Junxiao Chang found a BUG with page
map counting as described here [1]. This issue pointed out that the
udmabuf driver was making direct use of subpages of hugetlb pages. This
is not a good idea, and no other mm code attempts such use. In addition
to the mapcount issue, this also causes issues with hugetlb vmemmap
optimization and page poisoning.
For now, remove hugetlb support.
If udmabuf wants to be used on hugetlb mappings, it should be changed to
only use complete hugetlb pages. This will require different alignment
and size requirements on the UDMABUF_CREATE API.
[1] https://lore.kernel.org/linux-mm/20230512072036.1027784-1-junxiao.chang@intel.com/
Link: https://lkml.kernel.org/r/20230608204927.88711-1-mike.kravetz@oracle.com
Fixes: 16c243e99d ("udmabuf: Add support for mapping hugepages (v4)")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Junxiao Chang <junxiao.chang@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since commit 8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.
So remove it in the files in this commit, none of which can be built as
modules.
Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
The reason behind that patch is associated with videobuf2 subsystem
(or more genrally with v4l2 framework) and user created
dma buffers (udmabuf). In some circumstances
when dealing with V4L2_MEMORY_DMABUF buffers videobuf2 subsystem
wants to use dma_buf_vmap() method on the attached dma buffer.
As udmabuf does not have .vmap operation implemented,
such dma_buf_vmap() natually fails.
videobuf2_common: __vb2_queue_alloc: allocated 3 buffers, 1 plane(s) each
videobuf2_common: __prepare_dmabuf: buffer for plane 0 changed
videobuf2_common: __prepare_dmabuf: failed to map dmabuf for plane 0
videobuf2_common: __buf_prepare: buffer preparation failed: -14
The patch itself seems to be strighforward.
It adds implementation of .vmap and .vunmap methods
to 'struct dma_buf_ops udmabuf_ops'.
.vmap method itself uses vm_map_ram() to map pages linearly
into the kernel virtual address space.
.vunmap removes mapping created earlier by .vmap.
All locking and 'vmapping counting' is done in dma_buf.c
so it seems to be redundant/unnecessary in .vmap/.vunmap.
Signed-off-by: Lukasz Wiecaszek <lukasz.wiecaszek@gmail.com>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221117171810.75637-1-lukasz.wiecaszek@gmail.com
Signed-off-by: Christian König <christian.koenig@amd.com>
When userspace mmaps dma-buf's fd, the dma-buf reservation lock must be
held. Add locking sanity check to the dma-buf mmaping callback to ensure
that the locking assumption won't regress in the future.
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221110201349.351294-4-dmitry.osipenko@collabora.com
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Merge tag 'pull-file_inode' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull file_inode() updates from Al Vrio:
"whack-a-mole: cropped up open-coded file_inode() uses..."
* tag 'pull-file_inode' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
orangefs: use ->f_mapping
_nfs42_proc_copy(): use ->f_mapping instead of file_inode()->i_mapping
dma_buf: no need to bother with file_inode()->i_mapping
nfs_finish_open(): don't open-code file_inode()
bprm_fill_uid(): don't open-code file_inode()
sgx: use ->f_mapping...
exfat_iterate(): don't open-code file_inode(file)
ibmvmc: don't open-code file_inode()
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Backmerge tag 'v5.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next
Backmerge in rc6 so I can merge msm next easier.
Linux 5.19-rc6
Signed-off-by: Dave Airlie <airlied@redhat.com>
Check vm_fault->pgoff before using it. When we removed the warning, we
also removed the check.
Fixes: 7b26e4e211 ("udmabuf: drop WARN_ON() check.")
Reported-by: zdi-disclosures@trendmicro.com
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
problem was in ubuf->pages == ZERO_PTR.
ubuf->pagecount is calculated from arguments passed from user-space. If
user creates udmabuf with list.size == 0 then ubuf->pagecount will be
also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
Fix it by validating ubuf->pagecount before passing it to
kmalloc_array().
Fixes: fbb0de7950 ("Add udmabuf misc device")
Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20211230142649.23022-1-paskripkin@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Syzbot reported general protection fault in udmabuf_create. The problem
was in wrong error handling.
In commit 16c243e99d ("udmabuf: Add support for mapping hugepages (v4)")
shmem_read_mapping_page() call was replaced with find_get_page_flags(),
but find_get_page_flags() returns NULL on failure instead PTR_ERR().
Wrong error checking was causing GPF in get_page(), since passed page
was equal to NULL. Fix it by changing if (IS_ER(!hpage)) to if (!hpage)
Reported-by: syzbot+e9cd3122a37c5d6c51e8@syzkaller.appspotmail.com
Fixes: 16c243e99d ("udmabuf: Add support for mapping hugepages (v4)")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210811175052.21254-1-paskripkin@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Default list_limit and size_limit_mb are not big enough to cover all
possible use cases. For example, list_limit could be well over its default,
1024 if only one or several pages are chained in all individual list entries
when creating dmabuf backed by >4MB buffer. list_limit and size_limit_mb are
now defined as module parameters so that those can be optionally configured
by root with proper values to remove these constraints.
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210611212107.9876-1-dongwon.kim@intel.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
If the VMM's (Qemu) memory backend is backed up by memfd + Hugepages
(hugetlbfs and not THP), we have to first find the hugepage(s) where
the Guest allocations are located and then extract the regular 4k
sized subpages from them.
v2: Ensure that the subpage and hugepage offsets are calculated correctly
when the range of subpage allocations cuts across multiple hugepages.
v3: Instead of repeatedly looking up the hugepage for each subpage,
only do it when the subpage allocation crosses over into a different
hugepage. (suggested by Gerd and DW)
v4: Fix the following warning identified by checkpatch:
CHECK:OPEN_ENDED_LINE: Lines should not end with a '('
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210609182915.592743-1-vivek.kasireddy@intel.com
[ kraxel: one more checkpatch format tweak ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
UAPI Changes:
Cross-subsystem Changes:
Core Changes:
- dev: More devm_drm convertions and removal of drm_dev_init
Driver Changes:
- i915: selftests improvements
- panfrost: support for Amlogic SoC
- vc4: one fix
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Merge tag 'drm-misc-next-2020-09-21' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-next for 5.10:
UAPI Changes:
Cross-subsystem Changes:
- virtio: Merged a PR for patches that will affect drm/virtio
Core Changes:
- dev: More devm_drm convertions and removal of drm_dev_init
- atomic: Split out drm_atomic_helper_calc_timestamping_constants of
drm_atomic_helper_update_legacy_modeset_state
- ttm: More rework
Driver Changes:
- i915: selftests improvements
- panfrost: support for Amlogic SoC
- vc4: one fix
- tree-wide: conversions to devm_drm_dev_alloc,
- ast: simplifications of the atomic modesetting code
- panfrost: multiple fixes
- vc4: multiple fixes
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20200921152956.2gxnsdgxmwhvjyut@gilmour.lan
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().
struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).
It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.
To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
I'm just going to put Chia's review comment here since it sums
the issue rather nicely:
"(1) Semantically, a dma-buf is in DMA domain. CPU access from the
importer must be surrounded by {begin,end}_cpu_access. This gives the
exporter a chance to move the buffer to the CPU domain temporarily.
(2) When the exporter itself has other means to do CPU access, it is
only reasonable for the exporter to move the buffer to the CPU domain
before access, and to the DMA domain after access. The exporter can
potentially reuse {begin,end}_cpu_access for that purpose.
Because of (1), udmabuf does need to implement the
{begin,end}_cpu_access hooks. But "begin" should mean
dma_sync_sg_for_cpu and "end" should mean dma_sync_sg_for_device.
Because of (2), if userspace wants to continuing accessing through the
memfd mapping, it should call udmabuf's {begin,end}_cpu_access to
avoid cache issues."
Reported-by: Chia-I Wu <olvaffe@gmail.com>
Suggested-by: Chia-I Wu <olvaffe@gmail.com>
Fixes: 284562e1f3 ("udmabuf: implement begin_cpu_access/end_cpu_access hooks")
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20191217230228.453-1-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
With the misc device, we should end up using the result of
get_arch_dma_ops(..) or dma-direct ops.
This can allow us to have WC mappings in the guest after
synchronization.
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20191203013627.85991-4-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
We accidentally forgot to set "ret" on this error path so it means we
return NULL instead of an error pointer. The caller checks for NULL and
changes it to an error pointer so it doesn't cause an issue at run time.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180914065615.GA12043@mwanda
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Create variable for the list length limit. Serves as documentation,
also allows to make it a module parameter if needed.
Also add a total size limit.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-8-kraxel@redhat.com
There is a potential execution path in which pointer memfd is NULL when
passed as argument to fput(), hence there is a NULL pointer dereference
in fput().
Fix this by null checking *memfd* before calling fput().
Addresses-Coverity-ID: 1473174 ("Explicit null dereferenced")
Fixes: fbb0de7950 ("Add udmabuf misc device")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180904190749.GA9308@embeddedor.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
A driver to let userspace turn memfd regions into dma-bufs.
Use case: Allows qemu create dmabufs for the vga framebuffer or
virtio-gpu ressources. Then they can be passed around to display
those guest things on the host. To spice client for classic full
framebuffer display, and hopefully some day to wayland server for
seamless guest window display.
qemu test branch:
https://git.kraxel.org/cgit/qemu/log/?h=sirius/udmabuf
Cc: David Airlie <airlied@linux.ie>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180827093444.23623-1-kraxel@redhat.com
Mike Kravetz