udmabuf: Don't assert held reservation lock for dma-buf mmapping

Don't assert held dma-buf reservation lock on memory mapping of exported
buffer.

We're going to change dma-buf mmap() locking policy such that exporters
will have to handle the lock. The previous locking policy caused deadlock
problem for DRM drivers in a case of self-imported dma-bufs once these
drivers are moved to use reservation lock universally. The problem is
solved by moving the lock down to exporters. This patch prepares udmabuf
for the locking policy update.

Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-4-dmitry.osipenko@collabora.com

udmabuf: revert 'Add support for mapping hugepages (v4)'

This effectively reverts commit 16c243e99d33 ("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: 16c243e99d33 ("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>

udmabuf: remove MODULE_LICENSE in non-modules

Since commit 8b41fc4454e ("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>

udmabuf: add vmap and vunmap methods to udmabuf_ops

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>

udmabuf: Assert held reservation lock for dma-buf mmapping

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

dma_buf: no need to bother with file_inode()->i_mapping

->f_mapping will do just fine

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

udmabuf: Set ubuf->sg = NULL if the creation of sg table fails

When userspace tries to map the dmabuf and if for some reason
(e.g. OOM) the creation of the sg table fails, ubuf->sg needs to be
set to NULL. Otherwise, when the userspace subsequently closes the
dmabuf fd, we'd try to erroneously free the invalid sg table from
release_udmabuf resulting in the following crash reported by syzbot:

general protection fault, probably for non-canonical address
0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 3609 Comm: syz-executor487 Not tainted
5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 07/22/2022
RIP: 0010:dma_unmap_sgtable include/linux/dma-mapping.h:378 [inline]
RIP: 0010:put_sg_table drivers/dma-buf/udmabuf.c:89 [inline]
RIP: 0010:release_udmabuf+0xcb/0x4f0 drivers/dma-buf/udmabuf.c:114
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 04 00 00 48 8d 7d 0c 4c
8b 63 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14
02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e2
RSP: 0018:ffffc900037efd30 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffffff8cb67800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff84ad27e0 RDI: 0000000000000000
RBP: fffffffffffffff4 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008c07c R12: ffff88801fa05000
R13: ffff888073db07e8 R14: ffff888025c25440 R15: 0000000000000000
FS: 0000555555fc4300(0000) GS:ffff8880b9a00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc1c0ce06e4 CR3: 00000000715e6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
dma_buf_release+0x157/0x2d0 drivers/dma-buf/dma-buf.c:78
__dentry_kill+0x42b/0x640 fs/dcache.c:612
dentry_kill fs/dcache.c:733 [inline]
dput+0x806/0xdb0 fs/dcache.c:913
__fput+0x39c/0x9d0 fs/file_table.c:333
task_work_run+0xdd/0x1a0 kernel/task_work.c:177
ptrace_notify+0x114/0x140 kernel/signal.c:2353
ptrace_report_syscall include/linux/ptrace.h:420 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:482 [inline]
syscall_exit_work kernel/entry/common.c:249 [inline]
syscall_exit_to_user_mode_prepare+0x129/0x280 kernel/entry/common.c:276
__syscall_exit_to_user_mode_work kernel/entry/common.c:281 [inline]
syscall_exit_to_user_mode+0x9/0x50 kernel/entry/common.c:294
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc1c0c35b6b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24
0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00
f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffd78a06090 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fc1c0c35b6b
RDX: 0000000020000280 RSI: 0000000040086200 RDI: 0000000000000006
RBP: 0000000000000007 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000c
R13: 0000000000000003 R14: 00007fc1c0cfe4a0 R15: 00007ffd78a06140
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dma_unmap_sgtable include/linux/dma-mapping.h:378 [inline]
RIP: 0010:put_sg_table drivers/dma-buf/udmabuf.c:89 [inline]
RIP: 0010:release_udmabuf+0xcb/0x4f0 drivers/dma-buf/udmabuf.c:114

Reported-by: syzbot+c80e9ef5d8bb45894db0@syzkaller.appspotmail.com
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220825063522.801264-1-vivek.kasireddy@intel.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

udmabuf: Set the DMA mask for the udmabuf device (v2)

If the DMA mask is not set explicitly, the following warning occurs
when the userspace tries to access the dma-buf via the CPU as
reported by syzbot here:

WARNING: CPU: 1 PID: 3595 at kernel/dma/mapping.c:188
__dma_map_sg_attrs+0x181/0x1f0 kernel/dma/mapping.c:188
Modules linked in:
CPU: 0 PID: 3595 Comm: syz-executor249 Not tainted
5.17.0-rc2-syzkaller-00316-g0457e5153e0e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__dma_map_sg_attrs+0x181/0x1f0 kernel/dma/mapping.c:188
Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 71 4c 8b 3d c0
83 b5 0d e9 db fe ff ff e8 b6 0f 13 00 0f 0b e8 af 0f 13 00 <0f> 0b 45
31 e4 e9 54 ff ff ff e8 a0 0f 13 00 49 8d 7f 50 48 b8 00
RSP: 0018:ffffc90002a07d68 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88807e25e2c0 RSI: ffffffff81649e91 RDI: ffff88801b848408
RBP: ffff88801b848000 R08: 0000000000000002 R09: ffff88801d86c74f
R10: ffffffff81649d72 R11: 0000000000000001 R12: 0000000000000002
R13: ffff88801d86c680 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555556e30300(0000) GS:ffff8880b9d00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200000cc CR3: 000000001d74a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
dma_map_sgtable+0x70/0xf0 kernel/dma/mapping.c:264
get_sg_table.isra.0+0xe0/0x160 drivers/dma-buf/udmabuf.c:72
begin_cpu_udmabuf+0x130/0x1d0 drivers/dma-buf/udmabuf.c:126
dma_buf_begin_cpu_access+0xfd/0x1d0 drivers/dma-buf/dma-buf.c:1164
dma_buf_ioctl+0x259/0x2b0 drivers/dma-buf/dma-buf.c:363
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f62fcf530f9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89
f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe3edab9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f62fcf530f9
RDX: 0000000020000200 RSI: 0000000040086200 RDI: 0000000000000006
RBP: 00007f62fcf170e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f62fcf17170
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>

v2: Dont't forget to deregister if DMA mask setup fails.

Reported-by: syzbot+10e27961f4da37c443b2@syzkaller.appspotmail.com
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220520205235.3687336-1-vivek.kasireddy@intel.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

udmabuf: add back sanity check

Check vm_fault->pgoff before using it. When we removed the warning, we
also removed the check.

Fixes: 7b26e4e2119d ("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>

udmabuf: validate ubuf->pagecount

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: fbb0de795078 ("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>

udmabuf: fix general protection fault in udmabuf_create

Syzbot reported general protection fault in udmabuf_create. The problem
was in wrong error handling.

In commit 16c243e99d33 ("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: 16c243e99d33 ("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>

udmabuf: configurable list_limit and size_limit_mb

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>

udmabuf: Add support for mapping hugepages (v4)

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>

dmabuf: fix common struct sg_table related issues

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>

udmabuf: Add missing compact_ioctl

Make sure we can use this on mixed systems.

Signed-off-by: Kristian H. Kristensen <hoegsberg@google.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200903181652.432067-1-hoegsberg@google.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

udmabuf: fix dma-buf cpu access

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: 284562e1f348 ("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>

udmabuf: implement begin_cpu_access/end_cpu_access hooks

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>

udmabuf: separate out creating/destroying scatter-table

These are nice functions and can be re-used.

Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20191203013627.85991-3-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

udmabuf: add a pointer to the miscdevice in dma-buf private data

Will be used later.

v2: rename 'udmabuf_misc' to 'device' (kraxel)

Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20191203013627.85991-2-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

udmabuf: use cache_sgt_mapping option

The GEM prime helpers do it, so should we. It's also possible to make
it optional later.

Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20191203013627.85991-1-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

udmabuf: Remove deleted map/unmap handlers.

Commit 7f0de8d80816 ("dma-buf: Drop dma_buf_k(un)map") removed map/unmap
handlers, but they still existed in udmabuf. Remove them there as well

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: 7f0de8d80816 ("dma-buf: Drop dma_buf_k(un)map")
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191126142516.630200-1-maarten.lankhorst@linux.intel.com

udmabuf: actually unmap the scatterlist

unmap_udmabuf fails to actually unmap the scatterlist, leaving dangling
mappings around.

Fixes: fbb0de795078 ("Add udmabuf misc device")
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190604202331.17482-1-l.stach@pengutronix.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/dma-buf/udmabuf.c: convert to use vm_fault_t

Use new return type vm_fault_t for fault handler.

Link: http://lkml.kernel.org/r/20181106173628.GA12989@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

udmabuf: set read/write flag when exporting

Otherwise, mmap fails when done with PROT_WRITE.

Suggested-by: Gurchetan Singh <gurchetansingh@chromium.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20181114122029.16766-1-kraxel@redhat.com

udmabuf: fix error code in map_udmabuf()

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>

udmabuf: use sizeof(variable) instead of sizeof(type)

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-13-kraxel@redhat.com

udmabuf: drop WARN_ON() check.

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-12-kraxel@redhat.com

udmabuf: use ENOTTY for invalid ioctls

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-11-kraxel@redhat.com

udmabuf: use EBADFD in case we didn't got a memfd

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-10-kraxel@redhat.com

udmabuf: improve udmabuf_create error handling

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-9-kraxel@redhat.com

udmabuf: rework limits

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

udmabuf: constify udmabuf_create args

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-6-kraxel@redhat.com

udmabuf: constify udmabuf_ops

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-5-kraxel@redhat.com

udmabuf: use pgoff_t for pagecount

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-4-kraxel@redhat.com

udmabuf: improve map_udmabuf error handling

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-3-kraxel@redhat.com

udmabuf: sort headers, drop uapi/ path prefix

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-2-kraxel@redhat.com

dma-buf/udmabuf: Fix NULL pointer dereference in udmabuf_create

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: fbb0de795078 ("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>

Add udmabuf misc device

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