This requires a bit of background. Properly done a modeset driver's
unload/remove sequence should be
drm_dev_unplug();
drm_atomic_helper_shutdown();
drm_dev_put();
The trouble is that the drm_dev_unplugged() checks are by design racy,
they do not synchronize against all outstanding ioctl. This is because
those ioctl could block forever (both for modeset and for driver
specific ioctls), leading to deadlocks in hotunplug. Instead the code
sections that touch the hardware need to be annotated with
drm_dev_enter/exit, to avoid accessing hardware resources after the
unload/remove has finished.
To avoid use-after-free issues all the involved userspace visible
objects are supposed to hold a reference on the underlying drm_device,
like drm_file does.
The issue now is that we missed one, the atomic modeset ioctl can be run
in a nonblocking fashion, and in that case it cannot rely on the implied
drm_device reference provided by the ioctl calling context. This can
result in a use-after-free if an nonblocking atomic commit is carefully
raced against a driver unload.
Fix this by unconditionally grabbing a drm_device reference for any
drm_atomic_state structures. Strictly speaking this isn't required for
blocking commits and TEST_ONLY calls, but it's the simpler approach.
Thanks to shanzhulig for the initial idea of grabbing an unconditional
reference, I just added comments, a condensed commit message and fixed a
minor potential issue in where exactly we drop the final reference.
Reported-by: shanzhulig <shanzhulig@gmail.com>
Suggested-by: shanzhulig <shanzhulig@gmail.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge drm-next into msm-next to pick up external clk and PM dependencies
for improved a6xx GPU reset sequence.
Signed-off-by: Rob Clark <robdclark@chromium.org>
The DRM_UT_STATE controls whether we're calling
drm_atomic_print_new_state() whenever a new state is committed. However,
that call is made in the drm_mode_atomic_ioctl(), whereas we have
multiple users of the drm_atomic_commit() function in the kernel
(framebuffer emulation, drm_atomic_helper_dirtyfb, etc.).
This leads to multiple states being committed but never actually
displayed even though we asked to have verbose atomic state debugging.
Let's move the call to drm_atomic_print_new_state() to
drm_atomic_commit() to make sure we don't miss any. Non-blocking commits
were never logged though, and it would create too much churn in the logs
to do so, so leave them out for now.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20220328124304.2309418-2-maxime@cerno.tech
Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
There's two stages of manual upload/invalidate displays:
- just handling dirtyfb and uploading the entire fb all the time
- looking at damage clips
In the latter case we support it through fbdev emulation (with
fb_defio), atomic property, and with the dirtfy clip rects.
Make sure at least the atomic property is set up as the main official
interface for this. Ideally we'd also check that
drm_atomic_helper_dirtyfb() is used and that fbdev defio is set up,
but that's quite a bit harder to do. Ideas very much welcome.
From a cursor audit drivers seem to be getting this right mostly, but
better to make sure. At least no one is bypassing the accessor
function.
v2:
- use drm_warn_once with a meaningful warning string (José)
- don't splat in the atomic check code for everyone (intel-gfx-ci)
Reviewed-by: José Roberto de Souza <jose.souza@intel.com> (v1)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723083457.696939-2-daniel.vetter@ffwll.ch
* devcoredump support for display errors
* dpu: irq cleanup/refactor
* dpu: dt bindings conversion to yaml
* dsi: dt bindings conversion to yaml
* mdp5: alpha/blend_mode/zpos support
* a6xx: cached coherent buffer support
* a660 support
* gpu iova fault improvements:
- info about which block triggered the fault, etc
- generation of gpu devcoredump on fault
* assortment of other cleanups and fixes
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rob Clark <robdclark@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CAF6AEGs4=qsGBBbyn-4JWqW4-YUSTKh67X3DsPQ=T2D9aXKqNA@mail.gmail.com
Merge misc updates from Andrew Morton:
- a few random little subsystems
- almost all of the MM patches which are staged ahead of linux-next
material. I'll trickle to post-linux-next work in as the dependents
get merged up.
Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
mm: cleanup kstrto*() usage
mm: fix fall-through warnings for Clang
mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
mm:backing-dev: use sysfs_emit in macro defining functions
mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
mm: use sysfs_emit for struct kobject * uses
mm: fix kernel-doc markups
zram: break the strict dependency from lzo
zram: add stat to gather incompressible pages since zram set up
zram: support page writeback
mm/process_vm_access: remove redundant initialization of iov_r
mm/zsmalloc.c: rework the list_add code in insert_zspage()
mm/zswap: move to use crypto_acomp API for hardware acceleration
mm/zswap: fix passing zero to 'PTR_ERR' warning
mm/zswap: make struct kernel_param_ops definitions const
userfaultfd/selftests: hint the test runner on required privilege
userfaultfd/selftests: fix retval check for userfaultfd_open()
userfaultfd/selftests: always dump something in modes
userfaultfd: selftests: make __{s,u}64 format specifiers portable
...
When doing an atomic modeset with ALLOW_MODESET drivers are allowed to
pull in arbitrary other resources, including CRTCs (e.g. when
reconfiguring global resources).
But in nonblocking mode userspace has then no idea this happened,
which can lead to spurious EBUSY calls, both:
- when that other CRTC is currently busy doing a page_flip the
ALLOW_MODESET commit can fail with an EBUSY
- on the other CRTC a normal atomic flip can fail with EBUSY because
of the additional commit inserted by the kernel without userspace's
knowledge
For blocking commits this isn't a problem, because everyone else will
just block until all the CRTC are reconfigured. Only thing userspace
can notice is the dropped frames without any reason for why frames got
dropped.
Consensus is that we need new uapi to handle this properly, but no one
has any idea what exactly the new uapi should look like. Since this
has been shipping for years already compositors need to deal no matter
what, so as a first step just try to enforce this across drivers
better with some checks.
v2: Add comments and a WARN_ON to enforce this only when allowed - we
don't want to silently convert page flips into blocking plane updates
just because the driver is buggy.
v3: Fix inverted WARN_ON (Pekka).
v4: Drop the uapi changes, only add a WARN_ON for now to enforce some
rules for drivers.
v5: Make the WARNING more informative (Daniel)
v6: Add unconditional debug output for compositor hackers to figure
out what's going on when they get an EBUSY (Daniel)
v7: Fix up old/new_crtc_state confusion for real (Pekka/Ville)
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
References: https://lists.freedesktop.org/archives/dri-devel/2018-July/182281.html
Bugzilla: https://gitlab.freedesktop.org/wayland/weston/issues/24#note_9568
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Cc: Simon Ser <contact@emersion.fr>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200925084651.3250104-1-daniel.vetter@ffwll.ch
One of the last remaining objects to not have its atomic state.
This is being motivated by our attempt to support runtime bus-format
negotiation between elements of the bridge chain.
This patch just paves the road for such a feature by adding a new
drm_bridge_state object inheriting from drm_private_obj so we can
re-use some of the existing state initialization/tracking logic.
v10:
* Add changelog to the commit message
v9:
* Clarify the fact that the bridge->atomic_reset() and
{connector,plane,crtc,...}->reset() semantics are different
* Move the drm_atomic_private_obj_init() call back to
drm_bridge_attach()
* Check the presence of ->atomic_duplicate_state instead of
->atomic_reset in drm_atomic_add_encoder_bridges()
* Fix copy&paste errors in the atomic bridge state helpers doc
* Add A-b/R-b tags
v8:
* Move bridge state helpers out of the CONFIG_DEBUGFS section
v7:
* Move helpers, struct-defs, ... to atomic helper files to avoid the
drm -> drm_kms_helper -> drm circular dep
* Stop providing default implementation for atomic state reset,
duplicate and destroy hooks (has to do with the helper/core split)
* Drop all R-b/T-b as helpers have now be moved to other places
v6:
* Made helpers private, removed doc and moved them to satisfy dependencies
* Renamed helpers to _default_
v5:
* Re-introduced the helpers from v4
v4:
* Fix the doc
* Kill default helpers (inlined)
* Fix drm_atomic_get_bridge_state() to check for an ERR_PTR()
* Add Neil's R-b
v3:
* No changes
v2:
* Use drm_for_each_bridge_in_chain()
* Rename helpers to be more consistent with the rest of the DRM API
* Improve/fix the doc
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200128135514.108171-2-boris.brezillon@collabora.com
Prepare for moving drm_fb_helper modesetting code to drm_client.
drm_client will be linked to drm.ko, so move
__drm_atomic_helper_disable_plane() and __drm_atomic_helper_set_config()
out of drm_kms_helper.ko.
While at it, fix two checkpatch complaints:
- WARNING: Block comments use a trailing */ on a separate line
- CHECK: Alignment should match open parenthesis
v7: Declare drm_mode_set and drm_plane_state
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190531140117.37751-2-noralf@tronnes.org
This pair of functions return the old/new private object state for the
given private_obj, or NULL if the private_obj is not part of the global
atomic state.
Reviewed-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
drm-misc-next for 5.1:
UAPI Changes:
Cross-subsystem Changes:
- Turn dma-buf fence sequence numbers into 64 bit numbers
Core Changes:
- Move to a common helper for the DP MST hotplug for radeon, i915 and
amdgpu
- i2c improvements for drm_dp_mst
- Removal of drm_syncobj_cb
- Introduction of an helper to create and attach the TV margin properties
Driver Changes:
- Improve cache flushes for v3d
- Reflection support for vc4
- HDMI overscan support for vc4
- Add implicit fencing support for rockchip and sun4i
- Switch to generic fbdev emulation for virtio
Signed-off-by: Dave Airlie <airlied@redhat.com>
[airlied: applied amdgpu merge fixup]
From: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190107180333.amklwycudbsub3s5@flea
FB_DAMAGE_CLIPS is an optional plane property to mark damaged regions
on the plane in framebuffer coordinates of the framebuffer attached to
the plane.
The layout of blob data is simply an array of "struct drm_mode_rect".
Unlike plane src coordinates, damage clips are not in 16.16 fixed point.
As plane src in framebuffer cannot be negative so are damage clips. In
damage clip, x1/y1 are inclusive and x2/y2 are exclusive.
This patch also exports the kernel internal drm_rect to userspace as
drm_mode_rect. This is because "struct drm_clip_rect" is not sufficient
to represent damage for current plane size.
Driver which are interested in enabling FB_DAMAGE_CLIPS property for a
plane should enable this property using drm_plane_enable_damage_clips.
v2:
- Input validation on damage clips against framebuffer size.
- Doc update, other minor changes.
Signed-off-by: Lukasz Spintzyk <lukasz.spintzyk@displaylink.com>
Signed-off-by: Deepak Rawat <drawat@vmware.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
drm-next is forwarded to v4.20-rc1, and we need this to make
a patch series apply.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>