From d07ea81611ed6e4fb8cc290f42d23dbcca2da2f8 Mon Sep 17 00:00:00 2001
From: Steven Price <steven.price@arm.com>
Date: Mon, 11 Nov 2019 13:07:19 +0000
Subject: [PATCH] dma_resv: Correct return type of dma_resv_lockdep()
subsys_initcall() expects a function which returns 'int'. Fix
dma_resv_lockdep() so it returns an 'int' error code.
Fixes: b2a8116e25 ("dma_resv: prime lockdep annotations")
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/c0a0c70d-e6fe-1103-2888-1ce1425f4a5d@arm.com
Full audit of everyone:
- i915, radeon, amdgpu should be clean per their maintainers.
- vram helpers should be fine, they don't do command submission, so
really no business holding struct_mutex while doing copy_*_user. But
I haven't checked them all.
- panfrost seems to dma_resv_lock only in panfrost_job_push, which
looks clean.
- v3d holds dma_resv locks in the tail of its v3d_submit_cl_ioctl(),
copying from/to userspace happens all in v3d_lookup_bos which is
outside of the critical section.
- vmwgfx has a bunch of ioctls that do their own copy_*_user:
- vmw_execbuf_process: First this does some copies in
vmw_execbuf_cmdbuf() and also in the vmw_execbuf_process() itself.
Then comes the usual ttm reserve/validate sequence, then actual
submission/fencing, then unreserving, and finally some more
copy_to_user in vmw_execbuf_copy_fence_user. Glossing over tons of
details, but looks all safe.
- vmw_fence_event_ioctl: No ttm_reserve/dma_resv_lock anywhere to be
seen, seems to only create a fence and copy it out.
- a pile of smaller ioctl in vmwgfx_ioctl.c, no reservations to be
found there.
Summary: vmwgfx seems to be fine too.
- virtio: There's virtio_gpu_execbuffer_ioctl, which does all the
copying from userspace before even looking up objects through their
handles, so safe. Plus the getparam/getcaps ioctl, also both safe.
- qxl only has qxl_execbuffer_ioctl, which calls into
qxl_process_single_command. There's a lovely comment before the
__copy_from_user_inatomic that the slowpath should be copied from
i915, but I guess that never happened. Try not to be unlucky and get
your CS data evicted between when it's written and the kernel tries
to read it. The only other copy_from_user is for relocs, but those
are done before qxl_release_reserve_list(), which seems to be the
only thing reserving buffers (in the ttm/dma_resv sense) in that
code. So looks safe.
- A debugfs file in nouveau_debugfs_pstate_set() and the usif ioctl in
usif_ioctl() look safe. nouveau_gem_ioctl_pushbuf() otoh breaks this
everywhere and needs to be fixed up.
v2: Thomas pointed at that vmwgfx calls dma_resv_init while it holds a
dma_resv lock of a different object already. Christian mentioned that
ttm core does this too for ghost objects. intel-gfx-ci highlighted
that i915 has similar issues.
Unfortunately we can't do this in the usual module init functions,
because kernel threads don't have an ->mm - we have to wait around for
some user thread to do this.
Solution is to spawn a worker (but only once). It's horrible, but it
works.
v3: We can allocate mm! (Chris). Horrible worker hack out, clean
initcall solution in.
v4: Annotate with __init (Rob Herring)
Cc: Rob Herring <robh@kernel.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: "VMware Graphics" <linux-graphics-maintainer@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191104173801.2972-1-daniel.vetter@ffwll.ch
This causes kernel crash when testing lima driver.
Cc: Christian König <christian.koenig@amd.com>
Fixes: b8c036dfc6 ("dma-buf: simplify reservation_object_get_fences_rcu a bit")
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190922074900.853-1-yuq825@gmail.com
This reverts
67c97fb79a ("dma-buf: add reservation_object_fences helper")
dd7a7d1ff2 ("drm/i915: use new reservation_object_fences helper")
0e1d8083bd ("dma-buf: further relax reservation_object_add_shared_fence")
5d344f58da ("dma-buf: nuke reservation_object seq number")
The scenario that defeats simply grabbing a set of shared/exclusive
fences and using them blissfully under RCU is that any of those fences
may be reallocated by a SLAB_TYPESAFE_BY_RCU fence slab cache. In this
scenario, while keeping the rcu_read_lock we need to establish that no
fence was changed in the dma_resv after a read (or full) memory barrier.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190814182401.25009-1-chris@chris-wilson.co.uk
Be more consistent with the naming of the other DMA-buf objects.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/323401/
