commit bf8975837dac156c33a4d15d46602700998cb6dd upstream.
We hardcode the maximum number of shared fences to 4, instead of
respecting num_fences. Use a minimum of 4, but more if num_fences
is higher.
This seems to have been an oversight when first implementing the
api.
Fixes: 04a5faa8cb ("reservation: update api and add some helpers")
Cc: <stable@vger.kernel.org> # v3.17+
Reported-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201124115707.406917-1-maarten.lankhorst@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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
Signed-off-by: Christian König <christian.koenig@amd.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/
Maarten Lankhorst