linux-toradex.git/drivers/dma-buf/dma-resv.c, branch v6.8

dma-buf: fix check in dma_resv_add_fence

2023-11-27T19:00:47+00:00

It's valid to add the same fence multiple times to a dma-resv object and
we shouldn't need one extra slot for each.

Signed-off-by: Christian König 
Reviewed-by: Thomas Hellström 
Fixes: a3f7c10a269d5 ("dma-buf/dma-resv: check if the new fence is really later")
Cc: stable@vger.kernel.org # v5.19+
Link: https://patchwork.freedesktop.org/patch/msgid/20231115093035.1889-1-christian.koenig@amd.com

dma-buf/dma-resv: Stop leaking on krealloc() failure

2023-07-15T11:57:30+00:00

Currently dma_resv_get_fences() will leak the previously
allocated array if the fence iteration got restarted and
the krealloc_array() fails.

Free the old array by hand, and make sure we still clear
the returned *fences so the caller won't end up accessing
freed memory. Some (but not all) of the callers of
dma_resv_get_fences() seem to still trawl through the
array even when dma_resv_get_fences() failed. And let's
zero out *num_fences as well for good measure.

Cc: Sumit Semwal 
Cc: Christian König 
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Fixes: d3c80698c9f5 ("dma-buf: use new iterator in dma_resv_get_fences v3")
Signed-off-by: Ville Syrjälä 
Reviewed-by: Christian König 
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20230713194745.1751-1-ville.syrjala@linux.intel.com
Signed-off-by: Christian König

dma-buf/dma-resv.c: fix a typo

2023-04-17T06:24:31+00:00

The dma_resv_wait_timeout() function return a value greater than zero
on success.

Signed-off-by: Sui Jingfeng 
Reviewed-by: Christian König 
Signed-off-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/20230416143849.1142779-1-suijingfeng@loongson.cn

dma-buf/dma-resv: Add a way to set fence deadline

2023-03-28T20:39:02+00:00

Add a way to set a deadline on remaining resv fences according to the
requested usage.

Signed-off-by: Rob Clark 
Reviewed-by: Christian König

dma-buf: Proactively round up to kmalloc bucket size

2022-11-01T17:04:52+00:00

Instead of discovering the kmalloc bucket size _after_ allocation, round
up proactively so the allocation is explicitly made for the full size,
allowing the compiler to correctly reason about the resulting size of
the buffer through the existing __alloc_size() hint.

Cc: Sumit Semwal 
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Christian König 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20221018090858.never.941-kees@kernel.org

dma-buf/dma-resv: check if the new fence is really later

2022-08-25T11:10:30+00:00

Previously when we added a fence to a dma_resv object we always
assumed the the newer than all the existing fences.

With Jason's work to add an UAPI to explicit export/import that's not
necessary the case any more. So without this check we would allow
userspace to force the kernel into an use after free error.

Since the change is very small and defensive it's probably a good
idea to backport this to stable kernels as well just in case others
are using the dma_resv object in the same way.

Signed-off-by: Christian König 
Reviewed-by: Jason Ekstrand 
Link: https://patchwork.freedesktop.org/patch/msgid/20220810172617.140047-1-christian.koenig@amd.com
Cc: stable@vger.kernel.org # v5.19+

dma-buf: Fix one use-after-free of fence

2022-07-07T08:24:59+00:00

Need get the new fence when we replace the old one.

Fixes: 047a1b877ed48 ("dma-buf & drm/amdgpu: remove dma_resv workaround")
Signed-off-by: xinhui pan 
Reviewed-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/20220707080241.20060-1-xinhui.pan@amd.com
Signed-off-by: Christian König

dma-buf: drop seq count based update

2022-04-07T10:53:54+00:00

This should be possible now since we don't have the distinction
between exclusive and shared fences any more.

The only possible pitfall is that a dma_fence would be reused during the
RCU grace period, but even that could be handled with a single extra check.

Signed-off-by: Christian König 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-15-christian.koenig@amd.com

dma-buf: add DMA_RESV_USAGE_BOOKKEEP v3

2022-04-07T10:53:54+00:00

Add an usage for submissions independent of implicit sync but still
interesting for memory management.

v2: cleanup the kerneldoc a bit
v3: separate amdgpu changes from this

Signed-off-by: Christian König 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-10-christian.koenig@amd.com

dma-buf: add DMA_RESV_USAGE_KERNEL v3

2022-04-07T10:53:54+00:00

Add an usage for kernel submissions. Waiting for those are mandatory for
dynamic DMA-bufs.

As a precaution this patch also changes all occurrences where fences are
added as part of memory management in TTM, VMWGFX and i915 to use the
new value because it now becomes possible for drivers to ignore fences
with the WRITE usage.

v2: use "must" in documentation, fix whitespaces
v3: separate out some driver changes and better document why some
    changes should still be part of this patch.

Signed-off-by: Christian König 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-5-christian.koenig@amd.com