linux-toradex.git/drivers/dma-buf/sw_sync.c, branch v6.19

dma-buf/sw-sync: always taint the kernel when sw-sync is used

2025-11-25T09:07:08+00:00

The SW-sync functionality should only be used for testing and debugging
since it is inherently unsave.

Signed-off-by: Christian König 
Acked-by: Sumit Semwal 
Link: https://lore.kernel.org/r/20251120150018.27385-3-christian.koenig@amd.com

dma-fence: Change signature of __dma_fence_is_later

2025-05-15T13:05:29+00:00

With the goal of reducing the need for drivers to touch (and dereference)
fence->ops, we change the prototype of __dma_fence_is_later() to take
fence instead of fence->ops.

Signed-off-by: Tvrtko Ursulin 
Reviewed-by: Christian König 
Link: https://lore.kernel.org/r/20250515095004.28318-2-tvrtko.ursulin@igalia.com
Signed-off-by: Christian König

BackMerge tag 'v6.15-rc5' into drm-next

2025-05-06T06:39:25+00:00

Linux 6.15-rc5, requested by tzimmerman for fixes required in drm-next.

Signed-off-by: Dave Airlie

dma-buf/sw_sync: Decrement refcount on error in sw_sync_ioctl_get_deadline()

2025-04-11T12:22:22+00:00

Call dma_fence_put(fence) before returning an error if
dma_fence_to_sync_pt() fails.  Use an unwind ladder at the
end of the function to do the cleanup.

Fixes: 70e67aaec2f4 ("dma-buf/sw_sync: Add fence deadline support")
Signed-off-by: Dan Carpenter 
Reviewed-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/a010a1ac-107b-4fc0-a052-9fd3706ad690@stanley.mountain
Signed-off-by: Christian König

dma-buf/dma-fence: remove unnecessary callbacks

2025-03-06T14:20:53+00:00

The fence_value_str and timeline_value_str callbacks were just an
unnecessary abstraction in the SW sync implementation.

The only caller of those callbacks already knew that the fence in
questions is a timeline_fence. So print the values directly instead
of using a redirection.

Additional to that remove the implementations from virtgpu and vgem.
As far as I can see those were never used in the first place.

Signed-off-by: Christian König 
Reviewed-by: Simona Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20250211163109.12200-3-christian.koenig@amd.com

dma-buf/sw_sync: remove pointless enable_signaling implementation

2024-10-09T12:23:17+00:00

Just returning true here is a no-op, remove the optional callback.

Signed-off-by: Christian König 
Reviewed-by: Simona Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20240911085903.1496-3-christian.koenig@amd.com

dma-buf/sw_sync: Add fence deadline support

2023-12-01T23:18:46+00:00

This consists of simply storing the most recent deadline, and adding an
ioctl to retrieve the deadline.  This can be used in conjunction with
the SET_DEADLINE ioctl on a fence fd for testing.  Ie. create various
sw_sync fences, merge them into a fence-array, set deadline on the
fence-array and confirm that it is propagated properly to each fence.

v2: Switch UABI to express deadline as u64
v3: More verbose UAPI docs, show how to convert from timespec
v4: Better comments, track the soonest deadline, as a normal fence
    implementation would, return an error if no deadline set.

Signed-off-by: Rob Clark 
Reviewed-by: Christian König 
Acked-by: Pekka Paalanen 
Signed-off-by: Dmitry Baryshkov 
Link: https://patchwork.freedesktop.org/patch/msgid/20230823215458.203366-4-robdclark@gmail.com

dma-buf/sw_sync: Avoid recursive lock during fence signal

2023-08-23T08:22:49+00:00

If a signal callback releases the sw_sync fence, that will trigger a
deadlock as the timeline_fence_release recurses onto the fence->lock
(used both for signaling and the the timeline tree).

To avoid that, temporarily hold an extra reference to the signalled
fences until after we drop the lock.

(This is an alternative implementation of https://patchwork.kernel.org/patch/11664717/
which avoids some potential UAF issues with the original patch.)

v2: Remove now obsolete comment, use list_move_tail() and
    list_del_init()

Reported-by: Bas Nieuwenhuizen 
Fixes: d3c6dd1fb30d ("dma-buf/sw_sync: Synchronize signal vs syncpt free")
Signed-off-by: Rob Clark 
Link: https://patchwork.freedesktop.org/patch/msgid/20230818145939.39697-1-robdclark@gmail.com
Reviewed-by: Christian König 
Signed-off-by: Christian König

dma-buf/sw_sync: Replace all non-returning strlcpy with strscpy

2023-05-24T11:02:25+00:00

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh 
Reviewed-by: Kees Cook 
Signed-off-by: Sumit Semwal 
Link: https://patchwork.freedesktop.org/patch/msgid/20230523021943.2406847-1-azeemshaikh38@gmail.com

compat_ioctl: move more drivers to compat_ptr_ioctl

2019-10-23T15:23:44+00:00

The .ioctl and .compat_ioctl file operations have the same prototype so
they can both point to the same function, which works great almost all
the time when all the commands are compatible.

One exception is the s390 architecture, where a compat pointer is only
31 bit wide, and converting it into a 64-bit pointer requires calling
compat_ptr(). Most drivers here will never run in s390, but since we now
have a generic helper for it, it's easy enough to use it consistently.

I double-checked all these drivers to ensure that all ioctl arguments
are used as pointers or are ignored, but are not interpreted as integer
values.

Acked-by: Jason Gunthorpe 
Acked-by: Daniel Vetter 
Acked-by: Mauro Carvalho Chehab 
Acked-by: Greg Kroah-Hartman 
Acked-by: David Sterba 
Acked-by: Darren Hart (VMware) 
Acked-by: Jonathan Cameron 
Acked-by: Bjorn Andersson 
Acked-by: Dan Williams 
Signed-off-by: Arnd Bergmann