Commit ebb1ca74 authored Jul 08, 2021 by Jason Ekstrand Committed by Daniel Vetter Jul 08, 2021

drm/i915/gem: Disallow creating contexts with too many engines



There's no sense in allowing userspace to create more engines than it
can possibly access via execbuf.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210708154835.528166-13-jason@jlekstrand.net

parent 5ac545b8

drivers/gpu/drm/i915/gem/i915_gem_context.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1639,11 +1639,11 @@ set_engines(struct i915_gem_context *ctx,
		return -EINVAL;
		}

		/*
		* Note that I915_EXEC_RING_MASK limits execbuf to only using the
		* first 64 engines defined here.
		*/
		num_engines = (args->size - sizeof(user)) / sizeof(user->engines);
		/* RING_MASK has no shift so we can use it directly here */
		if (num_engines > I915_EXEC_RING_MASK + 1)
		return -EINVAL;

		set.engines = alloc_engines(num_engines);
		if (!set.engines)
		return -ENOMEM;