drm/i915/gem: Check for a closed context when looking up an engine (a22f3478) · Commits · 戴 / test

Beware that the context may already be closed as we try to lookup an engine. Closes: https://gitlab.freedesktop.org/drm/intel/issues/1389 Fixes: ("drm/i915/gem: Consolidate ctx->engines[] release") Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200316161447.18410-1-chris@chris-wilson.co.uk

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

+6 −2

Original line number	Diff line number	Diff line
		@@ -192,12 +192,16 @@ i915_gem_context_unlock_engines(struct i915_gem_context *ctx)
		static inline struct intel_context *
		i915_gem_context_get_engine(struct i915_gem_context *ctx, unsigned int idx)
		{
		struct intel_context *ce = ERR_PTR(-EINVAL);
		struct intel_context *ce;

		rcu_read_lock(); {
		struct i915_gem_engines *e = rcu_dereference(ctx->engines);
		if (likely(idx < e->num_engines && e->engines[idx]))
		if (unlikely(!e)) /* context was closed! */
		ce = ERR_PTR(-ENOENT);
		else if (likely(idx < e->num_engines && e->engines[idx]))
		ce = intel_context_get(e->engines[idx]);
		else
		ce = ERR_PTR(-EINVAL);
		} rcu_read_unlock();

		return ce;

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