drm/i915/gem: Check for a closed context when looking up an engine

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: 130a95e909 ("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
(cherry picked from commit a22f347834)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Chris Wilson 2020-03-16 16:14:47 +00:00 committed by Rodrigo Vivi
parent e50c951ea6
commit 16e5c2f0d3
1 changed files with 6 additions and 2 deletions

View File

@ -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;