From 30bd90d6e61f624ff446525e33dd070d5ee46f87 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 16 Mar 2020 16:14:47 +0000
Subject: drm/i915/gem: Check for a closed context when looking up an engine
Git-commit: 16e5c2f0d30178d977cd461f3f46deb250b5b5ea
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
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: 130a95e9098e ("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 a22f34783476a39d157b60485285aaa43554cb2d)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/gem/i915_gem_context.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index 57b7ae2893e1..f1d884d304bd 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -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;
--
2.28.0