drm/amdgpu: add a missing lock for AMDGPU_SCHED

mgr->ctx_handles should be protected by mgr->lock.

v2: improve commit message
v3: add a Fixes tag

Signed-off-by Chia-I Wu <[email protected]>

Reviewed-by Christian König <[email protected]>

Fixes 52c6a62c64fac ("drm/amdgpu: add interface for editing a foreign process's priority v3")

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c +5 -2

index e9b45089a28a6..863b2a34b2d64 100644
@@ -38,6 +38,7 @@ static int amdgpu_sched_process_priority_override(struct amdgpu_device *adev,
 {
        struct fd f = fdget(fd);
        struct amdgpu_fpriv *fpriv;
+       struct amdgpu_ctx_mgr *mgr;
        struct amdgpu_ctx *ctx;
        uint32_t id;
        int r;

@@ -51,8 +52,11 @@ static int amdgpu_sched_process_priority_override(struct amdgpu_device *adev,
                return r;
        }
 
-       idr_for_each_entry(&fpriv->ctx_mgr.ctx_handles, ctx, id)
+       mgr = &fpriv->ctx_mgr;
+       mutex_lock(&mgr->lock);
+       idr_for_each_entry(&mgr->ctx_handles, ctx, id)
                amdgpu_ctx_priority_override(ctx, priority);
+       mutex_unlock(&mgr->lock);
 
        fdput(f);
        return 0;
--

2.40.1.495.gc816e09b53d-goog