[PATCH v3] drm/amdgpu: add a missing lock for AMDGPU_SCHED

[Chia-I Wu]

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

v2: improve commit message
v3: add a Fixes tag

Signed-off-by: Chia-I Wu <olva...@gmail.com>
Reviewed-by: Christian König <christian.koe...@amd.com>
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(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
index e9b45089a28a6..863b2a34b2d64 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
@@ -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