drm/amdgpu: make the CTX ioctl thread-safe

The existing locks were protecting the list, but not the elements.

v2: rename hlock to lock

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

3 files changed, 12 insertions, 12 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 65246abcee27..cef3a43ab0aa 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1056,7 +1056,7 @@ struct amdgpu_ctx_mgr {
         struct amdgpu_device *adev;
         struct idr ctx_handles;
         /* lock for IDR system */
-        struct mutex hlock;
+        struct mutex lock;
 };
 
 /*
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index ffb13a66e288..0dc3a4ebd5d3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -33,9 +33,7 @@ static void amdgpu_ctx_do_release(struct kref *ref)
         ctx = container_of(ref, struct amdgpu_ctx, refcount);
         mgr = &ctx->fpriv->ctx_mgr;
 
-        mutex_lock(&mgr->hlock);
         idr_remove(&mgr->ctx_handles, ctx->id);
-        mutex_unlock(&mgr->hlock);
         kfree(ctx);
 }
 
@@ -49,20 +47,20 @@ int amdgpu_ctx_alloc(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv, uin
         if (!ctx)
                 return -ENOMEM;
 
-        mutex_lock(&mgr->hlock);
+        mutex_lock(&mgr->lock);
         r = idr_alloc(&mgr->ctx_handles, ctx, 0, 0, GFP_KERNEL);
         if (r < 0) {
-                mutex_unlock(&mgr->hlock);
+                mutex_unlock(&mgr->lock);
                 kfree(ctx);
                 return r;
         }
-        mutex_unlock(&mgr->hlock);
         *id = (uint32_t)r;
 
         memset(ctx, 0, sizeof(*ctx));
         ctx->id = *id;
         ctx->fpriv = fpriv;
         kref_init(&ctx->refcount);
+        mutex_unlock(&mgr->lock);
 
         return 0;
 }
@@ -72,13 +70,14 @@ int amdgpu_ctx_free(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv, uint
         struct amdgpu_ctx *ctx;
         struct amdgpu_ctx_mgr *mgr = &fpriv->ctx_mgr;
 
-        rcu_read_lock();
+        mutex_lock(&mgr->lock);
         ctx = idr_find(&mgr->ctx_handles, id);
-        rcu_read_unlock();
         if (ctx) {
                 kref_put(&ctx->refcount, amdgpu_ctx_do_release);
+                mutex_unlock(&mgr->lock);
                 return 0;
         }
+        mutex_unlock(&mgr->lock);
         return -EINVAL;
 }
 
@@ -87,14 +86,15 @@ int amdgpu_ctx_query(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv, uin
         struct amdgpu_ctx *ctx;
         struct amdgpu_ctx_mgr *mgr = &fpriv->ctx_mgr;
 
-        rcu_read_lock();
+        mutex_lock(&mgr->lock);
         ctx = idr_find(&mgr->ctx_handles, id);
-        rcu_read_unlock();
         if (ctx) {
                 /* state should alter with CS activity */
                 *state = ctx->state;
+                mutex_unlock(&mgr->lock);
                 return 0;
         }
+        mutex_unlock(&mgr->lock);
         return -EINVAL;
 }
 
@@ -111,7 +111,7 @@ void amdgpu_ctx_fini(struct amdgpu_fpriv *fpriv)
                         DRM_ERROR("ctx (id=%ul) is still alive\n",ctx->id);
         }
 
-        mutex_destroy(&mgr->hlock);
+        mutex_destroy(&mgr->lock);
 }
 
 int amdgpu_ctx_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 2d50c6dbdcbb..02c450d0be1a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -497,7 +497,7 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
         idr_init(&fpriv->bo_list_handles);
 
         /* init context manager */
-        mutex_init(&fpriv->ctx_mgr.hlock);
+        mutex_init(&fpriv->ctx_mgr.lock);
         idr_init(&fpriv->ctx_mgr.ctx_handles);
         fpriv->ctx_mgr.adev = adev;