qcacld-3.0: Fix build error without MSM_PLATFORM

Compiler is throwing error - undefined variable 'bus_bw_work' after
MSM_PLATFORM disabled.

Wrap the related code within MSM_PLATFORM.

CRs-Fixed: 2113835
Change-Id: I628df9de911fb17670d63ce577a614408c545aec

core/hdd/inc/wlan_hdd_main.h

@@ -2093,7 +2093,7 @@ void hdd_bus_bw_compute_timer_try_stop(struct hdd_context *hdd_ctx);
 
 /**
  * hdd_bus_bandwidth_init() - Initialize bus bandwidth data structures.
- * hdd_ctx: HDD context
+ * @hdd_ctx: HDD context
  *
  * Initialize bus bandwidth related data structures like spinlock and timer.
  *
@@ -2103,13 +2103,23 @@ int hdd_bus_bandwidth_init(struct hdd_context *hdd_ctx);
 
 /**
  * hdd_bus_bandwidth_destroy() - Destroy bus bandwidth data structures.
- * hdd_ctx: HDD context
+ * @hdd_ctx: HDD context
  *
  * Destroy bus bandwidth related data structures like timer.
  *
  * Return: None.
  */
 void hdd_bus_bandwidth_destroy(struct hdd_context *hdd_ctx);
+
+/**
+ * hdd_bus_bw_cancel_work() - Cancel the bus_bw_work worker
+ * @hdd_ctx: HDD context
+ *
+ * Cancel the bus_bw_work to stop monitor link state.
+ *
+ * Return: None.
+ */
+void hdd_bus_bw_cancel_work(struct hdd_context *hdd_ctx);
 #else
 
 static inline void hdd_bus_bw_compute_timer_start(struct hdd_context *hdd_ctx)
@@ -2136,6 +2146,10 @@ static inline int hdd_bus_bandwidth_init(struct hdd_context *hdd_ctx)
 static inline void hdd_bus_bandwidth_destroy(struct hdd_context *hdd_ctx)
 {
 }
+
+static inline void hdd_bus_bw_cancel_work(struct hdd_context *hdd_ctx)
+{
+}
 #endif
 
 int hdd_qdf_trace_enable(QDF_MODULE_ID module_id, uint32_t bitmask);

core/hdd/src/wlan_hdd_main.c

@@ -4205,9 +4205,18 @@ QDF_STATUS hdd_close_adapter(struct hdd_context *hdd_ctx, struct hdd_adapter *ad
 	}
 	adapterNode = pCurrent;
 	if (QDF_STATUS_SUCCESS == status) {
+		/*
+		 * Here we are stopping global bus_bw timer & work per adapter.
+		 *
+		 * The reason is to fix one race condition between
+		 * bus bandwidth work and cleaning up an adapter.
+		 * Under some conditions, it is possible for the bus bandwidth
+		 * work to access a particularly destroyed adapter, leading to
+		 * use-after-free.
+		 */
 		hdd_debug("wait for bus bw work to flush");
 		hdd_bus_bw_compute_timer_stop(hdd_ctx);
-		cancel_work_sync(&hdd_ctx->bus_bw_work);
+		hdd_bus_bw_cancel_work(hdd_ctx);
 
 		/* cleanup adapter */
 		policy_mgr_clear_concurrency_mode(hdd_ctx->hdd_psoc,
@@ -6630,6 +6639,12 @@ void hdd_bus_bandwidth_destroy(struct hdd_context *hdd_ctx)
 	hdd_ctx->bus_bw_timer_running = false;
 	qdf_spinlock_destroy(&hdd_ctx->bus_bw_timer_lock);
 }
+
+void hdd_bus_bw_cancel_work(struct hdd_context *hdd_ctx)
+{
+	if (hdd_ctx)
+		cancel_work_sync(&hdd_ctx->bus_bw_work);
+}
 #endif
 
 /**