155 	 * Save a pointer to the shadow stack itself on shadow stack as a form of token.  in save_cfiss_state()
156 	 * A token on the shadow stack gives the following properties:  in save_cfiss_state()
157 	 * - Safe save and restore for shadow stack switching. Any save of a shadow stack  in save_cfiss_state()
158 	 *   must have saved a token on the shadow stack. Similarly any restore of shadow  in save_cfiss_state()
159 	 *   stack must check the token before restore. Since writing to the shadow stack with  in save_cfiss_state()
160 	 *   address of the shadow stack itself is not easily allowed, a restore without a save  in save_cfiss_state()
162 	 * - A natural break. A token in shadow stack provides a natural break in shadow stack  in save_cfiss_state()
163 	 *   So a single linear range can be bucketed into different shadow stack segments. Any  in save_cfiss_state()
181 	 * Restore shadow stack as a form of token stored on the shadow stack itself as a safe  in __restore_cfiss_state()
183 	 * A token on the shadow stack gives the following properties:  in __restore_cfiss_state()
184 	 * - Safe save and restore for shadow stack switching. Any save of shadow stack  in __restore_cfiss_state()
185 	 *   must have saved a token on shadow stack. Similarly any restore of shadow  in __restore_cfiss_state()
186 	 *   stack must check the token before restore. Since writing to a shadow stack with  in __restore_cfiss_state()
187 	 *   the address of shadow stack itself is not easily allowed, a restore without a save  in __restore_cfiss_state()
189 	 * - A natural break. A token in the shadow stack provides a natural break in shadow stack  in __restore_cfiss_state()
190 	 *   So a single linear range can be bucketed into different shadow stack segments.  in __restore_cfiss_state()