Hello Dave, The patch is used to fix the output of trace.c. When I was using trace command to display function tracer's data. The following information is displayed. <cut> crash> trace show version = 6 cpus=2 <idle>-0 [001] 20067.827943: function: 0xffffffff81089fa40xffffffff8109e423 <idle>-0 [001] 20067.827944: function: 0xffffffff811115a40xffffffff8109e4cd <idle>-0 [001] 20067.827944: function: 0xffffffff81097a140xffffffff8109e44f <idle>-0 [001] 20067.827945: function: 0xffffffff81089fa40xffffffff8109e479 <idle>-0 [001] 20067.827945: function: 0xffffffff81089fa40xffffffff8109e482 ... <cut> In tmp_fprintf, function snprintf is used to output data. However, if the following situation happends, the last character is omitted which causes the above bug. <cut> snprintf(buf, 10, "123456789\n"); /* '\n' is omitted */ <cut> With the patch, the output is like below. <cut> crash> trace show version = 6 cpus=2 <idle>-0 [001] 20067.827943: function: debug_lockdep_rcu_enabled <-- walk_tg_tree_from <idle>-0 [001] 20067.827944: function: rcu_is_cpu_idle <-- walk_tg_tree_from <idle>-0 [001] 20067.827944: function: tg_nop <-- walk_tg_tree_from <idle>-0 [001] 20067.827945: function: debug_lockdep_rcu_enabled <-- walk_tg_tree_from <idle>-0 [001] 20067.827945: function: debug_lockdep_rcu_enabled <-- walk_tg_tree_from ... <cut> -- -- Regards Qiao Nuohan