[PATCH v3 09/11] tracing: Replace strncpy() with __get_task_comm()

Yafang Shao
2024-06-21T02:32:26Z

Using __get_task_comm() to read the task comm ensures that the name is
always NUL-terminated, regardless of the source string. This approach also
facilitates future extensions to the task comm.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
kernel/trace/trace.c | 2 +-
kernel/trace/trace_events_hist.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 578a49ff5c32..ce94a86154a2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1907,7 +1907,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
max_data->critical_start = data->critical_start;
max_data->critical_end = data->critical_end;

- strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
+ __get_task_comm(max_data->comm, TASK_COMM_LEN, tsk);
max_data->pid = tsk->pid;
/*
* If tsk == current, then use current_uid(), as that does not use
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6ece1308d36a..721d4758a79f 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1599,7 +1599,7 @@ static inline void save_comm(char *comm, struct task_struct *task)
return;
}

- strncpy(comm, task->comm, TASK_COMM_LEN);
+ __get_task_comm(comm, TASK_COMM_LEN, task);
}

static void hist_elt_data_free(struct hist_elt_data *elt_data)
--
2.39.1