Signed-off-by: Stefan Metzmacher <metze@xxxxxxxxx>
---
fs/io-wq.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/fs/io-wq.c b/fs/io-wq.c
index d6b15a627f9a..5c7d2a8c112e 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -588,7 +588,19 @@ static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
return false;
}
- sprintf(tsk_comm, "iou-wrk-%d", wq->task_pid);
+ /*
+ * The limit value of pid_max_max/PID_MAX_LIMIT
+ * is 4 * 1024 * 1024 = 4194304.
+ *
+ * TASK_COMM_LEN is 16, so we have 15 chars to fill.
+ *
+ * With "iou-wrk-4194304" we just fit into 15 chars.
+ * If that ever changes we may better add some special
+ * handling for PF_IO_WORKER in proc_task_name(), as that
+ * allows up to 63 chars.
+ */
+ WARN_ON(snprintf(tsk_comm, sizeof(tsk_comm),
+ "iou-wrk-%d", wq->task_pid) >= sizeof(tsk_comm));
set_task_comm(tsk, tsk_comm);
tsk->pf_io_worker = worker;
@@ -780,7 +792,19 @@ static int io_wq_fork_manager(struct io_wq *wq)
if (!IS_ERR(tsk)) {
char tsk_comm[TASK_COMM_LEN];
- sprintf(tsk_comm, "iou-mgr-%d", wq->task_pid);
+ /*
+ * The limit value of pid_max_max/PID_MAX_LIMIT
+ * is 4 * 1024 * 1024 = 4194304.
+ *
+ * TASK_COMM_LEN is 16, so we have 15 chars to fill.
+ *
+ * With "iou-mgr-4194304" we just fit into 15 chars.
+ * If that ever changes we may better add some special
+ * handling for PF_IO_WORKER in proc_task_name(), as that
+ * allows up to 63 chars.
+ */
+ WARN_ON(snprintf(tsk_comm, sizeof(tsk_comm),
+ "iou-mgr-%d", wq->task_pid) >= sizeof(tsk_comm));
set_task_comm(tsk, tsk_comm);
wq->manager = get_task_struct(tsk);
--
2.25.1
