Hello Tony Lindgren,
The patch 925ea0fa5277: "tty: n_gsm: Fix packet data hex dump output"
from May 12, 2022, leads to the following Smatch static checker
warning:
drivers/tty/n_gsm.c:720 gsm_data_kick()
warn: sleeping in atomic context
drivers/tty/n_gsm.c
698 static void gsm_data_kick(struct gsm_mux *gsm, struct gsm_dlci *dlci)
699 {
700 struct gsm_msg *msg, *nmsg;
701 int len;
702
703 list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) {
704 if (gsm->constipated && msg->addr)
705 continue;
706 if (gsm->encoding != 0) {
707 gsm->txframe[0] = GSM1_SOF;
708 len = gsm_stuff_frame(msg->data,
709 gsm->txframe + 1, msg->len);
710 gsm->txframe[len + 1] = GSM1_SOF;
711 len += 2;
712 } else {
713 gsm->txframe[0] = GSM0_SOF;
714 memcpy(gsm->txframe + 1 , msg->data, msg->len);
715 gsm->txframe[msg->len + 1] = GSM0_SOF;
716 len = msg->len + 2;
717 }
718
719 if (debug & 4)
--> 720 gsm_hex_dump_bytes(__func__, gsm->txframe, len);
gsm_control_message() is holding a spin lock so gsm_hex_dump_bytes()
might need to use GFP_ATOMIC instead of GFP_KERNEL.
721 if (gsmld_output(gsm, gsm->txframe, len) <= 0)
722 break;
723 /* FIXME: Can eliminate one SOF in many more cases */
724 gsm->tx_bytes -= msg->len;
725
726 list_del(&msg->list);
727 kfree(msg);
728
729 if (dlci) {
730 tty_port_tty_wakeup(&dlci->port);
731 } else {
732 int i = 0;
733
734 for (i = 0; i < NUM_DLCI; i++)
735 if (gsm->dlci[i])
736 tty_port_tty_wakeup(&gsm->dlci[i]->port);
737 }
738 }
739 }
regards,
dan carpenter
