From: Zheyu Ma zheyuma97@gmail.com
stable inclusion from linux-4.19.207 commit 84bf0fb189d512cb890381e6af855bc26b7b2294
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[ Upstream commit 240e126c28df084222f0b661321e8e3ecb0d232e ]
uart_handle_dcd_change() requires a port lock to be held and will emit a warning when lockdep is enabled.
Held corresponding lock to fix the following warnings.
[ 132.528648] WARNING: CPU: 5 PID: 11600 at drivers/tty/serial/serial_core.c:3046 uart_handle_dcd_change+0xf4/0x120 [ 132.530482] Modules linked in: [ 132.531050] CPU: 5 PID: 11600 Comm: jsm Not tainted 5.14.0-rc1-00003-g7fef2edf7cc7-dirty #31 [ 132.535268] RIP: 0010:uart_handle_dcd_change+0xf4/0x120 [ 132.557100] Call Trace: [ 132.557562] ? __free_pages+0x83/0xb0 [ 132.558213] neo_parse_modem+0x156/0x220 [ 132.558897] neo_param+0x399/0x840 [ 132.559495] jsm_tty_open+0x12f/0x2d0 [ 132.560131] uart_startup.part.18+0x153/0x340 [ 132.560888] ? lock_is_held_type+0xe9/0x140 [ 132.561660] uart_port_activate+0x7f/0xe0 [ 132.562351] ? uart_startup.part.18+0x340/0x340 [ 132.563003] tty_port_open+0x8d/0xf0 [ 132.563523] ? uart_set_options+0x1e0/0x1e0 [ 132.564125] uart_open+0x24/0x40 [ 132.564604] tty_open+0x15c/0x630
Signed-off-by: Zheyu Ma zheyuma97@gmail.com Link: https://lore.kernel.org/r/1626242003-3809-1-git-send-email-zheyuma97@gmail.c... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/tty/serial/jsm/jsm_neo.c | 2 ++ drivers/tty/serial/jsm/jsm_tty.c | 3 +++ 2 files changed, 5 insertions(+)
diff --git a/drivers/tty/serial/jsm/jsm_neo.c b/drivers/tty/serial/jsm/jsm_neo.c index bf0e2a4cb0cef..c6f927a76c3be 100644 --- a/drivers/tty/serial/jsm/jsm_neo.c +++ b/drivers/tty/serial/jsm/jsm_neo.c @@ -815,7 +815,9 @@ static void neo_parse_isr(struct jsm_board *brd, u32 port) /* Parse any modem signal changes */ jsm_dbg(INTR, &ch->ch_bd->pci_dev, "MOD_STAT: sending to parse_modem_sigs\n"); + spin_lock_irqsave(&ch->uart_port.lock, lock_flags); neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr)); + spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags); } }
diff --git a/drivers/tty/serial/jsm/jsm_tty.c b/drivers/tty/serial/jsm/jsm_tty.c index 689774c073ca4..8438454ca653f 100644 --- a/drivers/tty/serial/jsm/jsm_tty.c +++ b/drivers/tty/serial/jsm/jsm_tty.c @@ -187,6 +187,7 @@ static void jsm_tty_break(struct uart_port *port, int break_state)
static int jsm_tty_open(struct uart_port *port) { + unsigned long lock_flags; struct jsm_board *brd; struct jsm_channel *channel = container_of(port, struct jsm_channel, uart_port); @@ -240,6 +241,7 @@ static int jsm_tty_open(struct uart_port *port) channel->ch_cached_lsr = 0; channel->ch_stops_sent = 0;
+ spin_lock_irqsave(&port->lock, lock_flags); termios = &port->state->port.tty->termios; channel->ch_c_cflag = termios->c_cflag; channel->ch_c_iflag = termios->c_iflag; @@ -259,6 +261,7 @@ static int jsm_tty_open(struct uart_port *port) jsm_carrier(channel);
channel->ch_open_count++; + spin_unlock_irqrestore(&port->lock, lock_flags);
jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n"); return 0;