The tty lock is held when the tty driver's hangup() method is called
(from the lone call-site, __tty_hangup()). The call-tree audit [1]
of tty_port_hangup() is a closed graph of the callers of
tty_port_hangup(); ie., all callers originate only from __tty_hangup().
Of these callers, none drop the tty lock prior to calling
tty_port_hangup().
[1]
Call-tree audit of tty_port_hangup()
__tty_hangup()
tty->ops->hangup() --+
|
rs_hangup():arch/ia64/hp/sim/simserial.c
line_hangup():arch/um/drivers/line.c
gdm_tty_hangup():drivers/staging/gdm724x/gdm_tty.c
fwtty_hangup():drivers/staging/fwserial/fwserial.c
acm_tty_hangup():drivers/usb/class/cdc-acm.c
serial_hangup():drivers/usb/serial/usb-serial.c
ipoctal_hangup():drivers/ipack/devices/ipoctal.c
cy_hangup():drivers/tty/cyclades.c
isicom_hangup():drivers/tty/isicom.c
rp_hangup():drivers/tty/rocket.c
dashtty_hangup():drivers/tty/metag_da.c
moxa_hangup():drivers/tty/moxa.c
gsmtty_hangup():drivers/tty/n_gsm.c
goldfish_tty_hangup():drivers/tty/goldfish.c
ehv_bc_tty_hangup():drivers/tty/ehv_bytechan.c
mxser_hangup():drivers/tty/mxser.c
kgdb_nmi_tty_hangup():drivers/tty/serial/kgdb_nmi.c
ifx_spi_hangup():drivers/tty/serial/ifx6x60.c
ntty_hangup():drivers/tty/nozomi.c
capinc_tty_hangup():drivers/isdn/capi/capi.c
mgslpc_hangup():drivers/char/pcmcia/synclink_cs.c
sdio_uart_hangup():drivers/mmc/card/sdio_uart.c
rfcomm_tty_hangup():net/bluetooth/rfcomm/tty.c
|
+- tty_port_hangup()
Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/tty_port.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 69e072b..7309594 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -227,6 +227,8 @@ out:
*
* Perform port level tty hangup flag and count changes. Drop the tty
* reference.
+ *
+ * Caller holds tty lock.
*/
void tty_port_hangup(struct tty_port *port)
--
2.0.0
--
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