6.6-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
commit 91d35ec9b3956d6b3cf789c1593467e58855b03a upstream.
The RFCOMM driver confuses the local and remote modem control signals, which specifically means that the reported DTR and RTS state will instead reflect the remote end (i.e. DSR and CTS).
This issue dates back to the original driver (and a follow-on update) merged in 2002, which resulted in a non-standard implementation of TIOCMSET that allowed controlling also the TS07.10 IC and DV signals by mapping them to the RI and DCD input flags, while TIOCMGET failed to return the actual state of DTR and RTS.
Note that the bogus control of input signals in tiocmset() is just dead code as those flags will have been masked out by the tty layer since 2003.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/bluetooth/rfcomm/tty.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-)
--- a/net/bluetooth/rfcomm/tty.c +++ b/net/bluetooth/rfcomm/tty.c @@ -651,8 +651,8 @@ static void rfcomm_dev_modem_status(stru tty_port_tty_hangup(&dev->port, true);
dev->modem_status = - ((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) | - ((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) | + ((v24_sig & RFCOMM_V24_RTC) ? TIOCM_DSR : 0) | + ((v24_sig & RFCOMM_V24_RTR) ? TIOCM_CTS : 0) | ((v24_sig & RFCOMM_V24_IC) ? TIOCM_RI : 0) | ((v24_sig & RFCOMM_V24_DV) ? TIOCM_CD : 0); } @@ -1063,10 +1063,14 @@ static void rfcomm_tty_hangup(struct tty static int rfcomm_tty_tiocmget(struct tty_struct *tty) { struct rfcomm_dev *dev = tty->driver_data; + struct rfcomm_dlc *dlc = dev->dlc; + u8 v24_sig;
BT_DBG("tty %p dev %p", tty, dev);
- return dev->modem_status; + rfcomm_dlc_get_modem_status(dlc, &v24_sig); + + return (v24_sig & (TIOCM_DTR | TIOCM_RTS)) | dev->modem_status; }
static int rfcomm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) @@ -1079,23 +1083,15 @@ static int rfcomm_tty_tiocmset(struct tt
rfcomm_dlc_get_modem_status(dlc, &v24_sig);
- if (set & TIOCM_DSR || set & TIOCM_DTR) + if (set & TIOCM_DTR) v24_sig |= RFCOMM_V24_RTC; - if (set & TIOCM_RTS || set & TIOCM_CTS) + if (set & TIOCM_RTS) v24_sig |= RFCOMM_V24_RTR; - if (set & TIOCM_RI) - v24_sig |= RFCOMM_V24_IC; - if (set & TIOCM_CD) - v24_sig |= RFCOMM_V24_DV;
- if (clear & TIOCM_DSR || clear & TIOCM_DTR) + if (clear & TIOCM_DTR) v24_sig &= ~RFCOMM_V24_RTC; - if (clear & TIOCM_RTS || clear & TIOCM_CTS) + if (clear & TIOCM_RTS) v24_sig &= ~RFCOMM_V24_RTR; - if (clear & TIOCM_RI) - v24_sig &= ~RFCOMM_V24_IC; - if (clear & TIOCM_CD) - v24_sig &= ~RFCOMM_V24_DV;
rfcomm_dlc_set_modem_status(dlc, v24_sig);