From d450b5a0196b6442cf3f29fc611d9c8daa56b559 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 13 Oct 2008 10:39:58 +0100 Subject: [PATCH] tty: kref usage for isicom and moxa Rather than blindly keep taking krefs we reorder the code in a few places to pass the tty down to the right place (which is important as from the user side it is not the case that tty == port->tty in all situations). For the irq and related paths use the krefs to stop the tty being freed under us. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/char/isicom.c | 61 ++++++++++++++++++++++--------------------- drivers/char/moxa.c | 61 +++++++++++++++++++++++++++---------------- 2 files changed, 69 insertions(+), 53 deletions(-) diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c index 8f7cc190b62..7d30ee1d3fc 100644 --- a/drivers/char/isicom.c +++ b/drivers/char/isicom.c @@ -421,17 +421,16 @@ static void isicom_tx(unsigned long _data) if (retries >= 100) goto unlock; + tty = tty_port_tty_get(&port->port); + if (tty == NULL) + goto put_unlock; + for (; count > 0; count--, port++) { /* port not active or tx disabled to force flow control */ if (!(port->port.flags & ASYNC_INITIALIZED) || !(port->status & ISI_TXOK)) continue; - tty = port->port.tty; - - if (tty == NULL) - continue; - txcount = min_t(short, TX_SIZE, port->xmit_cnt); if (txcount <= 0 || tty->stopped || tty->hw_stopped) continue; @@ -489,6 +488,8 @@ static void isicom_tx(unsigned long _data) tty_wakeup(tty); } +put_unlock: + tty_kref_put(tty); unlock: spin_unlock_irqrestore(&isi_card[card].card_lock, flags); /* schedule another tx for hopefully in about 10ms */ @@ -547,7 +548,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } - tty = port->port.tty; + tty = tty_port_tty_get(&port->port); if (tty == NULL) { word_count = byte_count >> 1; while (byte_count > 1) { @@ -588,7 +589,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) } if (port->port.flags & ASYNC_CTS_FLOW) { - if (port->port.tty->hw_stopped) { + if (tty->hw_stopped) { if (header & ISI_CTS) { port->port.tty->hw_stopped = 0; /* start tx ing */ @@ -597,7 +598,7 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) tty_wakeup(tty); } } else if (!(header & ISI_CTS)) { - port->port.tty->hw_stopped = 1; + tty->hw_stopped = 1; /* stop tx ing */ port->status &= ~(ISI_TXOK | ISI_CTS); } @@ -660,24 +661,21 @@ static irqreturn_t isicom_interrupt(int irq, void *dev_id) } outw(0x0000, base+0x04); /* enable interrupts */ spin_unlock(&card->card_lock); + tty_kref_put(tty); return IRQ_HANDLED; } -static void isicom_config_port(struct isi_port *port) +static void isicom_config_port(struct tty_struct *tty) { + struct isi_port *port = tty->driver_data; struct isi_board *card = port->card; - struct tty_struct *tty; unsigned long baud; unsigned long base = card->base; u16 channel_setup, channel = port->channel, shift_count = card->shift_count; unsigned char flow_ctrl; - tty = port->port.tty; - - if (tty == NULL) - return; /* FIXME: Switch to new tty baud API */ baud = C_BAUD(tty); if (baud & CBAUDEX) { @@ -690,7 +688,7 @@ static void isicom_config_port(struct isi_port *port) /* 1,2,3,4 => 57.6, 115.2, 230, 460 kbps resp. */ if (baud < 1 || baud > 4) - port->port.tty->termios->c_cflag &= ~CBAUDEX; + tty->termios->c_cflag &= ~CBAUDEX; else baud += 15; } @@ -797,8 +795,9 @@ static inline void isicom_setup_board(struct isi_board *bp) spin_unlock_irqrestore(&bp->card_lock, flags); } -static int isicom_setup_port(struct isi_port *port) +static int isicom_setup_port(struct tty_struct *tty) { + struct isi_port *port = tty->driver_data; struct isi_board *card = port->card; unsigned long flags; @@ -808,8 +807,7 @@ static int isicom_setup_port(struct isi_port *port) return -ENOMEM; spin_lock_irqsave(&card->card_lock, flags); - if (port->port.tty) - clear_bit(TTY_IO_ERROR, &port->port.tty->flags); + clear_bit(TTY_IO_ERROR, &tty->flags); if (port->port.count == 1) card->count++; @@ -823,7 +821,7 @@ static int isicom_setup_port(struct isi_port *port) InterruptTheCard(card->base); } - isicom_config_port(port); + isicom_config_port(tty); port->port.flags |= ASYNC_INITIALIZED; spin_unlock_irqrestore(&card->card_lock, flags); @@ -934,8 +932,8 @@ static int isicom_open(struct tty_struct *tty, struct file *filp) port->port.count++; tty->driver_data = port; - port->port.tty = tty; - error = isicom_setup_port(port); + tty_port_tty_set(&port->port, tty); + error = isicom_setup_port(tty); if (error == 0) error = block_til_ready(tty, filp, port); return error; @@ -955,15 +953,17 @@ static void isicom_shutdown_port(struct isi_port *port) struct isi_board *card = port->card; struct tty_struct *tty; - tty = port->port.tty; + tty = tty_port_tty_get(&port->port); - if (!(port->port.flags & ASYNC_INITIALIZED)) + if (!(port->port.flags & ASYNC_INITIALIZED)) { + tty_kref_put(tty); return; + } tty_port_free_xmit_buf(&port->port); port->port.flags &= ~ASYNC_INITIALIZED; /* 3rd October 2000 : Vinayak P Risbud */ - port->port.tty = NULL; + tty_port_tty_set(&port->port, NULL); /*Fix done by Anil .S on 30-04-2001 remote login through isi port has dtr toggle problem @@ -1243,9 +1243,10 @@ static int isicom_tiocmset(struct tty_struct *tty, struct file *file, return 0; } -static int isicom_set_serial_info(struct isi_port *port, - struct serial_struct __user *info) +static int isicom_set_serial_info(struct tty_struct *tty, + struct serial_struct __user *info) { + struct isi_port *port = tty->driver_data; struct serial_struct newinfo; int reconfig_port; @@ -1276,7 +1277,7 @@ static int isicom_set_serial_info(struct isi_port *port, if (reconfig_port) { unsigned long flags; spin_lock_irqsave(&port->card->card_lock, flags); - isicom_config_port(port); + isicom_config_port(tty); spin_unlock_irqrestore(&port->card->card_lock, flags); } unlock_kernel(); @@ -1318,7 +1319,7 @@ static int isicom_ioctl(struct tty_struct *tty, struct file *filp, return isicom_get_serial_info(port, argp); case TIOCSSERIAL: - return isicom_set_serial_info(port, argp); + return isicom_set_serial_info(tty, argp); default: return -ENOIOCTLCMD; @@ -1341,7 +1342,7 @@ static void isicom_set_termios(struct tty_struct *tty, return; spin_lock_irqsave(&port->card->card_lock, flags); - isicom_config_port(port); + isicom_config_port(tty); spin_unlock_irqrestore(&port->card->card_lock, flags); if ((old_termios->c_cflag & CRTSCTS) && @@ -1419,7 +1420,7 @@ static void isicom_hangup(struct tty_struct *tty) port->port.count = 0; port->port.flags &= ~ASYNC_NORMAL_ACTIVE; - port->port.tty = NULL; + tty_port_tty_set(&port->port, NULL); wake_up_interruptible(&port->port.open_wait); } diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c index d3d7864e0c1..5df4003ad87 100644 --- a/drivers/char/moxa.c +++ b/drivers/char/moxa.c @@ -205,7 +205,7 @@ static int moxa_tiocmset(struct tty_struct *tty, struct file *file, static void moxa_poll(unsigned long); static void moxa_set_tty_param(struct tty_struct *, struct ktermios *); static void moxa_setup_empty_event(struct tty_struct *); -static void moxa_shut_down(struct moxa_port *); +static void moxa_shut_down(struct tty_struct *); /* * moxa board interface functions: */ @@ -217,7 +217,7 @@ static void MoxaPortLineCtrl(struct moxa_port *, int, int); static void MoxaPortFlowCtrl(struct moxa_port *, int, int, int, int, int); static int MoxaPortLineStatus(struct moxa_port *); static void MoxaPortFlushData(struct moxa_port *, int); -static int MoxaPortWriteData(struct moxa_port *, const unsigned char *, int); +static int MoxaPortWriteData(struct tty_struct *, const unsigned char *, int); static int MoxaPortReadData(struct moxa_port *); static int MoxaPortTxQueue(struct moxa_port *); static int MoxaPortRxQueue(struct moxa_port *); @@ -332,6 +332,7 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, for (i = 0; i < MAX_BOARDS; i++) { p = moxa_boards[i].ports; for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) { + struct tty_struct *ttyp; memset(&tmp, 0, sizeof(tmp)); if (!moxa_boards[i].ready) goto copy; @@ -344,10 +345,12 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, if (status & 4) tmp.dcd = 1; - if (!p->port.tty || !p->port.tty->termios) + ttyp = tty_port_tty_get(&p->port); + if (!ttyp || !ttyp->termios) tmp.cflag = p->cflag; else - tmp.cflag = p->port.tty->termios->c_cflag; + tmp.cflag = ttyp->termios->c_cflag; + tty_kref_put(tty); copy: if (copy_to_user(argm, &tmp, sizeof(tmp))) { mutex_unlock(&moxa_openlock); @@ -880,8 +883,14 @@ static void moxa_board_deinit(struct moxa_board_conf *brd) /* pci hot-un-plug support */ for (a = 0; a < brd->numPorts; a++) - if (brd->ports[a].port.flags & ASYNC_INITIALIZED) - tty_hangup(brd->ports[a].port.tty); + if (brd->ports[a].port.flags & ASYNC_INITIALIZED) { + struct tty_struct *tty = tty_port_tty_get( + &brd->ports[a].port); + if (tty) { + tty_hangup(tty); + tty_kref_put(tty); + } + } while (1) { opened = 0; for (a = 0; a < brd->numPorts; a++) @@ -1096,13 +1105,14 @@ static void __exit moxa_exit(void) module_init(moxa_init); module_exit(moxa_exit); -static void moxa_close_port(struct moxa_port *ch) +static void moxa_close_port(struct tty_struct *tty) { - moxa_shut_down(ch); + struct moxa_port *ch = tty->driver_data; + moxa_shut_down(tty); MoxaPortFlushData(ch, 2); ch->port.flags &= ~ASYNC_NORMAL_ACTIVE; - ch->port.tty->driver_data = NULL; - ch->port.tty = NULL; + tty->driver_data = NULL; + tty_port_tty_set(&ch->port, NULL); } static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp, @@ -1161,7 +1171,7 @@ static int moxa_open(struct tty_struct *tty, struct file *filp) ch = &brd->ports[port % MAX_PORTS_PER_BOARD]; ch->port.count++; tty->driver_data = ch; - ch->port.tty = tty; + tty_port_tty_set(&ch->port, tty); if (!(ch->port.flags & ASYNC_INITIALIZED)) { ch->statusflags = 0; moxa_set_tty_param(tty, tty->termios); @@ -1179,7 +1189,7 @@ static int moxa_open(struct tty_struct *tty, struct file *filp) if (retval) { if (ch->port.count) /* 0 means already hung up... */ if (--ch->port.count == 0) - moxa_close_port(ch); + moxa_close_port(tty); } else ch->port.flags |= ASYNC_NORMAL_ACTIVE; mutex_unlock(&moxa_openlock); @@ -1219,7 +1229,7 @@ static void moxa_close(struct tty_struct *tty, struct file *filp) tty_wait_until_sent(tty, 30 * HZ); /* 30 seconds timeout */ } - moxa_close_port(ch); + moxa_close_port(tty); unlock: mutex_unlock(&moxa_openlock); } @@ -1234,7 +1244,7 @@ static int moxa_write(struct tty_struct *tty, return 0; spin_lock_bh(&moxa_lock); - len = MoxaPortWriteData(ch, buf, count); + len = MoxaPortWriteData(tty, buf, count); spin_unlock_bh(&moxa_lock); ch->statusflags |= LOWWAIT; @@ -1409,7 +1419,7 @@ static void moxa_hangup(struct tty_struct *tty) return; } ch->port.count = 0; - moxa_close_port(ch); + moxa_close_port(tty); mutex_unlock(&moxa_openlock); wake_up_interruptible(&ch->port.open_wait); @@ -1417,11 +1427,14 @@ static void moxa_hangup(struct tty_struct *tty) static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd) { + struct tty_struct *tty; dcd = !!dcd; - if (dcd != p->DCDState && p->port.tty && C_CLOCAL(p->port.tty)) { - if (!dcd) - tty_hangup(p->port.tty); + if (dcd != p->DCDState) { + tty = tty_port_tty_get(&p->port); + if (tty && C_CLOCAL(tty) && !dcd) + tty_hangup(tty); + tty_kref_put(tty); } p->DCDState = dcd; } @@ -1429,7 +1442,7 @@ static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd) static int moxa_poll_port(struct moxa_port *p, unsigned int handle, u16 __iomem *ip) { - struct tty_struct *tty = p->port.tty; + struct tty_struct *tty = tty_port_tty_get(&p->port); void __iomem *ofsAddr; unsigned int inited = p->port.flags & ASYNC_INITIALIZED; u16 intr; @@ -1476,6 +1489,7 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle, tty_insert_flip_char(tty, 0, TTY_BREAK); tty_schedule_flip(tty); } + tty_kref_put(tty); if (intr & IntrLine) moxa_new_dcdstate(p, readb(ofsAddr + FlagStat) & DCD_state); @@ -1560,9 +1574,9 @@ static void moxa_setup_empty_event(struct tty_struct *tty) spin_unlock_bh(&moxa_lock); } -static void moxa_shut_down(struct moxa_port *ch) +static void moxa_shut_down(struct tty_struct *tty) { - struct tty_struct *tp = ch->port.tty; + struct moxa_port *ch = tty->driver_data; if (!(ch->port.flags & ASYNC_INITIALIZED)) return; @@ -1572,7 +1586,7 @@ static void moxa_shut_down(struct moxa_port *ch) /* * If we're a modem control device and HUPCL is on, drop RTS & DTR. */ - if (C_HUPCL(tp)) + if (C_HUPCL(tty)) MoxaPortLineCtrl(ch, 0, 0); spin_lock_bh(&moxa_lock); @@ -1953,9 +1967,10 @@ static int MoxaPortLineStatus(struct moxa_port *port) return val; } -static int MoxaPortWriteData(struct moxa_port *port, +static int MoxaPortWriteData(struct tty_struct *tty, const unsigned char *buffer, int len) { + struct moxa_port *port = tty->driver_data; void __iomem *baseAddr, *ofsAddr, *ofs; unsigned int c, total; u16 head, tail, tx_mask, spage, epage; -- 2.41.1