From: Jiri Slaby Date: Sat, 19 Sep 2009 20:13:12 +0000 (-0700) Subject: cyclades: add tty refcounting X-Git-Tag: v2.6.32-rc1~627^2~71 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d13549f804d2965a9f279a8ff867f35d949572c8;p=platform%2Fkernel%2Flinux-3.10.git cyclades: add tty refcounting While this is not problem for Y card handlers (they are protected by card_lock), Z handlers and other functions may dereference NULL at any point after hangup/close. Even if (tty == NULL) was already performed in the handler. Note that it's not an issue for Y cards just for now. After switching to tty_port_close_* et al. this will be a problem. So add refcounting to them all. Also proc .show doesn't take a tty reference and it should (along with a ldisc one). While at it and changing prototypes (adding tty param), prepend cy_ to functions which don't have it yet. Signed-off-by: Jiri Slaby Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c index 2dafc2d..e2f731b 100644 --- a/drivers/char/cyclades.c +++ b/drivers/char/cyclades.c @@ -850,7 +850,7 @@ MODULE_DEVICE_TABLE(pci, cy_pci_dev_id); #endif static void cy_start(struct tty_struct *); -static void set_line_char(struct cyclades_port *); +static void cy_set_line_char(struct cyclades_port *, struct tty_struct *); static int cyz_issue_cmd(struct cyclades_card *, __u32, __u8, __u32); #ifdef CONFIG_ISA static unsigned detect_isa_irq(void __iomem *); @@ -1011,8 +1011,9 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip, save_car = readb(base_addr + (CyCAR << index)); cy_writeb(base_addr + (CyCAR << index), save_xir); + tty = tty_port_tty_get(&info->port); /* if there is nowhere to put the data, discard it */ - if (info->port.tty == NULL) { + if (tty == NULL) { if ((readb(base_addr + (CyRIVR << index)) & CyIVRMask) == CyIVRRxEx) { /* exception */ data = readb(base_addr + (CyRDSR << index)); @@ -1024,7 +1025,6 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip, goto end; } /* there is an open port for this data */ - tty = info->port.tty; if ((readb(base_addr + (CyRIVR << index)) & CyIVRMask) == CyIVRRxEx) { /* exception */ data = readb(base_addr + (CyRDSR << index)); @@ -1041,6 +1041,7 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip, if (data & info->ignore_status_mask) { info->icount.rx++; + tty_kref_put(tty); return; } if (tty_buffer_request_room(tty, 1)) { @@ -1121,6 +1122,7 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip, info->idle_stats.recv_idle = jiffies; } tty_schedule_flip(tty); + tty_kref_put(tty); end: /* end of service */ cy_writeb(base_addr + (CyRIR << index), save_xir & 0x3f); @@ -1131,6 +1133,7 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip, void __iomem *base_addr) { struct cyclades_port *info; + struct tty_struct *tty; int char_count, index = cinfo->bus_index; u8 save_xir, channel, save_car, outch; @@ -1154,7 +1157,8 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip, goto end; } info = &cinfo->ports[channel + chip * 4]; - if (info->port.tty == NULL) { + tty = tty_port_tty_get(&info->port); + if (tty == NULL) { cy_writeb(base_addr + (CySRER << index), readb(base_addr + (CySRER << index)) & ~CyTxRdy); goto end; @@ -1205,7 +1209,7 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip, ~CyTxRdy); goto done; } - if (info->port.tty->stopped || info->port.tty->hw_stopped) { + if (tty->stopped || tty->hw_stopped) { cy_writeb(base_addr + (CySRER << index), readb(base_addr + (CySRER << index)) & ~CyTxRdy); @@ -1241,7 +1245,8 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip, } done: - tty_wakeup(info->port.tty); + tty_wakeup(tty); + tty_kref_put(tty); end: /* end of service */ cy_writeb(base_addr + (CyTIR << index), save_xir & 0x3f); @@ -1252,6 +1257,7 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip, void __iomem *base_addr) { struct cyclades_port *info; + struct tty_struct *tty; int index = cinfo->bus_index; u8 save_xir, channel, save_car, mdm_change, mdm_status; @@ -1265,7 +1271,8 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip, mdm_change = readb(base_addr + (CyMISR << index)); mdm_status = readb(base_addr + (CyMSVR1 << index)); - if (!info->port.tty) + tty = tty_port_tty_get(&info->port); + if (!tty) goto end; if (mdm_change & CyANY_DELTA) { @@ -1284,27 +1291,27 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip, if ((mdm_change & CyDCD) && (info->port.flags & ASYNC_CHECK_CD)) { if (!(mdm_status & CyDCD)) { - tty_hangup(info->port.tty); + tty_hangup(tty); info->port.flags &= ~ASYNC_NORMAL_ACTIVE; } wake_up_interruptible(&info->port.open_wait); } if ((mdm_change & CyCTS) && (info->port.flags & ASYNC_CTS_FLOW)) { - if (info->port.tty->hw_stopped) { + if (tty->hw_stopped) { if (mdm_status & CyCTS) { /* cy_start isn't used because... !!! */ - info->port.tty->hw_stopped = 0; + tty->hw_stopped = 0; cy_writeb(base_addr + (CySRER << index), readb(base_addr + (CySRER << index)) | CyTxRdy); - tty_wakeup(info->port.tty); + tty_wakeup(tty); } } else { if (!(mdm_status & CyCTS)) { /* cy_stop isn't used because ... !!! */ - info->port.tty->hw_stopped = 1; + tty->hw_stopped = 1; cy_writeb(base_addr + (CySRER << index), readb(base_addr + (CySRER << index)) & ~CyTxRdy); @@ -1315,6 +1322,7 @@ static void cyy_chip_modem(struct cyclades_card *cinfo, int chip, } if (mdm_change & CyRI) { }*/ + tty_kref_put(tty); end: /* end of service */ cy_writeb(base_addr + (CyMIR << index), save_xir & 0x3f); @@ -1449,11 +1457,10 @@ cyz_issue_cmd(struct cyclades_card *cinfo, return 0; } /* cyz_issue_cmd */ -static void cyz_handle_rx(struct cyclades_port *info, +static void cyz_handle_rx(struct cyclades_port *info, struct tty_struct *tty, struct BUF_CTRL __iomem *buf_ctrl) { struct cyclades_card *cinfo = info->card; - struct tty_struct *tty = info->port.tty; unsigned int char_count; int len; #ifdef BLOCKMOVE @@ -1542,11 +1549,10 @@ static void cyz_handle_rx(struct cyclades_port *info, } } -static void cyz_handle_tx(struct cyclades_port *info, +static void cyz_handle_tx(struct cyclades_port *info, struct tty_struct *tty, struct BUF_CTRL __iomem *buf_ctrl) { struct cyclades_card *cinfo = info->card; - struct tty_struct *tty = info->port.tty; u8 data; unsigned int char_count; #ifdef BLOCKMOVE @@ -1642,7 +1648,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo) special_count = 0; delta_count = 0; info = &cinfo->ports[channel]; - tty = info->port.tty; + tty = tty_port_tty_get(&info->port); if (tty == NULL) continue; @@ -1674,7 +1680,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo) C_RS_DCD) { wake_up_interruptible(&info->port.open_wait); } else { - tty_hangup(info->port.tty); + tty_hangup(tty); wake_up_interruptible(&info->port.open_wait); info->port.flags &= ~ASYNC_NORMAL_ACTIVE; } @@ -1706,7 +1712,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo) printk(KERN_DEBUG "cyz_interrupt: rcvd intr, card %d, " "port %ld\n", info->card, channel); #endif - cyz_handle_rx(info, buf_ctrl); + cyz_handle_rx(info, tty, buf_ctrl); break; case C_CM_TXBEMPTY: case C_CM_TXLOWWM: @@ -1716,7 +1722,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo) printk(KERN_DEBUG "cyz_interrupt: xmit intr, card %d, " "port %ld\n", info->card, channel); #endif - cyz_handle_tx(info, buf_ctrl); + cyz_handle_tx(info, tty, buf_ctrl); break; #endif /* CONFIG_CYZ_INTR */ case C_CM_FATAL: @@ -1729,6 +1735,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo) wake_up_interruptible(&info->delta_msr_wait); if (special_count) tty_schedule_flip(tty); + tty_kref_put(tty); } } @@ -1774,7 +1781,6 @@ static void cyz_poll(unsigned long arg) { struct cyclades_card *cinfo; struct cyclades_port *info; - struct tty_struct *tty; struct FIRM_ID __iomem *firm_id; struct ZFW_CTRL __iomem *zfw_ctrl; struct BUF_CTRL __iomem *buf_ctrl; @@ -1802,13 +1808,19 @@ static void cyz_poll(unsigned long arg) cyz_handle_cmd(cinfo); for (port = 0; port < cinfo->nports; port++) { + struct tty_struct *tty; + info = &cinfo->ports[port]; - tty = info->port.tty; buf_ctrl = &(zfw_ctrl->buf_ctrl[port]); + tty = tty_port_tty_get(&info->port); + /* OK to pass NULL to the handle functions below. + They need to drop the data in that case. */ + if (!info->throttle) - cyz_handle_rx(info, buf_ctrl); - cyz_handle_tx(info, buf_ctrl); + cyz_handle_rx(info, tty, buf_ctrl); + cyz_handle_tx(info, tty, buf_ctrl); + tty_kref_put(tty); } /* poll every 'cyz_polling_cycle' period */ expires = jiffies + cyz_polling_cycle; @@ -1824,7 +1836,7 @@ static void cyz_poll(unsigned long arg) /* This is called whenever a port becomes active; interrupts are enabled and DTR & RTS are turned on. */ -static int startup(struct cyclades_port *info) +static int cy_startup(struct cyclades_port *info, struct tty_struct *tty) { struct cyclades_card *card; unsigned long flags; @@ -1848,8 +1860,7 @@ static int startup(struct cyclades_port *info) } if (!info->type) { - if (info->port.tty) - set_bit(TTY_IO_ERROR, &info->port.tty->flags); + set_bit(TTY_IO_ERROR, &tty->flags); free_page(page); goto errout; } @@ -1861,7 +1872,7 @@ static int startup(struct cyclades_port *info) spin_unlock_irqrestore(&card->card_lock, flags); - set_line_char(info); + cy_set_line_char(info, tty); if (!cy_is_Z(card)) { chip = channel >> 2; @@ -1900,8 +1911,7 @@ static int startup(struct cyclades_port *info) readb(base_addr + (CySRER << index)) | CyRxData); info->port.flags |= ASYNC_INITIALIZED; - if (info->port.tty) - clear_bit(TTY_IO_ERROR, &info->port.tty->flags); + clear_bit(TTY_IO_ERROR, &tty->flags); info->xmit_cnt = info->xmit_head = info->xmit_tail = 0; info->breakon = info->breakoff = 0; memset((char *)&info->idle_stats, 0, sizeof(info->idle_stats)); @@ -1984,8 +1994,7 @@ static int startup(struct cyclades_port *info) /* enable send, recv, modem !!! */ info->port.flags |= ASYNC_INITIALIZED; - if (info->port.tty) - clear_bit(TTY_IO_ERROR, &info->port.tty->flags); + clear_bit(TTY_IO_ERROR, &tty->flags); info->xmit_cnt = info->xmit_head = info->xmit_tail = 0; info->breakon = info->breakoff = 0; memset((char *)&info->idle_stats, 0, sizeof(info->idle_stats)); @@ -2047,7 +2056,7 @@ static void start_xmit(struct cyclades_port *info) * This routine shuts down a serial port; interrupts are disabled, * and DTR is dropped if the hangup on close termio flag is on. */ -static void shutdown(struct cyclades_port *info) +static void cy_shutdown(struct cyclades_port *info, struct tty_struct *tty) { struct cyclades_card *card; unsigned long flags; @@ -2083,7 +2092,7 @@ static void shutdown(struct cyclades_port *info) free_page((unsigned long)temp); } cy_writeb(base_addr + (CyCAR << index), (u_char) channel); - if (!info->port.tty || (info->port.tty->termios->c_cflag & HUPCL)) { + if (tty->termios->c_cflag & HUPCL) { cy_writeb(base_addr + (CyMSVR1 << index), ~CyRTS); cy_writeb(base_addr + (CyMSVR2 << index), ~CyDTR); #ifdef CY_DEBUG_DTR @@ -2097,8 +2106,7 @@ static void shutdown(struct cyclades_port *info) /* it may be appropriate to clear _XMIT at some later date (after testing)!!! */ - if (info->port.tty) - set_bit(TTY_IO_ERROR, &info->port.tty->flags); + set_bit(TTY_IO_ERROR, &tty->flags); info->port.flags &= ~ASYNC_INITIALIZED; spin_unlock_irqrestore(&card->card_lock, flags); } else { @@ -2132,7 +2140,7 @@ static void shutdown(struct cyclades_port *info) free_page((unsigned long)temp); } - if (!info->port.tty || (info->port.tty->termios->c_cflag & HUPCL)) { + if (tty->termios->c_cflag & HUPCL) { cy_writel(&ch_ctrl[channel].rs_control, (__u32)(readl(&ch_ctrl[channel].rs_control) & ~(C_RS_RTS | C_RS_DTR))); @@ -2147,8 +2155,7 @@ static void shutdown(struct cyclades_port *info) #endif } - if (info->port.tty) - set_bit(TTY_IO_ERROR, &info->port.tty->flags); + set_bit(TTY_IO_ERROR, &tty->flags); info->port.flags &= ~ASYNC_INITIALIZED; spin_unlock_irqrestore(&card->card_lock, flags); @@ -2436,7 +2443,6 @@ static int cy_open(struct tty_struct *tty, struct file *filp) printk(KERN_DEBUG "cyc:cy_open ttyC%d\n", info->line); #endif tty->driver_data = info; - info->port.tty = tty; if (serial_paranoia_check(info, tty->name, "cy_open")) return -ENODEV; @@ -2462,7 +2468,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp) /* * Start up serial port */ - retval = startup(info); + retval = cy_startup(info, tty); if (retval) return retval; @@ -2476,6 +2482,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp) } info->throttle = 0; + tty_port_tty_set(&info->port, tty); #ifdef CY_DEBUG_OPEN printk(KERN_DEBUG "cyc:cy_open done\n"); @@ -2705,13 +2712,13 @@ static void cy_close(struct tty_struct *tty, struct file *filp) } spin_unlock_irqrestore(&card->card_lock, flags); - shutdown(info); + cy_shutdown(info, tty); cy_flush_buffer(tty); tty_ldisc_flush(tty); spin_lock_irqsave(&card->card_lock, flags); tty->closing = 0; - info->port.tty = NULL; + tty_port_tty_set(&info->port, NULL); if (info->port.blocked_open) { spin_unlock_irqrestore(&card->card_lock, flags); if (info->port.close_delay) { @@ -2957,7 +2964,7 @@ static void cyy_baud_calc(struct cyclades_port *info, __u32 baud) * This routine finds or computes the various line characteristics. * It used to be called config_setup */ -static void set_line_char(struct cyclades_port *info) +static void cy_set_line_char(struct cyclades_port *info, struct tty_struct *tty) { struct cyclades_card *card; unsigned long flags; @@ -2967,28 +2974,26 @@ static void set_line_char(struct cyclades_port *info) int baud, baud_rate = 0; int i; - if (!info->port.tty || !info->port.tty->termios) + if (!tty->termios) /* XXX can this happen at all? */ return; if (info->line == -1) return; - cflag = info->port.tty->termios->c_cflag; - iflag = info->port.tty->termios->c_iflag; + cflag = tty->termios->c_cflag; + iflag = tty->termios->c_iflag; /* * Set up the tty->alt_speed kludge */ - if (info->port.tty) { - if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI) - info->port.tty->alt_speed = 57600; - if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI) - info->port.tty->alt_speed = 115200; - if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI) - info->port.tty->alt_speed = 230400; - if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP) - info->port.tty->alt_speed = 460800; - } + if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI) + tty->alt_speed = 57600; + if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI) + tty->alt_speed = 115200; + if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI) + tty->alt_speed = 230400; + if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP) + tty->alt_speed = 460800; card = info->card; channel = info->line - card->first_line; @@ -2998,7 +3003,7 @@ static void set_line_char(struct cyclades_port *info) index = card->bus_index; /* baud rate */ - baud = tty_get_baud_rate(info->port.tty); + baud = tty_get_baud_rate(tty); if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) { if (info->custom_divisor) @@ -3123,9 +3128,8 @@ static void set_line_char(struct cyclades_port *info) /* set line characteristics according configuration */ - cy_writeb(base_addr + (CySCHR1 << index), - START_CHAR(info->port.tty)); - cy_writeb(base_addr + (CySCHR2 << index), STOP_CHAR(info->port.tty)); + cy_writeb(base_addr + (CySCHR1 << index), START_CHAR(tty)); + cy_writeb(base_addr + (CySCHR2 << index), STOP_CHAR(tty)); cy_writeb(base_addr + (CyCOR1 << index), info->cor1); cy_writeb(base_addr + (CyCOR2 << index), info->cor2); cy_writeb(base_addr + (CyCOR3 << index), info->cor3); @@ -3141,7 +3145,7 @@ static void set_line_char(struct cyclades_port *info) (info->default_timeout ? info->default_timeout : 0x02)); /* 10ms rx timeout */ - if (C_CLOCAL(info->port.tty)) { + if (C_CLOCAL(tty)) { /* without modem intr */ cy_writeb(base_addr + (CySRER << index), readb(base_addr + (CySRER << index)) | CyMdmCh); @@ -3204,8 +3208,7 @@ static void set_line_char(struct cyclades_port *info) #endif } - if (info->port.tty) - clear_bit(TTY_IO_ERROR, &info->port.tty->flags); + clear_bit(TTY_IO_ERROR, &tty->flags); spin_unlock_irqrestore(&card->card_lock, flags); } else { @@ -3224,7 +3227,7 @@ static void set_line_char(struct cyclades_port *info) ch_ctrl = &(zfw_ctrl->ch_ctrl[channel]); /* baud rate */ - baud = tty_get_baud_rate(info->port.tty); + baud = tty_get_baud_rate(tty); if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) { if (info->custom_divisor) @@ -3335,8 +3338,7 @@ static void set_line_char(struct cyclades_port *info) "was %x\n", info->line, retval); } - if (info->port.tty) - clear_bit(TTY_IO_ERROR, &info->port.tty->flags); + clear_bit(TTY_IO_ERROR, &tty->flags); } } /* set_line_char */ @@ -3365,7 +3367,7 @@ get_serial_info(struct cyclades_port *info, } /* get_serial_info */ static int -set_serial_info(struct cyclades_port *info, +cy_set_serial_info(struct cyclades_port *info, struct tty_struct *tty, struct serial_struct __user *new_info) { struct serial_struct new_serial; @@ -3403,10 +3405,10 @@ set_serial_info(struct cyclades_port *info, check_and_exit: if (info->port.flags & ASYNC_INITIALIZED) { - set_line_char(info); + cy_set_line_char(info, tty); return 0; } else { - return startup(info); + return cy_startup(info, tty); } } /* set_serial_info */ @@ -3955,7 +3957,7 @@ cy_ioctl(struct tty_struct *tty, struct file *file, ret_val = get_serial_info(info, argp); break; case TIOCSSERIAL: - ret_val = set_serial_info(info, argp); + ret_val = cy_set_serial_info(info, tty, argp); break; case TIOCSERGETLSR: /* Get line status register */ ret_val = get_lsr_info(info, argp); @@ -4055,7 +4057,7 @@ static void cy_set_termios(struct tty_struct *tty, struct ktermios *old_termios) printk(KERN_DEBUG "cyc:cy_set_termios ttyC%d\n", info->line); #endif - set_line_char(info); + cy_set_line_char(info, tty); if ((old_termios->c_cflag & CRTSCTS) && !(tty->termios->c_cflag & CRTSCTS)) { @@ -4299,13 +4301,13 @@ static void cy_hangup(struct tty_struct *tty) return; cy_flush_buffer(tty); - shutdown(info); + cy_shutdown(info, tty); info->port.count = 0; #ifdef CY_DEBUG_COUNT printk(KERN_DEBUG "cyc:cy_hangup (%d): setting count to 0\n", current->pid); #endif - info->port.tty = NULL; + tty_port_tty_set(&info->port, NULL); info->port.flags &= ~ASYNC_NORMAL_ACTIVE; wake_up_interruptible(&info->port.open_wait); } /* cy_hangup */ @@ -5191,18 +5193,30 @@ static int cyclades_proc_show(struct seq_file *m, void *v) for (j = 0; j < cy_card[i].nports; j++) { info = &cy_card[i].ports[j]; - if (info->port.count) + if (info->port.count) { + /* XXX is the ldisc num worth this? */ + struct tty_struct *tty; + struct tty_ldisc *ld; + int num = 0; + tty = tty_port_tty_get(&info->port); + if (tty) { + ld = tty_ldisc_ref(tty); + if (ld) { + num = ld->ops->num; + tty_ldisc_deref(ld); + } + tty_kref_put(tty); + } seq_printf(m, "%3d %8lu %10lu %8lu " - "%10lu %8lu %9lu %6ld\n", info->line, + "%10lu %8lu %9lu %6d\n", info->line, (cur_jifs - info->idle_stats.in_use) / HZ, info->idle_stats.xmit_bytes, (cur_jifs - info->idle_stats.xmit_idle)/ HZ, info->idle_stats.recv_bytes, (cur_jifs - info->idle_stats.recv_idle)/ HZ, info->idle_stats.overruns, - /* FIXME: double check locking */ - (long)info->port.tty->ldisc->ops->num); - else + num); + } else seq_printf(m, "%3d %8lu %10lu %8lu " "%10lu %8lu %9lu %6ld\n", info->line, 0L, 0L, 0L, 0L, 0L, 0L, 0L);