[PATCH 04/12] mxser: Use the new locking rules to fix setserialproperly
From: Alan Cox
Date: Wed Nov 18 2009 - 09:32:01 EST
Propogate the init/shutdown mutex through the setserial logic. Use the proper
locks for the various bits still using the BKL. Kill the BKL in this driver.
Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---
drivers/char/mxser.c | 145 +++++++++++++++++++++++++++-----------------------
1 files changed, 78 insertions(+), 67 deletions(-)
diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c
index 9dac516..4c803c7 100644
--- a/drivers/char/mxser.c
+++ b/drivers/char/mxser.c
@@ -23,7 +23,6 @@
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
-#include <linux/smp_lock.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
@@ -1229,6 +1228,7 @@ static int mxser_set_serial_info(struct tty_struct *tty,
struct serial_struct __user *new_info)
{
struct mxser_port *info = tty->driver_data;
+ struct tty_port *port = &info->port;
struct serial_struct new_serial;
speed_t baud;
unsigned long sl_flags;
@@ -1244,7 +1244,7 @@ static int mxser_set_serial_info(struct tty_struct *tty,
new_serial.port != info->ioaddr)
return -EINVAL;
- flags = info->port.flags & ASYNC_SPD_MASK;
+ flags = port->flags & ASYNC_SPD_MASK;
if (!capable(CAP_SYS_ADMIN)) {
if ((new_serial.baud_base != info->baud_base) ||
@@ -1258,16 +1258,17 @@ static int mxser_set_serial_info(struct tty_struct *tty,
* OK, past this point, all the error checking has been done.
* At this point, we start making changes.....
*/
- info->port.flags = ((info->port.flags & ~ASYNC_FLAGS) |
+ port->flags = ((port->flags & ~ASYNC_FLAGS) |
(new_serial.flags & ASYNC_FLAGS));
- info->port.close_delay = new_serial.close_delay * HZ / 100;
- info->port.closing_wait = new_serial.closing_wait * HZ / 100;
- tty->low_latency = (info->port.flags & ASYNC_LOW_LATENCY)
- ? 1 : 0;
- if ((info->port.flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
+ port->close_delay = new_serial.close_delay * HZ / 100;
+ port->closing_wait = new_serial.closing_wait * HZ / 100;
+ tty->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+ if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
(new_serial.baud_base != info->baud_base ||
new_serial.custom_divisor !=
info->custom_divisor)) {
+ if (new_serial.custom_divisor == 0)
+ return -EINVAL;
baud = new_serial.baud_base / new_serial.custom_divisor;
tty_encode_baud_rate(tty, baud, baud);
}
@@ -1277,18 +1278,16 @@ static int mxser_set_serial_info(struct tty_struct *tty,
process_txrx_fifo(info);
- if (info->port.flags & ASYNC_INITIALIZED) {
- if (flags != (info->port.flags & ASYNC_SPD_MASK)) {
+ if (test_bit(ASYNCB_INITIALIZED, &port->flags)) {
+ if (flags != (port->flags & ASYNC_SPD_MASK)) {
spin_lock_irqsave(&info->slock, sl_flags);
mxser_change_speed(tty, NULL);
spin_unlock_irqrestore(&info->slock, sl_flags);
}
} else {
- mutex_lock(&info->port.mutex);
- retval = mxser_activate(&info->port, tty);
+ retval = mxser_activate(port, tty);
if (retval == 0)
- set_bit(ASYNCB_INITIALIZED, &info->port.flags);
- mutex_unlock(&info->port.mutex);
+ set_bit(ASYNCB_INITIALIZED, &port->flags);
}
return retval;
}
@@ -1478,7 +1477,8 @@ static int __init mxser_read_register(int port, unsigned short *regs)
static int mxser_ioctl_special(unsigned int cmd, void __user *argp)
{
- struct mxser_port *port;
+ struct mxser_port *ip;
+ struct tty_port *port;
struct tty_struct *tty;
int result, status;
unsigned int i, j;
@@ -1494,38 +1494,39 @@ static int mxser_ioctl_special(unsigned int cmd, void __user *argp)
case MOXA_CHKPORTENABLE:
result = 0;
- lock_kernel();
for (i = 0; i < MXSER_BOARDS; i++)
for (j = 0; j < MXSER_PORTS_PER_BOARD; j++)
if (mxser_boards[i].ports[j].ioaddr)
result |= (1 << i);
- unlock_kernel();
return put_user(result, (unsigned long __user *)argp);
case MOXA_GETDATACOUNT:
- lock_kernel();
+ /* The receive side is locked by port->slock but it isn't
+ clear that an exact snapshot is worth copying here */
if (copy_to_user(argp, &mxvar_log, sizeof(mxvar_log)))
ret = -EFAULT;
- unlock_kernel();
return ret;
case MOXA_GETMSTATUS: {
struct mxser_mstatus ms, __user *msu = argp;
- lock_kernel();
for (i = 0; i < MXSER_BOARDS; i++)
for (j = 0; j < MXSER_PORTS_PER_BOARD; j++) {
- port = &mxser_boards[i].ports[j];
+ ip = &mxser_boards[i].ports[j];
+ port = &ip->port;
memset(&ms, 0, sizeof(ms));
- if (!port->ioaddr)
+ mutex_lock(&port->mutex);
+ if (!ip->ioaddr)
goto copy;
- tty = tty_port_tty_get(&port->port);
+ tty = tty_port_tty_get(port);
if (!tty || !tty->termios)
- ms.cflag = port->normal_termios.c_cflag;
+ ms.cflag = ip->normal_termios.c_cflag;
else
ms.cflag = tty->termios->c_cflag;
tty_kref_put(tty);
- status = inb(port->ioaddr + UART_MSR);
+ spin_lock_irq(&ip->slock);
+ status = inb(ip->ioaddr + UART_MSR);
+ spin_unlock_irq(&ip->slock);
if (status & UART_MSR_DCD)
ms.dcd = 1;
if (status & UART_MSR_DSR)
@@ -1533,13 +1534,11 @@ static int mxser_ioctl_special(unsigned int cmd, void __user *argp)
if (status & UART_MSR_CTS)
ms.cts = 1;
copy:
- if (copy_to_user(msu, &ms, sizeof(ms))) {
- unlock_kernel();
+ mutex_unlock(&port->mutex);
+ if (copy_to_user(msu, &ms, sizeof(ms)))
return -EFAULT;
- }
msu++;
}
- unlock_kernel();
return 0;
}
case MOXA_ASPP_MON_EXT: {
@@ -1551,41 +1550,48 @@ static int mxser_ioctl_special(unsigned int cmd, void __user *argp)
if (!me)
return -ENOMEM;
- lock_kernel();
for (i = 0, p = 0; i < MXSER_BOARDS; i++) {
for (j = 0; j < MXSER_PORTS_PER_BOARD; j++, p++) {
if (p >= ARRAY_SIZE(me->rx_cnt)) {
i = MXSER_BOARDS;
break;
}
- port = &mxser_boards[i].ports[j];
- if (!port->ioaddr)
+ ip = &mxser_boards[i].ports[j];
+ port = &ip->port;
+
+ mutex_lock(&port->mutex);
+ if (!ip->ioaddr) {
+ mutex_unlock(&port->mutex);
continue;
+ }
- status = mxser_get_msr(port->ioaddr, 0, p);
+ spin_lock_irq(&ip->slock);
+ status = mxser_get_msr(ip->ioaddr, 0, p);
if (status & UART_MSR_TERI)
- port->icount.rng++;
+ ip->icount.rng++;
if (status & UART_MSR_DDSR)
- port->icount.dsr++;
+ ip->icount.dsr++;
if (status & UART_MSR_DDCD)
- port->icount.dcd++;
+ ip->icount.dcd++;
if (status & UART_MSR_DCTS)
- port->icount.cts++;
+ ip->icount.cts++;
- port->mon_data.modem_status = status;
- me->rx_cnt[p] = port->mon_data.rxcnt;
- me->tx_cnt[p] = port->mon_data.txcnt;
- me->up_rxcnt[p] = port->mon_data.up_rxcnt;
- me->up_txcnt[p] = port->mon_data.up_txcnt;
+ ip->mon_data.modem_status = status;
+ me->rx_cnt[p] = ip->mon_data.rxcnt;
+ me->tx_cnt[p] = ip->mon_data.txcnt;
+ me->up_rxcnt[p] = ip->mon_data.up_rxcnt;
+ me->up_txcnt[p] = ip->mon_data.up_txcnt;
me->modem_status[p] =
- port->mon_data.modem_status;
- tty = tty_port_tty_get(&port->port);
+ ip->mon_data.modem_status;
+ spin_unlock_irq(&ip->slock);
+
+ tty = tty_port_tty_get(&ip->port);
if (!tty || !tty->termios) {
- cflag = port->normal_termios.c_cflag;
- iflag = port->normal_termios.c_iflag;
- me->baudrate[p] = tty_termios_baud_rate(&port->normal_termios);
+ cflag = ip->normal_termios.c_cflag;
+ iflag = ip->normal_termios.c_iflag;
+ me->baudrate[p] = tty_termios_baud_rate(&ip->normal_termios);
} else {
cflag = tty->termios->c_cflag;
iflag = tty->termios->c_iflag;
@@ -1604,16 +1610,15 @@ static int mxser_ioctl_special(unsigned int cmd, void __user *argp)
if (iflag & (IXON | IXOFF))
me->flowctrl[p] |= 0x0C;
- if (port->type == PORT_16550A)
+ if (ip->type == PORT_16550A)
me->fifo[p] = 1;
- opmode = inb(port->opmode_ioaddr) >>
- ((p % 4) * 2);
+ opmode = inb(ip->opmode_ioaddr)>>((p % 4) * 2);
opmode &= OP_MODE_MASK;
me->iftype[p] = opmode;
+ mutex_unlock(&port->mutex);
}
}
- unlock_kernel();
if (copy_to_user(argp, me, sizeof(*me)))
ret = -EFAULT;
kfree(me);
@@ -1650,6 +1655,7 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct mxser_port *info = tty->driver_data;
+ struct tty_port *port = &info->port;
struct async_icount cnow;
unsigned long flags;
void __user *argp = (void __user *)arg;
@@ -1674,20 +1680,20 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
opmode != RS422_MODE &&
opmode != RS485_4WIRE_MODE)
return -EFAULT;
- lock_kernel();
mask = ModeMask[p];
shiftbit = p * 2;
+ spin_lock_irq(&info->slock);
val = inb(info->opmode_ioaddr);
val &= mask;
val |= (opmode << shiftbit);
outb(val, info->opmode_ioaddr);
- unlock_kernel();
+ spin_unlock_irq(&info->slock);
} else {
- lock_kernel();
shiftbit = p * 2;
+ spin_lock_irq(&info->slock);
opmode = inb(info->opmode_ioaddr) >> shiftbit;
+ spin_unlock_irq(&info->slock);
opmode &= OP_MODE_MASK;
- unlock_kernel();
if (put_user(opmode, (int __user *)argp))
return -EFAULT;
}
@@ -1700,14 +1706,14 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
switch (cmd) {
case TIOCGSERIAL:
- lock_kernel();
+ mutex_lock(&port->mutex);
retval = mxser_get_serial_info(tty, argp);
- unlock_kernel();
+ mutex_unlock(&port->mutex);
return retval;
case TIOCSSERIAL:
- lock_kernel();
+ mutex_lock(&port->mutex);
retval = mxser_set_serial_info(tty, argp);
- unlock_kernel();
+ mutex_unlock(&port->mutex);
return retval;
case TIOCSERGETLSR: /* Get line status register */
return mxser_get_lsr_info(info, argp);
@@ -1753,31 +1759,33 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
case MOXA_HighSpeedOn:
return put_user(info->baud_base != 115200 ? 1 : 0, (int __user *)argp);
case MOXA_SDS_RSTICOUNTER:
- lock_kernel();
+ spin_lock_irq(&info->slock);
info->mon_data.rxcnt = 0;
info->mon_data.txcnt = 0;
- unlock_kernel();
+ spin_unlock_irq(&info->slock);
return 0;
case MOXA_ASPP_OQUEUE:{
int len, lsr;
- lock_kernel();
len = mxser_chars_in_buffer(tty);
+ spin_lock(&info->slock);
lsr = inb(info->ioaddr + UART_LSR) & UART_LSR_THRE;
+ spin_unlock_irq(&info->slock);
len += (lsr ? 0 : 1);
- unlock_kernel();
return put_user(len, (int __user *)argp);
}
case MOXA_ASPP_MON: {
int mcr, status;
- lock_kernel();
+ spin_lock(&info->slock);
status = mxser_get_msr(info->ioaddr, 1, tty->index);
mxser_check_modem_status(tty, info, status);
mcr = inb(info->ioaddr + UART_MCR);
+ spin_unlock(&info->slock);
+
if (mcr & MOXA_MUST_MCR_XON_FLAG)
info->mon_data.hold_reason &= ~NPPI_NOTIFY_XOFFHOLD;
else
@@ -1792,7 +1800,7 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
info->mon_data.hold_reason |= NPPI_NOTIFY_CTSHOLD;
else
info->mon_data.hold_reason &= ~NPPI_NOTIFY_CTSHOLD;
- unlock_kernel();
+
if (copy_to_user(argp, &info->mon_data,
sizeof(struct mxser_mon)))
return -EFAULT;
@@ -1951,6 +1959,7 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
{
struct mxser_port *info = tty->driver_data;
unsigned long orig_jiffies, char_time;
+ unsigned long flags;
int lsr;
if (info->type == PORT_UNKNOWN)
@@ -1990,19 +1999,21 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
timeout, char_time);
printk("jiff=%lu...", jiffies);
#endif
- lock_kernel();
+ spin_lock_irqsave(&info->slock, flags);
while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
#endif
+ spin_unlock_irqrestore(&info->slock, flags);
schedule_timeout_interruptible(char_time);
if (signal_pending(current))
break;
if (timeout && time_after(jiffies, orig_jiffies + timeout))
break;
+ spin_lock_irqsave(&info->slock, flags);
}
+ spin_unlock_irqrestore(&info->slock, flags);
set_current_state(TASK_RUNNING);
- unlock_kernel();
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
--
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