On Monday 28 March 2005 06:02, Russell King wrote:
> Looks like something in the input layer went bang. The code in
> serport_ldisc_write_wakeup is:
>
> 0: 8b 80 a8 09 00 00 mov 0x9a8(%eax),%eax
> 6: 8b 40 14 mov 0x14(%eax),%eax
> 9: 8b 50 70 mov 0x70(%eax),%edx <====
> c: 85 d2 test %edx,%edx
> e: 74 09 je 0x19
>
> and the marked line exploded on you. The above instructions correspond
> with:
>
> 0: struct serport *sp = (struct serport *) tty->disc_data;
> 6: serio_drv_write_wakeup(sp->serio);
> 9: if (serio->drv
>
> So, "serio" was this strange 0xf3a6cdf8 value. But why? One for the
> input people I think.
Reuben, could you please try the patch below? Thanks!
Russell, could you please tell me if ldisc->write_wakeup (tty_wakwup) and
ldisc->read are allowed to be called from an IRQ context? IOW I wonder if
I can use spil_lock_bh instead of spil_lock_irqsave to protect serport
flags.
--
Dmitry
serport.c | 98 +++++++++++++++++++++++++++++++++++++++++++-------------------
1 files changed, 68 insertions(+), 30 deletions(-)
Index: dtor/drivers/input/serio/serport.c
===================================================================
--- dtor.orig/drivers/input/serio/serport.c
+++ dtor/drivers/input/serio/serport.c
@@ -27,11 +27,15 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS_LDISC(N_MOUSE);
#define SERPORT_BUSY 1
+#define SERPORT_ACTIVE 2
+#define SERPORT_DEAD 3
struct serport {
struct tty_struct *tty;
wait_queue_head_t wait;
struct serio *serio;
+ struct serio_device_id id;
+ spinlock_t lock;
unsigned long flags;
};
@@ -45,11 +49,29 @@ static int serport_serio_write(struct se
return -(serport->tty->driver->write(serport->tty, &data, 1) != 1);
}
+static int serport_serio_open(struct serio *serio)
+{
+ struct serport *serport = serio->port_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&serport->lock, flags);
+ set_bit(SERPORT_ACTIVE, &serport->flags);
+ spin_unlock_irqrestore(&serport->lock, flags);
+
+ return 0;
+}
+
+
static void serport_serio_close(struct serio *serio)
{
struct serport *serport = serio->port_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&serport->lock, flags);
+ clear_bit(SERPORT_ACTIVE, &serport->flags);
+ set_bit(SERPORT_DEAD, &serport->flags);
+ spin_unlock_irqrestore(&serport->lock, flags);
- serport->serio->id.type = 0;
wake_up_interruptible(&serport->wait);
}
@@ -61,36 +83,21 @@ static void serport_serio_close(struct s
static int serport_ldisc_open(struct tty_struct *tty)
{
struct serport *serport;
- struct serio *serio;
- char name[64];
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- serport = kmalloc(sizeof(struct serport), GFP_KERNEL);
- serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
- if (unlikely(!serport || !serio)) {
- kfree(serport);
- kfree(serio);
+ serport = kcalloc(1, sizeof(struct serport), GFP_KERNEL);
+ if (!serport)
return -ENOMEM;
- }
- memset(serport, 0, sizeof(struct serport));
- serport->serio = serio;
- set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
serport->tty = tty;
- tty->disc_data = serport;
-
- memset(serio, 0, sizeof(struct serio));
- strlcpy(serio->name, "Serial port", sizeof(serio->name));
- snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
- serio->id.type = SERIO_RS232;
- serio->write = serport_serio_write;
- serio->close = serport_serio_close;
- serio->port_data = serport;
-
+ spin_lock_init(&serport->lock);
init_waitqueue_head(&serport->wait);
+ tty->disc_data = serport;
+ set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+
return 0;
}
@@ -100,7 +107,8 @@ static int serport_ldisc_open(struct tty
static void serport_ldisc_close(struct tty_struct *tty)
{
- struct serport *serport = (struct serport*) tty->disc_data;
+ struct serport *serport = (struct serport *) tty->disc_data;
+
kfree(serport);
}
@@ -116,9 +124,19 @@ static void serport_ldisc_close(struct t
static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
{
struct serport *serport = (struct serport*) tty->disc_data;
+ unsigned long flags;
int i;
+
+ spin_lock_irqsave(&serport->lock, flags);
+
+ if (!test_bit(SERPORT_ACTIVE, &serport->flags))
+ goto out;
+
for (i = 0; i < count; i++)
serio_interrupt(serport->serio, cp[i], 0, NULL);
+
+out:
+ spin_unlock_irqrestore(&serport->lock, flags);
}
/*
@@ -141,16 +159,33 @@ static int serport_ldisc_room(struct tty
static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
{
struct serport *serport = (struct serport*) tty->disc_data;
+ struct serio *serio;
char name[64];
if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
return -EBUSY;
+ serport->serio = serio = kcalloc(1, sizeof(struct serio), GFP_KERNEL);
+ if (!serio)
+ return -ENOMEM;
+
+ strlcpy(serio->name, "Serial port", sizeof(serio->name));
+ snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
+ serio->id = serport->id;
+ serio->id.type = SERIO_RS232;
+ serio->write = serport_serio_write;
+ serio->open = serport_serio_open;
+ serio->close = serport_serio_close;
+ serio->port_data = serport;
+
serio_register_port(serport->serio);
printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));
- wait_event_interruptible(serport->wait, !serport->serio->id.type);
+
+ wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
serio_unregister_port(serport->serio);
+ serport->serio = NULL;
+ clear_bit(SERPORT_DEAD, &serport->flags);
clear_bit(SERPORT_BUSY, &serport->flags);
return 0;
@@ -163,16 +198,15 @@ static ssize_t serport_ldisc_read(struct
static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg)
{
struct serport *serport = (struct serport*) tty->disc_data;
- struct serio *serio = serport->serio;
unsigned long type;
if (cmd == SPIOCSTYPE) {
if (get_user(type, (unsigned long __user *) arg))
return -EFAULT;
- serio->id.proto = type & 0x000000ff;
- serio->id.id = (type & 0x0000ff00) >> 8;
- serio->id.extra = (type & 0x00ff0000) >> 16;
+ serport->id.proto = type & 0x000000ff;
+ serport->id.id = (type & 0x0000ff00) >> 8;
+ serport->id.extra = (type & 0x00ff0000) >> 16;
return 0;
}
@@ -182,9 +216,13 @@ static int serport_ldisc_ioctl(struct tt
static void serport_ldisc_write_wakeup(struct tty_struct * tty)
{
- struct serport *sp = (struct serport *) tty->disc_data;
+ struct serport *serport = (struct serport *) tty->disc_data;
+ unsigned long flags;
- serio_drv_write_wakeup(sp->serio);
+ spin_lock_irqsave(&serport->lock, flags);
+ if (test_bit(SERPORT_ACTIVE, &serport->flags))
+ serio_drv_write_wakeup(serport->serio);
+ spin_unlock_irqrestore(&serport->lock, flags);
}
/*
-
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