tty: core: Improve debug message content

Output the function name, tty name, and invariant failure (if applicable).
Add the tty count to the tty_open() message. Fix the disassociate_ctty()
message, which printed the NULL pointer and the wrong message.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Hurley 2015-07-12 22:49:07 -04:00 committed by Greg Kroah-Hartman
parent 4fef53518f
commit 3a6b02dc1f

View File

@ -531,7 +531,8 @@ static void __proc_set_tty(struct tty_struct *tty)
spin_unlock_irqrestore(&tty->ctrl_lock, flags);
tty->session = get_pid(task_session(current));
if (current->signal->tty) {
printk(KERN_DEBUG "tty not NULL!!\n");
printk(KERN_DEBUG "%s: %s: current tty %s not NULL!!\n",
__func__, tty->name, current->signal->tty->name);
tty_kref_put(current->signal->tty);
}
put_pid(current->signal->tty_old_pgrp);
@ -929,8 +930,7 @@ void disassociate_ctty(int on_exit)
tty_kref_put(tty);
} else {
#ifdef TTY_DEBUG_HANGUP
printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
" = NULL", tty);
printk(KERN_DEBUG "%s: no current tty\n", __func__);
#endif
}
@ -1712,8 +1712,8 @@ static int tty_release_checks(struct tty_struct *tty, int idx)
{
#ifdef TTY_PARANOIA_CHECK
if (idx < 0 || idx >= tty->driver->num) {
printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n",
__func__, tty->name);
printk(KERN_DEBUG "%s: %s: bad idx %d\n",
__func__, tty->name, idx);
return -1;
}
@ -1722,20 +1722,22 @@ static int tty_release_checks(struct tty_struct *tty, int idx)
return 0;
if (tty != tty->driver->ttys[idx]) {
printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n",
__func__, idx, tty->name);
printk(KERN_DEBUG "%s: %s: bad driver table[%d] = %p\n",
__func__, tty->name, idx, tty->driver->ttys[idx]);
return -1;
}
if (tty->driver->other) {
struct tty_struct *o_tty = tty->link;
if (o_tty != tty->driver->other->ttys[idx]) {
printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n",
__func__, idx, tty->name);
printk(KERN_DEBUG "%s: %s: bad other table[%d] = %p\n",
__func__, tty->name, idx,
tty->driver->other->ttys[idx]);
return -1;
}
if (o_tty->link != tty) {
printk(KERN_DEBUG "%s: bad pty pointers\n", __func__);
printk(KERN_DEBUG "%s: %s: bad link = %p\n",
__func__, tty->name, o_tty->link);
return -1;
}
}
@ -2106,7 +2108,8 @@ retry_open:
tty->driver->subtype == PTY_TYPE_MASTER)
noctty = 1;
#ifdef TTY_DEBUG_HANGUP
printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name);
printk(KERN_DEBUG "%s: %s: (tty count=%d)\n", __func__, tty->name,
tty->count);
#endif
if (tty->ops->open)
retval = tty->ops->open(tty, filp);
@ -2116,8 +2119,8 @@ retry_open:
if (retval) {
#ifdef TTY_DEBUG_HANGUP
printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__,
retval, tty->name);
printk(KERN_DEBUG "%s: %s: error %d, releasing...\n", __func__,
tty->name, retval);
#endif
tty_unlock(tty); /* need to call tty_release without BTM */
tty_release(inode, filp);