From: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/char/tty_io.c | 46 ++++++++++++++++++++++++------------------
1 files changed, 27 insertions(+), 19 deletions(-)
diff -puN drivers/char/tty_io.c~dynpty-fix drivers/char/tty_io.c
--- 25/drivers/char/tty_io.c~dynpty-fix Fri May 28 17:01:33 2004
+++ 25-akpm/drivers/char/tty_io.c Fri May 28 17:01:33 2004
@@ -1068,6 +1068,7 @@ static void release_dev(struct file * fi
{
struct tty_struct *tty, *o_tty;
int pty_master, tty_closing, o_tty_closing, do_sleep;
+ int devpts_master;
int idx;
char buf[64];
@@ -1082,6 +1083,7 @@ static void release_dev(struct file * fi
idx = tty->index;
pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER);
+ devpts_master = pty_master && (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM);
o_tty = tty->link;
#ifdef TTY_PARANOIA_CHECK
@@ -1298,19 +1300,21 @@ static void release_dev(struct file * fi
o_tty->ldisc = ldiscs[N_TTY];
}
+ /*
+ * The release_mem function takes care of the details of clearing
+ * the slots and preserving the termios structure.
+ */
+ release_mem(tty, idx);
+
#ifdef CONFIG_UNIX98_PTYS
- if (filp->f_dentry->d_inode->i_rdev == MKDEV(TTYAUX_MAJOR,2)) {
+ /* Make this pty number available for reallocation */
+ if (devpts_master) {
down(&allocated_ptys_lock);
idr_remove(&allocated_ptys, idx);
up(&allocated_ptys_lock);
}
#endif
- /*
- * The release_mem function takes care of the details of clearing
- * the slots and preserving the termios structure.
- */
- release_mem(tty, idx);
}
/*
@@ -1330,11 +1334,15 @@ static int tty_open(struct inode * inode
struct tty_struct *tty;
int noctty, retval;
struct tty_driver *driver;
- int index = -1;
+ int index;
dev_t device = inode->i_rdev;
unsigned short saved_flags = filp->f_flags;
+
retry_open:
noctty = filp->f_flags & O_NOCTTY;
+ index = -1;
+ retval = 0;
+
if (device == MKDEV(TTYAUX_MAJOR,0)) {
if (!current->signal->tty)
return -ENXIO;
@@ -1392,22 +1400,20 @@ retry_open:
up(&allocated_ptys_lock);
return -EIO;
}
+ up(&allocated_ptys_lock);
+
driver = ptm_driver;
retval = init_dev(driver, index, &tty);
if (retval) {
+ down(&allocated_ptys_lock);
idr_remove(&allocated_ptys, index);
up(&allocated_ptys_lock);
return retval;
}
+
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
- if (devpts_pty_new(tty->link)) {
- /* BADNESS - need to destroy both ptm and pts! */
- idr_remove(&allocated_ptys, index);
- up(&allocated_ptys_lock);
- return -ENOMEM;
- }
- up(&allocated_ptys_lock);
- noctty = 1;
+ if (devpts_pty_new(tty->link))
+ retval = -ENOMEM;
} else
#endif
{
@@ -1429,10 +1435,12 @@ got_driver:
#ifdef TTY_DEBUG_HANGUP
printk(KERN_DEBUG "opening %s...", tty->name);
#endif
- if (tty->driver->open)
- retval = tty->driver->open(tty, filp);
- else
- retval = -ENODEV;
+ if (!retval) {
+ if (tty->driver->open)
+ retval = tty->driver->open(tty, filp);
+ else
+ retval = -ENODEV;
+ }
filp->f_flags = saved_flags;
if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
_