X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=91f530c6170ee73ba76f3b12bfd517518289fcaa;hb=9bf4aaab3e101692164d49b7ca357651eb691cb6;hp=0c762379a2d9f2b79a09510ad84d63839ca3f91a;hpb=db216c3d5e4c040e557a50f8f5d35d5c415e8c1c;p=linux-2.6.git diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 0c762379a..91f530c61 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -91,6 +91,7 @@ #include #include #include +#include #include #include @@ -128,6 +129,8 @@ DECLARE_MUTEX(tty_sem); #ifdef CONFIG_UNIX98_PTYS extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ extern int pty_limit; /* Config limit on Unix98 ptys */ +static DEFINE_IDR(allocated_ptys); +static DECLARE_MUTEX(allocated_ptys_lock); #endif extern void disable_early_printk(void); @@ -342,18 +345,12 @@ EXPORT_SYMBOL(tty_check_change); static ssize_t hung_up_tty_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { - /* Can't seek (pread) on ttys. */ - if (ppos != &file->f_pos) - return -ESPIPE; return 0; } static ssize_t hung_up_tty_write(struct file * file, const char __user * buf, size_t count, loff_t *ppos) { - /* Can't seek (pwrite) on ttys. */ - if (ppos != &file->f_pos) - return -ESPIPE; return -EIO; } @@ -645,10 +642,6 @@ static ssize_t tty_read(struct file * file, char __user * buf, size_t count, struct tty_struct * tty; struct inode *inode; - /* Can't seek (pread) on ttys. */ - if (ppos != &file->f_pos) - return -ESPIPE; - tty = (struct tty_struct *)file->private_data; inode = file->f_dentry->d_inode; if (tty_paranoia_check(tty, inode, "tty_read")) @@ -723,10 +716,6 @@ static ssize_t tty_write(struct file * file, const char __user * buf, size_t cou struct tty_struct * tty; struct inode *inode = file->f_dentry->d_inode; - /* Can't seek (pwrite) on ttys. */ - if (ppos != &file->f_pos) - return -ESPIPE; - tty = (struct tty_struct *)file->private_data; if (tty_paranoia_check(tty, inode, "tty_write")) return -EIO; @@ -752,9 +741,6 @@ ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t if (p) { ssize_t res; - /* Can't seek (pwrite) on ttys. */ - if (ppos != &file->f_pos) - return -ESPIPE; res = vfs_write(p, buf, count, &p->f_pos); fput(p); return res; @@ -1065,6 +1051,7 @@ static void release_dev(struct file * filp) { struct tty_struct *tty, *o_tty; int pty_master, tty_closing, o_tty_closing, do_sleep; + int devpts_master, devpts; int idx; char buf[64]; @@ -1079,6 +1066,8 @@ static void release_dev(struct file * filp) idx = tty->index; pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER); + devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; + devpts_master = pty_master && devpts; o_tty = tty->link; #ifdef TTY_PARANOIA_CHECK @@ -1295,11 +1284,21 @@ static void release_dev(struct file * filp) 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 + /* Make this pty number available for reallocation */ + if (devpts) { + down(&allocated_ptys_lock); + idr_remove(&allocated_ptys, idx); + up(&allocated_ptys_lock); + } +#endif + } /* @@ -1322,8 +1321,13 @@ static int tty_open(struct inode * inode, struct file * filp) int index; dev_t device = inode->i_rdev; unsigned short saved_flags = filp->f_flags; + + nonseekable_open(inode, filp); retry_open: noctty = filp->f_flags & O_NOCTTY; + index = -1; + retval = 0; + if (device == MKDEV(TTYAUX_MAJOR,0)) { if (!current->signal->tty) return -ENXIO; @@ -1344,13 +1348,8 @@ retry_open: } #endif if (device == MKDEV(TTYAUX_MAJOR,1)) { - struct console *c = console_drivers; - for (c = console_drivers; c; c = c->next) { - if (!c->device) - continue; - driver = c->device(c, &index); - if (!driver) - continue; + driver = console_device(&index); + if (driver) { /* Don't let /dev/console block */ filp->f_flags |= O_NONBLOCK; noctty = 1; @@ -1361,24 +1360,40 @@ retry_open: #ifdef CONFIG_UNIX98_PTYS if (device == MKDEV(TTYAUX_MAJOR,2)) { + int idr_ret; + /* find a device that is not in use. */ - static int next_ptmx_dev = 0; - retval = -1; + down(&allocated_ptys_lock); + if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) { + up(&allocated_ptys_lock); + return -ENOMEM; + } + idr_ret = idr_get_new(&allocated_ptys, NULL, &index); + if (idr_ret < 0) { + up(&allocated_ptys_lock); + if (idr_ret == -EAGAIN) + return -ENOMEM; + return -EIO; + } + if (index >= pty_limit) { + idr_remove(&allocated_ptys, index); + up(&allocated_ptys_lock); + return -EIO; + } + up(&allocated_ptys_lock); + driver = ptm_driver; - while (driver->refcount < pty_limit) { - index = next_ptmx_dev; - next_ptmx_dev = (next_ptmx_dev+1) % driver->num; - if (!init_dev(driver, index, &tty)) - goto ptmx_found; /* ok! */ + retval = init_dev(driver, index, &tty); + if (retval) { + down(&allocated_ptys_lock); + idr_remove(&allocated_ptys, index); + up(&allocated_ptys_lock); + return retval; } - return -EIO; /* no free ptys */ - ptmx_found: + set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ - if (devpts_pty_new(tty->link)) { - /* BADNESS - need to destroy both ptm and pts! */ - return -ENOMEM; - } - noctty = 1; + if (devpts_pty_new(tty->link)) + retval = -ENOMEM; } else #endif { @@ -1400,10 +1415,12 @@ 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)) @@ -1415,6 +1432,14 @@ got_driver: tty->name); #endif +#ifdef CONFIG_UNIX98_PTYS + if (index != -1) { + down(&allocated_ptys_lock); + idr_remove(&allocated_ptys, index); + up(&allocated_ptys_lock); + } +#endif + release_dev(filp); if (retval != -ERESTARTSYS) return retval;