lkml.org 
[lkml]   [2008]   [Oct]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 51/80] pty: If the administrator creates a device for a ptmx slave we should not error
    Date
    From: Alan Cox <alan@redhat.com>

    The open path for ptmx slaves is via the ptmx device. Opening them any
    other way is not allowed. Vegard Nossum found that previously this was not
    the case and mknod foo c 128 42; cat foo would produce nasty diagnostics

    Signed-off-by: Alan Cox <alan@redhat.com>
    ---

    drivers/char/tty_io.c | 18 ++++++++++++------
    1 files changed, 12 insertions(+), 6 deletions(-)


    diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
    index f40298e..2e96ce0 100644
    --- a/drivers/char/tty_io.c
    +++ b/drivers/char/tty_io.c
    @@ -1227,7 +1227,8 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
    * init_dev - initialise a tty device
    * @driver: tty driver we are opening a device on
    * @idx: device index
    - * @tty: returned tty structure
    + * @ret_tty: returned tty structure
    + * @first_ok: ok to open a new device (used by ptmx)
    *
    * Prepare a tty device. This may not be a "new" clean device but
    * could also be an active device. The pty drivers require special
    @@ -1248,7 +1249,7 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
    */

    static int init_dev(struct tty_driver *driver, int idx,
    - struct tty_struct **ret_tty)
    + struct tty_struct **ret_tty, int first_ok)
    {
    struct tty_struct *tty, *o_tty;
    struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc;
    @@ -1279,6 +1280,11 @@ static int init_dev(struct tty_driver *driver, int idx,
    }
    if (tty) goto fast_track;

    + if (driver->subtype == PTY_TYPE_MASTER &&
    + (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) {
    + retval = -EIO;
    + goto end_init;
    + }
    /*
    * First time open is complex, especially for PTY devices.
    * This code guarantees that either everything succeeds and the
    @@ -1413,7 +1419,7 @@ static int init_dev(struct tty_driver *driver, int idx,

    if (retval)
    goto release_mem_out;
    - goto success;
    + goto success;

    /*
    * This fast open can be used if the tty is already open.
    @@ -1795,7 +1801,7 @@ static void release_dev(struct file *filp)
    }

    /**
    - * tty_open - open a tty device
    + * __tty_open - open a tty device
    * @inode: inode of device file
    * @filp: file pointer to tty
    *
    @@ -1874,7 +1880,7 @@ retry_open:
    return -ENODEV;
    }
    got_driver:
    - retval = init_dev(driver, index, &tty);
    + retval = init_dev(driver, index, &tty, 0);
    mutex_unlock(&tty_mutex);
    if (retval)
    return retval;
    @@ -1971,7 +1977,7 @@ static int __ptmx_open(struct inode *inode, struct file *filp)
    return index;

    mutex_lock(&tty_mutex);
    - retval = init_dev(ptm_driver, index, &tty);
    + retval = init_dev(ptm_driver, index, &tty, 1);
    mutex_unlock(&tty_mutex);

    if (retval)


    \
     
     \ /
      Last update: 2008-10-13 11:55    [W:0.024 / U:59.132 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site