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authorKonstantin Khlebnikov <khlebnikov@openvz.org>2012-01-05 13:04:21 +0400
committerGreg Kroah-Hartman <gregkh@suse.de>2012-01-24 13:56:10 -0800
commit593a27c4b212e2afdf772a1f8dcb894e91bda0fa (patch)
tree6b670f6ec0ef138fcfa6e68f3b2a456f86941efd /drivers/tty/tty_io.c
parentdcd6c92267155e70a94b3927bce681ce74b80d1f (diff)
tty: cleanup prohibition of direct opening for unix98 pty master
cleanup hack added in v2.6.27-3203-g15582d3 comment from that patch: : pty: If the administrator creates a device for a ptmx slave we should not error : : 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> : Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> devpts_get_tty() returns non-null only for inodes on devpts, but there is no inodes for master-devices, /dev/ptmx (/dev/pts/ptmx) is the only way to open them. Thus we can completely forbid lookup for master-devices and eliminate that hack in tty_init_dev() because tty_open() will get EIO from tty_driver_lookup_tty(). Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/tty/tty_io.c')
-rw-r--r--drivers/tty/tty_io.c12
1 files changed, 2 insertions, 10 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index e41b9bbc107..fbcc1406380 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1365,7 +1365,6 @@ static int tty_reopen(struct tty_struct *tty)
* @driver: tty driver we are opening a device on
* @idx: device index
* @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
@@ -1385,18 +1384,11 @@ static int tty_reopen(struct tty_struct *tty)
* relaxed for the (most common) case of reopening a tty.
*/
-struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
- int first_ok)
+struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
{
struct tty_struct *tty;
int retval;
- /* Check if pty master is being opened multiple times */
- if (driver->subtype == PTY_TYPE_MASTER &&
- (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) {
- return ERR_PTR(-EIO);
- }
-
/*
* First time open is complex, especially for PTY devices.
* This code guarantees that either everything succeeds and the
@@ -1950,7 +1942,7 @@ retry_open:
if (retval)
tty = ERR_PTR(retval);
} else
- tty = tty_init_dev(driver, index, 0);
+ tty = tty_init_dev(driver, index);
mutex_unlock(&tty_mutex);
if (driver)