Jiri Slaby a38df1a013 TTY: pty, fix pty counting ... commit 24d406a6bf upstream. tty_operations->remove is normally called like: queue_release_one_tty ->tty_shutdown ->tty_driver_remove_tty ->tty_operations->remove However tty_shutdown() is called from queue_release_one_tty() only if tty_operations->shutdown is NULL. But for pty, it is not. pty_unix98_shutdown() is used there as ->shutdown. So tty_operations->remove of pty (i.e. pty_unix98_remove()) is never called. This results in invalid pty_count. I.e. what can be seen in /proc/sys/kernel/pty/nr. I see this was already reported at: https://lkml.org/lkml/2009/11/5/370 But it was not fixed since then. This patch is kind of a hackish way. The problem lies in ->install. We allocate there another tty (so-called tty->link). So ->install is called once, but ->remove twice, for both tty and tty->link. The fix here is to count both tty and tty->link and divide the count by 2 for user. And to have ->remove called, let's make tty_driver_remove_tty() global and call that from pty_unix98_shutdown() (tty_operations->shutdown). While at it, let's document that when ->shutdown is defined, tty_shutdown() is not called. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>		2011-10-03 11:39:49 -07:00
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acpi	Merge branches 'd3cold', 'bugzilla-37412' and 'bugzilla-38152' into release	2011-07-14 00:16:38 -04:00
asm-generic	Merge branches 'gpio/merge' and 'spi/merge' of git://git.secretlab.ca/git/linux-2.6	2011-06-17 10:36:32 -07:00
crypto
drm	drm/i915: Fix typo in DRM_I915_OVERLAY_PUT_IMAGE ioctl define	2011-08-15 18:31:35 -07:00
keys
linux	TTY: pty, fix pty counting	2011-10-03 11:39:49 -07:00
math-emu
media	[media] tuner-core/v4l2-subdev: document that the type field has to be filled in	2011-07-07 15:04:23 -03:00
mtd
net	ipv6: make fragment identifications less predictable	2011-08-15 18:31:37 -07:00
pcmcia
rdma	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband	2011-05-26 12:13:57 -07:00
rxrpc
scsi	[SCSI] libsas: Add option for SATA soft reset	2011-05-26 22:49:33 -05:00
sound	ALSA: sb16 - Fix build errors on MIPS and others with 13bit ioctl size	2011-06-30 15:33:57 +02:00
target	[SCSI] target: Convert REPORT_LUNs to use int_to_scsilun	2011-05-24 13:02:42 -04:00
trace	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4	2011-06-21 10:22:35 -07:00
video	Merge branches 'common/fbdev' and 'common/fbdev-meram' of master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6	2011-05-24 15:49:57 +09:00
xen	xen: allow enable use of VGA console on dom0	2011-08-15 18:31:34 -07:00
Kbuild