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authorArnd Bergmann <arnd@arndb.de>2010-06-18 14:58:07 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 13:47:44 -0700
commit11dbf203922dc70a340417c895c95fb96f6b7068 (patch)
tree7c79b79c74a184a7d67d3f54af4e37dee930d11e /drivers/char/pty.c
parenta0821df6e57c8af0053963d0d08c8d5198ea077d (diff)
downloadblackbird-obmc-linux-11dbf203922dc70a340417c895c95fb96f6b7068.tar.gz
blackbird-obmc-linux-11dbf203922dc70a340417c895c95fb96f6b7068.zip
tty: avoid recursive BTM in pty_close
When the console has been redirected, a hangup of the tty will cause tty_release to be called under the big tty_mutex, which leads to a deadlock because hangup is also called under the BTM. This moves the BTM deeper into the tty_hangup function so we can close the redirected tty without holding the BTM. In case of pty, we now need to drop the BTM before calling tty_vhangup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Kacur <jkacur@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/char/pty.c')
-rw-r--r--drivers/char/pty.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index f2d7a76fab54..ad46eae1f9bb 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -62,7 +62,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
if (tty->driver == ptm_driver)
devpts_pty_kill(tty->link);
#endif
- tty_vhangup_locked(tty->link);
+ tty_unlock();
+ tty_vhangup(tty->link);
+ tty_lock();
}
}
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