Commit d6847793 authored Jul 12, 2015 by Peter Hurley Committed by Greg Kroah-Hartman Jul 23, 2015

pty: Add debug message for ptmx open



Opens of /dev/ptmx don't use tty_open() so debug messages are
not printed for those opens; print a debug message with the
open count (which must always be 1) if TTY_DEBUG_HANGUP is defined.

NB: Each tty core source file undefs support for debug messages.
The relevant source file must be patched/edited to enable these
messages.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent fb6edc91

drivers/tty/pty.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,12 @@
		#include <linux/mutex.h>
		#include <linux/poll.h>

		#undef TTY_DEBUG_HANGUP
		#ifdef TTY_DEBUG_HANGUP
		# define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
		#else
		# define tty_debug_hangup(tty, f, args...) do {} while (0)
		#endif

		#ifdef CONFIG_UNIX98_PTYS
		static struct tty_driver *ptm_driver;
		@@ -779,6 +785,8 @@ static int ptmx_open(struct inode inode, struct file filp)
		if (retval)
		goto err_release;

		tty_debug_hangup(tty, "(tty count=%d)\n", tty->count);

		tty_unlock(tty);
		return 0;
		err_release: