From d684779335856d8177514b42a801d46088d897b0 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Sun, 12 Jul 2015 22:49:13 -0400 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 4d5e8409769c..4d5937c185c1 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -26,6 +26,12 @@ #include #include +#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: -- 2.20.1