tty: Add ldisc hangup debug messages (fc575ee6) · Commits · 戴 / test

drivers/tty/tty_ldisc.c

+19 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,17 @@
		#include <linux/uaccess.h>
		#include <linux/ratelimit.h>

		#undef LDISC_DEBUG_HANGUP

		#ifdef LDISC_DEBUG_HANGUP
		#define tty_ldisc_debug(tty, f, args...) ({ \
		char __b[64]; \
		printk(KERN_DEBUG "%s: %s: " f, __func__, tty_name(tty, __b), ##args); \
		})
		#else
		#define tty_ldisc_debug(tty, f, args...)
		#endif

		/*
		* This guards the refcounted line discipline lists. The lock
		* must be taken with irqs off because there are hangup path
		@@ -822,6 +833,8 @@ void tty_ldisc_hangup(struct tty_struct *tty)
		int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
		int err = 0;

		tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc);

		/*
		* FIXME! What are the locking issues here? This may me overdoing
		* things... This question is especially important now that we've
		@@ -878,6 +891,8 @@ void tty_ldisc_hangup(struct tty_struct *tty)
		mutex_unlock(&tty->ldisc_mutex);
		if (reset)
		tty_reset_termios(tty);

		tty_ldisc_debug(tty, "re-opened ldisc: %p\n", tty->ldisc);
		}

		/**
		@@ -944,6 +959,8 @@ void tty_ldisc_release(struct tty_struct tty, struct tty_struct o_tty)
		* it does not race with the set_ldisc code path.
		*/

		tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc);

		tty_ldisc_halt(tty, o_tty, MAX_SCHEDULE_TIMEOUT);

		tty_lock_pair(tty, o_tty);
		@@ -955,6 +972,8 @@ void tty_ldisc_release(struct tty_struct tty, struct tty_struct o_tty)
		tty_unlock_pair(tty, o_tty);
		/* And the memory resources remaining (buffers, termios) will be
		disposed of when the kref hits zero */

		tty_ldisc_debug(tty, "ldisc closed\n");
		}

		/**

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