Commit 2116bda6 authored by Richard Weinberger's avatar Richard Weinberger
Browse files

um: Use tty_port in SIGWINCH handler 



The tty below tty_port might get destroyed by the tty layer
while we hold a reference to it.
So we have to carry tty_port around...

Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent cc4f0248

arch/um/drivers/chan.h

+1 −1
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ extern int console_write_chan(struct chan *chan, const char *buf, 
extern int console_open_chan(struct line *line, struct console *co);

extern void deactivate_chan(struct chan *chan, int irq);

extern void reactivate_chan(struct chan *chan, int irq);

extern void chan_enable_winch(struct chan *chan, struct tty_struct *tty);

extern void chan_enable_winch(struct chan *chan, struct tty_port *port);

extern int enable_chan(struct line *line);

extern void close_chan(struct line *line);

extern int chan_window_size(struct line *line,

arch/um/drivers/chan_kern.c

+2 −2
Original line number Diff line number Diff line
@@ -122,10 +122,10 @@ static int open_chan(struct list_head *chans) 
	return err;

}



void chan_enable_winch(struct chan *chan, struct tty_struct *tty)

void chan_enable_winch(struct chan *chan, struct tty_port *port)

{

	if (chan && chan->primary && chan->ops->winch)

		register_winch(chan->fd, tty);

		register_winch(chan->fd, port);

}



static void line_timer_cb(struct work_struct *work)

arch/um/drivers/chan_user.c

+6 −6
Original line number Diff line number Diff line
@@ -216,7 +216,7 @@ static int winch_thread(void *arg) 
	}

}



static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out,

static int winch_tramp(int fd, struct tty_port *port, int *fd_out,

		       unsigned long *stack_out)

{

	struct winch_data data;
@@ -271,7 +271,7 @@ static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out, 
	return err;

}



void register_winch(int fd, struct tty_struct *tty)

void register_winch(int fd, struct tty_port *port)

{

	unsigned long stack;

	int pid, thread, count, thread_fd = -1;
@@ -281,17 +281,17 @@ void register_winch(int fd, struct tty_struct *tty) 
		return;



	pid = tcgetpgrp(fd);

	if (is_skas_winch(pid, fd, tty)) {

		register_winch_irq(-1, fd, -1, tty, 0);

	if (is_skas_winch(pid, fd, port)) {

		register_winch_irq(-1, fd, -1, port, 0);

		return;

	}



	if (pid == -1) {

		thread = winch_tramp(fd, tty, &thread_fd, &stack);

		thread = winch_tramp(fd, port, &thread_fd, &stack);

		if (thread < 0)

			return;



		register_winch_irq(thread_fd, fd, thread, tty, stack);

		register_winch_irq(thread_fd, fd, thread, port, stack);



		count = write(thread_fd, &c, sizeof(c));

		if (count != sizeof(c))

arch/um/drivers/chan_user.h

+3 −3
Original line number Diff line number Diff line
@@ -38,10 +38,10 @@ extern int generic_window_size(int fd, void *unused, unsigned short *rows_out, 
			       unsigned short *cols_out);

extern void generic_free(void *data);



struct tty_struct;

extern void register_winch(int fd,  struct tty_struct *tty);

struct tty_port;

extern void register_winch(int fd,  struct tty_port *port);

extern void register_winch_irq(int fd, int tty_fd, int pid,

			       struct tty_struct *tty, unsigned long stack);

			       struct tty_port *port, unsigned long stack);



#define __channel_help(fn, prefix) \

__uml_help(fn, prefix "[0-9]*=<channel description>\n" \

arch/um/drivers/line.c

+10 −6
Original line number Diff line number Diff line
@@ -305,7 +305,7 @@ static int line_activate(struct tty_port *port, struct tty_struct *tty) 
		return ret;



	if (!line->sigio) {

		chan_enable_winch(line->chan_out, tty);

		chan_enable_winch(line->chan_out, port);

		line->sigio = 1;

	}
@@ -603,7 +603,7 @@ struct winch { 
	int fd;

	int tty_fd;

	int pid;

	struct tty_struct *tty;

	struct tty_port *port;

	unsigned long stack;

	struct work_struct work;

};
@@ -657,7 +657,7 @@ static irqreturn_t winch_interrupt(int irq, void *data) 
			goto out;

		}

	}

	tty = winch->tty;

	tty = tty_port_tty_get(winch->port);

	if (tty != NULL) {

		line = tty->driver_data;

		if (line != NULL) {
@@ -665,6 +665,7 @@ static irqreturn_t winch_interrupt(int irq, void *data) 
					 &tty->winsize.ws_col);

			kill_pgrp(tty->pgrp, SIGWINCH, 1);

		}

		tty_kref_put(tty);

	}

 out:

	if (winch->fd != -1)
@@ -672,7 +673,7 @@ static irqreturn_t winch_interrupt(int irq, void *data) 
	return IRQ_HANDLED;

}



void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,

void register_winch_irq(int fd, int tty_fd, int pid, struct tty_port *port,

			unsigned long stack)

{

	struct winch *winch;
@@ -687,7 +688,7 @@ void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty, 
				   .fd  	= fd,

				   .tty_fd 	= tty_fd,

				   .pid  	= pid,

				   .tty 	= tty,

				   .port 	= port,

				   .stack	= stack });



	if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
@@ -716,15 +717,18 @@ static void unregister_winch(struct tty_struct *tty) 
{

	struct list_head *ele, *next;

	struct winch *winch;

	struct tty_struct *wtty;



	spin_lock(&winch_handler_lock);



	list_for_each_safe(ele, next, &winch_handlers) {

		winch = list_entry(ele, struct winch, list);

		if (winch->tty == tty) {

		wtty = tty_port_tty_get(winch->port);

		if (wtty == tty) {

			free_winch(winch);

			break;

		}

		tty_kref_put(wtty);

	}

	spin_unlock(&winch_handler_lock);

}