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: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/drivers/chan.h b/arch/um/drivers/chan.h
index 78f1b89..c512b03 100644
--- a/arch/um/drivers/chan.h
+++ b/arch/um/drivers/chan.h
@@ -37,7 +37,7 @@
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,
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 15c553c..80b47cb 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -122,10 +122,10 @@
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)
diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index 9be670a..3fd7c3e 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -216,7 +216,7 @@
}
}
-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 @@
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 @@
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))
diff --git a/arch/um/drivers/chan_user.h b/arch/um/drivers/chan_user.h
index dc693298..03f1b56 100644
--- a/arch/um/drivers/chan_user.h
+++ b/arch/um/drivers/chan_user.h
@@ -38,10 +38,10 @@
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" \
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 232243a..be541cf 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -305,7 +305,7 @@
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 @@
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 @@
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 @@
&tty->winsize.ws_col);
kill_pgrp(tty->pgrp, SIGWINCH, 1);
}
+ tty_kref_put(tty);
}
out:
if (winch->fd != -1)
@@ -672,7 +673,7 @@
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 @@
.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 @@
{
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);
}