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/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);
}