um: fix free_winch() mess
while not doing free_irq() from irq handler is commendable, kfree() on the
data passed to said handler before free_irq() is Not Good(tm). Freeing
the stack it's being run on is also not nice... Solution: delay actually
freeing stuff.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 91bf1894..364c8a1 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -721,43 +721,53 @@
int pid;
struct tty_struct *tty;
unsigned long stack;
+ struct work_struct work;
};
-static void free_winch(struct winch *winch, int free_irq_ok)
+static void __free_winch(struct work_struct *work)
{
- int fd = winch->fd;
- winch->fd = -1;
- if (free_irq_ok)
- free_irq(WINCH_IRQ, winch);
-
- list_del(&winch->list);
+ struct winch *winch = container_of(work, struct winch, work);
+ free_irq(WINCH_IRQ, winch);
if (winch->pid != -1)
os_kill_process(winch->pid, 1);
- if (fd != -1)
- os_close_file(fd);
if (winch->stack != 0)
free_stack(winch->stack, 0);
kfree(winch);
}
+static void free_winch(struct winch *winch)
+{
+ int fd = winch->fd;
+ winch->fd = -1;
+ if (fd != -1)
+ os_close_file(fd);
+ list_del(&winch->list);
+ __free_winch(&winch->work);
+}
+
static irqreturn_t winch_interrupt(int irq, void *data)
{
struct winch *winch = data;
struct tty_struct *tty;
struct line *line;
+ int fd = winch->fd;
int err;
char c;
- if (winch->fd != -1) {
- err = generic_read(winch->fd, &c, NULL);
+ if (fd != -1) {
+ err = generic_read(fd, &c, NULL);
if (err < 0) {
if (err != -EAGAIN) {
+ winch->fd = -1;
+ list_del(&winch->list);
+ os_close_file(fd);
printk(KERN_ERR "winch_interrupt : "
"read failed, errno = %d\n", -err);
printk(KERN_ERR "fd %d is losing SIGWINCH "
"support\n", winch->tty_fd);
- free_winch(winch, 0);
+ INIT_WORK(&winch->work, __free_winch);
+ schedule_work(&winch->work);
return IRQ_HANDLED;
}
goto out;
@@ -829,7 +839,7 @@
list_for_each_safe(ele, next, &winch_handlers) {
winch = list_entry(ele, struct winch, list);
if (winch->tty == tty) {
- free_winch(winch, 1);
+ free_winch(winch);
break;
}
}
@@ -845,7 +855,7 @@
list_for_each_safe(ele, next, &winch_handlers) {
winch = list_entry(ele, struct winch, list);
- free_winch(winch, 1);
+ free_winch(winch);
}
spin_unlock(&winch_handler_lock);