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um: fix free_winch() mess

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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>
This commit is contained in:
Al Viro 2011-09-14 16:21:31 -07:00 committed by Linus Torvalds
parent 45cd5e2d4e
commit 7cf3cf21aa
1 changed files with 24 additions and 14 deletions
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38
arch/um/drivers/line.c
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@ -721,43 +721,53 @@ struct winch {
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 @@ static void unregister_winch(struct tty_struct *tty)
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 @@ static void winch_cleanup(void)
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);