From 0ee9cbb3c705903db9c258047d9ce87096e6a1a1 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date: Wed, 30 Apr 2008 00:53:32 -0700
Subject: [PATCH] tty_ioctl: locking for tty_wait_until_sent
This function still depends on the big kernel lock in some cases. Push
locking into the function ready for removal of the BKL from ioctl call paths.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/char/tty_ioctl.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index d6353d89b451..851cfcd2702a 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
+#include <linux/smp_lock.h>
#include <asm/io.h>
#include <asm/uaccess.h>
@@ -61,11 +62,13 @@ void tty_wait_until_sent(struct tty_struct *tty, long timeout)
return;
if (!timeout)
timeout = MAX_SCHEDULE_TIMEOUT;
+ lock_kernel();
if (wait_event_interruptible_timeout(tty->write_wait,
- !tty->driver->chars_in_buffer(tty), timeout) < 0)
- return;
- if (tty->driver->wait_until_sent)
- tty->driver->wait_until_sent(tty, timeout);
+ !tty->driver->chars_in_buffer(tty), timeout) >= 0) {
+ if (tty->driver->wait_until_sent)
+ tty->driver->wait_until_sent(tty, timeout);
+ }
+ unlock_kernel();
}
EXPORT_SYMBOL(tty_wait_until_sent);
--
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