3 files changed, 18 insertions, 14 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 1838aa3d24fe..7ce1ac4baa6d 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -407,7 +407,7 @@ struct entropy_store {
 	/* read-write data: */
 	spinlock_t lock;
 	unsigned add_ptr;
-	int entropy_count;
+	int entropy_count;	/* Must at no time exceed ->POOLBITS! */
 	int input_rotate;
 };
 
@@ -520,6 +520,7 @@ static void mix_pool_bytes(struct entropy_store *r, const void *in, int bytes)
 static void credit_entropy_bits(struct entropy_store *r, int nbits)
 {
 	unsigned long flags;
+	int entropy_count;
 
 	if (!nbits)
 		return;
@@ -527,20 +528,20 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
 	spin_lock_irqsave(&r->lock, flags);
 
 	DEBUG_ENT("added %d entropy credits to %s\n", nbits, r->name);
-	r->entropy_count += nbits;
-	if (r->entropy_count < 0) {
+	entropy_count = r->entropy_count;
+	entropy_count += nbits;
+	if (entropy_count < 0) {
 		DEBUG_ENT("negative entropy/overflow\n");
-		r->entropy_count = 0;
-	} else if (r->entropy_count > r->poolinfo->POOLBITS)
-		r->entropy_count = r->poolinfo->POOLBITS;
+		entropy_count = 0;
+	} else if (entropy_count > r->poolinfo->POOLBITS)
+		entropy_count = r->poolinfo->POOLBITS;
+	r->entropy_count = entropy_count;
 
 	/* should we wake readers? */
-	if (r == &input_pool &&
-	    r->entropy_count >= random_read_wakeup_thresh) {
+	if (r == &input_pool && entropy_count >= random_read_wakeup_thresh) {
 		wake_up_interruptible(&random_read_wait);
 		kill_fasync(&fasync, SIGIO, POLL_IN);
 	}
-
 	spin_unlock_irqrestore(&r->lock, flags);
 }
 
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index a27160ba21d7..daeb8f766971 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2498,7 +2498,7 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
 /**
  *	tty_do_resize		-	resize event
  *	@tty: tty being resized
- *	@real_tty: real tty (if using a pty/tty pair)
+ *	@real_tty: real tty (not the same as tty if using a pty/tty pair)
  *	@rows: rows (character)
  *	@cols: cols (character)
  *
@@ -2512,7 +2512,8 @@ int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
 	struct pid *pgrp, *rpgrp;
 	unsigned long flags;
 
-	mutex_lock(&tty->termios_mutex);
+	/* For a PTY we need to lock the tty side */
+	mutex_lock(&real_tty->termios_mutex);
 	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
 		goto done;
 	/* Get the PID values and reference them so we can
@@ -2533,7 +2534,7 @@ int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
 	tty->winsize = *ws;
 	real_tty->winsize = *ws;
 done:
-	mutex_unlock(&tty->termios_mutex);
+	mutex_unlock(&real_tty->termios_mutex);
 	return 0;
 }
 
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index ea9fc5d03b99..bf34e4597421 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -937,12 +937,14 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
 			return 0;
 #endif
 	case TIOCGSOFTCAR:
-		return put_user(C_CLOCAL(tty) ? 1 : 0,
+		/* FIXME: for correctness we may need to take the termios
+		   lock here - review */
+		return put_user(C_CLOCAL(real_tty) ? 1 : 0,
 						(int __user *)arg);
 	case TIOCSSOFTCAR:
 		if (get_user(arg, (unsigned int __user *) arg))
 			return -EFAULT;
-		return tty_change_softcar(tty, arg);
+		return tty_change_softcar(real_tty, arg);
 	default:
 		return -ENOIOCTLCMD;
 	}