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;
         }