tty: Use the preferred form for passing the size of a structure type

Use the preferred form for passing the size of a structure type. The
alternative form where the structure type is spelled out hurts
readability and introduces an opportunity for a bug when the object
type is changed but the corresponding object identifier to which the
sizeof operator is applied is not.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/b04dd8cdd67bd6ffde3fd12940aeef35fdb824a6.1595543280.git.gustavoars@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 629fbafc9b7e64538a9df6c8700306c1e787f3c8..ceed72c9a88f78505200248ca83b970218ccff71 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1405,7 +1405,7 @@ void tty_save_termios(struct tty_struct *tty)
        /* Stash the termios data */
        tp = tty->driver->termios[idx];
        if (tp == NULL) {
-               tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
+               tp = kmalloc(sizeof(*tp), GFP_KERNEL);
                if (tp == NULL)
                        return;
                tty->driver->termios[idx] = tp;
@@ -2489,7 +2489,7 @@ static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *
        struct serial_struct v;
        int flags;
 
-       if (copy_from_user(&v, ss, sizeof(struct serial_struct)))
+       if (copy_from_user(&v, ss, sizeof(*ss)))
                return -EFAULT;
 
        flags = v.flags & ASYNC_DEPRECATED;
@@ -2507,11 +2507,11 @@ static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *
        struct serial_struct v;
        int err;
 
-       memset(&v, 0, sizeof(struct serial_struct));
+       memset(&v, 0, sizeof(v));
        if (!tty->ops->get_serial)
                return -ENOTTY;
        err = tty->ops->get_serial(tty, &v);
-       if (!err && copy_to_user(ss, &v, sizeof(struct serial_struct)))
+       if (!err && copy_to_user(ss, &v, sizeof(v)))
                err = -EFAULT;
        return err;
 }
@@ -2705,7 +2705,7 @@ static int compat_tty_tiocsserial(struct tty_struct *tty,
        struct serial_struct v;
        int flags;
 
-       if (copy_from_user(&v32, ss, sizeof(struct serial_struct32)))
+       if (copy_from_user(&v32, ss, sizeof(*ss)))
                return -EFAULT;
 
        memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base));
@@ -2743,7 +2743,7 @@ static int compat_tty_tiocgserial(struct tty_struct *tty,
                        0xfffffff : ptr_to_compat(v.iomem_base);
                v32.iomem_reg_shift = v.iomem_reg_shift;
                v32.port_high = v.port_high;
-               if (copy_to_user(ss, &v32, sizeof(struct serial_struct32)))
+               if (copy_to_user(ss, &v32, sizeof(v32)))
                        err = -EFAULT;
        }
        return err;
@@ -3215,7 +3215,7 @@ struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
        if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1))
                return ERR_PTR(-EINVAL);
 
-       driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
+       driver = kzalloc(sizeof(*driver), GFP_KERNEL);
        if (!driver)
                return ERR_PTR(-ENOMEM);