spidev: quit messing with access_ok()
authorAl Viro <viro@zeniv.linux.org.uk>
Thu, 20 Apr 2017 19:47:34 +0000 (15:47 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Thu, 29 Jun 2017 22:00:52 +0000 (18:00 -0400)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
drivers/spi/spidev.c

index 9a2a79a871ba009fcfa8b7e2b52002c8845d94ce..221741f382606688a1fafa5d6ad3f7a163f6571e 100644 (file)
@@ -254,10 +254,6 @@ static int spidev_message(struct spidev_data *spidev,
                                goto done;
                        }
                        k_tmp->rx_buf = rx_buf;
-                       if (!access_ok(VERIFY_WRITE, (u8 __user *)
-                                               (uintptr_t) u_tmp->rx_buf,
-                                               u_tmp->len))
-                               goto done;
                        rx_buf += k_tmp->len;
                }
                if (u_tmp->tx_buf) {
@@ -305,7 +301,7 @@ static int spidev_message(struct spidev_data *spidev,
        rx_buf = spidev->rx_buffer;
        for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
                if (u_tmp->rx_buf) {
-                       if (__copy_to_user((u8 __user *)
+                       if (copy_to_user((u8 __user *)
                                        (uintptr_t) u_tmp->rx_buf, rx_buf,
                                        u_tmp->len)) {
                                status = -EFAULT;
@@ -355,7 +351,6 @@ spidev_get_ioc_message(unsigned int cmd, struct spi_ioc_transfer __user *u_ioc,
 static long
 spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-       int                     err = 0;
        int                     retval = 0;
        struct spidev_data      *spidev;
        struct spi_device       *spi;
@@ -367,19 +362,6 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
        if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
                return -ENOTTY;
 
-       /* Check access direction once here; don't repeat below.
-        * IOC_DIR is from the user perspective, while access_ok is
-        * from the kernel perspective; so they look reversed.
-        */
-       if (_IOC_DIR(cmd) & _IOC_READ)
-               err = !access_ok(VERIFY_WRITE,
-                               (void __user *)arg, _IOC_SIZE(cmd));
-       if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE)
-               err = !access_ok(VERIFY_READ,
-                               (void __user *)arg, _IOC_SIZE(cmd));
-       if (err)
-               return -EFAULT;
-
        /* guard against device removal before, or while,
         * we issue this ioctl.
         */
@@ -402,31 +384,31 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
        switch (cmd) {
        /* read requests */
        case SPI_IOC_RD_MODE:
-               retval = __put_user(spi->mode & SPI_MODE_MASK,
+               retval = put_user(spi->mode & SPI_MODE_MASK,
                                        (__u8 __user *)arg);
                break;
        case SPI_IOC_RD_MODE32:
-               retval = __put_user(spi->mode & SPI_MODE_MASK,
+               retval = put_user(spi->mode & SPI_MODE_MASK,
                                        (__u32 __user *)arg);
                break;
        case SPI_IOC_RD_LSB_FIRST:
-               retval = __put_user((spi->mode & SPI_LSB_FIRST) ?  1 : 0,
+               retval = put_user((spi->mode & SPI_LSB_FIRST) ?  1 : 0,
                                        (__u8 __user *)arg);
                break;
        case SPI_IOC_RD_BITS_PER_WORD:
-               retval = __put_user(spi->bits_per_word, (__u8 __user *)arg);
+               retval = put_user(spi->bits_per_word, (__u8 __user *)arg);
                break;
        case SPI_IOC_RD_MAX_SPEED_HZ:
-               retval = __put_user(spidev->speed_hz, (__u32 __user *)arg);
+               retval = put_user(spidev->speed_hz, (__u32 __user *)arg);
                break;
 
        /* write requests */
        case SPI_IOC_WR_MODE:
        case SPI_IOC_WR_MODE32:
                if (cmd == SPI_IOC_WR_MODE)
-                       retval = __get_user(tmp, (u8 __user *)arg);
+                       retval = get_user(tmp, (u8 __user *)arg);
                else
-                       retval = __get_user(tmp, (u32 __user *)arg);
+                       retval = get_user(tmp, (u32 __user *)arg);
                if (retval == 0) {
                        u32     save = spi->mode;
 
@@ -445,7 +427,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                }
                break;
        case SPI_IOC_WR_LSB_FIRST:
-               retval = __get_user(tmp, (__u8 __user *)arg);
+               retval = get_user(tmp, (__u8 __user *)arg);
                if (retval == 0) {
                        u32     save = spi->mode;
 
@@ -462,7 +444,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                }
                break;
        case SPI_IOC_WR_BITS_PER_WORD:
-               retval = __get_user(tmp, (__u8 __user *)arg);
+               retval = get_user(tmp, (__u8 __user *)arg);
                if (retval == 0) {
                        u8      save = spi->bits_per_word;
 
@@ -475,7 +457,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                }
                break;
        case SPI_IOC_WR_MAX_SPEED_HZ:
-               retval = __get_user(tmp, (__u32 __user *)arg);
+               retval = get_user(tmp, (__u32 __user *)arg);
                if (retval == 0) {
                        u32     save = spi->max_speed_hz;
 
@@ -525,8 +507,6 @@ spidev_compat_ioc_message(struct file *filp, unsigned int cmd,
        struct spi_ioc_transfer         *ioc;
 
        u_ioc = (struct spi_ioc_transfer __user *) compat_ptr(arg);
-       if (!access_ok(VERIFY_READ, u_ioc, _IOC_SIZE(cmd)))
-               return -EFAULT;
 
        /* guard against device removal before, or while,
         * we issue this ioctl.