fix abuses of ptrdiff_t

Use of ptrdiff_t in places like

-                       if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
+                       if (!access_ok(VERIFY_WRITE, (u8 __user *)
+                                               (ptrdiff_t) u_tmp->rx_buf,
+                                               u_tmp->len))

is wrong; for one thing, it's a bad C (it's what uintptr_t is for; in general
we are not even promised that ptrdiff_t is large enough to hold a pointer,
just enough to hold a difference between two pointers within the same object).
For another, it confuses the fsck out of sparse.

Use unsigned long or uintptr_t instead.  There are several places misusing
ptrdiff_t; fixed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index c55459c592b8..b3518ca9f04e 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -184,14 +184,14 @@ static int spidev_message(struct spidev_data *spidev,
                 if (u_tmp->rx_buf) {
                         k_tmp->rx_buf = buf;
                         if (!access_ok(VERIFY_WRITE, (u8 __user *)
-                                                (ptrdiff_t) u_tmp->rx_buf,
+                                                (uintptr_t) u_tmp->rx_buf,
                                                 u_tmp->len))
                                 goto done;
                 }
                 if (u_tmp->tx_buf) {
                         k_tmp->tx_buf = buf;
                         if (copy_from_user(buf, (const u8 __user *)
-                                                (ptrdiff_t) u_tmp->tx_buf,
+                                                (uintptr_t) u_tmp->tx_buf,
                                         u_tmp->len))
                                 goto done;
                 }
@@ -224,7 +224,7 @@ static int spidev_message(struct spidev_data *spidev,
         for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
                 if (u_tmp->rx_buf) {
                         if (__copy_to_user((u8 __user *)
-                                        (ptrdiff_t) u_tmp->rx_buf, buf,
+                                        (uintptr_t) u_tmp->rx_buf, buf,
                                         u_tmp->len)) {
                                 status = -EFAULT;
                                 goto done;