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, 2 insertions, 0 deletions

diff --git a/include/linux/types.h b/include/linux/types.h
index 4f0dad21c917..f4f8d19158e4 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -37,6 +37,8 @@ typedef __kernel_gid32_t	gid_t;
 typedef __kernel_uid16_t        uid16_t;
 typedef __kernel_gid16_t        gid16_t;
 
+typedef unsigned long           uintptr_t;
+
 #ifdef CONFIG_UID16
 /* This is defined by include/asm-{arch}/posix_types.h */
 typedef __kernel_old_uid_t      old_uid_t;