[PATCH v2 14/20] mips: csum_and_copy_{to,from}_user() are never called under KERNEL_DS

[Al Viro]

From: Al Viro <v...@zeniv.linux.org.uk>

they are only called for iovec-backed iov_iter and under KERNEL_DS an
attempt to create such a beast will yield a kvec-backed one.

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
 arch/mips/include/asm/checksum.h | 32 +++++++-------------------------
 1 file changed, 7 insertions(+), 25 deletions(-)

diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
index b882cacea3ee..5cf4ce11c821 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -41,22 +41,6 @@ __wsum __csum_partial_copy_from_user(const void *src, void 
*dst,
                                     int len, __wsum sum, int *err_ptr);
 __wsum __csum_partial_copy_to_user(const void *src, void *dst,
                                   int len, __wsum sum, int *err_ptr);
-/*
- * this is a new version of the above that records errors it finds in *errp,
- * but continues and zeros the rest of the buffer.
- */
-static inline
-__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
-                                  __wsum sum, int *err_ptr)
-{
-       might_fault();
-       if (uaccess_kernel())
-               return __csum_partial_copy_kernel((__force void *)src, dst,
-                                                 len, sum, err_ptr);
-       else
-               return __csum_partial_copy_from_user((__force void *)src, dst,
-                                                    len, sum, err_ptr);
-}
 
 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
 static inline
@@ -65,9 +49,12 @@ __wsum csum_and_copy_from_user(const void __user *src, void 
*dst, int len)
        __wsum sum = ~0U;
        int err = 0;
 
+       might_fault();
+
        if (!access_ok(src, len))
                return 0;
-       sum = csum_partial_copy_from_user(src, dst, len, sum, &err);
+       sum = __csum_partial_copy_from_user((__force void *)src, dst,
+                                                    len, sum, &err);
        return err ? 0 : sum;
 }
 
@@ -84,14 +71,9 @@ __wsum csum_and_copy_to_user(const void *src, void __user 
*dst, int len)
        might_fault();
        if (!access_ok(dst, len))
                return 0;
-       if (uaccess_kernel())
-               sum = __csum_partial_copy_kernel(src,
-                                                 (__force void *)dst,
-                                                 len, sum, &err);
-       else
-               sum = __csum_partial_copy_to_user(src,
-                                                  (__force void *)dst,
-                                                  len, sum, &err);
+       sum = __csum_partial_copy_to_user(src,
+                                          (__force void *)dst,
+                                          len, sum, &err);
        return err ? 0 : sum;
 }
 
-- 
2.11.0