[RFC][PATCH 14/14] take the dummy csum_and_copy_from_user() into net/checksum.h

Al Viro
2020-03-27T23:31:35Z

now that can be done conveniently - all non-trivial cases have
_HAVE_ARCH_COPY_AND_CSUM_FROM_USER defined, so the fallback in
net/checksum.h is used only for dummy (copy_from_user, then
csum_partial) implementation. Allowing us to get rid of all
dummy instances, both of csum_and_copy_from_user() and
csum_partial_copy_from_user().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/c6x/lib/checksum.c | 22 ----------------------
arch/ia64/include/asm/checksum.h | 11 -----------
arch/ia64/lib/csum_partial_copy.c | 18 ------------------
arch/nios2/include/asm/checksum.h | 2 --
arch/parisc/include/asm/checksum.h | 8 --------
arch/parisc/lib/checksum.c | 14 --------------
arch/s390/include/asm/checksum.h | 19 -------------------
arch/x86/um/asm/checksum.h | 20 --------------------
include/asm-generic/checksum.h | 9 ---------
include/net/checksum.h | 8 ++------
lib/checksum.c | 20 --------------------
11 files changed, 2 insertions(+), 149 deletions(-)

diff --git a/arch/c6x/lib/checksum.c b/arch/c6x/lib/checksum.c
index 46940844c553..335ca4900808 100644
--- a/arch/c6x/lib/checksum.c
+++ b/arch/c6x/lib/checksum.c
@@ -4,28 +4,6 @@
#include <linux/module.h>
#include <net/checksum.h>

-#include <asm/byteorder.h>
-
-/*
- * copy from fs while checksumming, otherwise like csum_partial
- */
-__wsum
-csum_partial_copy_from_user(const void __user *src, void *dst, int len,
- __wsum sum, int *csum_err)
-{
- int missing;
-
- missing = __copy_from_user(dst, src, len);
- if (missing) {
- memset(dst + len - missing, 0, missing);
- *csum_err = -EFAULT;
- } else
- *csum_err = 0;
-
- return csum_partial(dst, len, sum);
-}
-EXPORT_SYMBOL(csum_partial_copy_from_user);
-
/* These are from csum_64plus.S */
EXPORT_SYMBOL(csum_partial);
EXPORT_SYMBOL(csum_partial_copy);
diff --git a/arch/ia64/include/asm/checksum.h b/arch/ia64/include/asm/checksum.h
index 279ea4dcee79..2a1c64629cdc 100644
--- a/arch/ia64/include/asm/checksum.h
+++ b/arch/ia64/include/asm/checksum.h
@@ -37,17 +37,6 @@ extern __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
*/
extern __wsum csum_partial(const void *buff, int len, __wsum sum);

-#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
-/*
- * Same as csum_partial, but copies from src while it checksums.
- *
- * Here it is even more important to align src and dst on a 32-bit (or
- * even better 64-bit) boundary.
- */
-extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
- int len, __wsum sum,
- int *errp);
-
extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum);

diff --git a/arch/ia64/lib/csum_partial_copy.c b/arch/ia64/lib/csum_partial_copy.c
index ab59eb399900..5d147a33d648 100644
--- a/arch/ia64/lib/csum_partial_copy.c
+++ b/arch/ia64/lib/csum_partial_copy.c
@@ -104,24 +104,6 @@ unsigned long do_csum_c(const unsigned char * buff, int len, unsigned int psum)
* But it's very tricky to get right even in C.
*/
__wsum
-csum_and_copy_from_user(const void __user *src, void *dst,
- int len, __wsum psum, int *errp)
-{
- /* XXX Fixme
- * for now we separate the copy from checksum for obvious
- * alignment difficulties. Look at the Alpha code and you'll be
- * scared.
- */
-
- if (copy_from_user(dst, src, len))
- *errp = -EFAULT;
-
- return csum_partial(dst, len, psum);
-}
-
-EXPORT_SYMBOL(csum_and_copy_from_user);
-
-__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
{
memcpy(dst, src, len);
diff --git a/arch/nios2/include/asm/checksum.h b/arch/nios2/include/asm/checksum.h
index 703c5ee63421..ec39698d3bea 100644
--- a/arch/nios2/include/asm/checksum.h
+++ b/arch/nios2/include/asm/checksum.h
@@ -14,8 +14,6 @@
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
extern __wsum csum_partial_copy(const void *src, void *dst, int len,
__wsum sum);
-extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
- int len, __wsum sum, int *csum_err);
#define csum_partial_copy_nocheck(src, dst, len, sum) \
csum_partial_copy((src), (dst), (len), (sum))

diff --git a/arch/parisc/include/asm/checksum.h b/arch/parisc/include/asm/checksum.h
index 7c69ce9634c7..fe8c63b2d2c3 100644
--- a/arch/parisc/include/asm/checksum.h
+++ b/arch/parisc/include/asm/checksum.h
@@ -26,14 +26,6 @@ extern __wsum csum_partial(const void *, int, __wsum);
*/
extern __wsum csum_partial_copy_nocheck(const void *, void *, int, __wsum);

-#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
-/*
- * this is a new version of the above that records errors it finds in *errp,
- * but continues and zeros the rest of the buffer.
- */
-extern __wsum csum_and_copy_from_user(const void __user *src,
- void *dst, int len, __wsum sum, int *errp);
-
/*
* Optimized for IP headers, which always checksum on 4 octet boundaries.
*
diff --git a/arch/parisc/lib/checksum.c b/arch/parisc/lib/checksum.c
index 4e47c2ff2bcd..c6f161583549 100644
--- a/arch/parisc/lib/checksum.c
+++ b/arch/parisc/lib/checksum.c
@@ -123,17 +123,3 @@ __wsum csum_partial_copy_nocheck(const void *src, void *dst,
return sum;
}
EXPORT_SYMBOL(csum_partial_copy_nocheck);
-
-/*
- * Copy from userspace and compute checksum. If we catch an exception
- * then zero the rest of the buffer.
- */
-__wsum csum_and_copy_from_user(const void __user *src,
- void *dst, int len,
- __wsum sum, int *err_ptr)
-{
- if (copy_from_user(dst, src, len))
- *err_ptr = -EFAULT;
- return csum_partial(dst, len, sum);
-}
-EXPORT_SYMBOL(csum_and_copy_from_user);
diff --git a/arch/s390/include/asm/checksum.h b/arch/s390/include/asm/checksum.h
index 91e376b0d28c..6d01c96aeb5c 100644
--- a/arch/s390/include/asm/checksum.h
+++ b/arch/s390/include/asm/checksum.h
@@ -39,25 +39,6 @@ csum_partial(const void *buff, int len, __wsum sum)
return sum;
}

-/*
- * the same as csum_partial_copy, but copies from user space.
- *
- * here even more important to align src and dst on a 32-bit (or even
- * better 64-bit) boundary
- *
- * Copy from userspace and compute checksum.
- */
-static inline __wsum
-csum_partial_copy_from_user(const void __user *src, void *dst,
- int len, __wsum sum,
- int *err_ptr)
-{
- if (unlikely(copy_from_user(dst, src, len)))
- *err_ptr = -EFAULT;
- return csum_partial(dst, len, sum);
-}
-
-
static inline __wsum
csum_partial_copy_nocheck (const void *src, void *dst, int len, __wsum sum)
{
diff --git a/arch/x86/um/asm/checksum.h b/arch/x86/um/asm/checksum.h
index 2a56cac64687..ff6bba2c8ab6 100644
--- a/arch/x86/um/asm/checksum.h
+++ b/arch/x86/um/asm/checksum.h
@@ -36,26 +36,6 @@ __wsum csum_partial_copy_nocheck(const void *src, void *dst,
return csum_partial(dst, len, sum);
}

-/*
- * the same as csum_partial, but copies from src while it
- * checksums, and handles user-space pointer exceptions correctly, when needed.
- *
- * here even more important to align src and dst on a 32-bit (or even
- * better 64-bit) boundary
- */
-
-static __inline__
-__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
- int len, __wsum sum, int *err_ptr)
-{
- if (copy_from_user(dst, src, len)) {
- *err_ptr = -EFAULT;
- return (__force __wsum)-1;
- }
-
- return csum_partial(dst, len, sum);
-}
-
/**
* csum_fold - Fold and invert a 32bit checksum.
* sum: 32bit unfolded sum
diff --git a/include/asm-generic/checksum.h b/include/asm-generic/checksum.h
index 34785c0f57b0..5a80f8e54300 100644
--- a/include/asm-generic/checksum.h
+++ b/include/asm-generic/checksum.h
@@ -25,15 +25,6 @@ extern __wsum csum_partial(const void *buff, int len, __wsum sum);
*/
extern __wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum);

-/*
- * the same as csum_partial_copy, but copies from user space.
- *
- * here even more important to align src and dst on a 32-bit (or even
- * better 64-bit) boundary
- */
-extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
- int len, __wsum sum, int *csum_err);
-
#ifndef csum_partial_copy_nocheck
#define csum_partial_copy_nocheck(src, dst, len, sum) \
csum_partial_copy((src), (dst), (len), (sum))
diff --git a/include/net/checksum.h b/include/net/checksum.h
index 97bf4885a962..5f9c73c0eeb9 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -26,13 +26,9 @@ static inline
__wsum csum_and_copy_from_user (const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
- if (access_ok(src, len))
- return csum_partial_copy_from_user(src, dst, len, sum, err_ptr);
-
- if (len)
+ if (copy_from_user(dst, src, len))
*err_ptr = -EFAULT;
-
- return sum;
+ return csum_partial(dst, len, sum);
}
#endif

diff --git a/lib/checksum.c b/lib/checksum.c
index de032ad96f4a..7ac65a0000ff 100644
--- a/lib/checksum.c
+++ b/lib/checksum.c
@@ -146,26 +146,6 @@ __sum16 ip_compute_csum(const void *buff, int len)
EXPORT_SYMBOL(ip_compute_csum);

/*
- * copy from fs while checksumming, otherwise like csum_partial
- */
-__wsum
-csum_partial_copy_from_user(const void __user *src, void *dst, int len,
- __wsum sum, int *csum_err)
-{
- int missing;
-
- missing = __copy_from_user(dst, src, len);
- if (missing) {
- memset(dst + len - missing, 0, missing);
- *csum_err = -EFAULT;
- } else
- *csum_err = 0;
-
- return csum_partial(dst, len, sum);
-}
-EXPORT_SYMBOL(csum_partial_copy_from_user);
-
-/*
* copy from ds while checksumming, otherwise like csum_partial
*/
__wsum
--
2.11.0