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WSL2-Linux-Kernel
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Merge branch 'uaccess.csum' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 

Pull uaccess/csum updates from Al Viro:
 "Regularize the sitation with uaccess checksum primitives:

   - fold csum_partial_... into csum_and_copy_..._user()

   - on x86 collapse several access_ok()/stac()/clac() into
     user_access_begin()/user_access_end()"

* 'uaccess.csum' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  default csum_and_copy_to_user(): don't bother with access_ok()
  take the dummy csum_and_copy_from_user() into net/checksum.h
  arm: switch to csum_and_copy_from_user()
  sh32: convert to csum_and_copy_from_user()
  m68k: convert to csum_and_copy_from_user()
  xtensa: switch to providing csum_and_copy_from_user()
  sparc: switch to providing csum_and_copy_from_user()
  parisc: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
  alpha: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
  ia64: turn csum_partial_copy_from_user() into csum_and_copy_from_user()
  ia64: csum_partial_copy_nocheck(): don't abuse csum_partial_copy_from_user()
  x86: switch 32bit csum_and_copy_to_user() to user_access_{begin,end}()
  x86: switch both 32bit and 64bit to providing csum_and_copy_from_user()
  x86_64: csum_..._copy_..._user(): switch to unsafe_..._user()
  get rid of csum_partial_copy_to_user()
This commit is contained in:
Linus Torvalds 2020-06-01 16:03:37 -07:00
Родитель b23c4771ff 001c1a655f
Коммит 4b01285e16
25 изменённых файлов: 88 добавлений и 225 удалений
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3
arch/alpha/include/asm/checksum.h
Просмотреть файл

@ -41,7 +41,8 @@ extern __wsum csum_partial(const void *buff, int len, __wsum sum);
* here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*/
__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *errp);
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *errp);
__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);

6
arch/alpha/lib/csum_partial_copy.c
Просмотреть файл

@ -325,7 +325,7 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
}
__wsum
csum_partial_copy_from_user(const void __user *src, void *dst, int len,
csum_and_copy_from_user(const void __user *src, void *dst, int len,
__wsum sum, int *errp)
{
unsigned long checksum = (__force u32) sum;
@ -369,7 +369,7 @@ csum_partial_copy_from_user(const void __user *src, void *dst, int len,
}
return (__force __wsum)checksum;
}
EXPORT_SYMBOL(csum_partial_copy_from_user);
EXPORT_SYMBOL(csum_and_copy_from_user);
__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
@ -377,7 +377,7 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
__wsum checksum;
mm_segment_t oldfs = get_fs();
set_fs(KERNEL_DS);
checksum = csum_partial_copy_from_user((__force const void __user *)src,
checksum = csum_and_copy_from_user((__force const void __user *)src,
dst, len, sum, NULL);
set_fs(oldfs);
return checksum;

14
arch/arm/include/asm/checksum.h
Просмотреть файл

@ -40,6 +40,20 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
__wsum
csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
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)
*err_ptr = -EFAULT;
return sum;
}
/*
* Fold a partial checksum without adding pseudo headers
*/

22
arch/c6x/lib/checksum.c
Просмотреть файл

@ -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);

10
arch/ia64/include/asm/checksum.h
Просмотреть файл

@ -37,16 +37,6 @@ extern __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
*/
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
/*
* 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_partial_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);

32
arch/ia64/lib/csum_partial_copy.c
Просмотреть файл

@ -103,39 +103,11 @@ out:
* This is very ugly but temporary. THIS NEEDS SERIOUS ENHANCEMENTS.
* But it's very tricky to get right even in C.
*/
extern unsigned long do_csum(const unsigned char *, long);
__wsum
csum_partial_copy_from_user(const void __user *src, void *dst,
int len, __wsum psum, int *errp)
{
unsigned long result;
/* 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) != 0 && errp)
*errp = -EFAULT;
result = do_csum(dst, len);
/* add in old sum, and carry.. */
result += (__force u32)psum;
/* 32+c bits -> 32 bits */
result = (result & 0xffffffff) + (result >> 32);
return (__force __wsum)result;
}
EXPORT_SYMBOL(csum_partial_copy_from_user);
__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
{
return csum_partial_copy_from_user((__force const void __user *)src,
dst, len, sum, NULL);
memcpy(dst, src, len);
return csum_partial(dst, len, sum);
}
EXPORT_SYMBOL(csum_partial_copy_nocheck);

3
arch/m68k/include/asm/checksum.h
Просмотреть файл

@ -30,7 +30,8 @@ __wsum csum_partial(const void *buff, int len, __wsum sum);
* better 64-bit) boundary
*/
extern __wsum csum_partial_copy_from_user(const void __user *src,
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
extern __wsum csum_and_copy_from_user(const void __user *src,
void *dst,
int len, __wsum sum,
int *csum_err);

4
arch/m68k/lib/checksum.c
Просмотреть файл

@ -129,7 +129,7 @@ EXPORT_SYMBOL(csum_partial);
*/
__wsum
csum_partial_copy_from_user(const void __user *src, void *dst,
csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *csum_err)
{
/*
@ -316,7 +316,7 @@ csum_partial_copy_from_user(const void __user *src, void *dst,
return(sum);
}
EXPORT_SYMBOL(csum_partial_copy_from_user);
EXPORT_SYMBOL(csum_and_copy_from_user);
/*

2
arch/nios2/include/asm/checksum.h
Просмотреть файл

@ -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))

7
arch/parisc/include/asm/checksum.h
Просмотреть файл

@ -26,13 +26,6 @@ extern __wsum csum_partial(const void *, int, __wsum);
*/
extern __wsum csum_partial_copy_nocheck(const void *, void *, int, __wsum);
/*
* 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_partial_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.
*

20
arch/parisc/lib/checksum.c
Просмотреть файл

@ -123,23 +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_partial_copy_from_user(const void __user *src,
void *dst, int len,
__wsum sum, int *err_ptr)
{
int missing;
missing = copy_from_user(dst, src, len);
if (missing) {
memset(dst + len - missing, 0, missing);
*err_ptr = -EFAULT;
}
return csum_partial(dst, len, sum);
}
EXPORT_SYMBOL(csum_partial_copy_from_user);

19
arch/s390/include/asm/checksum.h
Просмотреть файл

@ -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)
{

9
arch/sh/include/asm/checksum_32.h
Просмотреть файл

@ -48,12 +48,17 @@ __wsum csum_partial_copy_nocheck(const void *src, void *dst,
return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
}
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
__wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
return csum_partial_copy_generic((__force const void *)src, dst,
if (access_ok(src, len))
return csum_partial_copy_generic((__force const void *)src, dst,
len, sum, err_ptr, NULL);
if (len)
*err_ptr = -EFAULT;
return sum;
}
/*

1
arch/sparc/include/asm/checksum.h
Просмотреть файл

@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ___ASM_SPARC_CHECKSUM_H
#define ___ASM_SPARC_CHECKSUM_H
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
#if defined(__sparc__) && defined(__arch64__)
#include <asm/checksum_64.h>
#else

15
arch/sparc/include/asm/checksum_32.h
Просмотреть файл

@ -60,7 +60,7 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
}
static inline __wsum
csum_partial_copy_from_user(const void __user *src, void *dst, int len,
csum_and_copy_from_user(const void __user *src, void *dst, int len,
__wsum sum, int *err)
{
register unsigned long ret asm("o0") = (unsigned long)src;
@ -68,6 +68,12 @@ csum_partial_copy_from_user(const void __user *src, void *dst, int len,
register int l asm("g1") = len;
register __wsum s asm("g7") = sum;
if (unlikely(!access_ok(src, len))) {
if (len)
*err = -EFAULT;
return sum;
}
__asm__ __volatile__ (
".section __ex_table,#alloc\n\t"
".align 4\n\t"
@ -83,8 +89,10 @@ csum_partial_copy_from_user(const void __user *src, void *dst, int len,
return (__force __wsum)ret;
}
#define HAVE_CSUM_COPY_USER
static inline __wsum
csum_partial_copy_to_user(const void *src, void __user *dst, int len,
csum_and_copy_to_user(const void *src, void __user *dst, int len,
__wsum sum, int *err)
{
if (!access_ok(dst, len)) {
@ -113,9 +121,6 @@ csum_partial_copy_to_user(const void *src, void __user *dst, int len,
}
}
#define HAVE_CSUM_COPY_USER
#define csum_and_copy_to_user csum_partial_copy_to_user
/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
* the majority of the time.
*/

2
arch/sparc/include/asm/checksum_64.h
Просмотреть файл

@ -46,7 +46,7 @@ long __csum_partial_copy_from_user(const void __user *src,
__wsum sum);
static inline __wsum
csum_partial_copy_from_user(const void __user *src,
csum_and_copy_from_user(const void __user *src,
void *dst, int len,
__wsum sum, int *err)
{

2
arch/x86/include/asm/checksum.h
Просмотреть файл

@ -1,4 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 */
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
#define HAVE_CSUM_COPY_USER
#ifdef CONFIG_X86_32
# include <asm/checksum_32.h>
#else

21
arch/x86/include/asm/checksum_32.h
Просмотреть файл

@ -44,18 +44,21 @@ static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst,
return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
}
static inline __wsum csum_partial_copy_from_user(const void __user *src,
void *dst,
int len, __wsum sum,
int *err_ptr)
static inline __wsum csum_and_copy_from_user(const void __user *src,
void *dst, int len,
__wsum sum, int *err_ptr)
{
__wsum ret;
might_sleep();
stac();
if (!user_access_begin(src, len)) {
if (len)
*err_ptr = -EFAULT;
return sum;
}
ret = csum_partial_copy_generic((__force void *)src, dst,
len, sum, err_ptr, NULL);
clac();
user_access_end();
return ret;
}
@ -173,7 +176,6 @@ static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
/*
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
static inline __wsum csum_and_copy_to_user(const void *src,
void __user *dst,
int len, __wsum sum,
@ -182,11 +184,10 @@ static inline __wsum csum_and_copy_to_user(const void *src,
__wsum ret;
might_sleep();
if (access_ok(dst, len)) {
stac();
if (user_access_begin(dst, len)) {
ret = csum_partial_copy_generic(src, (__force void *)dst,
len, sum, NULL, err_ptr);
clac();
user_access_end();
return ret;
}

12
arch/x86/include/asm/checksum_64.h
Просмотреть файл

@ -129,27 +129,19 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
*/
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
#define HAVE_CSUM_COPY_USER 1
/* Do not call this directly. Use the wrappers below */
extern __visible __wsum csum_partial_copy_generic(const void *src, const void *dst,
int len, __wsum sum,
int *src_err_ptr, int *dst_err_ptr);
extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum isum, int *errp);
extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst,
extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
int len, __wsum isum, int *errp);
extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum);
/* Old names. To be removed. */
#define csum_and_copy_to_user csum_partial_copy_to_user
#define csum_and_copy_from_user csum_partial_copy_from_user
/**
* ip_compute_csum - Compute an 16bit IP checksum.
* @buff: buffer address.

35
arch/x86/lib/csum-wrappers_64.c
Просмотреть файл

@ -10,7 +10,7 @@
#include <asm/smap.h>
/**
* csum_partial_copy_from_user - Copy and checksum from user space.
* csum_and_copy_from_user - Copy and checksum from user space.
* @src: source address (user space)
* @dst: destination address
* @len: number of bytes to be copied.
@ -21,13 +21,13 @@
* src and dst are best aligned to 64bits.
*/
__wsum
csum_partial_copy_from_user(const void __user *src, void *dst,
csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum isum, int *errp)
{
might_sleep();
*errp = 0;
if (!likely(access_ok(src, len)))
if (!user_access_begin(src, len))
goto out_err;
/*
@ -42,8 +42,7 @@ csum_partial_copy_from_user(const void __user *src, void *dst,
while (((unsigned long)src & 6) && len >= 2) {
__u16 val16;
if (__get_user(val16, (const __u16 __user *)src))
goto out_err;
unsafe_get_user(val16, (const __u16 __user *)src, out);
*(__u16 *)dst = val16;
isum = (__force __wsum)add32_with_carry(
@ -53,25 +52,26 @@ csum_partial_copy_from_user(const void __user *src, void *dst,
len -= 2;
}
}
stac();
isum = csum_partial_copy_generic((__force const void *)src,
dst, len, isum, errp, NULL);
clac();
user_access_end();
if (unlikely(*errp))
goto out_err;
return isum;
out:
user_access_end();
out_err:
*errp = -EFAULT;
memset(dst, 0, len);
return isum;
}
EXPORT_SYMBOL(csum_partial_copy_from_user);
EXPORT_SYMBOL(csum_and_copy_from_user);
/**
* csum_partial_copy_to_user - Copy and checksum to user space.
* csum_and_copy_to_user - Copy and checksum to user space.
* @src: source address
* @dst: destination address (user space)
* @len: number of bytes to be copied.
@ -82,14 +82,14 @@ EXPORT_SYMBOL(csum_partial_copy_from_user);
* src and dst are best aligned to 64bits.
*/
__wsum
csum_partial_copy_to_user(const void *src, void __user *dst,
csum_and_copy_to_user(const void *src, void __user *dst,
int len, __wsum isum, int *errp)
{
__wsum ret;
might_sleep();
if (unlikely(!access_ok(dst, len))) {
if (!user_access_begin(dst, len)) {
*errp = -EFAULT;
return 0;
}
@ -100,9 +100,7 @@ csum_partial_copy_to_user(const void *src, void __user *dst,
isum = (__force __wsum)add32_with_carry(
(__force unsigned)isum, val16);
*errp = __put_user(val16, (__u16 __user *)dst);
if (*errp)
return isum;
unsafe_put_user(val16, (__u16 __user *)dst, out);
src += 2;
dst += 2;
len -= 2;
@ -110,13 +108,16 @@ csum_partial_copy_to_user(const void *src, void __user *dst,
}
*errp = 0;
stac();
ret = csum_partial_copy_generic(src, (void __force *)dst,
len, isum, NULL, errp);
clac();
user_access_end();
return ret;
out:
user_access_end();
*errp = -EFAULT;
return isum;
}
EXPORT_SYMBOL(csum_partial_copy_to_user);
EXPORT_SYMBOL(csum_and_copy_to_user);
/**
* csum_partial_copy_nocheck - Copy and checksum.

20
arch/x86/um/asm/checksum.h
Просмотреть файл

@ -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

11
arch/xtensa/include/asm/checksum.h
Просмотреть файл

@ -44,8 +44,6 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
/*
* Note: when you get a NULL pointer exception here this means someone
* passed in an incorrect kernel address to one of these functions.
*
* If you use these functions directly please don't forget the access_ok().
*/
static inline
__wsum csum_partial_copy_nocheck(const void *src, void *dst,
@ -54,12 +52,17 @@ __wsum csum_partial_copy_nocheck(const void *src, void *dst,
return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
}
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
__wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
return csum_partial_copy_generic((__force const void *)src, dst,
if (access_ok(dst, len))
return csum_partial_copy_generic((__force const void *)src, dst,
len, sum, err_ptr, NULL);
if (len)
*err_ptr = -EFAULT;
return sum;
}
/*

9
include/asm-generic/checksum.h
Просмотреть файл

@ -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))

14
include/net/checksum.h
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@ -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
@ -42,10 +38,8 @@ static __inline__ __wsum csum_and_copy_to_user
{
sum = csum_partial(src, len, sum);
if (access_ok(dst, len)) {
if (copy_to_user(dst, src, len) == 0)
return sum;
}
if (copy_to_user(dst, src, len) == 0)
return sum;
if (len)
*err_ptr = -EFAULT;

20
lib/checksum.c
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@ -145,26 +145,6 @@ __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
*/