2005-04-17 00:20:36 +02:00
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/*
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* iovec manipulation routines.
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Fixes:
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* Andrew Lunn : Errors in iovec copying.
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* Pedro Roque : Added memcpy_fromiovecend and
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* csum_..._fromiovecend.
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* Andi Kleen : fixed error handling for 2.1
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* Alexey Kuznetsov: 2.1 optimisations
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* Andi Kleen : Fix csum*fromiovecend for IPv6.
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*/
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/net.h>
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#include <linux/in6.h>
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#include <asm/uaccess.h>
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#include <asm/byteorder.h>
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#include <net/checksum.h>
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#include <net/sock.h>
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/*
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* Verify iovec. The caller must ensure that the iovec is big enough
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* to hold the message iovec.
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*
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2005-05-01 17:59:08 +02:00
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* Save time not doing access_ok. copy_*_user will make this work
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2005-04-17 00:20:36 +02:00
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* in any case.
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*/
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int verify_iovec(struct msghdr *m, struct iovec *iov, char *address, int mode)
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{
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int size, err, ct;
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2007-02-09 15:24:36 +01:00
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2005-04-17 00:20:36 +02:00
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if (m->msg_namelen) {
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if (mode == VERIFY_READ) {
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err = move_addr_to_kernel(m->msg_name, m->msg_namelen,
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address);
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if (err < 0)
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return err;
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}
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m->msg_name = address;
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} else {
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m->msg_name = NULL;
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}
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size = m->msg_iovlen * sizeof(struct iovec);
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if (copy_from_user(iov, m->msg_iov, size))
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return -EFAULT;
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m->msg_iov = iov;
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err = 0;
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for (ct = 0; ct < m->msg_iovlen; ct++) {
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err += iov[ct].iov_len;
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/*
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* Goal is not to verify user data, but to prevent returning
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* negative value, which is interpreted as errno.
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* Overflow is still possible, but it is harmless.
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*/
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if (err < 0)
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return -EMSGSIZE;
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}
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return err;
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}
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/*
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* Copy kernel to iovec. Returns -EFAULT on error.
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*
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* Note: this modifies the original iovec.
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*/
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2007-02-09 15:24:36 +01:00
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2005-04-17 00:20:36 +02:00
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int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
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{
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while (len > 0) {
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if (iov->iov_len) {
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int copy = min_t(unsigned int, iov->iov_len, len);
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if (copy_to_user(iov->iov_base, kdata, copy))
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return -EFAULT;
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kdata += copy;
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len -= copy;
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iov->iov_len -= copy;
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iov->iov_base += copy;
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}
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iov++;
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}
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return 0;
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}
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/*
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* Copy iovec to kernel. Returns -EFAULT on error.
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*
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* Note: this modifies the original iovec.
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*/
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2007-02-09 15:24:36 +01:00
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2005-04-17 00:20:36 +02:00
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int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
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{
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while (len > 0) {
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if (iov->iov_len) {
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int copy = min_t(unsigned int, len, iov->iov_len);
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if (copy_from_user(kdata, iov->iov_base, copy))
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return -EFAULT;
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len -= copy;
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kdata += copy;
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iov->iov_base += copy;
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iov->iov_len -= copy;
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}
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iov++;
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}
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return 0;
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}
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/*
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* For use with ip_build_xmit
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*/
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int memcpy_fromiovecend(unsigned char *kdata, struct iovec *iov, int offset,
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int len)
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{
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/* Skip over the finished iovecs */
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while (offset >= iov->iov_len) {
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offset -= iov->iov_len;
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iov++;
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}
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while (len > 0) {
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u8 __user *base = iov->iov_base + offset;
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int copy = min_t(unsigned int, len, iov->iov_len - offset);
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offset = 0;
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if (copy_from_user(kdata, base, copy))
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return -EFAULT;
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len -= copy;
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kdata += copy;
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iov++;
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}
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return 0;
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}
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/*
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* And now for the all-in-one: copy and checksum from a user iovec
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* directly to a datagram
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* Calls to csum_partial but the last must be in 32 bit chunks
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*
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* ip_build_xmit must ensure that when fragmenting only the last
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* call to this function will be unaligned also.
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*/
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int csum_partial_copy_fromiovecend(unsigned char *kdata, struct iovec *iov,
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2006-11-15 06:36:14 +01:00
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int offset, unsigned int len, __wsum *csump)
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2005-04-17 00:20:36 +02:00
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{
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2006-11-15 06:36:14 +01:00
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__wsum csum = *csump;
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2005-04-17 00:20:36 +02:00
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int partial_cnt = 0, err = 0;
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/* Skip over the finished iovecs */
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while (offset >= iov->iov_len) {
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offset -= iov->iov_len;
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iov++;
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}
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while (len > 0) {
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u8 __user *base = iov->iov_base + offset;
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int copy = min_t(unsigned int, len, iov->iov_len - offset);
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offset = 0;
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/* There is a remnant from previous iov. */
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if (partial_cnt) {
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int par_len = 4 - partial_cnt;
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/* iov component is too short ... */
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if (par_len > copy) {
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if (copy_from_user(kdata, base, copy))
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goto out_fault;
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kdata += copy;
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base += copy;
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partial_cnt += copy;
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len -= copy;
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iov++;
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if (len)
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continue;
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*csump = csum_partial(kdata - partial_cnt,
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partial_cnt, csum);
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goto out;
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}
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if (copy_from_user(kdata, base, par_len))
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goto out_fault;
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csum = csum_partial(kdata - partial_cnt, 4, csum);
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kdata += par_len;
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base += par_len;
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copy -= par_len;
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len -= par_len;
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partial_cnt = 0;
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}
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if (len > copy) {
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partial_cnt = copy % 4;
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if (partial_cnt) {
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copy -= partial_cnt;
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if (copy_from_user(kdata + copy, base + copy,
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2007-02-09 15:24:36 +01:00
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partial_cnt))
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2005-04-17 00:20:36 +02:00
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goto out_fault;
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}
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}
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if (copy) {
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csum = csum_and_copy_from_user(base, kdata, copy,
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csum, &err);
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if (err)
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goto out;
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}
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len -= copy + partial_cnt;
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kdata += copy + partial_cnt;
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iov++;
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}
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2007-02-09 15:24:36 +01:00
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*csump = csum;
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2005-04-17 00:20:36 +02:00
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out:
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return err;
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out_fault:
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err = -EFAULT;
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goto out;
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}
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EXPORT_SYMBOL(csum_partial_copy_fromiovecend);
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EXPORT_SYMBOL(memcpy_fromiovec);
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EXPORT_SYMBOL(memcpy_fromiovecend);
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EXPORT_SYMBOL(memcpy_toiovec);
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