mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 02:15:21 +07:00
06ebb06d49
Check for cases when the caller requests 0 bytes instead of running off and dereferencing potentially invalid iovecs. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
113 lines
2.2 KiB
C
113 lines
2.2 KiB
C
#include <linux/uaccess.h>
|
|
#include <linux/export.h>
|
|
#include <linux/uio.h>
|
|
|
|
/*
|
|
* Copy iovec to kernel. Returns -EFAULT on error.
|
|
*
|
|
* Note: this modifies the original iovec.
|
|
*/
|
|
|
|
int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
|
|
{
|
|
while (len > 0) {
|
|
if (iov->iov_len) {
|
|
int copy = min_t(unsigned int, len, iov->iov_len);
|
|
if (copy_from_user(kdata, iov->iov_base, copy))
|
|
return -EFAULT;
|
|
len -= copy;
|
|
kdata += copy;
|
|
iov->iov_base += copy;
|
|
iov->iov_len -= copy;
|
|
}
|
|
iov++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(memcpy_fromiovec);
|
|
|
|
/*
|
|
* Copy kernel to iovec. Returns -EFAULT on error.
|
|
*
|
|
* Note: this modifies the original iovec.
|
|
*/
|
|
|
|
int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
|
|
{
|
|
while (len > 0) {
|
|
if (iov->iov_len) {
|
|
int copy = min_t(unsigned int, iov->iov_len, len);
|
|
if (copy_to_user(iov->iov_base, kdata, copy))
|
|
return -EFAULT;
|
|
kdata += copy;
|
|
len -= copy;
|
|
iov->iov_len -= copy;
|
|
iov->iov_base += copy;
|
|
}
|
|
iov++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(memcpy_toiovec);
|
|
|
|
/*
|
|
* Copy kernel to iovec. Returns -EFAULT on error.
|
|
*/
|
|
|
|
int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata,
|
|
int offset, int len)
|
|
{
|
|
int copy;
|
|
for (; len > 0; ++iov) {
|
|
/* Skip over the finished iovecs */
|
|
if (unlikely(offset >= iov->iov_len)) {
|
|
offset -= iov->iov_len;
|
|
continue;
|
|
}
|
|
copy = min_t(unsigned int, iov->iov_len - offset, len);
|
|
if (copy_to_user(iov->iov_base + offset, kdata, copy))
|
|
return -EFAULT;
|
|
offset = 0;
|
|
kdata += copy;
|
|
len -= copy;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(memcpy_toiovecend);
|
|
|
|
/*
|
|
* Copy iovec to kernel. Returns -EFAULT on error.
|
|
*/
|
|
|
|
int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
|
|
int offset, int len)
|
|
{
|
|
/* No data? Done! */
|
|
if (len == 0)
|
|
return 0;
|
|
|
|
/* Skip over the finished iovecs */
|
|
while (offset >= iov->iov_len) {
|
|
offset -= iov->iov_len;
|
|
iov++;
|
|
}
|
|
|
|
while (len > 0) {
|
|
u8 __user *base = iov->iov_base + offset;
|
|
int copy = min_t(unsigned int, len, iov->iov_len - offset);
|
|
|
|
offset = 0;
|
|
if (copy_from_user(kdata, base, copy))
|
|
return -EFAULT;
|
|
len -= copy;
|
|
kdata += copy;
|
|
iov++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(memcpy_fromiovecend);
|