[mirror_ubuntu-bionic-kernel.git] / lib / iovec.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.
 */

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);
Commit	Line	Data
d2f83e90 RR	1	#include <linux/uaccess.h>
	2	#include <linux/export.h>
	3	#include <linux/uio.h>
	4
	5	/*
	6	* Copy iovec to kernel. Returns -EFAULT on error.
	7	*
	8	* Note: this modifies the original iovec.
	9	*/
	10
	11	int memcpy_fromiovec(unsigned char kdata, struct iovec iov, int len)
	12	{
	13	while (len > 0) {
	14	if (iov->iov_len) {
	15	int copy = min_t(unsigned int, len, iov->iov_len);
	16	if (copy_from_user(kdata, iov->iov_base, copy))
	17	return -EFAULT;
	18	len -= copy;
	19	kdata += copy;
	20	iov->iov_base += copy;
	21	iov->iov_len -= copy;
	22	}
	23	iov++;
	24	}
	25
	26	return 0;
	27	}
	28	EXPORT_SYMBOL(memcpy_fromiovec);
	29
ac5ccdba MT	30	/*
	31	* Copy kernel to iovec. Returns -EFAULT on error.
	32	*/
	33
	34	int memcpy_toiovecend(const struct iovec iov, unsigned char kdata,
	35	int offset, int len)
	36	{
	37	int copy;
	38	for (; len > 0; ++iov) {
	39	/* Skip over the finished iovecs */
	40	if (unlikely(offset >= iov->iov_len)) {
	41	offset -= iov->iov_len;
	42	continue;
	43	}
	44	copy = min_t(unsigned int, iov->iov_len - offset, len);
	45	if (copy_to_user(iov->iov_base + offset, kdata, copy))
	46	return -EFAULT;
	47	offset = 0;
	48	kdata += copy;
	49	len -= copy;
	50	}
	51
	52	return 0;
	53	}
	54	EXPORT_SYMBOL(memcpy_toiovecend);
	55
	56	/*
	57	* Copy iovec to kernel. Returns -EFAULT on error.
	58	*/
	59
	60	int memcpy_fromiovecend(unsigned char kdata, const struct iovec iov,
	61	int offset, int len)
	62	{
06ebb06d SL	63	/* No data? Done! */
	64	if (len == 0)
	65	return 0;
	66
ac5ccdba MT	67	/* Skip over the finished iovecs */
	68	while (offset >= iov->iov_len) {
	69	offset -= iov->iov_len;
	70	iov++;
	71	}
	72
	73	while (len > 0) {
	74	u8 __user *base = iov->iov_base + offset;
	75	int copy = min_t(unsigned int, len, iov->iov_len - offset);
	76
	77	offset = 0;
	78	if (copy_from_user(kdata, base, copy))
	79	return -EFAULT;
	80	len -= copy;
	81	kdata += copy;
	82	iov++;
	83	}
	84
	85	return 0;
	86	}
	87	EXPORT_SYMBOL(memcpy_fromiovecend);