Re: [PATCH] iovec: move memcpy_from/toiovecend to lib/iovec.c
From: Randy Dunlap
Date: Thu Jun 19 2014 - 15:12:22 EST
On 06/19/14 11:22, Michael S. Tsirkin wrote:
> ERROR: "memcpy_fromiovecend" [drivers/vhost/vhost_scsi.ko] undefined!
>
> commit 9f977ef7b671f6169eca78bf40f230fe84b7c7e5
> vhost-scsi: Include prot_bytes into expected data transfer length
> in target-pending makes drivers/vhost/scsi.c call memcpy_fromiovecend().
> This function is not available when CONFIG_NET is not enabled.
>
> socket.h already includes uio.h, so no callers need updating.
>
> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> [build-tested]
Thanks.
> ---
>
> David, could you please ack merging this through
> target-pending to avoid dependency issues?
>
> Thanks!
>
> include/linux/socket.h | 4 ----
> include/linux/uio.h | 4 ++++
> lib/iovec.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++
> net/core/iovec.c | 55 --------------------------------------------------
> 4 files changed, 59 insertions(+), 59 deletions(-)
>
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index 8e98297..ec538fc 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -305,8 +305,6 @@ struct ucred {
> /* IPX options */
> #define IPX_TYPE 1
>
> -extern int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
> - int offset, int len);
> extern int csum_partial_copy_fromiovecend(unsigned char *kdata,
> struct iovec *iov,
> int offset,
> @@ -315,8 +313,6 @@ extern unsigned long iov_pages(const struct iovec *iov, int offset,
> unsigned long nr_segs);
>
> extern int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode);
> -extern int memcpy_toiovecend(const struct iovec *v, unsigned char *kdata,
> - int offset, int len);
> extern int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr);
> extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data);
>
> diff --git a/include/linux/uio.h b/include/linux/uio.h
> index 199bcc3..8a4709a 100644
> --- a/include/linux/uio.h
> +++ b/include/linux/uio.h
> @@ -89,5 +89,9 @@ static inline size_t iov_iter_count(struct iov_iter *i)
>
> int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
> int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len);
> +int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
> + int offset, int len);
> +int memcpy_toiovecend(const struct iovec *v, unsigned char *kdata,
> + int offset, int len);
>
> #endif
> diff --git a/lib/iovec.c b/lib/iovec.c
> index 454baa8..7a7c2da 100644
> --- a/lib/iovec.c
> +++ b/lib/iovec.c
> @@ -51,3 +51,58 @@ int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
> 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)
> +{
> + /* 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);
> diff --git a/net/core/iovec.c b/net/core/iovec.c
> index b618694..827dd6b 100644
> --- a/net/core/iovec.c
> +++ b/net/core/iovec.c
> @@ -75,61 +75,6 @@ int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *a
> }
>
> /*
> - * 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)
> -{
> - /* 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);
> -
> -/*
> * And now for the all-in-one: copy and checksum from a user iovec
> * directly to a datagram
> * Calls to csum_partial but the last must be in 32 bit chunks
>
--
~Randy
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