On Fri, May 17, 2013 at 09:12:39AM +0930, Rusty Russell wrote:
> Joe Perches <j...@perches.com> writes:
> > On Thu, 2013-05-16 at 13:04 +0930, Rusty Russell wrote:
> >> Asias He <as...@redhat.com> writes:
> >> > On Wed, May 15, 2013 at 02:47:53PM +0930, Rusty Russell wrote:
> > []
> >> > Other users are using memcpy_fromiovec and friends outside net. It seems
> >> > a good idea to put it in a util library. e.g.  crypto/algif_skcipher.c
> >> > which also depends on NET for it.
> >
> > []
> >> Subject: Hoist memcpy_fromiovec into lib/
> >
> > You'll need the "friends" memcpy_toiovec too.
> >
> > $ git grep -E \bmemcpy\w+iovec\w*"
> > crypto/algif_hash.c:    err = memcpy_toiovec(msg->msg_iov, ctx->result, 
> > len);
> > crypto/algif_skcipher.c:                        err = 
> > memcpy_fromiovec(page_address(sg_page(sg)) +
> > crypto/algif_skcipher.c:                        err = 
> > memcpy_fromiovec(page_address(sg_page(sg + i)),
> > drivers/dma/iovlock.c:#include <net/tcp.h> /* for memcpy_toiovec */
> > drivers/dma/iovlock.c:          return memcpy_toiovec(iov, kdata, len);
> > drivers/dma/iovlock.c:          err = memcpy_toiovec(iov, vaddr + offset, 
> > len);
> > drivers/isdn/mISDN/socket.c:    if (memcpy_fromiovec(skb_put(skb, len), 
> > msg->msg_iov, len)) {
> > drivers/misc/vmw_vmci/vmci_queue_pair.c:                        err = 
> > memcpy_fromiovec((u8 *)va + page_o
> > drivers/misc/vmw_vmci/vmci_queue_pair.c:                        err = 
> > memcpy_toiovec(iov, (u8 *)va + pag
> 
> Fascinating.  These all indirectly depend on NET, so there's no problem
> at the moment.  But it is a bit weird...
> 
> crypto/algif_hash.c: depends on CRYPTO_USER_API_HASH -> NET
> crypto/algif_skcipher.c: depends on CRYPTO_USER_API_SKCIPHER -> NET
> drivers/dma/iovlock.c: depends on NET_DMA -> NET
> drivers/isdn/mISDN/socket.c: depends on MISDN -> ISDN -> NET
> drivers/misc/vmw_vmci/vmci_queue_pair.c: depends on VMCI -> NET
> 
> Patch welcome.
> 
> Meanwhile, to avoid more bikeshedding I've put the patch I posted with
> all acks in my fixes branch.  One cycle through linux-next, then
> straight to Linus.

Not in 3.10-rc2 yes - still plan to merge for 3.10?

> Subject: Hoist memcpy_fromiovec into lib/
> 
> ERROR: "memcpy_fromiovec" [drivers/vhost/vhost_scsi.ko] undefined!
> 
> That function is only present with CONFIG_NET.  Turns out that
> crypto/algif_skcipher.c also uses that outside net, but it actually
> needs sockets anyway.
> 
> socket.h already include uio.h, so no callers need updating.
> 
> Reported-by: Randy Dunlap <rdun...@infradead.org>
> Acked-by: David S. Miller <da...@davemloft.net>
> Acked-by: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au>
> 
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index 428c37a..7266775 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -305,7 +305,6 @@ struct ucred {
>  
>  extern void cred_to_ucred(struct pid *pid, const struct cred *cred, struct 
> ucred *ucred);
>  
> -extern int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int 
> len);
>  extern int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
>                              int offset, int len);
>  extern int csum_partial_copy_fromiovecend(unsigned char *kdata, 
> diff --git a/include/linux/uio.h b/include/linux/uio.h
> index 629aaf5..21628d3 100644
> --- a/include/linux/uio.h
> +++ b/include/linux/uio.h
> @@ -35,4 +35,6 @@ static inline size_t iov_length(const struct iovec *iov, 
> unsigned long nr_segs)
>  }
>  
>  unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t 
> to);
> +
> +int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
>  #endif
> diff --git a/lib/Makefile b/lib/Makefile
> index e9c52e1..2377211 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -9,7 +9,7 @@ endif
>  
>  lib-y := ctype.o string.o vsprintf.o cmdline.o \
>        rbtree.o radix-tree.o dump_stack.o timerqueue.o\
> -      idr.o int_sqrt.o extable.o \
> +      idr.o int_sqrt.o extable.o iovec.o \
>        sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
>        proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
>        is_single_threaded.o plist.o decompress.o kobject_uevent.o \
> diff --git a/lib/iovec.c b/lib/iovec.c
> new file mode 100644
> index 0000000..632c5ea
> --- /dev/null
> +++ b/lib/iovec.c
> @@ -0,0 +1,29 @@
> +#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);
> +
> diff --git a/net/core/iovec.c b/net/core/iovec.c
> index 7e7aeb0..d81257f 100644
> --- a/net/core/iovec.c
> +++ b/net/core/iovec.c
> @@ -125,31 +125,6 @@ int memcpy_toiovecend(const struct iovec *iov, unsigned 
> char *kdata,
>  EXPORT_SYMBOL(memcpy_toiovecend);
>  
>  /*
> - *   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 iovec from kernel. Returns -EFAULT on error.
>   */
>  
--
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