From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] vhost-scsi: Depend on NET for memcpy_fromiovec Date: Thu, 23 May 2013 10:30:38 +0300 Message-ID: <20130523073038.GA15378@redhat.com> References: <20130515095558.918f2b29ba318a477eb5dde2@canb.auug.org.au> <1368579583-13097-1-git-send-email-asias@redhat.com> <8761yk254u.fsf@rustcorp.com.au> <20130516020848.GB23441@hj.localdomain> <87d2sra97h.fsf@rustcorp.com.au> <1368676505.2194.47.camel@joe-AO722> <878v3ea3v4.fsf@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <878v3ea3v4.fsf@rustcorp.com.au> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Rusty Russell Cc: Stephen Rothwell , kvm@vger.kernel.org, netdev@vger.kernel.org, Randy Dunlap , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, target-devel@vger.kernel.org, linux-next@vger.kernel.org, Joe Perches List-Id: linux-next.vger.kernel.org On Fri, May 17, 2013 at 09:12:39AM +0930, Rusty Russell wrote: > Joe Perches writes: > > On Thu, 2013-05-16 at 13:04 +0930, Rusty Russell wrote: > >> Asias He 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 /* 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 > Acked-by: David S. Miller > Acked-by: Michael S. Tsirkin > Signed-off-by: Rusty Russell > > 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 > +#include > +#include > + > +/* > + * 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. > */ >