From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v2 18/18] vhost: vhost_scsi_handle_vq() should just use copy_from_user() Date: Tue, 3 Feb 2015 11:05:14 +0200 Message-ID: <20150203090514.GC2830@redhat.com> References: <20150131035513.GK29656@ZenIV.linux.org.uk> <1422863977-17668-18-git-send-email-viro@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , netdev@vger.kernel.org, "Nicholas A. Bellinger" , kvm@vger.kernel.org To: Al Viro Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47577 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750983AbbBCJFU (ORCPT ); Tue, 3 Feb 2015 04:05:20 -0500 Content-Disposition: inline In-Reply-To: <1422863977-17668-18-git-send-email-viro@ZenIV.linux.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Feb 02, 2015 at 07:59:37AM +0000, Al Viro wrote: > From: Al Viro > > it has just verified that it asks no more than the length of the > first segment of iovec. > > And with that the last user of stuff in lib/iovec.c is gone. > RIP. > > Cc: Michael S. Tsirkin > Cc: Nicholas A. Bellinger > Cc: kvm@vger.kernel.org > Signed-off-by: Al Viro BTW it should really be __copy_from_user since the iovec is pre-validated by vhost core. Still Nicholas is rewriting it all anyway, so not worth the time to optimize it, so Acked-by: Michael S. Tsirkin But, can you pls copy virtualization@lists.linux-foundation.org ? I think some guys working on virtio might only hang out there. > --- > drivers/vhost/scsi.c | 2 +- > include/linux/uio.h | 2 -- > lib/Makefile | 2 +- > lib/iovec.c | 36 ------------------------------------ > 4 files changed, 2 insertions(+), 40 deletions(-) > delete mode 100644 lib/iovec.c > > diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c > index d695b16..dc78d87 100644 > --- a/drivers/vhost/scsi.c > +++ b/drivers/vhost/scsi.c > @@ -1079,7 +1079,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) > req_size, vq->iov[0].iov_len); > break; > } > - ret = memcpy_fromiovecend(req, &vq->iov[0], 0, req_size); > + ret = copy_from_user(req, vq->iov[0].iov_base, req_size); > if (unlikely(ret)) { > vq_err(vq, "Faulted on virtio_scsi_cmd_req\n"); > break; > diff --git a/include/linux/uio.h b/include/linux/uio.h > index 02bd8a9..3e0cb4e 100644 > --- a/include/linux/uio.h > +++ b/include/linux/uio.h > @@ -135,6 +135,4 @@ static inline void iov_iter_reexpand(struct iov_iter *i, size_t count) > size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); > size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); > > -int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, > - int offset, int len); > #endif > diff --git a/lib/Makefile b/lib/Makefile > index 3c3b30b..1071d06 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -24,7 +24,7 @@ obj-y += lockref.o > > obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ > bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ > - gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o clz_ctz.o \ > + gcd.o lcm.o list_sort.o uuid.o flex_array.o clz_ctz.o \ > bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \ > percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o > obj-y += string_helpers.o > diff --git a/lib/iovec.c b/lib/iovec.c > deleted file mode 100644 > index d8f17a9..0000000 > --- a/lib/iovec.c > +++ /dev/null > @@ -1,36 +0,0 @@ > -#include > -#include > -#include > - > -/* > - * 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); > -- > 2.1.4