[PATCH v3 18/18] vhost: vhost_scsi_handle_vq() should just use copy_from_user()

From: Al Viro <viro@ZenIV.linux.org.uk>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org,
	virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: [PATCH v3 18/18] vhost: vhost_scsi_handle_vq() should just use copy_from_user()
Date: Wed,  4 Feb 2015 06:40:09 +0000	[thread overview]
Message-ID: <1423032009-18367-18-git-send-email-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20150204063730.GG29656@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

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 <mst@redhat.com>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 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 <linux/uaccess.h>
-#include <linux/export.h>
-#include <linux/uio.h>
-
-/*
- *	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
