[iov_iter] new primitives - copy_from_iter_full() and friends
copy_from_iter_full(), copy_from_iter_full_nocache() and
csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
et.al., advancing iterator only in case of successful full copy
and returning whether it had been successful or not.
Convert some obvious users. *NOTE* - do not blindly assume that
something is a good candidate for those unless you are sure that
not advancing iov_iter in failure case is the right thing in
this case. Anything that does short read/short write kind of
stuff (or is in a loop, etc.) is unlikely to be a good one.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
index c4a75a1..233e850 100644
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -181,7 +181,7 @@ static inline ssize_t vhci_get_user(struct vhci_data *data,
if (!skb)
return -ENOMEM;
- if (copy_from_iter(skb_put(skb, len), len, from) != len) {
+ if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
kfree_skb(skb);
return -EFAULT;
}
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 070e329..19d81ca 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -673,7 +673,6 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
int depth;
bool zerocopy = false;
size_t linear;
- ssize_t n;
if (q->flags & IFF_VNET_HDR) {
vnet_hdr_len = q->vnet_hdr_sz;
@@ -684,8 +683,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
len -= vnet_hdr_len;
err = -EFAULT;
- n = copy_from_iter(&vnet_hdr, sizeof(vnet_hdr), from);
- if (n != sizeof(vnet_hdr))
+ if (!copy_from_iter_full(&vnet_hdr, sizeof(vnet_hdr), from))
goto err;
iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr));
if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 8093e39..4fa2d75 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1171,7 +1171,6 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
bool zerocopy = false;
int err;
u32 rxhash;
- ssize_t n;
if (!(tun->dev->flags & IFF_UP))
return -EIO;
@@ -1181,8 +1180,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
return -EINVAL;
len -= sizeof(pi);
- n = copy_from_iter(&pi, sizeof(pi), from);
- if (n != sizeof(pi))
+ if (!copy_from_iter_full(&pi, sizeof(pi), from))
return -EFAULT;
}
@@ -1191,8 +1189,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
return -EINVAL;
len -= tun->vnet_hdr_sz;
- n = copy_from_iter(&gso, sizeof(gso), from);
- if (n != sizeof(gso))
+ if (!copy_from_iter_full(&gso, sizeof(gso), from))
return -EFAULT;
if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 17989b7..0bfd1e2 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -949,7 +949,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
goto error_mutex;
}
if (!io_data->read &&
- copy_from_iter(data, data_len, &io_data->data) != data_len) {
+ !copy_from_iter_full(data, data_len, &io_data->data)) {
ret = -EFAULT;
goto error_mutex;
}
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index bd82dd1..10b2576 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -667,7 +667,7 @@ ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
return -ENOMEM;
}
- if (unlikely(copy_from_iter(buf, len, from) != len)) {
+ if (unlikely(!copy_from_iter_full(buf, len, from))) {
value = -EFAULT;
goto out;
}
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 6e29d05..b296985 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -922,8 +922,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
*/
iov_iter_init(&out_iter, WRITE, vq->iov, out, out_size);
- ret = copy_from_iter(req, req_size, &out_iter);
- if (unlikely(ret != req_size)) {
+ if (unlikely(!copy_from_iter_full(req, req_size, &out_iter))) {
vq_err(vq, "Faulted on copy_from_iter\n");
vhost_scsi_send_bad_target(vs, vq, head, out);
continue;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index c6f2d89..06e8b81 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1862,8 +1862,7 @@ static int get_indirect(struct vhost_virtqueue *vq,
i, count);
return -EINVAL;
}
- if (unlikely(copy_from_iter(&desc, sizeof(desc), &from) !=
- sizeof(desc))) {
+ if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) {
vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",
i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);
return -EINVAL;
diff --git a/fs/ncpfs/file.c b/fs/ncpfs/file.c
index dd38ca1..83ca772 100644
--- a/fs/ncpfs/file.c
+++ b/fs/ncpfs/file.c
@@ -203,7 +203,7 @@ ncp_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
bufsize - (pos % bufsize),
iov_iter_count(from));
- if (copy_from_iter(bouncebuffer, to_write, from) != to_write) {
+ if (!copy_from_iter_full(bouncebuffer, to_write, from)) {
errno = -EFAULT;
break;
}
diff --git a/fs/orangefs/devorangefs-req.c b/fs/orangefs/devorangefs-req.c
index 516ffb4..b0ced66 100644
--- a/fs/orangefs/devorangefs-req.c
+++ b/fs/orangefs/devorangefs-req.c
@@ -355,7 +355,6 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
__u64 tag;
} head;
int total = ret = iov_iter_count(iter);
- int n;
int downcall_size = sizeof(struct orangefs_downcall_s);
int head_size = sizeof(head);
@@ -372,8 +371,7 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
return -EFAULT;
}
- n = copy_from_iter(&head, head_size, iter);
- if (n < head_size) {
+ if (!copy_from_iter_full(&head, head_size, iter)) {
gossip_err("%s: failed to copy head.\n", __func__);
return -EFAULT;
}
@@ -407,8 +405,7 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
return ret;
}
- n = copy_from_iter(&op->downcall, downcall_size, iter);
- if (n != downcall_size) {
+ if (!copy_from_iter_full(&op->downcall, downcall_size, iter)) {
gossip_err("%s: failed to copy downcall.\n", __func__);
goto Efault;
}
@@ -462,10 +459,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
goto Enomem;
}
memset(op->downcall.trailer_buf, 0, op->downcall.trailer_size);
- n = copy_from_iter(op->downcall.trailer_buf,
- op->downcall.trailer_size,
- iter);
- if (n != op->downcall.trailer_size) {
+ if (!copy_from_iter_full(op->downcall.trailer_buf,
+ op->downcall.trailer_size, iter)) {
gossip_err("%s: failed to copy trailer.\n", __func__);
vfree(op->downcall.trailer_buf);
goto Efault;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 6e22b54..e57c0cc 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -89,7 +89,9 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i);
size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
+bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i);
size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
+bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i);
size_t iov_iter_zero(size_t bytes, struct iov_iter *);
unsigned long iov_iter_alignment(const struct iov_iter *i);
unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
@@ -155,6 +157,7 @@ static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
}
size_t csum_and_copy_to_iter(const 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);
+bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
int import_iovec(int type, const struct iovec __user * uvector,
unsigned nr_segs, unsigned fast_segs,
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index f7a55e9..f6bda15 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -748,7 +748,7 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from)
return -ENOMEM;
buf[len] = '\0';
- if (copy_from_iter(buf, len, from) != len) {
+ if (!copy_from_iter_full(buf, len, from)) {
kfree(buf);
return -EFAULT;
}
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f2bd21b..83c00b7 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -568,6 +568,31 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(copy_from_iter);
+bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;
+ if (unlikely(i->type & ITER_PIPE)) {
+ WARN_ON(1);
+ return false;
+ }
+ if (unlikely(i->count < bytes)) \
+ return false;
+
+ iterate_all_kinds(i, bytes, v, ({
+ if (__copy_from_user((to += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len))
+ return false;
+ 0;}),
+ memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+ v.bv_offset, v.bv_len),
+ memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+ )
+
+ iov_iter_advance(i, bytes);
+ return true;
+}
+EXPORT_SYMBOL(copy_from_iter_full);
+
size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
@@ -587,6 +612,30 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(copy_from_iter_nocache);
+bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;
+ if (unlikely(i->type & ITER_PIPE)) {
+ WARN_ON(1);
+ return false;
+ }
+ if (unlikely(i->count < bytes)) \
+ return false;
+ iterate_all_kinds(i, bytes, v, ({
+ if (__copy_from_user_nocache((to += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len))
+ return false;
+ 0;}),
+ memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+ v.bv_offset, v.bv_len),
+ memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+ )
+
+ iov_iter_advance(i, bytes);
+ return true;
+}
+EXPORT_SYMBOL(copy_from_iter_full_nocache);
+
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
@@ -1008,7 +1057,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
}
iterate_and_advance(i, bytes, v, ({
int err = 0;
- next = csum_and_copy_from_user(v.iov_base,
+ next = csum_and_copy_from_user(v.iov_base,
(to += v.iov_len) - v.iov_len,
v.iov_len, 0, &err);
if (!err) {
@@ -1037,6 +1086,51 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
}
EXPORT_SYMBOL(csum_and_copy_from_iter);
+bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *to = addr;
+ __wsum sum, next;
+ size_t off = 0;
+ sum = *csum;
+ if (unlikely(i->type & ITER_PIPE)) {
+ WARN_ON(1);
+ return false;
+ }
+ if (unlikely(i->count < bytes))
+ return false;
+ iterate_all_kinds(i, bytes, v, ({
+ int err = 0;
+ next = csum_and_copy_from_user(v.iov_base,
+ (to += v.iov_len) - v.iov_len,
+ v.iov_len, 0, &err);
+ if (err)
+ return false;
+ sum = csum_block_add(sum, next, off);
+ off += v.iov_len;
+ 0;
+ }), ({
+ char *p = kmap_atomic(v.bv_page);
+ next = csum_partial_copy_nocheck(p + v.bv_offset,
+ (to += v.bv_len) - v.bv_len,
+ v.bv_len, 0);
+ kunmap_atomic(p);
+ sum = csum_block_add(sum, next, off);
+ off += v.bv_len;
+ }),({
+ next = csum_partial_copy_nocheck(v.iov_base,
+ (to += v.iov_len) - v.iov_len,
+ v.iov_len, 0);
+ sum = csum_block_add(sum, next, off);
+ off += v.iov_len;
+ })
+ )
+ *csum = sum;
+ iov_iter_advance(i, bytes);
+ return true;
+}
+EXPORT_SYMBOL(csum_and_copy_from_iter_full);
+
size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
struct iov_iter *i)
{
@@ -1051,7 +1145,7 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
iterate_and_advance(i, bytes, v, ({
int err = 0;
next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len,
- v.iov_base,
+ v.iov_base,
v.iov_len, 0, &err);
if (!err) {
sum = csum_block_add(sum, next, off);
diff --git a/net/atm/common.c b/net/atm/common.c
index 6dc1230..a3ca922 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -630,7 +630,7 @@ int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
goto out;
skb->dev = NULL; /* for paths shared with net_device interfaces */
ATM_SKB(skb)->atm_options = vcc->atm_options;
- if (copy_from_iter(skb_put(skb, size), size, &m->msg_iter) != size) {
+ if (!copy_from_iter_full(skb_put(skb, size), size, &m->msg_iter)) {
kfree_skb(skb);
error = -EFAULT;
goto out;
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 577f1c0..ce0b5dd 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2127,7 +2127,7 @@ static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
struct sk_buff **frag;
int sent = 0;
- if (copy_from_iter(skb_put(skb, count), count, &msg->msg_iter) != count)
+ if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
return -EFAULT;
sent += count;
@@ -2147,8 +2147,8 @@ static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
*frag = tmp;
- if (copy_from_iter(skb_put(*frag, count), count,
- &msg->msg_iter) != count)
+ if (!copy_from_iter_full(skb_put(*frag, count), count,
+ &msg->msg_iter))
return -EFAULT;
sent += count;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d2238b2..588ec20 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2432,14 +2432,11 @@ static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
struct virtio_net_hdr *vnet_hdr)
{
- int n;
-
if (*len < sizeof(*vnet_hdr))
return -EINVAL;
*len -= sizeof(*vnet_hdr);
- n = copy_from_iter(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter);
- if (n != sizeof(*vnet_hdr))
+ if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
return -EFAULT;
return __packet_snd_vnet_parse(vnet_hdr, *len);
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 17201aa..a22be50 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -268,7 +268,7 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
__skb_queue_tail(list, skb);
skb_copy_to_linear_data(skb, mhdr, mhsz);
pktpos = skb->data + mhsz;
- if (copy_from_iter(pktpos, dsz, &m->msg_iter) == dsz)
+ if (copy_from_iter_full(pktpos, dsz, &m->msg_iter))
return dsz;
rc = -EFAULT;
goto error;
@@ -299,7 +299,7 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
if (drem < pktrem)
pktrem = drem;
- if (copy_from_iter(pktpos, pktrem, &m->msg_iter) != pktrem) {
+ if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) {
rc = -EFAULT;
goto error;
}
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index d580ad0..f89f190 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1074,7 +1074,7 @@ long keyctl_instantiate_key_common(key_serial_t id,
}
ret = -EFAULT;
- if (copy_from_iter(payload, plen, from) != plen)
+ if (!copy_from_iter_full(payload, plen, from))
goto error2;
}
