Commit 43b39dcd authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by David S. Miller

tun: fix tun_chr_aio_read so that aio works

aio_read gets const struct iovec * but tun_chr_aio_read casts this to struct
iovec * and modifies the iovec. As a result, attempts to use io_submit
to get packets from a tun device fail with weird errors such as EINVAL.

Fix by using the new skb_copy_datagram_const_iovec.
Signed-off-by: default avatarMichael S. Tsirkin <>
Signed-off-by: default avatarDavid S. Miller <>
parent 0a1ec07a
......@@ -683,7 +683,7 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
/* Put packet to the user space buffer */
static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
struct sk_buff *skb,
struct iovec *iv, int len)
const struct iovec *iv, int len)
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
......@@ -697,7 +697,7 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
pi.flags |= TUN_PKT_STRIP;
if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
return -EFAULT;
total += sizeof(pi);
......@@ -730,14 +730,15 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
gso.csum_offset = skb->csum_offset;
} /* else everything is zero */
if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
return -EFAULT;
total += sizeof(gso);
len = min_t(int, skb->len, len);
skb_copy_datagram_iovec(skb, 0, iv, len);
skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
total += len;
......@@ -792,7 +793,7 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
ret = tun_put_user(tun, skb, iv, len);
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