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tun: make tun_build_skb() thread safe

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tun_build_skb() is not thread safe since it uses per queue page frag,
this will break things when multiple threads are sending through same
queue. Switch to use per-thread generator (no lock involved).

Fixes: 66ccbc9c87 ("tap: use build_skb() for small packet")
Tested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2017-08-16 22:14:33 +08:00 committed by David S. Miller
parent ba5c4dac03
commit 0bbd7dad34
1 changed files with 1 additions and 6 deletions
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7
drivers/net/tun.c
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@ -175,7 +175,6 @@ struct tun_file {
struct list_head next;
struct tun_struct *detached;
struct skb_array tx_array;
struct page_frag alloc_frag;
};
struct tun_flow_entry {
@ -578,8 +577,6 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
}
if (tun)
skb_array_cleanup(&tfile->tx_array);
if (tfile->alloc_frag.page)
put_page(tfile->alloc_frag.page);
sock_put(&tfile->sk);
}
}
@ -1272,7 +1269,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
struct virtio_net_hdr *hdr,
int len, int *generic_xdp)
{
struct page_frag *alloc_frag = &tfile->alloc_frag;
struct page_frag *alloc_frag = &current->task_frag;
struct sk_buff *skb;
struct bpf_prog *xdp_prog;
int buflen = SKB_DATA_ALIGN(len + TUN_RX_PAD) +
@ -2580,8 +2577,6 @@ static int tun_chr_open(struct inode *inode, struct file * file)
tfile->sk.sk_write_space = tun_sock_write_space;
tfile->sk.sk_sndbuf = INT_MAX;
tfile->alloc_frag.page = NULL;
file->private_data = tfile;
INIT_LIST_HEAD(&tfile->next);