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| author | Haiyang Zhang <haiyangz@microsoft.com> | 2020-02-06 14:01:05 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-07 11:33:01 +0100 |
| commit | 184367dce4f744bde54377203305ccc8889aa79f (patch) | |
| tree | c2d9b5c2ef577f04482af7065944b71f5ddc0fe0 | |
| parent | 6910fe95c61880e75b1c3a20eb13a6fd01ca501a (diff) | |
| download | linux-184367dce4f744bde54377203305ccc8889aa79f.tar.gz linux-184367dce4f744bde54377203305ccc8889aa79f.tar.bz2 linux-184367dce4f744bde54377203305ccc8889aa79f.zip | |
hv_netvsc: Fix XDP refcnt for synthetic and VF NICs
The caller of XDP_SETUP_PROG has already incremented refcnt in
__bpf_prog_get(), so drivers should only increment refcnt by
num_queues - 1.
To fix the issue, update netvsc_xdp_set() to add the correct number
to refcnt.
Hold a refcnt in netvsc_xdp_set()’s other caller, netvsc_attach().
And, do the same in netvsc_vf_setxdp(). Otherwise, every time when VF is
removed and added from the host side, the refcnt will be decreased by one,
which may cause page fault when unloading xdp program.
Fixes: 351e1581395f ("hv_netvsc: Add XDP support")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/hyperv/netvsc_bpf.c | 13 | ||||
| -rw-r--r-- | drivers/net/hyperv/netvsc_drv.c | 5 |
2 files changed, 15 insertions, 3 deletions
diff --git a/drivers/net/hyperv/netvsc_bpf.c b/drivers/net/hyperv/netvsc_bpf.c index 20adfe544294..b86611041db6 100644 --- a/drivers/net/hyperv/netvsc_bpf.c +++ b/drivers/net/hyperv/netvsc_bpf.c @@ -120,7 +120,7 @@ int netvsc_xdp_set(struct net_device *dev, struct bpf_prog *prog, } if (prog) - bpf_prog_add(prog, nvdev->num_chn); + bpf_prog_add(prog, nvdev->num_chn - 1); for (i = 0; i < nvdev->num_chn; i++) rcu_assign_pointer(nvdev->chan_table[i].bpf_prog, prog); @@ -136,6 +136,7 @@ int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog) { struct netdev_bpf xdp; bpf_op_t ndo_bpf; + int ret; ASSERT_RTNL(); @@ -148,10 +149,18 @@ int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog) memset(&xdp, 0, sizeof(xdp)); + if (prog) + bpf_prog_inc(prog); + xdp.command = XDP_SETUP_PROG; xdp.prog = prog; - return ndo_bpf(vf_netdev, &xdp); + ret = ndo_bpf(vf_netdev, &xdp); + + if (ret && prog) + bpf_prog_put(prog); + + return ret; } static u32 netvsc_xdp_query(struct netvsc_device *nvdev) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 8fc71bd49894..65e12cb07f45 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -1059,9 +1059,12 @@ static int netvsc_attach(struct net_device *ndev, prog = dev_info->bprog; if (prog) { + bpf_prog_inc(prog); ret = netvsc_xdp_set(ndev, prog, NULL, nvdev); - if (ret) + if (ret) { + bpf_prog_put(prog); goto err1; + } } /* In any case device is now ready */ |