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authorHaiyang Zhang <haiyangz@microsoft.com>2020-02-06 14:01:05 -0800
committerDavid S. Miller <davem@davemloft.net>2020-02-07 11:33:01 +0100
commit184367dce4f744bde54377203305ccc8889aa79f (patch)
treec2d9b5c2ef577f04482af7065944b71f5ddc0fe0
parent6910fe95c61880e75b1c3a20eb13a6fd01ca501a (diff)
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.c13
-rw-r--r--drivers/net/hyperv/netvsc_drv.c5
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 */