From 559260fd9d9a43afa4f8dd518969a1cc7dd40418 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 23 Jun 2022 04:34:36 +0000 Subject: ipmr: do not acquire mrt_lock in ioctl(SIOCGETVIFCNT) rcu_read_lock() protection is good enough. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/ipmr.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) (limited to 'net/ipv4/ipmr.c') diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 8a94f9a459cd..bc8b7504fde6 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1611,20 +1611,20 @@ int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg) if (vr.vifi >= mrt->maxvif) return -EINVAL; vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); - read_lock(&mrt_lock); + rcu_read_lock(); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { - vr.icount = vif->pkt_in; - vr.ocount = vif->pkt_out; - vr.ibytes = vif->bytes_in; - vr.obytes = vif->bytes_out; - read_unlock(&mrt_lock); + vr.icount = READ_ONCE(vif->pkt_in); + vr.ocount = READ_ONCE(vif->pkt_out); + vr.ibytes = READ_ONCE(vif->bytes_in); + vr.obytes = READ_ONCE(vif->bytes_out); + rcu_read_unlock(); if (copy_to_user(arg, &vr, sizeof(vr))) return -EFAULT; return 0; } - read_unlock(&mrt_lock); + rcu_read_unlock(); return -EADDRNOTAVAIL; case SIOCGETSGCNT: if (copy_from_user(&sr, arg, sizeof(sr))) @@ -1686,20 +1686,20 @@ int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) if (vr.vifi >= mrt->maxvif) return -EINVAL; vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); - read_lock(&mrt_lock); + rcu_read_lock(); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { - vr.icount = vif->pkt_in; - vr.ocount = vif->pkt_out; - vr.ibytes = vif->bytes_in; - vr.obytes = vif->bytes_out; - read_unlock(&mrt_lock); + vr.icount = READ_ONCE(vif->pkt_in); + vr.ocount = READ_ONCE(vif->pkt_out); + vr.ibytes = READ_ONCE(vif->bytes_in); + vr.obytes = READ_ONCE(vif->bytes_out); + rcu_read_unlock(); if (copy_to_user(arg, &vr, sizeof(vr))) return -EFAULT; return 0; } - read_unlock(&mrt_lock); + rcu_read_unlock(); return -EADDRNOTAVAIL; case SIOCGETSGCNT: if (copy_from_user(&sr, arg, sizeof(sr))) @@ -1835,8 +1835,8 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, goto out_free; if (vif->flags & VIFF_REGISTER) { - vif->pkt_out++; - vif->bytes_out += skb->len; + WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1); + WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len); vif_dev->stats.tx_bytes += skb->len; vif_dev->stats.tx_packets++; rcu_read_lock(); @@ -1885,8 +1885,8 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, goto out_free; } - vif->pkt_out++; - vif->bytes_out += skb->len; + WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1); + WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len); skb_dst_drop(skb); skb_dst_set(skb, &rt->dst); @@ -2002,8 +2002,10 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt, } forward: - mrt->vif_table[vif].pkt_in++; - mrt->vif_table[vif].bytes_in += skb->len; + WRITE_ONCE(mrt->vif_table[vif].pkt_in, + mrt->vif_table[vif].pkt_in + 1); + WRITE_ONCE(mrt->vif_table[vif].bytes_in, + mrt->vif_table[vif].bytes_in + skb->len); /* Forward the frame */ if (c->mfc_origin == htonl(INADDR_ANY) && -- cgit