diff mbox series

[v2,net-next,12/19] ip6mr: do not acquire mrt_lock in ioctl(SIOCGETMIFCNT_IN6)

Message ID 20220623043449.1217288-13-edumazet@google.com (mailing list archive)
State Accepted
Commit 638cf4a24a09d14c51415dd0964f978f97d54642
Delegated to: Netdev Maintainers
Headers show
Series ipmr: get rid of rwlocks | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 2 maintainers not CCed: yoshfuji@linux-ipv6.org dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 86 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet June 23, 2022, 4:34 a.m. UTC 
rcu_read_lock() protection is good enough.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/ip6mr.c | 42 ++++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 20 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index fa6720377e82d732ccafa02b37cc28e0ab1cea07..b4ad606e24bdaf12c233f642cee303f06ccfa4eb 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -1896,20 +1896,20 @@  int ip6mr_ioctl(struct sock *sk, int cmd, void __user *arg)
 		if (vr.mifi >= mrt->maxvif)
 			return -EINVAL;
 		vr.mifi = array_index_nospec(vr.mifi, mrt->maxvif);
-		read_lock(&mrt_lock);
+		rcu_read_lock();
 		vif = &mrt->vif_table[vr.mifi];
 		if (VIF_EXISTS(mrt, vr.mifi)) {
-			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_IN6:
 		if (copy_from_user(&sr, arg, sizeof(sr)))
@@ -1971,20 +1971,20 @@  int ip6mr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
 		if (vr.mifi >= mrt->maxvif)
 			return -EINVAL;
 		vr.mifi = array_index_nospec(vr.mifi, mrt->maxvif);
-		read_lock(&mrt_lock);
+		rcu_read_lock();
 		vif = &mrt->vif_table[vr.mifi];
 		if (VIF_EXISTS(mrt, vr.mifi)) {
-			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_IN6:
 		if (copy_from_user(&sr, arg, sizeof(sr)))
@@ -2038,8 +2038,8 @@  static int ip6mr_forward2(struct net *net, struct mr_table *mrt,
 
 #ifdef CONFIG_IPV6_PIMSM_V2
 	if (vif->flags & MIFF_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();
@@ -2077,8 +2077,8 @@  static int ip6mr_forward2(struct net *net, struct mr_table *mrt,
 	 * result in receiving multiple packets.
 	 */
 	skb->dev = vif_dev;
-	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);
 
 	/* We are about to write */
 	/* XXX: extension headers? */
@@ -2168,8 +2168,10 @@  static void ip6_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