diff mbox series

[net-next,3/3] neighbour: no longer hold RTNL in neigh_dump_info()

Message ID 20240418095106.3680616-4-edumazet@google.com (mailing list archive)
State Accepted
Commit ba0f780694237d96a1d6366f931cd716fb0f7ab5
Delegated to: Netdev Maintainers
Headers show
Series neighbour: convert neigh_dump_info() to RCU | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 930 this patch: 930
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 938 this patch: 938
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 941 this patch: 941
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-04-19--00-00 (tests: 961)

Commit Message

Eric Dumazet April 18, 2024, 9:51 a.m. UTC 
neigh_dump_table() is already relying on RCU protection.

pneigh_dump_table() is using its own protection (tbl->lock)

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/core/neighbour.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 2f9efc89e94e0f6d9e1491019583babb7bae77c7..13f2629091ef9ecd70a83f047a146c0990f308d9 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2721,7 +2721,6 @@  static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
 	if (filter->dev_idx || filter->master_idx)
 		flags |= NLM_F_DUMP_FILTERED;
 
-	rcu_read_lock();
 	nht = rcu_dereference(tbl->nht);
 
 	for (h = s_h; h < (1 << nht->hash_shift); h++) {
@@ -2745,7 +2744,6 @@  static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
 		}
 	}
 out:
-	rcu_read_unlock();
 	cb->args[1] = h;
 	cb->args[2] = idx;
 	return err;
@@ -2879,8 +2877,9 @@  static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
 
 	s_t = cb->args[0];
 
+	rcu_read_lock();
 	for (t = 0; t < NEIGH_NR_TABLES; t++) {
-		tbl = rcu_dereference_rtnl(neigh_tables[t]);
+		tbl = rcu_dereference(neigh_tables[t]);
 
 		if (!tbl)
 			continue;
@@ -2896,6 +2895,7 @@  static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
 		if (err < 0)
 			break;
 	}
+	rcu_read_unlock();
 
 	cb->args[0] = t;
 	return err;
@@ -3892,7 +3892,8 @@  static int __init neigh_init(void)
 {
 	rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, 0);
-	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, neigh_get, neigh_dump_info, 0);
+	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, neigh_get, neigh_dump_info,
+		      RTNL_FLAG_DUMP_UNLOCKED);
 
 	rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
 		      0);