[PATCH net-next] gtp: annotate PDP lookups under RTNL
From: Runyu Xiao <hidden>
Date: 2026-07-01 12:44:48
Also in:
lkml
Subsystem:
gtp (gprs tunneling protocol), networking drivers, the rest · Maintainers:
Pablo Neira Ayuso, Harald Welte, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The GTP PDP lookup helpers are shared by RCU-protected data and report paths and RTNL-protected control paths such as gtp_genl_new_pdp(). The helpers walk RCU hlists, but they do not currently pass the RTNL condition for the control-path lookups. Pass lockdep_rtnl_is_held() to the PDP hlist iterators. Existing RCU-reader callers remain valid because the RCU-list macros also accept an active RCU read-side section; the added condition only documents the non-RCU protection already used by RTNL control paths. This was found by our static analysis tool and then manually reviewed against the current tree. The dynamic triage evidence is a target-matched CONFIG_PROVE_RCU_LIST warning; the change is limited to documenting the existing protection contract. This is a lockdep annotation cleanup. It does not change PDP lifetime or hash updates. Signed-off-by: Runyu Xiao <redacted> --- drivers/net/gtp.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 5cb59d72bc82..b94073c55f17 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c@@ -151,7 +151,8 @@ static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid, u16 family) head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; - hlist_for_each_entry_rcu(pdp, head, hlist_tid) { + hlist_for_each_entry_rcu(pdp, head, hlist_tid, + lockdep_rtnl_is_held()) { if (pdp->af == family && pdp->gtp_version == GTP_V0 && pdp->u.v0.tid == tid)
@@ -168,7 +169,8 @@ static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid, u16 family) head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; - hlist_for_each_entry_rcu(pdp, head, hlist_tid) { + hlist_for_each_entry_rcu(pdp, head, hlist_tid, + lockdep_rtnl_is_held()) { if (pdp->af == family && pdp->gtp_version == GTP_V1 && pdp->u.v1.i_tei == tid)
@@ -185,7 +187,8 @@ static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size]; - hlist_for_each_entry_rcu(pdp, head, hlist_addr) { + hlist_for_each_entry_rcu(pdp, head, hlist_addr, + lockdep_rtnl_is_held()) { if (pdp->af == AF_INET && pdp->ms.addr.s_addr == ms_addr) return pdp;
@@ -220,7 +223,8 @@ static struct pdp_ctx *ipv6_pdp_find(struct gtp_dev *gtp, head = >p->addr_hash[ipv6_hashfn(ms_addr) % gtp->hash_size]; - hlist_for_each_entry_rcu(pdp, head, hlist_addr) { + hlist_for_each_entry_rcu(pdp, head, hlist_addr, + lockdep_rtnl_is_held()) { if (pdp->af == AF_INET6 && ipv6_pdp_addr_equal(&pdp->ms.addr6, ms_addr)) return pdp;
--
2.34.1