diff options
| author | Kuniyuki Iwashima <kuniyu@google.com> | 2025-10-22 08:39:46 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-10-25 03:57:20 +0300 |
| commit | 35d7c70870338aa6a367b9e4ed528914320b0be0 (patch) | |
| tree | 25f31933b82ba8fff2d9e2136ab999f1282242bb /include | |
| parent | 06d6322280d95757cef1e3ee0fc62c644629523e (diff) | |
| download | linux-35d7c70870338aa6a367b9e4ed528914320b0be0.tar.xz | |
neighbour: Annotate access to neigh_parms fields.
NEIGH_VAR() is read locklessly in the fast path, and IPv6 ndisc uses
NEIGH_VAR_SET() locklessly.
The next patch will convert neightbl_dump_info() to RCU.
Let's annotate accesses to neigh_param with READ_ONCE() and WRITE_ONCE().
Note that ndisc_ifinfo_sysctl_change() uses &NEIGH_VAR() and we cannot
use '&' with READ_ONCE(), so NEIGH_VAR_PTR() is introduced.
Note also that NEIGH_VAR_INIT() does not need WRITE_ONCE() as it is before
parms is published. Also, the only user hippi_neigh_setup_dev() is no
longer called since commit e3804cbebb67 ("net: remove COMPAT_NET_DEV_OPS"),
which looks wrong, but probably no one uses HIPPI and RoadRunner.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251022054004.2514876-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/neighbour.h | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 4a30bd458c5a..998ff9eccebb 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -92,15 +92,17 @@ struct neigh_parms { static inline void neigh_var_set(struct neigh_parms *p, int index, int val) { set_bit(index, p->data_state); - p->data[index] = val; + WRITE_ONCE(p->data[index], val); } -#define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr]) +#define __NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr]) +#define NEIGH_VAR(p, attr) READ_ONCE(__NEIGH_VAR(p, attr)) +#define NEIGH_VAR_PTR(p, attr) (&(__NEIGH_VAR(p, attr))) /* In ndo_neigh_setup, NEIGH_VAR_INIT should be used. * In other cases, NEIGH_VAR_SET should be used. */ -#define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val) +#define NEIGH_VAR_INIT(p, attr, val) (__NEIGH_VAR(p, attr) = val) #define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val) static inline void neigh_parms_data_state_setall(struct neigh_parms *p) @@ -378,6 +380,13 @@ struct net *neigh_parms_net(const struct neigh_parms *parms) unsigned long neigh_rand_reach_time(unsigned long base); +static inline void neigh_set_reach_time(struct neigh_parms *p) +{ + unsigned long base = NEIGH_VAR(p, BASE_REACHABLE_TIME); + + WRITE_ONCE(p->reachable_time, neigh_rand_reach_time(base)); +} + void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, struct sk_buff *skb); struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, |