lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 7 Feb 2022 11:07:06 -0800 From: Eric Dumazet <eric.dumazet@...il.com> To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org> Cc: netdev <netdev@...r.kernel.org>, Eric Dumazet <edumazet@...gle.com>, Eric Dumazet <eric.dumazet@...il.com>, Oliver Hartkopp <socketcan@...tkopp.net> Subject: [PATCH net-next] can: gw: use call_rcu() instead of costly synchronize_rcu() From: Eric Dumazet <edumazet@...gle.com> Commit fb8696ab14ad ("can: gw: synchronize rcu operations before removing gw job entry") added three synchronize_rcu() calls to make sure one rcu grace period was observed before freeing a "struct cgw_job" (which are tiny objects). This should be converted to call_rcu() to avoid adding delays in device / network dismantles. Use the rcu_head that was already in struct cgw_job, not yet used. Signed-off-by: Eric Dumazet <edumazet@...gle.com> Cc: Oliver Hartkopp <socketcan@...tkopp.net> --- net/can/gw.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/net/can/gw.c b/net/can/gw.c index d8861e862f157aec36c417b71eb7e8f59bd064b9..20e74fe7d0906dccc65732b8f9e7e14e2d1192c3 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -577,6 +577,13 @@ static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj) gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj); } +static void cgw_job_free_rcu(struct rcu_head *rcu_head) +{ + struct cgw_job *gwj = container_of(rcu_head, struct cgw_job, rcu); + + kmem_cache_free(cgw_cache, gwj); +} + static int cgw_notifier(struct notifier_block *nb, unsigned long msg, void *ptr) { @@ -596,8 +603,7 @@ static int cgw_notifier(struct notifier_block *nb, if (gwj->src.dev == dev || gwj->dst.dev == dev) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); - synchronize_rcu(); - kmem_cache_free(cgw_cache, gwj); + call_rcu(&gwj->rcu, cgw_job_free_rcu); } } } @@ -1155,8 +1161,7 @@ static void cgw_remove_all_jobs(struct net *net) hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); - synchronize_rcu(); - kmem_cache_free(cgw_cache, gwj); + call_rcu(&gwj->rcu, cgw_job_free_rcu); } } @@ -1224,8 +1229,7 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); - synchronize_rcu(); - kmem_cache_free(cgw_cache, gwj); + call_rcu(&gwj->rcu, cgw_job_free_rcu); err = 0; break; } -- 2.35.0.263.gb82422642f-goog
Powered by blists - more mailing lists