6.12-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 2d20773aec14996b6cc4db92d885028319be683d ]
mctp_dump_addrinfo() is one of the last users of net->dev_index_head[] in the control path.
Switch to for_each_netdev_dump() for better scalability.
Use C99 for mctp_device_rtnl_msg_handlers[] to prepare future RTNL removal from mctp_dump_addrinfo()
(mdev->addrs is not yet RCU protected)
Signed-off-by: Eric Dumazet edumazet@google.com Cc: Matt Johnston matt@codeconstruct.com.au Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Acked-by: Jeremy Kerr jk@codeconstruct.com.au Link: https://patch.msgid.link/20241206223811.1343076-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: f11cf946c0a9 ("net: mctp: Don't access ifa_index when missing") Signed-off-by: Sasha Levin sashal@kernel.org --- net/mctp/device.c | 50 ++++++++++++++++++----------------------------- 1 file changed, 19 insertions(+), 31 deletions(-)
diff --git a/net/mctp/device.c b/net/mctp/device.c index 85cc5f31f1e7c..cdb18da96c4bc 100644 --- a/net/mctp/device.c +++ b/net/mctp/device.c @@ -20,8 +20,7 @@ #include <net/sock.h>
struct mctp_dump_cb { - int h; - int idx; + unsigned long ifindex; size_t a_idx; };
@@ -115,43 +114,29 @@ static int mctp_dump_addrinfo(struct sk_buff *skb, struct netlink_callback *cb) { struct mctp_dump_cb *mcb = (void *)cb->ctx; struct net *net = sock_net(skb->sk); - struct hlist_head *head; struct net_device *dev; struct ifaddrmsg *hdr; struct mctp_dev *mdev; - int ifindex; - int idx = 0, rc; + int ifindex, rc;
hdr = nlmsg_data(cb->nlh); // filter by ifindex if requested ifindex = hdr->ifa_index;
rcu_read_lock(); - for (; mcb->h < NETDEV_HASHENTRIES; mcb->h++, mcb->idx = 0) { - idx = 0; - head = &net->dev_index_head[mcb->h]; - hlist_for_each_entry_rcu(dev, head, index_hlist) { - if (idx >= mcb->idx && - (ifindex == 0 || ifindex == dev->ifindex)) { - mdev = __mctp_dev_get(dev); - if (mdev) { - rc = mctp_dump_dev_addrinfo(mdev, - skb, cb); - mctp_dev_put(mdev); - // Error indicates full buffer, this - // callback will get retried. - if (rc < 0) - goto out; - } - } - idx++; - // reset for next iteration - mcb->a_idx = 0; - } + for_each_netdev_dump(net, dev, mcb->ifindex) { + if (ifindex && ifindex != dev->ifindex) + continue; + mdev = __mctp_dev_get(dev); + if (!mdev) + continue; + rc = mctp_dump_dev_addrinfo(mdev, skb, cb); + mctp_dev_put(mdev); + if (rc < 0) + break; + mcb->a_idx = 0; } -out: rcu_read_unlock(); - mcb->idx = idx;
return skb->len; } @@ -525,9 +510,12 @@ static struct notifier_block mctp_dev_nb = { };
static const struct rtnl_msg_handler mctp_device_rtnl_msg_handlers[] = { - {THIS_MODULE, PF_MCTP, RTM_NEWADDR, mctp_rtm_newaddr, NULL, 0}, - {THIS_MODULE, PF_MCTP, RTM_DELADDR, mctp_rtm_deladdr, NULL, 0}, - {THIS_MODULE, PF_MCTP, RTM_GETADDR, NULL, mctp_dump_addrinfo, 0}, + {.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_NEWADDR, + .doit = mctp_rtm_newaddr}, + {.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_DELADDR, + .doit = mctp_rtm_deladdr}, + {.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_GETADDR, + .dumpit = mctp_dump_addrinfo}, };
int __init mctp_device_init(void)