[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240710151653.3786604-1-edumazet@google.com>
Date: Wed, 10 Jul 2024 15:16:53 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: netdev@...r.kernel.org, eric.dumazet@...il.com,
Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH v2 net-next] net: reduce rtnetlink_rcv_msg() stack usage
IFLA_MAX is increasing slowly but surely.
Some compilers use more than 512 bytes of stack in rtnetlink_rcv_msg()
because it calls rtnl_calcit() for RTM_GETLINK message.
Use noinline_for_stack attribute to not inline rtnl_calcit(),
and directly use nla_for_each_attr_type() (Jakub suggestion)
because we only care about IFLA_EXT_MASK at this stage.
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
net/core/rtnetlink.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index eabfc8290f5e29f2ef3e5c1481715ae9056ea689..87e67194f24046a8420bbb51c19fb0a686b9b06b 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3969,22 +3969,28 @@ static int rtnl_dellinkprop(struct sk_buff *skb, struct nlmsghdr *nlh,
return rtnl_linkprop(RTM_DELLINKPROP, skb, nlh, extack);
}
-static u32 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh)
+static noinline_for_stack u32 rtnl_calcit(struct sk_buff *skb,
+ struct nlmsghdr *nlh)
{
struct net *net = sock_net(skb->sk);
size_t min_ifinfo_dump_size = 0;
- struct nlattr *tb[IFLA_MAX+1];
u32 ext_filter_mask = 0;
struct net_device *dev;
- int hdrlen;
+ struct nlattr *nla;
+ int hdrlen, rem;
/* Same kernel<->userspace interface hack as in rtnl_dump_ifinfo. */
hdrlen = nlmsg_len(nlh) < sizeof(struct ifinfomsg) ?
sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg);
- if (nlmsg_parse_deprecated(nlh, hdrlen, tb, IFLA_MAX, ifla_policy, NULL) >= 0) {
- if (tb[IFLA_EXT_MASK])
- ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]);
+ if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
+ return NLMSG_GOODSIZE;
+
+ nla_for_each_attr_type(nla, IFLA_EXT_MASK,
+ nlmsg_attrdata(nlh, hdrlen),
+ nlmsg_attrlen(nlh, hdrlen), rem) {
+ if (nla_len(nla) == sizeof(u32))
+ ext_filter_mask = nla_get_u32(nla);
}
if (!ext_filter_mask)
--
2.45.2.993.g49e7a77208-goog
Powered by blists - more mailing lists