diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-07-10 15:16:53 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-07-11 17:13:58 -0700 |
| commit | cef4902b0fadfc4181176ef5713f0b7cf2a40d8f (patch) | |
| tree | 05b9cc1dd265e2c35070b570e13b5cfcd6044958 | |
| parent | b07593edd2faf310f9b758896f4f1c6054515be4 (diff) | |
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@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240710151653.3786604-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/core/rtnetlink.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index eabfc8290f5e..87e67194f240 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) |