From 9a99d4a50cb8ce516adf0f2436138d4c8e6e4535 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sun, 2 Jun 2013 15:00:52 +0000 Subject: [PATCH] icmp: avoid allocating large struct on stack struct icmp_bxm is a large struct, reduce stack usage by allocating it on heap. Cc: Eric Dumazet Cc: Joe Perches Cc: David S. Miller Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/ipv4/icmp.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 2864ca33bedc..5f7d11a45871 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -482,7 +482,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) { struct iphdr *iph; int room; - struct icmp_bxm icmp_param; + struct icmp_bxm *icmp_param; struct rtable *rt = skb_rtable(skb_in); struct ipcm_cookie ipc; struct flowi4 fl4; @@ -558,9 +558,13 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) } } + icmp_param = kmalloc(sizeof(*icmp_param), GFP_ATOMIC); + if (!icmp_param) + return; + sk = icmp_xmit_lock(net); if (sk == NULL) - return; + goto out_free; /* * Construct source address and options. @@ -586,7 +590,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) IPTOS_PREC_INTERNETCONTROL) : iph->tos; - if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in)) + if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb_in)) goto out_unlock; @@ -594,19 +598,19 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) * Prepare data for ICMP header. */ - icmp_param.data.icmph.type = type; - icmp_param.data.icmph.code = code; - icmp_param.data.icmph.un.gateway = info; - icmp_param.data.icmph.checksum = 0; - icmp_param.skb = skb_in; - icmp_param.offset = skb_network_offset(skb_in); + icmp_param->data.icmph.type = type; + icmp_param->data.icmph.code = code; + icmp_param->data.icmph.un.gateway = info; + icmp_param->data.icmph.checksum = 0; + icmp_param->skb = skb_in; + icmp_param->offset = skb_network_offset(skb_in); inet_sk(sk)->tos = tos; ipc.addr = iph->saddr; - ipc.opt = &icmp_param.replyopts.opt; + ipc.opt = &icmp_param->replyopts.opt; ipc.tx_flags = 0; rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, - type, code, &icmp_param); + type, code, icmp_param); if (IS_ERR(rt)) goto out_unlock; @@ -618,19 +622,21 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) room = dst_mtu(&rt->dst); if (room > 576) room = 576; - room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; + room -= sizeof(struct iphdr) + icmp_param->replyopts.opt.opt.optlen; room -= sizeof(struct icmphdr); - icmp_param.data_len = skb_in->len - icmp_param.offset; - if (icmp_param.data_len > room) - icmp_param.data_len = room; - icmp_param.head_len = sizeof(struct icmphdr); + icmp_param->data_len = skb_in->len - icmp_param->offset; + if (icmp_param->data_len > room) + icmp_param->data_len = room; + icmp_param->head_len = sizeof(struct icmphdr); - icmp_push_reply(&icmp_param, &fl4, &ipc, &rt); + icmp_push_reply(icmp_param, &fl4, &ipc, &rt); ende: ip_rt_put(rt); out_unlock: icmp_xmit_unlock(sk); +out_free: + kfree(icmp_param); out:; } EXPORT_SYMBOL(icmp_send); -- 2.20.1