Revision 0825ce70318e9c576acbdd5ceb4a8d563263cf8f authored by Eric Dumazet on 21 September 2018, 22:27:51 UTC, committed by David S. Miller on 24 September 2018, 04:55:25 UTC
As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC). This capture
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.

nfp uses NAPI for TX completions, so we better let core
networking stack call the napi->poll() to avoid the capture.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 58e0e22
Raw File
udplite.c
/*
 *  UDPLITEv6   An implementation of the UDP-Lite protocol over IPv6.
 *              See also net/ipv4/udplite.c
 *
 *  Authors:    Gerrit Renker       <gerrit@erg.abdn.ac.uk>
 *
 *  Changes:
 *  Fixes:
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
#include <linux/export.h>
#include <linux/proc_fs.h>
#include "udp_impl.h"

static int udplitev6_rcv(struct sk_buff *skb)
{
	return __udp6_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
}

static void udplitev6_err(struct sk_buff *skb,
			  struct inet6_skb_parm *opt,
			  u8 type, u8 code, int offset, __be32 info)
{
	__udp6_lib_err(skb, opt, type, code, offset, info, &udplite_table);
}

static const struct inet6_protocol udplitev6_protocol = {
	.handler	=	udplitev6_rcv,
	.err_handler	=	udplitev6_err,
	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};

struct proto udplitev6_prot = {
	.name		   = "UDPLITEv6",
	.owner		   = THIS_MODULE,
	.close		   = udp_lib_close,
	.connect	   = ip6_datagram_connect,
	.disconnect	   = udp_disconnect,
	.ioctl		   = udp_ioctl,
	.init		   = udplite_sk_init,
	.destroy	   = udpv6_destroy_sock,
	.setsockopt	   = udpv6_setsockopt,
	.getsockopt	   = udpv6_getsockopt,
	.sendmsg	   = udpv6_sendmsg,
	.recvmsg	   = udpv6_recvmsg,
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
	.get_port	   = udp_v6_get_port,
	.memory_allocated  = &udp_memory_allocated,
	.sysctl_mem	   = sysctl_udp_mem,
	.obj_size	   = sizeof(struct udp6_sock),
	.h.udp_table	   = &udplite_table,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udpv6_setsockopt,
	.compat_getsockopt = compat_udpv6_getsockopt,
#endif
};

static struct inet_protosw udplite6_protosw = {
	.type		= SOCK_DGRAM,
	.protocol	= IPPROTO_UDPLITE,
	.prot		= &udplitev6_prot,
	.ops		= &inet6_dgram_ops,
	.flags		= INET_PROTOSW_PERMANENT,
};

int __init udplitev6_init(void)
{
	int ret;

	ret = inet6_add_protocol(&udplitev6_protocol, IPPROTO_UDPLITE);
	if (ret)
		goto out;

	ret = inet6_register_protosw(&udplite6_protosw);
	if (ret)
		goto out_udplitev6_protocol;
out:
	return ret;

out_udplitev6_protocol:
	inet6_del_protocol(&udplitev6_protocol, IPPROTO_UDPLITE);
	goto out;
}

void udplitev6_exit(void)
{
	inet6_unregister_protosw(&udplite6_protosw);
	inet6_del_protocol(&udplitev6_protocol, IPPROTO_UDPLITE);
}

#ifdef CONFIG_PROC_FS
static struct udp_seq_afinfo udplite6_seq_afinfo = {
	.family		= AF_INET6,
	.udp_table	= &udplite_table,
};

static int __net_init udplite6_proc_init_net(struct net *net)
{
	if (!proc_create_net_data("udplite6", 0444, net->proc_net,
			&udp6_seq_ops, sizeof(struct udp_iter_state),
			&udplite6_seq_afinfo))
		return -ENOMEM;
	return 0;
}

static void __net_exit udplite6_proc_exit_net(struct net *net)
{
	remove_proc_entry("udplite6", net->proc_net);
}

static struct pernet_operations udplite6_net_ops = {
	.init = udplite6_proc_init_net,
	.exit = udplite6_proc_exit_net,
};

int __init udplite6_proc_init(void)
{
	return register_pernet_subsys(&udplite6_net_ops);
}

void udplite6_proc_exit(void)
{
	unregister_pernet_subsys(&udplite6_net_ops);
}
#endif
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