Revision 070e76cb3ffe43f6855492e77c96680c562598f0 authored by Leonid Yegoshin on 27 November 2014, 11:13:08 UTC, committed by Ralf Baechle on 27 November 2014, 16:21:56 UTC
There is a potential race when probing the TLB in TLBL/M/S exception
handlers for a matching entry. Between the time we hit a TLBL/S/M
exception and the time we get to execute the TLBP instruction, the
HTW may have replaced the TLB entry we are interested in hence the TLB
probe may fail. However, in the existing handlers, we never checked the
status of the TLBP (ie check the result in the C0/Index register). We
fix this by adding such a check when the core implements the HTW. If
we couldn't find a matching entry, we return back and try again.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.17+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8599/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 parent b4da18b
Raw File
ip_fib.h
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET  is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Definitions for the Forwarding Information Base.
 *
 * Authors:	A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *		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.
 */

#ifndef _NET_IP_FIB_H
#define _NET_IP_FIB_H

#include <net/flow.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <net/fib_rules.h>
#include <net/inetpeer.h>
#include <linux/percpu.h>

struct fib_config {
	u8			fc_dst_len;
	u8			fc_tos;
	u8			fc_protocol;
	u8			fc_scope;
	u8			fc_type;
	/* 3 bytes unused */
	u32			fc_table;
	__be32			fc_dst;
	__be32			fc_gw;
	int			fc_oif;
	u32			fc_flags;
	u32			fc_priority;
	__be32			fc_prefsrc;
	struct nlattr		*fc_mx;
	struct rtnexthop	*fc_mp;
	int			fc_mx_len;
	int			fc_mp_len;
	u32			fc_flow;
	u32			fc_nlflags;
	struct nl_info		fc_nlinfo;
 };

struct fib_info;
struct rtable;

struct fib_nh_exception {
	struct fib_nh_exception __rcu	*fnhe_next;
	int				fnhe_genid;
	__be32				fnhe_daddr;
	u32				fnhe_pmtu;
	__be32				fnhe_gw;
	unsigned long			fnhe_expires;
	struct rtable __rcu		*fnhe_rth_input;
	struct rtable __rcu		*fnhe_rth_output;
	unsigned long			fnhe_stamp;
};

struct fnhe_hash_bucket {
	struct fib_nh_exception __rcu	*chain;
};

#define FNHE_HASH_SHIFT		11
#define FNHE_HASH_SIZE		(1 << FNHE_HASH_SHIFT)
#define FNHE_RECLAIM_DEPTH	5

struct fib_nh {
	struct net_device	*nh_dev;
	struct hlist_node	nh_hash;
	struct fib_info		*nh_parent;
	unsigned int		nh_flags;
	unsigned char		nh_scope;
#ifdef CONFIG_IP_ROUTE_MULTIPATH
	int			nh_weight;
	int			nh_power;
#endif
#ifdef CONFIG_IP_ROUTE_CLASSID
	__u32			nh_tclassid;
#endif
	int			nh_oif;
	__be32			nh_gw;
	__be32			nh_saddr;
	int			nh_saddr_genid;
	struct rtable __rcu * __percpu *nh_pcpu_rth_output;
	struct rtable __rcu	*nh_rth_input;
	struct fnhe_hash_bucket	__rcu *nh_exceptions;
};

/*
 * This structure contains data shared by many of routes.
 */

struct fib_info {
	struct hlist_node	fib_hash;
	struct hlist_node	fib_lhash;
	struct net		*fib_net;
	int			fib_treeref;
	atomic_t		fib_clntref;
	unsigned int		fib_flags;
	unsigned char		fib_dead;
	unsigned char		fib_protocol;
	unsigned char		fib_scope;
	unsigned char		fib_type;
	__be32			fib_prefsrc;
	u32			fib_priority;
	u32			*fib_metrics;
#define fib_mtu fib_metrics[RTAX_MTU-1]
#define fib_window fib_metrics[RTAX_WINDOW-1]
#define fib_rtt fib_metrics[RTAX_RTT-1]
#define fib_advmss fib_metrics[RTAX_ADVMSS-1]
	int			fib_nhs;
#ifdef CONFIG_IP_ROUTE_MULTIPATH
	int			fib_power;
#endif
	struct rcu_head		rcu;
	struct fib_nh		fib_nh[0];
#define fib_dev		fib_nh[0].nh_dev
};


#ifdef CONFIG_IP_MULTIPLE_TABLES
struct fib_rule;
#endif

struct fib_table;
struct fib_result {
	unsigned char	prefixlen;
	unsigned char	nh_sel;
	unsigned char	type;
	unsigned char	scope;
	u32		tclassid;
	struct fib_info *fi;
	struct fib_table *table;
	struct list_head *fa_head;
};

struct fib_result_nl {
	__be32		fl_addr;   /* To be looked up*/
	u32		fl_mark;
	unsigned char	fl_tos;
	unsigned char   fl_scope;
	unsigned char   tb_id_in;

	unsigned char   tb_id;      /* Results */
	unsigned char	prefixlen;
	unsigned char	nh_sel;
	unsigned char	type;
	unsigned char	scope;
	int             err;      
};

#ifdef CONFIG_IP_ROUTE_MULTIPATH
#define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
#else /* CONFIG_IP_ROUTE_MULTIPATH */
#define FIB_RES_NH(res)		((res).fi->fib_nh[0])
#endif /* CONFIG_IP_ROUTE_MULTIPATH */

#ifdef CONFIG_IP_MULTIPLE_TABLES
#define FIB_TABLE_HASHSZ 256
#else
#define FIB_TABLE_HASHSZ 2
#endif

__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);

#define FIB_RES_SADDR(net, res)				\
	((FIB_RES_NH(res).nh_saddr_genid ==		\
	  atomic_read(&(net)->ipv4.dev_addr_genid)) ?	\
	 FIB_RES_NH(res).nh_saddr :			\
	 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
#define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
#define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
#define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)

#define FIB_RES_PREFSRC(net, res)	((res).fi->fib_prefsrc ? : \
					 FIB_RES_SADDR(net, res))

struct fib_table {
	struct hlist_node	tb_hlist;
	u32			tb_id;
	int			tb_default;
	int			tb_num_default;
	unsigned long		tb_data[0];
};

int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
		     struct fib_result *res, int fib_flags);
int fib_table_insert(struct fib_table *, struct fib_config *);
int fib_table_delete(struct fib_table *, struct fib_config *);
int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
		   struct netlink_callback *cb);
int fib_table_flush(struct fib_table *table);
void fib_free_table(struct fib_table *tb);



#ifndef CONFIG_IP_MULTIPLE_TABLES

#define TABLE_LOCAL_INDEX	0
#define TABLE_MAIN_INDEX	1

static inline struct fib_table *fib_get_table(struct net *net, u32 id)
{
	struct hlist_head *ptr;

	ptr = id == RT_TABLE_LOCAL ?
		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
	return hlist_entry(ptr->first, struct fib_table, tb_hlist);
}

static inline struct fib_table *fib_new_table(struct net *net, u32 id)
{
	return fib_get_table(net, id);
}

static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
			     struct fib_result *res)
{
	struct fib_table *table;

	table = fib_get_table(net, RT_TABLE_LOCAL);
	if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
		return 0;

	table = fib_get_table(net, RT_TABLE_MAIN);
	if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
		return 0;
	return -ENETUNREACH;
}

#else /* CONFIG_IP_MULTIPLE_TABLES */
int __net_init fib4_rules_init(struct net *net);
void __net_exit fib4_rules_exit(struct net *net);

struct fib_table *fib_new_table(struct net *net, u32 id);
struct fib_table *fib_get_table(struct net *net, u32 id);

int __fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res);

static inline int fib_lookup(struct net *net, struct flowi4 *flp,
			     struct fib_result *res)
{
	if (!net->ipv4.fib_has_custom_rules) {
		res->tclassid = 0;
		if (net->ipv4.fib_local &&
		    !fib_table_lookup(net->ipv4.fib_local, flp, res,
				      FIB_LOOKUP_NOREF))
			return 0;
		if (net->ipv4.fib_main &&
		    !fib_table_lookup(net->ipv4.fib_main, flp, res,
				      FIB_LOOKUP_NOREF))
			return 0;
		if (net->ipv4.fib_default &&
		    !fib_table_lookup(net->ipv4.fib_default, flp, res,
				      FIB_LOOKUP_NOREF))
			return 0;
		return -ENETUNREACH;
	}
	return __fib_lookup(net, flp, res);
}

#endif /* CONFIG_IP_MULTIPLE_TABLES */

/* Exported by fib_frontend.c */
extern const struct nla_policy rtm_ipv4_policy[];
void ip_fib_init(void);
__be32 fib_compute_spec_dst(struct sk_buff *skb);
int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
			u8 tos, int oif, struct net_device *dev,
			struct in_device *idev, u32 *itag);
void fib_select_default(struct fib_result *res);
#ifdef CONFIG_IP_ROUTE_CLASSID
static inline int fib_num_tclassid_users(struct net *net)
{
	return net->ipv4.fib_num_tclassid_users;
}
#else
static inline int fib_num_tclassid_users(struct net *net)
{
	return 0;
}
#endif

/* Exported by fib_semantics.c */
int ip_fib_check_default(__be32 gw, struct net_device *dev);
int fib_sync_down_dev(struct net_device *dev, int force);
int fib_sync_down_addr(struct net *net, __be32 local);
int fib_sync_up(struct net_device *dev);
void fib_select_multipath(struct fib_result *res);

/* Exported by fib_trie.c */
void fib_trie_init(void);
struct fib_table *fib_trie_table(u32 id);

static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
{
#ifdef CONFIG_IP_ROUTE_CLASSID
#ifdef CONFIG_IP_MULTIPLE_TABLES
	u32 rtag;
#endif
	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
#ifdef CONFIG_IP_MULTIPLE_TABLES
	rtag = res->tclassid;
	if (*itag == 0)
		*itag = (rtag<<16);
	*itag |= (rtag>>16);
#endif
#endif
}

void free_fib_info(struct fib_info *fi);

static inline void fib_info_put(struct fib_info *fi)
{
	if (atomic_dec_and_test(&fi->fib_clntref))
		free_fib_info(fi);
}

#ifdef CONFIG_PROC_FS
int __net_init fib_proc_init(struct net *net);
void __net_exit fib_proc_exit(struct net *net);
#else
static inline int fib_proc_init(struct net *net)
{
	return 0;
}
static inline void fib_proc_exit(struct net *net)
{
}
#endif

#endif  /* _NET_FIB_H */
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