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
snmp.h
/*
 *
 *		SNMP MIB entries for the IP subsystem.
 *		
 *		Alan Cox <gw4pts@gw4pts.ampr.org>
 *
 *		We don't chose to implement SNMP in the kernel (this would
 *		be silly as SNMP is a pain in the backside in places). We do
 *		however need to collect the MIB statistics and export them
 *		out of /proc (eventually)
 *
 *		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 _SNMP_H
#define _SNMP_H

#include <linux/cache.h>
#include <linux/snmp.h>
#include <linux/smp.h>

/*
 * Mibs are stored in array of unsigned long.
 */
/*
 * struct snmp_mib{}
 *  - list of entries for particular API (such as /proc/net/snmp)
 *  - name of entries.
 */
struct snmp_mib {
	const char *name;
	int entry;
};

#define SNMP_MIB_ITEM(_name,_entry)	{	\
	.name = _name,				\
	.entry = _entry,			\
}

#define SNMP_MIB_SENTINEL {	\
	.name = NULL,		\
	.entry = 0,		\
}

/*
 * We use unsigned longs for most mibs but u64 for ipstats.
 */
#include <linux/u64_stats_sync.h>

/* IPstats */
#define IPSTATS_MIB_MAX	__IPSTATS_MIB_MAX
struct ipstats_mib {
	/* mibs[] must be first field of struct ipstats_mib */
	u64		mibs[IPSTATS_MIB_MAX];
	struct u64_stats_sync syncp;
};

/* ICMP */
#define ICMP_MIB_MAX	__ICMP_MIB_MAX
struct icmp_mib {
	unsigned long	mibs[ICMP_MIB_MAX];
};

#define ICMPMSG_MIB_MAX	__ICMPMSG_MIB_MAX
struct icmpmsg_mib {
	atomic_long_t	mibs[ICMPMSG_MIB_MAX];
};

/* ICMP6 (IPv6-ICMP) */
#define ICMP6_MIB_MAX	__ICMP6_MIB_MAX
/* per network ns counters */
struct icmpv6_mib {
	unsigned long	mibs[ICMP6_MIB_MAX];
};
/* per device counters, (shared on all cpus) */
struct icmpv6_mib_device {
	atomic_long_t	mibs[ICMP6_MIB_MAX];
};

#define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
/* per network ns counters */
struct icmpv6msg_mib {
	atomic_long_t	mibs[ICMP6MSG_MIB_MAX];
};
/* per device counters, (shared on all cpus) */
struct icmpv6msg_mib_device {
	atomic_long_t	mibs[ICMP6MSG_MIB_MAX];
};


/* TCP */
#define TCP_MIB_MAX	__TCP_MIB_MAX
struct tcp_mib {
	unsigned long	mibs[TCP_MIB_MAX];
};

/* UDP */
#define UDP_MIB_MAX	__UDP_MIB_MAX
struct udp_mib {
	unsigned long	mibs[UDP_MIB_MAX];
};

/* Linux */
#define LINUX_MIB_MAX	__LINUX_MIB_MAX
struct linux_mib {
	unsigned long	mibs[LINUX_MIB_MAX];
};

/* Linux Xfrm */
#define LINUX_MIB_XFRMMAX	__LINUX_MIB_XFRMMAX
struct linux_xfrm_mib {
	unsigned long	mibs[LINUX_MIB_XFRMMAX];
};

#define DEFINE_SNMP_STAT(type, name)	\
	__typeof__(type) __percpu *name
#define DEFINE_SNMP_STAT_ATOMIC(type, name)	\
	__typeof__(type) *name
#define DECLARE_SNMP_STAT(type, name)	\
	extern __typeof__(type) __percpu *name

#define SNMP_INC_STATS_BH(mib, field)	\
			__this_cpu_inc(mib->mibs[field])

#define SNMP_INC_STATS_USER(mib, field)	\
			this_cpu_inc(mib->mibs[field])

#define SNMP_INC_STATS_ATOMIC_LONG(mib, field)	\
			atomic_long_inc(&mib->mibs[field])

#define SNMP_INC_STATS(mib, field)	\
			this_cpu_inc(mib->mibs[field])

#define SNMP_DEC_STATS(mib, field)	\
			this_cpu_dec(mib->mibs[field])

#define SNMP_ADD_STATS_BH(mib, field, addend)	\
			__this_cpu_add(mib->mibs[field], addend)

#define SNMP_ADD_STATS_USER(mib, field, addend)	\
			this_cpu_add(mib->mibs[field], addend)

#define SNMP_ADD_STATS(mib, field, addend)	\
			this_cpu_add(mib->mibs[field], addend)
#define SNMP_UPD_PO_STATS(mib, basefield, addend)	\
	do { \
		__typeof__((mib->mibs) + 0) ptr = mib->mibs;	\
		this_cpu_inc(ptr[basefield##PKTS]);		\
		this_cpu_add(ptr[basefield##OCTETS], addend);	\
	} while (0)
#define SNMP_UPD_PO_STATS_BH(mib, basefield, addend)	\
	do { \
		__typeof__((mib->mibs) + 0) ptr = mib->mibs;	\
		__this_cpu_inc(ptr[basefield##PKTS]);		\
		__this_cpu_add(ptr[basefield##OCTETS], addend);	\
	} while (0)


#if BITS_PER_LONG==32

#define SNMP_ADD_STATS64_BH(mib, field, addend) 			\
	do {								\
		__typeof__(*mib) *ptr = raw_cpu_ptr(mib);		\
		u64_stats_update_begin(&ptr->syncp);			\
		ptr->mibs[field] += addend;				\
		u64_stats_update_end(&ptr->syncp);			\
	} while (0)

#define SNMP_ADD_STATS64_USER(mib, field, addend) 			\
	do {								\
		local_bh_disable();					\
		SNMP_ADD_STATS64_BH(mib, field, addend);		\
		local_bh_enable();					\
	} while (0)

#define SNMP_ADD_STATS64(mib, field, addend)				\
		SNMP_ADD_STATS64_USER(mib, field, addend)

#define SNMP_INC_STATS64_BH(mib, field) SNMP_ADD_STATS64_BH(mib, field, 1)
#define SNMP_INC_STATS64_USER(mib, field) SNMP_ADD_STATS64_USER(mib, field, 1)
#define SNMP_INC_STATS64(mib, field) SNMP_ADD_STATS64(mib, field, 1)
#define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend)			\
	do {								\
		__typeof__(*mib) *ptr;				\
		ptr = raw_cpu_ptr((mib));				\
		u64_stats_update_begin(&ptr->syncp);			\
		ptr->mibs[basefield##PKTS]++;				\
		ptr->mibs[basefield##OCTETS] += addend;			\
		u64_stats_update_end(&ptr->syncp);			\
	} while (0)
#define SNMP_UPD_PO_STATS64(mib, basefield, addend)			\
	do {								\
		local_bh_disable();					\
		SNMP_UPD_PO_STATS64_BH(mib, basefield, addend);		\
		local_bh_enable();					\
	} while (0)
#else
#define SNMP_INC_STATS64_BH(mib, field)		SNMP_INC_STATS_BH(mib, field)
#define SNMP_INC_STATS64_USER(mib, field)	SNMP_INC_STATS_USER(mib, field)
#define SNMP_INC_STATS64(mib, field)		SNMP_INC_STATS(mib, field)
#define SNMP_DEC_STATS64(mib, field)		SNMP_DEC_STATS(mib, field)
#define SNMP_ADD_STATS64_BH(mib, field, addend) SNMP_ADD_STATS_BH(mib, field, addend)
#define SNMP_ADD_STATS64_USER(mib, field, addend) SNMP_ADD_STATS_USER(mib, field, addend)
#define SNMP_ADD_STATS64(mib, field, addend)	SNMP_ADD_STATS(mib, field, addend)
#define SNMP_UPD_PO_STATS64(mib, basefield, addend) SNMP_UPD_PO_STATS(mib, basefield, addend)
#define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend) SNMP_UPD_PO_STATS_BH(mib, basefield, addend)
#endif

#endif
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