From a8ceb5dbfde1092b466936bca0ff3be127ecf38e Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Tue, 5 Dec 2017 21:29:37 +0200 Subject: ptr_ring: add barriers Users of ptr_ring expect that it's safe to give the data structure a pointer and have it be available to consumers, but that actually requires an smb_wmb or a stronger barrier. In absence of such barriers and on architectures that reorder writes, consumer might read an un=initialized value from an skb pointer stored in the skb array. This was observed causing crashes. To fix, add memory barriers. The barrier we use is a wmb, the assumption being that producers do not need to read the value so we do not need to order these reads. Reported-by: George Cherian Suggested-by: Jason Wang Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: David S. Miller --- include/linux/ptr_ring.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include') diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 37b4bb2545b3..6866df4f31b5 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -101,12 +101,18 @@ static inline bool ptr_ring_full_bh(struct ptr_ring *r) /* Note: callers invoking this in a loop must use a compiler barrier, * for example cpu_relax(). Callers must hold producer_lock. + * Callers are responsible for making sure pointer that is being queued + * points to a valid data. */ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) { if (unlikely(!r->size) || r->queue[r->producer]) return -ENOSPC; + /* Make sure the pointer we are storing points to a valid data. */ + /* Pairs with smp_read_barrier_depends in __ptr_ring_consume. */ + smp_wmb(); + r->queue[r->producer++] = ptr; if (unlikely(r->producer >= r->size)) r->producer = 0; @@ -275,6 +281,9 @@ static inline void *__ptr_ring_consume(struct ptr_ring *r) if (ptr) __ptr_ring_discard_one(r); + /* Make sure anyone accessing data through the pointer is up to date. */ + /* Pairs with smp_wmb in __ptr_ring_produce. */ + smp_read_barrier_depends(); return ptr; } -- cgit v1.2.3 From 200809716aed1cac586fcac4c0551a688439be1f Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sun, 10 Dec 2017 16:56:00 +0800 Subject: fou: fix some member types in guehdr guehdr struct is used to build or parse gue packets, which are always in big endian. It's better to define all guehdr members as __beXX types. Also, in validate_gue_flags it's not good to use a __be32 variable for both Standard flags(__be16) and Private flags (__be32), and pass it to other funcions. This patch could fix a bunch of sparse warnings from fou. Fixes: 5024c33ac354 ("gue: Add infrastructure for flags and options") Signed-off-by: Xin Long Signed-off-by: David S. Miller --- include/net/gue.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/include/net/gue.h b/include/net/gue.h index 2fdb29ca74c2..fdad41469b65 100644 --- a/include/net/gue.h +++ b/include/net/gue.h @@ -44,10 +44,10 @@ struct guehdr { #else #error "Please fix " #endif - __u8 proto_ctype; - __u16 flags; + __u8 proto_ctype; + __be16 flags; }; - __u32 word; + __be32 word; }; }; @@ -84,11 +84,10 @@ static inline size_t guehdr_priv_flags_len(__be32 flags) * if there is an unknown standard or private flags, or the options length for * the flags exceeds the options length specific in hlen of the GUE header. */ -static inline int validate_gue_flags(struct guehdr *guehdr, - size_t optlen) +static inline int validate_gue_flags(struct guehdr *guehdr, size_t optlen) { + __be16 flags = guehdr->flags; size_t len; - __be32 flags = guehdr->flags; if (flags & ~GUE_FLAGS_ALL) return 1; @@ -101,12 +100,13 @@ static inline int validate_gue_flags(struct guehdr *guehdr, /* Private flags are last four bytes accounted in * guehdr_flags_len */ - flags = *(__be32 *)((void *)&guehdr[1] + len - GUE_LEN_PRIV); + __be32 pflags = *(__be32 *)((void *)&guehdr[1] + + len - GUE_LEN_PRIV); - if (flags & ~GUE_PFLAGS_ALL) + if (pflags & ~GUE_PFLAGS_ALL) return 1; - len += guehdr_priv_flags_len(flags); + len += guehdr_priv_flags_len(pflags); if (len > optlen) return 1; } -- cgit v1.2.3 From b5476022bbada3764609368f03329ca287528dc8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 11 Dec 2017 07:17:39 -0800 Subject: ipv4: igmp: guard against silly MTU values MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit IPv4 stack reacts to changes to small MTU, by disabling itself under RTNL. But there is a window where threads not using RTNL can see a wrong device mtu. This can lead to surprises, in igmp code where it is assumed the mtu is suitable. Fix this by reading device mtu once and checking IPv4 minimal MTU. This patch adds missing IPV4_MIN_MTU define, to not abuse ETH_MIN_MTU anymore. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/ip.h | 1 + net/ipv4/devinet.c | 2 +- net/ipv4/igmp.c | 24 +++++++++++++++--------- net/ipv4/ip_tunnel.c | 4 ++-- 4 files changed, 19 insertions(+), 12 deletions(-) (limited to 'include') diff --git a/include/net/ip.h b/include/net/ip.h index 9896f46cbbf1..af8addbaa3c1 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -34,6 +34,7 @@ #include #define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */ +#define IPV4_MIN_MTU 68 /* RFC 791 */ struct sock; diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index a4573bccd6da..7a93359fbc72 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1428,7 +1428,7 @@ skip: static bool inetdev_valid_mtu(unsigned int mtu) { - return mtu >= 68; + return mtu >= IPV4_MIN_MTU; } static void inetdev_send_gratuitous_arp(struct net_device *dev, diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index d1f8f302dbf3..50448a220a1f 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -404,16 +404,17 @@ static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel) } static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc, - int type, struct igmpv3_grec **ppgr) + int type, struct igmpv3_grec **ppgr, unsigned int mtu) { struct net_device *dev = pmc->interface->dev; struct igmpv3_report *pih; struct igmpv3_grec *pgr; - if (!skb) - skb = igmpv3_newpack(dev, dev->mtu); - if (!skb) - return NULL; + if (!skb) { + skb = igmpv3_newpack(dev, mtu); + if (!skb) + return NULL; + } pgr = skb_put(skb, sizeof(struct igmpv3_grec)); pgr->grec_type = type; pgr->grec_auxwords = 0; @@ -436,12 +437,17 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, struct igmpv3_grec *pgr = NULL; struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list; int scount, stotal, first, isquery, truncate; + unsigned int mtu; if (pmc->multiaddr == IGMP_ALL_HOSTS) return skb; if (ipv4_is_local_multicast(pmc->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports) return skb; + mtu = READ_ONCE(dev->mtu); + if (mtu < IPV4_MIN_MTU) + return skb; + isquery = type == IGMPV3_MODE_IS_INCLUDE || type == IGMPV3_MODE_IS_EXCLUDE; truncate = type == IGMPV3_MODE_IS_EXCLUDE || @@ -462,7 +468,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) { if (skb) igmpv3_sendpack(skb); - skb = igmpv3_newpack(dev, dev->mtu); + skb = igmpv3_newpack(dev, mtu); } } first = 1; @@ -498,12 +504,12 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, pgr->grec_nsrcs = htons(scount); if (skb) igmpv3_sendpack(skb); - skb = igmpv3_newpack(dev, dev->mtu); + skb = igmpv3_newpack(dev, mtu); first = 1; scount = 0; } if (first) { - skb = add_grhead(skb, pmc, type, &pgr); + skb = add_grhead(skb, pmc, type, &pgr, mtu); first = 0; } if (!skb) @@ -538,7 +544,7 @@ empty_source: igmpv3_sendpack(skb); skb = NULL; /* add_grhead will get a new one */ } - skb = add_grhead(skb, pmc, type, &pgr); + skb = add_grhead(skb, pmc, type, &pgr, mtu); } } if (pgr) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index fe6fee728ce4..5ddb1cb52bd4 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -349,8 +349,8 @@ static int ip_tunnel_bind_dev(struct net_device *dev) dev->needed_headroom = t_hlen + hlen; mtu -= (dev->hard_header_len + t_hlen); - if (mtu < 68) - mtu = 68; + if (mtu < IPV4_MIN_MTU) + mtu = IPV4_MIN_MTU; return mtu; } -- cgit v1.2.3 From 7a4fa29106d9a38ef005f5ab15d493c259f269c0 Mon Sep 17 00:00:00 2001 From: Yuval Mintz Date: Thu, 14 Dec 2017 15:54:29 +0200 Subject: net: sched: Add TCA_HW_OFFLOAD Qdiscs can be offloaded to HW, but current implementation isn't uniform. Instead, qdiscs either pass information about offload status via their TCA_OPTIONS or omit it altogether. Introduce a new attribute - TCA_HW_OFFLOAD that would form a uniform uAPI for the offloading status of qdiscs. Signed-off-by: Yuval Mintz Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- include/net/sch_generic.h | 1 + include/uapi/linux/rtnetlink.h | 1 + net/sched/sch_api.c | 2 ++ 3 files changed, 4 insertions(+) (limited to 'include') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 65d0d25f2648..83a3e47d5845 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -71,6 +71,7 @@ struct Qdisc { * qdisc_tree_decrease_qlen() should stop. */ #define TCQ_F_INVISIBLE 0x80 /* invisible by default in dump */ +#define TCQ_F_OFFLOADED 0x200 /* qdisc is offloaded to HW */ u32 limit; const struct Qdisc_ops *ops; struct qdisc_size_table __rcu *stab; diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index d8b5f80c2ea6..843e29aa3cac 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -557,6 +557,7 @@ enum { TCA_PAD, TCA_DUMP_INVISIBLE, TCA_CHAIN, + TCA_HW_OFFLOAD, __TCA_MAX }; diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index b6c4f536876b..0f1eab99ff4e 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -795,6 +795,8 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, tcm->tcm_info = refcount_read(&q->refcnt); if (nla_put_string(skb, TCA_KIND, q->ops->id)) goto nla_put_failure; + if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED))) + goto nla_put_failure; if (q->ops->dump && q->ops->dump(q, skb) < 0) goto nla_put_failure; qlen = q->q.qlen; -- cgit v1.2.3 From 4a98795bc8ea148b1ebbbf001283e06430cffe36 Mon Sep 17 00:00:00 2001 From: Yuval Mintz Date: Thu, 14 Dec 2017 15:54:31 +0200 Subject: pkt_sched: Remove TC_RED_OFFLOADED from uapi Following the previous patch, RED is now using the new uniform uapi for indicating it's offloaded. As a result, TC_RED_OFFLOADED is no longer utilized by kernel and can be removed [as it's still not part of any stable release]. Fixes: 602f3baf2218 ("net_sch: red: Add offload ability to RED qdisc") Signed-off-by: Yuval Mintz Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- include/uapi/linux/pkt_sched.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index af3cc2f4e1ad..37b5096ae97b 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -256,7 +256,6 @@ struct tc_red_qopt { #define TC_RED_ECN 1 #define TC_RED_HARDDROP 2 #define TC_RED_ADAPTATIVE 4 -#define TC_RED_OFFLOADED 8 }; struct tc_red_xstats { -- cgit v1.2.3