[PATCH bpf-next v2 2/2] bpf: split cgroup_bpf_enabled per attach type
From: Stanislav Fomichev <hidden>
Date: 2021-01-04 23:17:30
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), networking [general], the rest, user datagram protocol (udp) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn
When we attach any cgroup hook, the rest (even if unused/unattached) start to contribute small overhead. In particular, the one we want to avoid is __cgroup_bpf_run_filter_skb which does two redirections to get to the cgroup and pushes/pulls skb. Let's split cgroup_bpf_enabled to be per-attach to make sure only used attach types trigger. I've dropped some existing high-level cgroup_bpf_enabled in some places because BPF_PROG_CGROUP_XXX_RUN macros usually have another cgroup_bpf_enabled check. I also had to copy-paste BPF_CGROUP_RUN_SA_PROG_LOCK for GETPEERNAME/GETSOCKNAME because type for cgroup_bpf_enabled[type] has to be constant and known at compile time. Signed-off-by: Stanislav Fomichev <redacted> Acked-by: Song Liu <redacted> --- include/linux/bpf-cgroup.h | 36 +++++++++++++++++++----------------- kernel/bpf/cgroup.c | 14 ++++++-------- net/ipv4/af_inet.c | 9 +++++---- net/ipv4/udp.c | 7 +++---- net/ipv6/af_inet6.c | 9 +++++---- net/ipv6/udp.c | 7 +++---- 6 files changed, 41 insertions(+), 41 deletions(-)
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 72e69a0e1e8c..dd4b8e300746 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h@@ -23,8 +23,8 @@ struct ctl_table_header; #ifdef CONFIG_CGROUP_BPF -extern struct static_key_false cgroup_bpf_enabled_key; -#define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key) +extern struct static_key_false cgroup_bpf_enabled_key[MAX_BPF_ATTACH_TYPE]; +#define cgroup_bpf_enabled(type) static_branch_unlikely(&cgroup_bpf_enabled_key[type]) DECLARE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
@@ -185,7 +185,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_INET_INGRESS)) \ __ret = __cgroup_bpf_run_filter_skb(sk, skb, \ BPF_CGROUP_INET_INGRESS); \ \
@@ -195,7 +195,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled && sk && sk == skb->sk) { \ + if (cgroup_bpf_enabled(BPF_CGROUP_INET_EGRESS) && sk && sk == skb->sk) { \ typeof(sk) __sk = sk_to_full_sk(sk); \ if (sk_fullsock(__sk)) \ __ret = __cgroup_bpf_run_filter_skb(__sk, skb, \
@@ -207,7 +207,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_SK_PROG(sk, type) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) { \ + if (cgroup_bpf_enabled(type)) { \ __ret = __cgroup_bpf_run_filter_sk(sk, type); \ } \ __ret; \
@@ -228,7 +228,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_SA_PROG(sk, uaddr, type) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(type)) \ __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \ NULL); \ __ret; \
@@ -237,7 +237,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, type, t_ctx) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) { \ + if (cgroup_bpf_enabled(type)) { \ lock_sock(sk); \ __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \ t_ctx); \
@@ -252,8 +252,10 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr) \ BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET6_BIND, NULL) -#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (cgroup_bpf_enabled && \ - sk->sk_prot->pre_connect) +#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) \ + ((cgroup_bpf_enabled(BPF_CGROUP_INET4_CONNECT) || \ + cgroup_bpf_enabled(BPF_CGROUP_INET6_CONNECT)) && \ + (sk)->sk_prot->pre_connect) #define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) \ BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET4_CONNECT)
@@ -297,7 +299,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_SOCK_OPS_SK(sock_ops, sk) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_SOCK_OPS)) \ __ret = __cgroup_bpf_run_filter_sock_ops(sk, \ sock_ops, \ BPF_CGROUP_SOCK_OPS); \
@@ -307,7 +309,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled && (sock_ops)->sk) { \ + if (cgroup_bpf_enabled(BPF_CGROUP_SOCK_OPS) && (sock_ops)->sk) { \ typeof(sk) __sk = sk_to_full_sk((sock_ops)->sk); \ if (__sk && sk_fullsock(__sk)) \ __ret = __cgroup_bpf_run_filter_sock_ops(__sk, \
@@ -320,7 +322,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type, major, minor, access) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_DEVICE)) \ __ret = __cgroup_bpf_check_dev_permission(type, major, minor, \ access, \ BPF_CGROUP_DEVICE); \
@@ -332,7 +334,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, count, pos) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_SYSCTL)) \ __ret = __cgroup_bpf_run_filter_sysctl(head, table, write, \ buf, count, pos, \ BPF_CGROUP_SYSCTL); \
@@ -343,7 +345,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, kernel_optval) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_SETSOCKOPT)) \ __ret = __cgroup_bpf_run_filter_setsockopt(sock, level, \ optname, optval, \ optlen, \
@@ -354,7 +356,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_GETSOCKOPT)) \ get_user(__ret, optlen); \ __ret; \ })
@@ -363,7 +365,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, max_optlen, retval) \ ({ \ int __ret = retval; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_GETSOCKOPT)) \ __ret = __cgroup_bpf_run_filter_getsockopt(sock, level, \ optname, optval, \ optlen, max_optlen, \
@@ -427,7 +429,7 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, return 0; } -#define cgroup_bpf_enabled (0) +#define cgroup_bpf_enabled(type) (0) #define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, type, t_ctx) ({ 0; }) #define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (0) #define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index e6a5c7aec1ec..9f15c33a883c 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c@@ -20,7 +20,7 @@ #include "../cgroup/cgroup-internal.h" -DEFINE_STATIC_KEY_FALSE(cgroup_bpf_enabled_key); +DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_BPF_ATTACH_TYPE); EXPORT_SYMBOL(cgroup_bpf_enabled_key); void cgroup_bpf_offline(struct cgroup *cgrp)
@@ -129,7 +129,7 @@ static void cgroup_bpf_release(struct work_struct *work) if (pl->link) bpf_cgroup_link_auto_detach(pl->link); kfree(pl); - static_branch_dec(&cgroup_bpf_enabled_key); + static_branch_dec(&cgroup_bpf_enabled_key[type]); } old_array = rcu_dereference_protected( cgrp->bpf.effective[type],
@@ -500,7 +500,7 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, if (old_prog) bpf_prog_put(old_prog); else - static_branch_inc(&cgroup_bpf_enabled_key); + static_branch_inc(&cgroup_bpf_enabled_key[type]); bpf_cgroup_storages_link(new_storage, cgrp, type); return 0;
@@ -699,7 +699,7 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, cgrp->bpf.flags[type] = 0; if (old_prog) bpf_prog_put(old_prog); - static_branch_dec(&cgroup_bpf_enabled_key); + static_branch_dec(&cgroup_bpf_enabled_key[type]); return 0; cleanup:
@@ -1361,8 +1361,7 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level, * attached to the hook so we don't waste time allocating * memory and locking the socket. */ - if (!cgroup_bpf_enabled || - __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT)) + if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT)) return 0; /* Allocate a bit more than the initial user buffer for
@@ -1456,8 +1455,7 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, * attached to the hook so we don't waste time allocating * memory and locking the socket. */ - if (!cgroup_bpf_enabled || - __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT)) + if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT)) return retval; ctx.optlen = max_optlen;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index b94fa8eb831b..6ba2930ff49b 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c@@ -777,18 +777,19 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr, return -ENOTCONN; sin->sin_port = inet->inet_dport; sin->sin_addr.s_addr = inet->inet_daddr; + BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, + BPF_CGROUP_INET4_GETPEERNAME, + NULL); } else { __be32 addr = inet->inet_rcv_saddr; if (!addr) addr = inet->inet_saddr; sin->sin_port = inet->inet_sport; sin->sin_addr.s_addr = addr; - } - if (cgroup_bpf_enabled) BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, - peer ? BPF_CGROUP_INET4_GETPEERNAME : - BPF_CGROUP_INET4_GETSOCKNAME, + BPF_CGROUP_INET4_GETSOCKNAME, NULL); + } memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); return sizeof(*sin); }
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index dece195f212c..fc3c2e75e400 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -1124,7 +1124,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) rcu_read_unlock(); } - if (cgroup_bpf_enabled && !connected) { + if (cgroup_bpf_enabled(BPF_CGROUP_UDP4_SENDMSG) && !connected) { err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, (struct sockaddr *)usin, &ipc.addr); if (err)
@@ -1858,9 +1858,8 @@ int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); *addr_len = sizeof(*sin); - if (cgroup_bpf_enabled) - BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, - (struct sockaddr *)sin); + BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, + (struct sockaddr *)sin); } if (udp_sk(sk)->gro_enabled)
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index a7e3d170af51..fc985658dc91 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c@@ -527,18 +527,19 @@ int inet6_getname(struct socket *sock, struct sockaddr *uaddr, sin->sin6_addr = sk->sk_v6_daddr; if (np->sndflow) sin->sin6_flowinfo = np->flow_label; + BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, + BPF_CGROUP_INET6_GETPEERNAME, + NULL); } else { if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) sin->sin6_addr = np->saddr; else sin->sin6_addr = sk->sk_v6_rcv_saddr; sin->sin6_port = inet->inet_sport; - } - if (cgroup_bpf_enabled) BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, - peer ? BPF_CGROUP_INET6_GETPEERNAME : - BPF_CGROUP_INET6_GETSOCKNAME, + BPF_CGROUP_INET6_GETSOCKNAME, NULL); + } sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr, sk->sk_bound_dev_if); return sizeof(*sin);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 9008f5796ad4..50611bd63647 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c@@ -409,9 +409,8 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, } *addr_len = sizeof(*sin6); - if (cgroup_bpf_enabled) - BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, - (struct sockaddr *)sin6); + BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, + (struct sockaddr *)sin6); } if (udp_sk(sk)->gro_enabled)
@@ -1462,7 +1461,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) fl6.saddr = np->saddr; fl6.fl6_sport = inet->inet_sport; - if (cgroup_bpf_enabled && !connected) { + if (cgroup_bpf_enabled(BPF_CGROUP_UDP6_SENDMSG) && !connected) { err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, (struct sockaddr *)sin6, &fl6.saddr); if (err)
--
2.29.2.729.g45daf8777d-goog