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Message-Id: <20201217172324.2121488-3-sdf@google.com>
Date: Thu, 17 Dec 2020 09:23:24 -0800
From: Stanislav Fomichev <sdf@...gle.com>
To: netdev@...r.kernel.org, bpf@...r.kernel.org
Cc: ast@...nel.org, daniel@...earbox.net,
Stanislav Fomichev <sdf@...gle.com>
Subject: [PATCH bpf-next 2/2] bpf: split cgroup_bpf_enabled per attach type
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 <sdf@...gle.com>
---
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..05877980e4e6 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 0cb5d4376844..7986d9ef85f1 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -19,7 +19,7 @@
#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)
@@ -128,7 +128,7 @@ 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],
@@ -499,7 +499,7 @@ 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;
@@ -698,7 +698,7 @@ 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:
@@ -1371,8 +1371,7 @@ 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
@@ -1455,8 +1454,7 @@ 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
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