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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@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210115163501.805133-4-sdf@google.com
This commit is contained in:
Stanislav Fomichev 2021-01-15 08:35:01 -08:00 committed by Alexei Starovoitov
parent 20f2505fb4
commit a9ed15dae0
6 changed files with 42 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
include/linux/bpf-cgroup.h
View File

@ -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]);
@ -189,7 +189,7 @@ 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); \
\
@ -199,7 +199,7 @@ 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, \
@ -211,7 +211,7 @@ 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; \
@ -232,7 +232,7 @@ 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; \
@ -241,7 +241,7 @@ 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); \
@ -256,8 +256,10 @@ 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)
@ -301,7 +303,7 @@ 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); \
@ -311,7 +313,7 @@ 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, \
@ -324,7 +326,7 @@ 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); \
@ -336,7 +338,7 @@ 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); \
@ -347,7 +349,7 @@ 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, \
@ -358,7 +360,7 @@ 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; \
})
@ -367,7 +369,7 @@ 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)) \
if (!(sock)->sk_prot->bpf_bypass_getsockopt || \
!INDIRECT_CALL_INET_1((sock)->sk_prot->bpf_bypass_getsockopt, \
tcp_bpf_bypass_getsockopt, \
@ -382,7 +384,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key,
optlen, retval) \
({ \
int __ret = retval; \
if (cgroup_bpf_enabled) \
if (cgroup_bpf_enabled(BPF_CGROUP_GETSOCKOPT)) \
__ret = __cgroup_bpf_run_filter_getsockopt_kern( \
sock, level, optname, optval, optlen, retval); \
__ret; \
@ -444,7 +446,7 @@ 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; })

14
kernel/bpf/cgroup.c
View File

@ -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:
@ -1360,8 +1360,7 @@ 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
@ -1457,8 +1456,7 @@ 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;

9
net/ipv4/af_inet.c
View File

@ -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);
}

7
net/ipv4/udp.c
View File

@ -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)

9
net/ipv6/af_inet6.c
View File

@ -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);

7
net/ipv6/udp.c
View File

@ -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)