From bc4f0548f683a3d53359cef15f088d2d5bb4bc39 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 20 Jul 2020 09:33:58 -0700 Subject: [PATCH] bpf: Compute bpf_skc_to_*() helper socket btf ids at build time Currently, socket types (struct tcp_sock, udp_sock, etc.) used by bpf_skc_to_*() helpers are computed when vmlinux_btf is first built in the kernel. Commit 5a2798ab32ba ("bpf: Add BTF_ID_LIST/BTF_ID/BTF_ID_UNUSED macros") implemented a mechanism to compute btf_ids at kernel build time which can simplify kernel implementation and reduce runtime overhead by removing in-kernel btf_id calculation. This patch did exactly this, removing in-kernel btf_id computation and utilizing build-time btf_id computation. If CONFIG_DEBUG_INFO_BTF is not defined, BTF_ID_LIST will define an array with size of 5, which is not enough for btf_sock_ids. So define its own static array if CONFIG_DEBUG_INFO_BTF is not defined. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200720163358.1393023-1-yhs@fb.com --- include/linux/bpf.h | 4 ---- kernel/bpf/btf.c | 1 - net/core/filter.c | 49 ++++++++++++++++++------------------------------- 3 files changed, 18 insertions(+), 36 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index adb16bd..1df1c0f 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1541,7 +1541,6 @@ static inline bool bpf_map_is_dev_bound(struct bpf_map *map) struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr); void bpf_map_offload_map_free(struct bpf_map *map); -void init_btf_sock_ids(struct btf *btf); #else static inline int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) @@ -1567,9 +1566,6 @@ static inline struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) static inline void bpf_map_offload_map_free(struct bpf_map *map) { } -static inline void init_btf_sock_ids(struct btf *btf) -{ -} #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */ #if defined(CONFIG_BPF_STREAM_PARSER) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 03d6d43..315cde7 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3672,7 +3672,6 @@ struct btf *btf_parse_vmlinux(void) goto errout; bpf_struct_ops_init(btf, log); - init_btf_sock_ids(btf); btf_verifier_env_free(env); refcount_set(&btf->refcnt, 1); diff --git a/net/core/filter.c b/net/core/filter.c index 2bd129b..5a65fb4 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -9426,19 +9426,19 @@ void bpf_prog_change_xdp(struct bpf_prog *prev_prog, struct bpf_prog *prog) * sock_common as the first argument in its memory layout. */ #define BTF_SOCK_TYPE_xxx \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET, "inet_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_CONN, "inet_connection_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_REQ, "inet_request_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, "inet_timewait_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_REQ, "request_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK, "sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK_COMMON, "sock_common") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP, "tcp_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_REQ, "tcp_request_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, "tcp_timewait_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, "tcp6_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, "udp_sock") \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, "udp6_sock") + BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET, inet_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_CONN, inet_connection_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_REQ, inet_request_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, inet_timewait_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_REQ, request_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK, sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK_COMMON, sock_common) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP, tcp_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_REQ, tcp_request_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) enum { #define BTF_SOCK_TYPE(name, str) name, @@ -9447,26 +9447,13 @@ BTF_SOCK_TYPE_xxx MAX_BTF_SOCK_TYPE, }; -static int btf_sock_ids[MAX_BTF_SOCK_TYPE]; - -#ifdef CONFIG_BPF_SYSCALL -static const char *bpf_sock_types[] = { -#define BTF_SOCK_TYPE(name, str) str, +#ifdef CONFIG_DEBUG_INFO_BTF +BTF_ID_LIST(btf_sock_ids) +#define BTF_SOCK_TYPE(name, type) BTF_ID(struct, type) BTF_SOCK_TYPE_xxx #undef BTF_SOCK_TYPE -}; - -void init_btf_sock_ids(struct btf *btf) -{ - int i, btf_id; - - for (i = 0; i < MAX_BTF_SOCK_TYPE; i++) { - btf_id = btf_find_by_name_kind(btf, bpf_sock_types[i], - BTF_KIND_STRUCT); - if (btf_id > 0) - btf_sock_ids[i] = btf_id; - } -} +#else +static u32 btf_sock_ids[MAX_BTF_SOCK_TYPE]; #endif static bool check_arg_btf_id(u32 btf_id, u32 arg) -- 2.7.4