[bpf-next,v12,10/14] bpf, net: switch to dynamic registration

Message ID	20231207013950.1689269-11-thinker.li@gmail.com (mailing list archive)
State	Superseded
Delegated to:	BPF
Headers	show Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="i1Z1vMZ6" From: thinker.li@gmail.com To: bpf@vger.kernel.org, ast@kernel.org, martin.lau@linux.dev, song@kernel.org, kernel-team@meta.com, andrii@kernel.org, drosen@google.com Cc: sinquersw@gmail.com, kuifeng@meta.com, Kui-Feng Lee <thinker.li@gmail.com>, netdev@vger.kernel.org Subject: [PATCH bpf-next v12 10/14] bpf, net: switch to dynamic registration Date: Wed, 6 Dec 2023 17:39:46 -0800 Message-Id: <20231207013950.1689269-11-thinker.li@gmail.com> In-Reply-To: <20231207013950.1689269-1-thinker.li@gmail.com> References: <20231207013950.1689269-1-thinker.li@gmail.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	Registrating struct_ops types from modules \| expand [bpf-next,v12,00/14] Registrating struct_ops types from modules [bpf-next,v12,01/14] bpf: refactory struct_ops type initialization to a function. [bpf-next,v12,02/14] bpf: get type information with BPF_ID_LIST [bpf-next,v12,03/14] bpf, net: introduce bpf_struct_ops_desc. [bpf-next,v12,04/14] bpf: add struct_ops_tab to btf. [bpf-next,v12,05/14] bpf: make struct_ops_map support btfs other than btf_vmlinux. [bpf-next,v12,06/14] bpf: lookup struct_ops types from a given module BTF. [bpf-next,v12,07/14] bpf: pass attached BTF to the bpf_struct_ops subsystem [bpf-next,v12,08/14] bpf: hold module for bpf_struct_ops_map. [bpf-next,v12,09/14] bpf: validate value_type [bpf-next,v12,10/14] bpf, net: switch to dynamic registration [bpf-next,v12,11/14] libbpf: Find correct module BTFs for struct_ops maps and progs. [bpf-next,v12,12/14] bpf: export btf_ctx_access to modules. [bpf-next,v12,13/14] selftests/bpf: test case for register_bpf_struct_ops(). [bpf-next,v12,14/14] bpf: pass btf object id in bpf_map_info.

Context	Check	Description
netdev/tree_selection	success	Clearly marked for bpf-next, async
netdev/apply	fail	Patch does not apply to bpf-next
bpf/vmtest-bpf-next-PR	fail	merge-conflict

diff --git a/include/linux/bpf.h b/include/linux/bpf.h index bc4279cd61e9..fdfceae25e08 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1651,7 +1651,6 @@ struct bpf_struct_ops_desc { #if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL) #define BPF_MODULE_OWNER ((void *)((0xeB9FUL << 2) + POISON_POINTER_DELTA)) const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id); -void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log); bool bpf_struct_ops_get(const void *kdata); void bpf_struct_ops_put(const void *kdata); int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key, @@ -1697,10 +1696,6 @@ static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf * { return NULL; } -static inline void bpf_struct_ops_init(struct btf *btf, - struct bpf_verifier_log *log) -{ -} static inline bool bpf_try_module_get(const void *data, struct module *owner) { return try_module_get(owner); @@ -3239,6 +3234,14 @@ static inline bool bpf_is_subprog(const struct bpf_prog *prog) return prog->aux->func_idx != 0; } +int register_bpf_struct_ops(struct bpf_struct_ops *st_ops); + +#define REGISTER_BPF_STRUCT_OPS(st_ops, type) \ +({ \ + BTF_STRUCT_OPS_TYPE_EMIT(type); \ + register_bpf_struct_ops(st_ops); \ +}) + enum bpf_struct_ops_state { BPF_STRUCT_OPS_STATE_INIT, BPF_STRUCT_OPS_STATE_INUSE, @@ -3251,4 +3254,19 @@ struct bpf_struct_ops_common_value { enum bpf_struct_ops_state state; }; +/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is + * the map's value exposed to the userspace and its btf-type-id is + * stored at the map->btf_vmlinux_value_type_id. + * + */ +#define DEFINE_STRUCT_OPS_VALUE_TYPE(_name) \ +struct bpf_struct_ops_##_name { \ + struct bpf_struct_ops_common_value common; \ + struct _name data ____cacheline_aligned_in_smp; \ +} + +int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, + struct btf *btf, + struct bpf_verifier_log *log); + #endif /* _LINUX_BPF_H */ diff --git a/include/linux/btf.h b/include/linux/btf.h index e2f4b85cf82a..cabab3db5216 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -12,6 +12,8 @@ #include <uapi/linux/bpf.h> #define BTF_TYPE_EMIT(type) ((void)(type *)0) +#define BTF_STRUCT_OPS_TYPE_EMIT(type) \ + ((void)(struct bpf_struct_ops_##type *)0) #define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val) /* These need to be macros, as the expressions are used in assembler input */ diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index e8415b6b6d2b..9ca166c79d19 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -61,35 +61,6 @@ static DEFINE_MUTEX(update_mutex); #define VALUE_PREFIX "bpf_struct_ops_" #define VALUE_PREFIX_LEN (sizeof(VALUE_PREFIX) - 1) -/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is - * the map's value exposed to the userspace and its btf-type-id is - * stored at the map->btf_vmlinux_value_type_id. - * - */ -#define BPF_STRUCT_OPS_TYPE(_name) \ -extern struct bpf_struct_ops bpf_##_name; \ - \ -struct bpf_struct_ops_##_name { \ - struct bpf_struct_ops_common_value common; \ - struct _name data ____cacheline_aligned_in_smp; \ -}; -#include "bpf_struct_ops_types.h" -#undef BPF_STRUCT_OPS_TYPE - -enum { -#define BPF_STRUCT_OPS_TYPE(_name) BPF_STRUCT_OPS_TYPE_##_name, -#include "bpf_struct_ops_types.h" -#undef BPF_STRUCT_OPS_TYPE - __NR_BPF_STRUCT_OPS_TYPE, -}; - -static struct bpf_struct_ops_desc bpf_struct_ops[] = { -#define BPF_STRUCT_OPS_TYPE(_name) \ - [BPF_STRUCT_OPS_TYPE_##_name] = { .st_ops = &bpf_##_name }, -#include "bpf_struct_ops_types.h" -#undef BPF_STRUCT_OPS_TYPE -}; - const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = { }; @@ -144,9 +115,9 @@ static bool is_valid_value_type(struct btf *btf, s32 value_id, return true; } -static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, - struct btf *btf, - struct bpf_verifier_log *log) +int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, + struct btf *btf, + struct bpf_verifier_log *log) { struct bpf_struct_ops *st_ops = st_ops_desc->st_ops; const struct btf_member *member; @@ -160,7 +131,7 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, sizeof(value_name)) { pr_warn("struct_ops name %s is too long\n", st_ops->name); - return; + return -EINVAL; } sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name); @@ -169,13 +140,13 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, if (type_id < 0) { pr_warn("Cannot find struct %s in %s\n", st_ops->name, btf_get_name(btf)); - return; + return -EINVAL; } t = btf_type_by_id(btf, type_id); if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) { pr_warn("Cannot support #%u members in struct %s\n", btf_type_vlen(t), st_ops->name); - return; + return -EINVAL; } value_id = btf_find_by_name_kind(btf, value_name, @@ -183,10 +154,10 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, if (value_id < 0) { pr_warn("Cannot find struct %s in %s\n", value_name, btf_get_name(btf)); - return; + return -EINVAL; } if (!is_valid_value_type(btf, value_id, t, value_name)) - return; + return -EINVAL; for_each_member(i, t, member) { const struct btf_type *func_proto; @@ -195,13 +166,13 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, if (!*mname) { pr_warn("anon member in struct %s is not supported\n", st_ops->name); - break; + return -EOPNOTSUPP; } if (__btf_member_bitfield_size(t, member)) { pr_warn("bit field member %s in struct %s is not supported\n", mname, st_ops->name); - break; + return -EOPNOTSUPP; } func_proto = btf_type_resolve_func_ptr(btf, @@ -213,7 +184,7 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, &st_ops->func_models[i])) { pr_warn("Error in parsing func ptr %s in struct %s\n", mname, st_ops->name); - break; + return -EINVAL; } } @@ -221,6 +192,7 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, if (st_ops->init(btf)) { pr_warn("Error in init bpf_struct_ops %s\n", st_ops->name); + return -EINVAL; } else { st_ops_desc->type_id = type_id; st_ops_desc->type = t; @@ -229,35 +201,24 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, value_id); } } -} -void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log) -{ - struct bpf_struct_ops_desc *st_ops_desc; - u32 i; - - /* Ensure BTF type is emitted for "struct bpf_struct_ops_##_name" */ -#define BPF_STRUCT_OPS_TYPE(_name) BTF_TYPE_EMIT(struct bpf_struct_ops_##_name); -#include "bpf_struct_ops_types.h" -#undef BPF_STRUCT_OPS_TYPE - - for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) { - st_ops_desc = &bpf_struct_ops[i]; - bpf_struct_ops_desc_init(st_ops_desc, btf, log); - } + return 0; } static const struct bpf_struct_ops_desc * bpf_struct_ops_find_value(struct btf *btf, u32 value_id) { + const struct bpf_struct_ops_desc *st_ops_list; unsigned int i; + u32 cnt = 0; - if (!value_id || !btf) + if (!value_id) return NULL; - for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) { - if (bpf_struct_ops[i].value_id == value_id) - return &bpf_struct_ops[i]; + st_ops_list = btf_get_struct_ops(btf, &cnt); + for (i = 0; i < cnt; i++) { + if (st_ops_list[i].value_id == value_id) + return &st_ops_list[i]; } return NULL; @@ -266,14 +227,17 @@ bpf_struct_ops_find_value(struct btf *btf, u32 value_id) const struct bpf_struct_ops_desc * bpf_struct_ops_find(struct btf *btf, u32 type_id) { + const struct bpf_struct_ops_desc *st_ops_list; unsigned int i; + u32 cnt; - if (!type_id || !btf) + if (!type_id) return NULL; - for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) { - if (bpf_struct_ops[i].type_id == type_id) - return &bpf_struct_ops[i]; + st_ops_list = btf_get_struct_ops(btf, &cnt); + for (i = 0; i < cnt; i++) { + if (st_ops_list[i].type_id == type_id) + return &st_ops_list[i]; } return NULL; diff --git a/kernel/bpf/bpf_struct_ops_types.h b/kernel/bpf/bpf_struct_ops_types.h deleted file mode 100644 index 5678a9ddf817..000000000000 --- a/kernel/bpf/bpf_struct_ops_types.h +++ /dev/null @@ -1,12 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* internal file - do not include directly */ - -#ifdef CONFIG_BPF_JIT -#ifdef CONFIG_NET -BPF_STRUCT_OPS_TYPE(bpf_dummy_ops) -#endif -#ifdef CONFIG_INET -#include <net/tcp.h> -BPF_STRUCT_OPS_TYPE(tcp_congestion_ops) -#endif -#endif diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index edbe3cbf2dcc..5545dee3ff54 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -19,6 +19,7 @@ #include <linux/bpf_verifier.h> #include <linux/btf.h> #include <linux/btf_ids.h> +#include <linux/bpf.h> #include <linux/bpf_lsm.h> #include <linux/skmsg.h> #include <linux/perf_event.h> @@ -5792,8 +5793,6 @@ struct btf *btf_parse_vmlinux(void) /* btf_parse_vmlinux() runs under bpf_verifier_lock */ bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); - bpf_struct_ops_init(btf, log); - refcount_set(&btf->refcnt, 1); err = btf_alloc_id(btf); @@ -8621,11 +8620,21 @@ bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log, return !strncmp(reg_name, arg_name, cmp_len); } +#ifndef CONFIG_BPF_JIT +int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, + struct btf *btf, + struct bpf_verifier_log *log) +{ + return -ENOTSUPP; +} +#endif /* CONFIG_BPF_JIT */ + static int -btf_add_struct_ops(struct btf *btf, struct bpf_struct_ops *st_ops) +btf_add_struct_ops(struct btf *btf, struct bpf_struct_ops *st_ops, + struct bpf_verifier_log *log) { struct btf_struct_ops_tab *tab, *new_tab; - int i; + int i, err; if (!btf) return -ENOENT; @@ -8662,6 +8671,10 @@ btf_add_struct_ops(struct btf *btf, struct bpf_struct_ops *st_ops) tab->ops[btf->struct_ops_tab->cnt].st_ops = st_ops; + err = bpf_struct_ops_desc_init(&tab->ops[btf->struct_ops_tab->cnt], btf, log); + if (err) + return err; + btf->struct_ops_tab->cnt++; return 0; @@ -8677,3 +8690,31 @@ const struct bpf_struct_ops_desc *btf_get_struct_ops(struct btf *btf, u32 *ret_c *ret_cnt = btf->struct_ops_tab->cnt; return (const struct bpf_struct_ops_desc *)btf->struct_ops_tab->ops; } + +int register_bpf_struct_ops(struct bpf_struct_ops *st_ops) +{ + struct bpf_verifier_log *log; + struct btf *btf; + int err = 0; + + btf = btf_get_module_btf(st_ops->owner); + if (!btf) + return -EINVAL; + + log = kzalloc(sizeof(*log), GFP_KERNEL | __GFP_NOWARN); + if (!log) { + err = -ENOMEM; + goto errout; + } + + log->level = BPF_LOG_KERNEL; + + err = btf_add_struct_ops(btf, st_ops, log); + +errout: + kfree(log); + btf_put(btf); + + return err; +} +EXPORT_SYMBOL_GPL(register_bpf_struct_ops); diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c index ffa224053a6c..65a89580d5d2 100644 --- a/net/bpf/bpf_dummy_struct_ops.c +++ b/net/bpf/bpf_dummy_struct_ops.c @@ -7,7 +7,7 @@ #include <linux/bpf.h> #include <linux/btf.h> -extern struct bpf_struct_ops bpf_bpf_dummy_ops; +static struct bpf_struct_ops bpf_bpf_dummy_ops; /* A common type for test_N with return value in bpf_dummy_ops */ typedef int (*dummy_ops_test_ret_fn)(struct bpf_dummy_ops_state *state, ...); @@ -223,11 +223,13 @@ static int bpf_dummy_reg(void *kdata) return -EOPNOTSUPP; } +DEFINE_STRUCT_OPS_VALUE_TYPE(bpf_dummy_ops); + static void bpf_dummy_unreg(void *kdata) { } -struct bpf_struct_ops bpf_bpf_dummy_ops = { +static struct bpf_struct_ops bpf_bpf_dummy_ops = { .verifier_ops = &bpf_dummy_verifier_ops, .init = bpf_dummy_init, .check_member = bpf_dummy_ops_check_member, @@ -235,4 +237,11 @@ struct bpf_struct_ops bpf_bpf_dummy_ops = { .reg = bpf_dummy_reg, .unreg = bpf_dummy_unreg, .name = "bpf_dummy_ops", + .owner = THIS_MODULE, }; + +static int __init bpf_dummy_struct_ops_init(void) +{ + return REGISTER_BPF_STRUCT_OPS(&bpf_bpf_dummy_ops, bpf_dummy_ops); +} +late_initcall(bpf_dummy_struct_ops_init); diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c index 3c8b76578a2a..69f0e8961628 100644 --- a/net/ipv4/bpf_tcp_ca.c +++ b/net/ipv4/bpf_tcp_ca.c @@ -12,7 +12,7 @@ #include <net/bpf_sk_storage.h> /* "extern" is to avoid sparse warning. It is only used in bpf_struct_ops.c. */ -extern struct bpf_struct_ops bpf_tcp_congestion_ops; +static struct bpf_struct_ops bpf_tcp_congestion_ops; static u32 unsupported_ops[] = { offsetof(struct tcp_congestion_ops, get_info), @@ -277,7 +277,9 @@ static int bpf_tcp_ca_validate(void *kdata) return tcp_validate_congestion_control(kdata); } -struct bpf_struct_ops bpf_tcp_congestion_ops = { +DEFINE_STRUCT_OPS_VALUE_TYPE(tcp_congestion_ops); + +static struct bpf_struct_ops bpf_tcp_congestion_ops = { .verifier_ops = &bpf_tcp_ca_verifier_ops, .reg = bpf_tcp_ca_reg, .unreg = bpf_tcp_ca_unreg, @@ -287,10 +289,16 @@ struct bpf_struct_ops bpf_tcp_congestion_ops = { .init = bpf_tcp_ca_init, .validate = bpf_tcp_ca_validate, .name = "tcp_congestion_ops", + .owner = THIS_MODULE, }; static int __init bpf_tcp_ca_kfunc_init(void) { - return register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &bpf_tcp_ca_kfunc_set); + int ret; + + ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &bpf_tcp_ca_kfunc_set); + ret = ret ?: REGISTER_BPF_STRUCT_OPS(&bpf_tcp_congestion_ops, tcp_congestion_ops); + + return ret; } late_initcall(bpf_tcp_ca_kfunc_init);

[bpf-next,v12,10/14] bpf, net: switch to dynamic registration

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