From patchwork Fri Oct 27 21:17:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kui-Feng Lee X-Patchwork-Id: 13439175 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B96913FE30 for ; Fri, 27 Oct 2023 21:17:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Bh3wNGS5" Received: from mail-yw1-x1130.google.com (mail-yw1-x1130.google.com [IPv6:2607:f8b0:4864:20::1130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD20F129 for ; Fri, 27 Oct 2023 14:17:20 -0700 (PDT) Received: by mail-yw1-x1130.google.com with SMTP id 00721157ae682-5a82f176860so19013687b3.1 for ; Fri, 27 Oct 2023 14:17:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1698441440; x=1699046240; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=LIaFNR2jWts5aTPUB8q6Tuj+4zsQdN5CxwLohBhhDRQ=; b=Bh3wNGS5+V7orqsl87usyzN6DsT8wwye776mcboM+dSuK4kehjZ6X1qMkApFvfRTN+ d/rzxlHw2Y9XPHImT4UjYWyvwfSoXExcvNgQtBkZeNJzUVv3g0nZT7VX7XoBJUPVmuE+ KRQAqR3E2HCUK/tetAusxBeWOcuz+qNTu3zH4v+ial3iT6+7wbNIy0JamQQac9ybnvjp q6RB1k4v05DGJ98Ix5T3QQdht7Mf9MS1IaOQqWXo5l/InIInRIUOLLKNBaaByzVGHoLf fsDdttKxIGjbuTEwn44lMFEw4toyNC0n9OxPGVwCNWfB3Xw7dFZ/t8Dv3TOLiLjLfTY/ 90Gg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698441440; x=1699046240; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=LIaFNR2jWts5aTPUB8q6Tuj+4zsQdN5CxwLohBhhDRQ=; b=YJq0UiPhvYw/61sN8L2V+TSW0P3Nb77RKldTc366WZP4RL5sc5ralsON1ru/boRqJE oOoPpvS8RNt9NuMdgvsyR3Jg8Q8AcIx4HM5hxegKmUOYjjAtST1lqHYULUvwd2b1RWR8 vpmGyg+jqRB1tx2ELygsL1wVD4mUrga9iMoZwHfxC6z5bLVH5vWfI9FSKwJVpgHGVgiw EyB/Xo7M2NMCyQZEjBWpjXGntybhVYwShXxHsRA2e9LFvmFSJ9rJDx/dd5KYHtiJZrTl iS5nRUtLQGaXn4TStwhENykBLXmu7l5crTwb88BG8YpPiUG9/5tMGBdmcOF4nq9yNOLY D9Cw== X-Gm-Message-State: AOJu0YzIRB8x+FSJzFmYh1TU6QkwSKvE2D5Nl4h/XoEzGx+/FCwRFnJ+ EePwf1PJBah+YyDAUB6JgIQD+5fhqSQ= X-Google-Smtp-Source: AGHT+IH77v4puiYwOOzU9jGiuGKxf8Dp5n5NItCoZ1CtSjdfU3g/ovLhagG5KYj9Xxgso/+gOHha0Q== X-Received: by 2002:a81:aa06:0:b0:5a7:bb6e:796d with SMTP id i6-20020a81aa06000000b005a7bb6e796dmr4472100ywh.19.1698441439808; Fri, 27 Oct 2023 14:17:19 -0700 (PDT) Received: from kickker.attlocal.net ([2600:1700:6cf8:1240:41cd:a94b:292d:cd8]) by smtp.gmail.com with ESMTPSA id e133-20020a81698b000000b0059a34cfa2a5sm1080174ywc.67.2023.10.27.14.17.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Oct 2023 14:17:19 -0700 (PDT) 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 Subject: [PATCH bpf-next v7 08/10] libbpf: Find correct module BTFs for struct_ops maps and progs. Date: Fri, 27 Oct 2023 14:17:00 -0700 Message-Id: <20231027211702.1374597-9-thinker.li@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231027211702.1374597-1-thinker.li@gmail.com> References: <20231027211702.1374597-1-thinker.li@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net From: Kui-Feng Lee Locate the module BTFs for struct_ops maps and progs and pass them to the kernel. This ensures that the kernel correctly resolves type IDs from the appropriate module BTFs. For the map of a struct_ops object, the FD of the module BTF is set to bpf_map to keep a reference to the module BTF. The FD is passed to the kernel as value_type_btf_obj_fd when the struct_ops object is loaded. For a bpf_struct_ops prog, attach_btf_obj_fd of bpf_prog is the FD of a module BTF in the kernel. Signed-off-by: Kui-Feng Lee Acked-by: Andrii Nakryiko --- tools/lib/bpf/bpf.c | 4 +++- tools/lib/bpf/bpf.h | 5 ++++- tools/lib/bpf/libbpf.c | 50 ++++++++++++++++++++++++++++-------------- 3 files changed, 41 insertions(+), 18 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 9dc9625651dc..b133acfe08fb 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -169,7 +169,8 @@ int bpf_map_create(enum bpf_map_type map_type, __u32 max_entries, const struct bpf_map_create_opts *opts) { - const size_t attr_sz = offsetofend(union bpf_attr, map_extra); + const size_t attr_sz = offsetofend(union bpf_attr, + value_type_btf_obj_fd); union bpf_attr attr; int fd; @@ -191,6 +192,7 @@ int bpf_map_create(enum bpf_map_type map_type, attr.btf_key_type_id = OPTS_GET(opts, btf_key_type_id, 0); attr.btf_value_type_id = OPTS_GET(opts, btf_value_type_id, 0); attr.btf_vmlinux_value_type_id = OPTS_GET(opts, btf_vmlinux_value_type_id, 0); + attr.value_type_btf_obj_fd = OPTS_GET(opts, value_type_btf_obj_fd, 0); attr.inner_map_fd = OPTS_GET(opts, inner_map_fd, 0); attr.map_flags = OPTS_GET(opts, map_flags, 0); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index d0f53772bdc0..ffdd81c0196a 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -51,8 +51,11 @@ struct bpf_map_create_opts { __u32 numa_node; __u32 map_ifindex; + + __u32 value_type_btf_obj_fd; + size_t:0; }; -#define bpf_map_create_opts__last_field map_ifindex +#define bpf_map_create_opts__last_field value_type_btf_obj_fd LIBBPF_API int bpf_map_create(enum bpf_map_type map_type, const char *map_name, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e067be95da3c..0b0ad8461970 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -527,6 +527,7 @@ struct bpf_map { struct bpf_map_def def; __u32 numa_node; __u32 btf_var_idx; + int mod_btf_fd; __u32 btf_key_type_id; __u32 btf_value_type_id; __u32 btf_vmlinux_value_type_id; @@ -930,22 +931,29 @@ find_member_by_name(const struct btf *btf, const struct btf_type *t, return NULL; } +static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name, + __u16 kind, struct btf **res_btf, + struct module_btf **res_mod_btf); + #define STRUCT_OPS_VALUE_PREFIX "bpf_struct_ops_" static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix, const char *name, __u32 kind); static int -find_struct_ops_kern_types(const struct btf *btf, const char *tname, +find_struct_ops_kern_types(struct bpf_object *obj, const char *tname, + struct module_btf **mod_btf, const struct btf_type **type, __u32 *type_id, const struct btf_type **vtype, __u32 *vtype_id, const struct btf_member **data_member) { const struct btf_type *kern_type, *kern_vtype; const struct btf_member *kern_data_member; + struct btf *btf; __s32 kern_vtype_id, kern_type_id; __u32 i; - kern_type_id = btf__find_by_name_kind(btf, tname, BTF_KIND_STRUCT); + kern_type_id = find_ksym_btf_id(obj, tname, BTF_KIND_STRUCT, + &btf, mod_btf); if (kern_type_id < 0) { pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n", tname); @@ -999,14 +1007,16 @@ static bool bpf_map__is_struct_ops(const struct bpf_map *map) } /* Init the map's fields that depend on kern_btf */ -static int bpf_map__init_kern_struct_ops(struct bpf_map *map, - const struct btf *btf, - const struct btf *kern_btf) +static int bpf_map__init_kern_struct_ops(struct bpf_map *map) { const struct btf_member *member, *kern_member, *kern_data_member; const struct btf_type *type, *kern_type, *kern_vtype; __u32 i, kern_type_id, kern_vtype_id, kern_data_off; + struct bpf_object *obj = map->obj; + const struct btf *btf = obj->btf; struct bpf_struct_ops *st_ops; + const struct btf *kern_btf; + struct module_btf *mod_btf; void *data, *kern_data; const char *tname; int err; @@ -1014,16 +1024,19 @@ static int bpf_map__init_kern_struct_ops(struct bpf_map *map, st_ops = map->st_ops; type = st_ops->type; tname = st_ops->tname; - err = find_struct_ops_kern_types(kern_btf, tname, + err = find_struct_ops_kern_types(obj, tname, &mod_btf, &kern_type, &kern_type_id, &kern_vtype, &kern_vtype_id, &kern_data_member); if (err) return err; + kern_btf = mod_btf ? mod_btf->btf : obj->btf_vmlinux; + pr_debug("struct_ops init_kern %s: type_id:%u kern_type_id:%u kern_vtype_id:%u\n", map->name, st_ops->type_id, kern_type_id, kern_vtype_id); + map->mod_btf_fd = mod_btf ? mod_btf->fd : 0; map->def.value_size = kern_vtype->size; map->btf_vmlinux_value_type_id = kern_vtype_id; @@ -1099,6 +1112,8 @@ static int bpf_map__init_kern_struct_ops(struct bpf_map *map, return -ENOTSUP; } + if (mod_btf) + prog->attach_btf_obj_fd = mod_btf->fd; prog->attach_btf_id = kern_type_id; prog->expected_attach_type = kern_member_idx; @@ -1141,8 +1156,7 @@ static int bpf_object__init_kern_struct_ops_maps(struct bpf_object *obj) if (!bpf_map__is_struct_ops(map)) continue; - err = bpf_map__init_kern_struct_ops(map, obj->btf, - obj->btf_vmlinux); + err = bpf_map__init_kern_struct_ops(map); if (err) return err; } @@ -5201,8 +5215,10 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b create_attr.numa_node = map->numa_node; create_attr.map_extra = map->map_extra; - if (bpf_map__is_struct_ops(map)) + if (bpf_map__is_struct_ops(map)) { create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; + create_attr.value_type_btf_obj_fd = map->mod_btf_fd; + } if (obj->btf && btf__fd(obj->btf) >= 0) { create_attr.btf_fd = btf__fd(obj->btf); @@ -9479,9 +9495,9 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) return err; } -static int find_kernel_btf_id(struct bpf_object *obj, const char *attach_name, - enum bpf_attach_type attach_type, - int *btf_obj_fd, int *btf_type_id) +static int find_kernel_attach_btf_id(struct bpf_object *obj, const char *attach_name, + enum bpf_attach_type attach_type, + int *btf_obj_fd, int *btf_type_id) { int ret, i; @@ -9546,7 +9562,9 @@ static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attac *btf_obj_fd = 0; *btf_type_id = 1; } else { - err = find_kernel_btf_id(prog->obj, attach_name, attach_type, btf_obj_fd, btf_type_id); + err = find_kernel_attach_btf_id(prog->obj, attach_name, + attach_type, btf_obj_fd, + btf_type_id); } if (err) { pr_warn("prog '%s': failed to find kernel BTF type ID of '%s': %d\n", @@ -13004,9 +13022,9 @@ int bpf_program__set_attach_target(struct bpf_program *prog, err = bpf_object__load_vmlinux_btf(prog->obj, true); if (err) return libbpf_err(err); - err = find_kernel_btf_id(prog->obj, attach_func_name, - prog->expected_attach_type, - &btf_obj_fd, &btf_id); + err = find_kernel_attach_btf_id(prog->obj, attach_func_name, + prog->expected_attach_type, + &btf_obj_fd, &btf_id); if (err) return libbpf_err(err); }