From patchwork Thu Dec 7 01:39:47 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: 13482558 X-Patchwork-Delegate: bpf@iogearbox.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FffUNee3" Received: from mail-yw1-x1135.google.com (mail-yw1-x1135.google.com [IPv6:2607:f8b0:4864:20::1135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76141D63 for ; Wed, 6 Dec 2023 17:40:19 -0800 (PST) Received: by mail-yw1-x1135.google.com with SMTP id 00721157ae682-5c08c47c055so1572547b3.1 for ; Wed, 06 Dec 2023 17:40:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701913218; x=1702518018; 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=WtqwuSVZ229pwFOVG/4ChaMO8rG/hKzZhobZjCDXrRU=; b=FffUNee3MR0JLJmk3vvQNk4z5E2dE208nEYfbpBKS6rQy5o0AxVsMnNMyyRpwyS+Yz Yg9ouuDOAdUZTLzimHNpgvdgVMGVzoBdYY15PzwiWCiihpBBD1EcXfw3cDykyh9KUEsM uxN2fAY2WKLRl2GRjL05fZkVNWojsq6FcBzMCgtImNfut1LmgKs3y8KRqn+ERIRmE3MK jch//EK6qADGHkdFHjNM7wFBuwL0IfnWZtgU4Q/g9JKbe/ULjtS08m+MsS5HVmjLoX7M 5OJQeVaCkZhtTAgp+5fDnXrZ658ZIDTFtmK2hEu6uQ6RqTHITUWBPMMzS8dAw3e9yNXp 5U6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701913218; x=1702518018; 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=WtqwuSVZ229pwFOVG/4ChaMO8rG/hKzZhobZjCDXrRU=; b=b2g8PElca2o+2lty1rn43uOev1LKfuCgrNQ5has/PBVtGui1OA0EjQl8eMEy8n7fcs BRSMA6Aykr33aFNql7OzexmBCDJlQ7IXgtcrlNuP0hoPsgWkLoDRuAOIIfpGnMBehhZw aTsCHHxq1/W+jdksHxn8NSrRWKU5nN9N+lOAtTkixvhygPYEkuOc2mJYySorg13WyDxU rXaO/ObfobnLQFFpErkDP/3CvS29/K5fn9uDor4h2rff+0EN0gDoS+I+ET8uHEnqa9gZ FslXkBWFamduqz0AGA8kV8kRRTYLFa/ST8y96NK/4QQNf4F8HNkNyG1cMk0202jH3RcC irMQ== X-Gm-Message-State: AOJu0Yxp07b/YUtZqCCZPiUpDl7QSKu3mevdrYzCHlLpg1IGN1Er2yEo y4Vr5NQ8rMOokbwgF94pbWjpqFlAnx4= X-Google-Smtp-Source: AGHT+IEPyHr//7v0EW7Md17ZDVUqH7fOXxMkoXIHLMlTXETRYjOuDUp3zTmP2N1506XTSQH8/i9hvQ== X-Received: by 2002:a81:b70c:0:b0:5d7:1940:53c6 with SMTP id v12-20020a81b70c000000b005d7194053c6mr1624279ywh.62.1701913218054; Wed, 06 Dec 2023 17:40:18 -0800 (PST) Received: from kickker.attlocal.net ([2600:1700:6cf8:1240:c8f2:3a3b:3003:f559]) by smtp.gmail.com with ESMTPSA id v134-20020a81488c000000b005d997db3b2fsm60768ywa.23.2023.12.06.17.40.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Dec 2023 17:40:17 -0800 (PST) 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 v12 11/14] libbpf: Find correct module BTFs for struct_ops maps and progs. Date: Wed, 6 Dec 2023 17:39:47 -0800 Message-Id: <20231207013950.1689269-12-thinker.li@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231207013950.1689269-1-thinker.li@gmail.com> References: <20231207013950.1689269-1-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 | 38 ++++++++++++++++++++++++++++---------- 3 files changed, 35 insertions(+), 12 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 ea9b8158c20d..deeb8fac7990 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); @@ -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_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",