From patchwork Sun Oct 22 05:03:33 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: 13431637 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 98CF51C3A for ; Sun, 22 Oct 2023 05:03:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hRnqNaSJ" Received: from mail-yw1-x112f.google.com (mail-yw1-x112f.google.com [IPv6:2607:f8b0:4864:20::112f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDEE2E7 for ; Sat, 21 Oct 2023 22:03:57 -0700 (PDT) Received: by mail-yw1-x112f.google.com with SMTP id 00721157ae682-5a877e0f0d8so26608807b3.1 for ; Sat, 21 Oct 2023 22:03:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697951037; x=1698555837; 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=I6wJWGltynBxVGwKliNnTM1tqA0ScI0Kgt8VuWcqhzI=; b=hRnqNaSJKG+CvDkB+eyIIM+c85B4QiSUCSqOQsQdw0wdi6Nywg//r92lVs0mTByRWr Le1wMjpgdoGRCvMsMlnh5KGHAtR0/YgyqPApZRIrSy3swkrp1eWoUxiY3TV9xGqOPYbz gkpK/jKl6sOiP7Eganmk5RlZ4Eo1Kit3TjHV6smZPRCW8LgWnd2iaAKTpLS9LUZhPPj2 jhAVPZ+wKb5qiIfp5gxWf2PlQ5ghkwL7LbvTKYi/Qpal0EyMEIPhzjwluni3X+1HmkpY DK5dX76/1zUu0qKUiWl+CC0t9mi7QgYZX+1jo8fxrwvZ9Mzyczy7rrFjZanhhuMabIGR FmHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697951037; x=1698555837; 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=I6wJWGltynBxVGwKliNnTM1tqA0ScI0Kgt8VuWcqhzI=; b=OskBHaeeiLR7yrmRwvae+EdjwiG5NBXm9JaKGf59yDdfFGxtWotfui/tlFMBvM3jyS p1m9LflE9h3PB8c/XNsb/gniUVM7knjXxXrL+SZ+ckBH5Esp/j+nB2tCx/8omolbUPz4 3CYUpkUtAzXFOHy19xrLYvWwtXWxjtavfg9rYui33ibjX4PIkmT29dNVPcVjMw7TcUW+ vPFoUZ8w5mTRkI9GIOyf1t2qHkjH9XNMjy3adv/QkBa1yxGuZRp+vdHxmNRtAup2JMUx eMOlQYVo14l/VycjHRl1aSqcf27Q2RTqAmzfIb7g3C2FQ7anUylDhASNLl0EtrbX5qs6 lH+Q== X-Gm-Message-State: AOJu0YztIO93W73MnoTvC+ldnHOUV70Lf4cwxZPjxdD2FN1DI/x5K/0x 8vz15Hot/2CcTGNqjQzIOGi2YN0YbB4= X-Google-Smtp-Source: AGHT+IHEIq6PeCXWy91M9BmNj8xbFZKABtZ4xThD90gi5us0KPP5jXEa6yqBjXtFMOzeGUgj+EVPcA== X-Received: by 2002:a0d:cb0e:0:b0:5a7:bde8:84a4 with SMTP id n14-20020a0dcb0e000000b005a7bde884a4mr5838655ywd.14.1697951036768; Sat, 21 Oct 2023 22:03:56 -0700 (PDT) Received: from kickker.attlocal.net ([2600:1700:6cf8:1240:9904:3214:88c1:e733]) by smtp.gmail.com with ESMTPSA id j1-20020a0de001000000b005a8c392f498sm2035169ywe.82.2023.10.21.22.03.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 21 Oct 2023 22:03:56 -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 v6 08/10] libbpf: Find correct module BTFs for struct_ops maps and progs. Date: Sat, 21 Oct 2023 22:03:33 -0700 Message-Id: <20231022050335.2579051-9-thinker.li@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231022050335.2579051-1-thinker.li@gmail.com> References: <20231022050335.2579051-1-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 b0f1913763a3..af46488e4ea9 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 74c2887cfd24..1733cdc21241 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 3a6108e3238b..9ff95c3d6a92 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -519,6 +519,7 @@ 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; @@ -922,22 +923,29 @@ 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); @@ -991,14 +999,16 @@ 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; @@ -1006,16 +1016,19 @@ 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; @@ -1091,6 +1104,8 @@ 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; @@ -1133,8 +1148,7 @@ 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; } @@ -5193,8 +5207,10 @@ 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); @@ -9464,9 +9480,9 @@ 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; @@ -9531,7 +9547,9 @@ 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", @@ -12945,9 +12963,9 @@ 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); }