From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85507C4338F for ; Fri, 30 Jul 2021 05:23:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C53460E76 for ; Fri, 30 Jul 2021 05:23:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231897AbhG3FXH (ORCPT ); Fri, 30 Jul 2021 01:23:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229696AbhG3FXH (ORCPT ); Fri, 30 Jul 2021 01:23:07 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0996EC061765 for ; Thu, 29 Jul 2021 22:23:03 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id g23-20020a17090a5797b02901765d605e14so12730493pji.5 for ; Thu, 29 Jul 2021 22:23:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=oLWSV/ZYyYbOfxHVI474Gytzy7BuKYTbQ1F/xZKWAFA=; b=iLLUHPD+imc20OkfoPCTqRNXG2FnEPPnDn7WBBG7GWRnzraqZjaFa9Gae4wDydikRC cUDmIWqu29y8r+/xFRcsOL33dw9szVjQ3K721Ln2quky/hKkUob6QH2o4Ih4+wHg9ojY eHoHVTRwNdQXw2p3g8UdPHaWUB4SJtSilXszjgPHHfBX5SL+pOOlXAd0hK6bzKsefojq xsUfoNBSzn+hXGiAaXj+ARieiQYmRewkLIF3zkPs07YKQxTnEIeLJfQSbPHMf+Qcz8T9 GpP/PYPwdNJPFIi4mv2b5o9XdYiECh5AHe/PzVTl1GARPREZ4m7A/lZvC3CO7ked07mQ h9kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=oLWSV/ZYyYbOfxHVI474Gytzy7BuKYTbQ1F/xZKWAFA=; b=QNJzwHj9KvQ1gBBENMWQMf9hkoOscEM69eCClzWyQ7/IJRtD4chymCi08PrewSSSKY 3/yJjCnw1H/T9ycvReOA25SflNt9rqPonDBsmGFwH4iRav45EZDWUjpeLbix3n1EQAdd gWwLgQofwJqZIB57FuePC/AoMFMKtlLK+vsWDv8cCpj4NQ4CD0ZpouIWpjg6tEgTKQnO TLgZk0DHcZqUXn35ZtgLX22Z5Tr5MVgUh9LDZXAU6NMo58uxJCGeg3HvLRVHsv8VI71b F+EgHDDEvYgrlfQRSiaqTlsqFENJ0jjBVyJsaFCnDG6T6VC90xoAqYyFUk7wf30GMc58 MeYA== X-Gm-Message-State: AOAM532LRNJ+Car/wu5crnIl6lZ8Q+roj36e6+KO2tOykzL83bETzIB2 5n23QtWGTxPzpYpljjzpadw= X-Google-Smtp-Source: ABdhPJwCTVZ4KgI1I4e1WIRvW2QajbjiM+2Onc7AIkY4Jer6u2Y+NOVWJvFpxwE0Qor0A+deuNWhnA== X-Received: by 2002:aa7:864c:0:b029:34d:afdd:e70e with SMTP id a12-20020aa7864c0000b029034dafdde70emr1043997pfo.9.1627622582554; Thu, 29 Jul 2021 22:23:02 -0700 (PDT) Received: from [192.168.255.10] ([203.205.141.114]) by smtp.gmail.com with ESMTPSA id bg8sm563344pjb.4.2021.07.29.22.23.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 29 Jul 2021 22:23:02 -0700 (PDT) Subject: Re: [PATCH bpf-next v2] libbpf: add libbpf_load_vmlinux_btf/libbpf_load_module_btf APIs To: Andrii Nakryiko Cc: bpf , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Yonghong Song , john fastabend , Martin Lau References: <20210728165525.19104-1-hengqi.chen@gmail.com> From: Hengqi Chen Message-ID: <1987f2c1-9759-229f-6e67-f68948a23079@gmail.com> Date: Fri, 30 Jul 2021 13:22:59 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 2021/7/30 5:35 AM, Andrii Nakryiko wrote: > On Wed, Jul 28, 2021 at 9:55 AM Hengqi Chen wrote: >> >> Add two new APIs: libbpf_load_vmlinux_btf/libbpf_load_module_btf. >> libbpf_load_vmlinux_btf is just an alias to the existing API named >> libbpf_find_kernel_btf, rename it to be more precisely. >> libbpf_load_module_btf can be used to load module BTF, add it for >> completeness. These two APIs are useful for implementing tracing >> tools and introspection tools. >> This is part of the efforts towards libbpf 1.0. [1] >> >> [1] https://github.com/libbpf/libbpf/issues/280 >> >> Signed-off-by: Hengqi Chen >> --- >> tools/lib/bpf/btf.c | 15 ++++++++++++++- >> tools/lib/bpf/btf.h | 2 ++ >> tools/lib/bpf/libbpf.c | 4 ++-- >> tools/lib/bpf/libbpf.map | 2 ++ >> 4 files changed, 20 insertions(+), 3 deletions(-) >> >> diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c >> index b46760b93bb4..5f801739a1a2 100644 >> --- a/tools/lib/bpf/btf.c >> +++ b/tools/lib/bpf/btf.c >> @@ -4021,7 +4021,7 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d) >> */ >> if (d->hypot_adjust_canon) >> continue; >> - >> + >> if (t_kind == BTF_KIND_FWD && c_kind != BTF_KIND_FWD) >> d->map[t_id] = c_id; >> >> @@ -4395,6 +4395,11 @@ static int btf_dedup_remap_types(struct btf_dedup *d) >> * data out of it to use for target BTF. >> */ >> struct btf *libbpf_find_kernel_btf(void) >> +{ >> + return libbpf_load_vmlinux_btf(); >> +} >> + >> +struct btf *libbpf_load_vmlinux_btf(void) >> { >> struct { >> const char *path_fmt; >> @@ -4440,6 +4445,14 @@ struct btf *libbpf_find_kernel_btf(void) >> return libbpf_err_ptr(-ESRCH); >> } >> >> +struct btf *libbpf_load_module_btf(const char *module_name, struct btf *vmlinux_btf) > > In the light of Quentin's btf__load_from_kernel_by_id(), I'm now > wondering if it's better to keep the naming consistent as > btf__load_vmlinux_btf() and btf__load_module_btf()? And we should put > them after btf__parse() family of constructors, as just another set of > (special, but still) constructors. WDYT? > > Sorry for a bit of back and forth... > > Otherwise everything looks good, thanks. > Thanks for the review. Will update as you suggested. Sometimes naming is the hardest part of programming, I am not good at that. :) (BTW, Quentin's tweet led me to here) >> +{ >> + char path[80]; >> + >> + snprintf(path, sizeof(path), "/sys/kernel/btf/%s", module_name); >> + return btf__parse_split(path, vmlinux_btf); >> +} >> + >> int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx) >> { >> int i, n, err; >> diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h >> index 374e9f15de2e..1abf94e3bd9e 100644 >> --- a/tools/lib/bpf/btf.h >> +++ b/tools/lib/bpf/btf.h >> @@ -90,6 +90,8 @@ LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); >> LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); >> >> LIBBPF_API struct btf *libbpf_find_kernel_btf(void); >> +LIBBPF_API struct btf *libbpf_load_vmlinux_btf(void); >> +LIBBPF_API struct btf *libbpf_load_module_btf(const char *module_name, struct btf *vmlinux_btf); > > as mentioned above, let's move these right after btf__parse() family, > so that all BTF constructor APIs are listed first. > Sure, will do. >> >> LIBBPF_API int btf__find_str(struct btf *btf, const char *s); >> LIBBPF_API int btf__add_str(struct btf *btf, const char *s); >> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c >> index a1ca6fb0c6d8..321d8f4889af 100644 >> --- a/tools/lib/bpf/libbpf.c >> +++ b/tools/lib/bpf/libbpf.c >> @@ -2680,7 +2680,7 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force) >> if (!force && !obj_needs_vmlinux_btf(obj)) >> return 0; >> >> - obj->btf_vmlinux = libbpf_find_kernel_btf(); >> + obj->btf_vmlinux = libbpf_load_vmlinux_btf(); >> err = libbpf_get_error(obj->btf_vmlinux); >> if (err) { >> pr_warn("Error loading vmlinux BTF: %d\n", err); >> @@ -8297,7 +8297,7 @@ int libbpf_find_vmlinux_btf_id(const char *name, >> struct btf *btf; >> int err; >> >> - btf = libbpf_find_kernel_btf(); >> + btf = libbpf_load_vmlinux_btf(); >> err = libbpf_get_error(btf); >> if (err) { >> pr_warn("vmlinux BTF is not found\n"); >> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map >> index c240d488eb5e..2088bdbc0f50 100644 >> --- a/tools/lib/bpf/libbpf.map >> +++ b/tools/lib/bpf/libbpf.map >> @@ -377,4 +377,6 @@ LIBBPF_0.5.0 { >> bpf_object__gen_loader; >> btf_dump__dump_type_data; >> libbpf_set_strict_mode; >> + libbpf_load_vmlinux_btf; >> + libbpf_load_module_btf; >> } LIBBPF_0.4.0; >> -- >> 2.25.1 >>