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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61CF8C74A5B for ; Thu, 16 Mar 2023 23:24:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229638AbjCPXYK (ORCPT ); Thu, 16 Mar 2023 19:24:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229849AbjCPXYE (ORCPT ); Thu, 16 Mar 2023 19:24:04 -0400 Received: from mail-ed1-x531.google.com (mail-ed1-x531.google.com [IPv6:2a00:1450:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45574252A6; Thu, 16 Mar 2023 16:24:03 -0700 (PDT) Received: by mail-ed1-x531.google.com with SMTP id z21so13985678edb.4; Thu, 16 Mar 2023 16:24:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679009041; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=CqCtQMVO3PCNmsjowvSiFVl0zPMhdzWcCNuKutfxoQE=; b=a26VvhgERM18IXZx6e9ovqkeYzHc7Q79T+JbGF5qTRVWuj7YmEP2IgF007SC9Q6DwJ R22xbtM4DrKfg550WSHdK5o4aNooUnEUVvIN2HW4oUW1/HbsCIShguSYqQ8Df+RGNbIa Rumq5GOaf8lc/ZeVWQWSeTpNjWZ5a7uPSOWDZWunVRfeW5RL/FCJ7xyPyEhaAzczLW5V pGwTmppDOn1HUNG+j3EuHBVLiw8HGco13gpCvl4Mpph2TnYiZRYQ0QMgEw5dBei5G+fW tVxYtSAhlG9XncSVQU4F2c3lBUD43CjnYIQwsuauipKDhtlK+2jGLdyluPN6ob9RlSYH ijmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679009041; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CqCtQMVO3PCNmsjowvSiFVl0zPMhdzWcCNuKutfxoQE=; b=R2gc6CGW9dc8ekBnZGb4iAHnzGOHPn6U+xlf5HfjZSz8HFW2uS8S6JjjKXAv+KJ4d2 5P5Li+ESvE9E2jV8MTaDvGToaAsZG9Kv4uuOrr/YqlQc7tZAdxP1ergf0s8A6hR5Ajmp PNtDjtOFmsmJtLmn9LXN/F05R4gnTnm/0X0LIlwjCenq4P4ibroaC2uGaiQf+rE0FmtT vW8MfCpkgsaE7maslnJI4YsCsTmb6BPzjzpR4Ut2aQOV1PFtz0x0LKF+8ccoi/GqwaWE SE9Z9UlUxdrUjk/lLtUefRL7aRs+TJtGQei609ijRDwpdG8r5S+FuM5M8YCkUy5ofbDs Of4A== X-Gm-Message-State: AO0yUKUT5JucT0gpBg/KceePO5iqZHaUXJXHjnhuIx5jNZ+uqxgr+rMf XsTuKVREwoLgL44ZGOB4mQWGTjXeJ0I2Ysjz2/U= X-Google-Smtp-Source: AK7set8OQ9tCVJIvhtKpLllhpwxhWA6V/V4IiZFkSYa64gdCP3kpWTBJOtxzdxCmo0bdt83921jleBfgD+zsOC3kQmU= X-Received: by 2002:a17:906:8552:b0:8ab:b606:9728 with SMTP id h18-20020a170906855200b008abb6069728mr6256473ejy.5.1679009041332; Thu, 16 Mar 2023 16:24:01 -0700 (PDT) MIME-Version: 1.0 References: <20230315223607.50803-1-alexei.starovoitov@gmail.com> <20230315223607.50803-3-alexei.starovoitov@gmail.com> In-Reply-To: From: Andrii Nakryiko Date: Thu, 16 Mar 2023 16:23:49 -0700 Message-ID: Subject: Re: [PATCH bpf-next 2/2] selftests/bpf: Add test for bpf_kfunc_exists(). To: Alexei Starovoitov Cc: "David S. Miller" , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , David Vernet , Dave Marchevsky , Tejun Heo , Kumar Kartikeya Dwivedi , Network Development , bpf , Kernel Team Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, Mar 16, 2023 at 3:35=E2=80=AFPM Alexei Starovoitov wrote: > > On Thu, Mar 16, 2023 at 1:34=E2=80=AFPM Andrii Nakryiko > wrote: > > > > On Wed, Mar 15, 2023 at 3:36=E2=80=AFPM Alexei Starovoitov > > wrote: > > > > > > From: Alexei Starovoitov > > > > > > Add load and run time test for bpf_kfunc_exists() and check that the = verifier > > > performs dead code elimination for non-existing kfunc. > > > > > > Signed-off-by: Alexei Starovoitov > > > --- > > > > we have prog_tests/ksyms_btf.c and progs/test_ksyms_weak.c which do > > these kind of tests for variable ksyms, let's just add kfunc ksyms > > there (user-space part has also checking that captured pointer value > > is correct and stuff like that, we probably want that for kfuncs as > > well) > > That's where initially I tried to place the test, but test_ksyms_weak.c > is used in light skeleton as well which is pickier about > resolving ksyms. > libbpf was lucky in that sense. > It does: > if (btf_is_var(t)) > err =3D bpf_object__resolve_ksym_var_btf_id(obj, ext); > else > err =3D bpf_object__resolve_ksym_func_btf_id(obj, ext); > while gen_loader for lksel assumes bpf_call insn as the only option for k= func. > I figured I'll add basic support for kfunc detection first and > address lksel later when I have more time. > Hence the reason to pick: > .../selftests/bpf/progs/task_kfunc_success.c | 14 +++++++++++++- > as a location for the test. ok, sounds good, maybe mention this limitation in the commit message?