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 82B3DC6FD1F for ; Thu, 16 Mar 2023 20:34:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230350AbjCPUem (ORCPT ); Thu, 16 Mar 2023 16:34:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229985AbjCPUeh (ORCPT ); Thu, 16 Mar 2023 16:34:37 -0400 Received: from mail-ed1-x533.google.com (mail-ed1-x533.google.com [IPv6:2a00:1450:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1532A25E; Thu, 16 Mar 2023 13:34:29 -0700 (PDT) Received: by mail-ed1-x533.google.com with SMTP id eh3so12470385edb.11; Thu, 16 Mar 2023 13:34:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678998868; 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=AQGw4rmImHopv/OtWPakYC5hznOSVQLQps2bkjQMLxY=; b=M4As80V5GmS+0/rX5iSuN5ZUK/V9bl+3vO1ySZaWw4JIVlyzbWpIZXeKOnMyTE3mjz f0BI1u/cuPSZRF/kAtzpmP9+UIXqMEbXCu31IpLnL9N3nxD5hcwAKOJpFcYySNPlqdyX 3PjkOX+3WEfzRL9IFdZqUd7K+0IOA6D7nA1U/Sf9QARQBpeeekW5nWvLv03BxZElSoJa Gb3d5UMNiovs5c5VufwtgBCJ55B2YTT8ntGwiWDJThhiPfGVvAYw0ZZy7M49hJ/JPD6C H9rmxt9rImNfiMFjGGW4yLdpOx1f5X/8qT4YvIsDxCAkqGkeY1uFR/5qgywanpH8KJWC y0eQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678998868; 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=AQGw4rmImHopv/OtWPakYC5hznOSVQLQps2bkjQMLxY=; b=7l1TOrPvVPaHlrk5l8/v1HruGk/L22DEVZ3ELhckiNWMLzYG9OG/YnYJV6SEHGjM3C BrceGrEBgAXsVclF1n/FppTrxALw34pnveil7Y2o/yiiSiUOMaSzphR2/LIMOYa402KX loqBP5uVBcdH4Xfw5tr+Ctq+6pkcOGw9LbxT0wYO5DZCdoY+jeODWsYaYPWjCqkgC0Ve RGVeodXvrHYfqt9VfE+rOiF3rI/vm9qb4mauYwLRToUvtvRnn5vSf2lSOLvomeZRBwya oNhPEtRhKPOkd6ZpFBDjIyniaEX6qgSKNmcgC9ByvX89kW5SuQqKSfkpJ6ff16xRK0ss Stew== X-Gm-Message-State: AO0yUKVya5uZ0OyVsXC7654HPQbNmBaqtKqJvfFsQIuvZYTKQAS844gM UoFMukIg+kVeOiyEE/ei8NXZbvNqrFb8S54hyLw= X-Google-Smtp-Source: AK7set8aI6iGyNwk5Eczi8w4DESz0HedhKVVb82+qgKGfYbh8V24F5c7oo1E5oRZCBFS6oA9MIYI4Jy4DA+BqRvia+s= X-Received: by 2002:a17:907:c28:b0:922:26ae:c68c with SMTP id ga40-20020a1709070c2800b0092226aec68cmr385268ejc.5.1678998867959; Thu, 16 Mar 2023 13:34:27 -0700 (PDT) MIME-Version: 1.0 References: <20230315223607.50803-1-alexei.starovoitov@gmail.com> <20230315223607.50803-3-alexei.starovoitov@gmail.com> In-Reply-To: <20230315223607.50803-3-alexei.starovoitov@gmail.com> From: Andrii Nakryiko Date: Thu, 16 Mar 2023 13:34:12 -0700 Message-ID: Subject: Re: [PATCH bpf-next 2/2] selftests/bpf: Add test for bpf_kfunc_exists(). To: Alexei Starovoitov Cc: davem@davemloft.net, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, void@manifault.com, davemarchevsky@meta.com, tj@kernel.org, memxor@gmail.com, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org 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 veri= fier > 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) > .../selftests/bpf/progs/task_kfunc_success.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/too= ls/testing/selftests/bpf/progs/task_kfunc_success.c > index 4f61596b0242..c0a7774e0c79 100644 > --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c > +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c > @@ -17,6 +17,8 @@ int err, pid; > * TP_PROTO(struct task_struct *p, u64 clone_flags) > */ > > +void invalid_kfunc(void) __ksym __weak; > + > static bool is_test_kfunc_task(void) > { > int cur_pid =3D bpf_get_current_pid_tgid() >> 32; > @@ -26,7 +28,17 @@ static bool is_test_kfunc_task(void) > > static int test_acquire_release(struct task_struct *task) > { > - struct task_struct *acquired; > + struct task_struct *acquired =3D NULL; > + > + if (!bpf_kfunc_exists(bpf_task_acquire)) { > + err =3D 3; > + return 0; > + } > + if (bpf_kfunc_exists(invalid_kfunc)) { > + /* the verifier's dead code elimination should remove thi= s */ > + err =3D 4; > + asm volatile ("goto -1"); /* for (;;); */ > + } > > acquired =3D bpf_task_acquire(task); > bpf_task_release(acquired); > -- > 2.34.1 >