From mboxrd@z Thu Jan 1 00:00:00 1970 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 E6D8E18C1E for ; Fri, 18 Aug 2023 15:20:46 +0000 (UTC) Received: from mail-qk1-f182.google.com (mail-qk1-f182.google.com [209.85.222.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C522026BB for ; Fri, 18 Aug 2023 08:20:45 -0700 (PDT) Received: by mail-qk1-f182.google.com with SMTP id af79cd13be357-76d83954c40so65294485a.1 for ; Fri, 18 Aug 2023 08:20:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692372044; x=1692976844; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=XQoXaszgXNHt2owMkc8SAwAa6PGA1R7cXDpG3YgUdis=; b=i1eB1qOXKvx3pimfYhzWuPDYK2U4O8Cr3l7ltE4lzMKw5E5jlzdD/j6JfM5yd545eS 3CO9EjCJ5eFCLjiTxegq2oI9RRzEG65sedv+dJx3ZPoiHouYHyEGlPy03/jNUYw1e3y5 Xta4vs3TiGAMLoJW9HrJttCS91GEoSWf/SWr2Go7HDTBIggtWfDrOmV75d4U7maJbaYF xnV1ATb8fHc7T+broOR4xXGnEs3C9jrWk55FQhgey54dAkeAaNBv2LvYsdlzUAIyDrZU ssZvz4Yyd3I1szb+lRgD91UUK63Ha+QrQySiRJJMK6yCNY8hAQ/1uQw6ry2mNFi3f/tH tLbQ== X-Gm-Message-State: AOJu0YxN+6Bb9cPUIyS+BlwMXsxHU/bfIlENNcKsgZq0QsDGWZcD5i2g TctwkbZ0MvCMz95UfXOdSMY= X-Google-Smtp-Source: AGHT+IFIPnPBBG+mGseArgo/zti5URsZkps0wsdFoxu+N2i7ppuTQYN1v+kKSEFBRafZaXCpmZ017g== X-Received: by 2002:a05:622a:1aa9:b0:405:4eec:6341 with SMTP id s41-20020a05622a1aa900b004054eec6341mr3562557qtc.56.1692372043958; Fri, 18 Aug 2023 08:20:43 -0700 (PDT) Received: from maniforge ([2620:10d:c091:400::5:766]) by smtp.gmail.com with ESMTPSA id y10-20020ac8524a000000b0040ff2f2f172sm579550qtn.38.2023.08.18.08.20.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Aug 2023 08:20:43 -0700 (PDT) Date: Fri, 18 Aug 2023 10:20:41 -0500 From: David Vernet To: Dave Marchevsky Cc: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Kernel Team Subject: Re: [PATCH v3 bpf-next 2/2] selftests/bpf: Add CO-RE relocs kfunc flavors tests Message-ID: <20230818152041.GB14411@maniforge> References: <20230817225353.2570845-1-davemarchevsky@fb.com> <20230817225353.2570845-2-davemarchevsky@fb.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230817225353.2570845-2-davemarchevsky@fb.com> User-Agent: Mutt/2.2.10 (2023-03-25) X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Thu, Aug 17, 2023 at 03:53:53PM -0700, Dave Marchevsky wrote: > This patch adds selftests that exercise kfunc flavor relocation > functionality added in the previous patch. The actual kfunc defined in > kernel/bpf/helpers.c is > > struct task_struct *bpf_task_acquire(struct task_struct *p) > > The following relocation behaviors are checked: > > struct task_struct *bpf_task_acquire___one(struct task_struct *name) > * Should succeed despite differing param name > > struct task_struct *bpf_task_acquire___two(struct task_struct *p, void *ctx) > * Should fail because there is no two-param bpf_task_acquire > > struct task_struct *bpf_task_acquire___three(void *ctx) > * Should fail because, despite vmlinux's bpf_task_acquire having one param, > the types don't match > > Changelog: > v1 -> v2: https://lore.kernel.org/bpf/20230811201346.3240403-2-davemarchevsky@fb.com/ > * Change comment on bpf_task_acquire___two to more accurately reflect > that it fails in same codepath as bpf_task_acquire___three, and to > not mention dead code elimination as thats an implementation detail > (Yonghong) > > v2 -> v3: https://lore.kernel.org/bpf/20230816165813.3718580-2-davemarchevsky@fb.com/ > * Add test demonstrating that resolution success / failure of > one flavor variant is independent from success / failure of others, > and that none need succeed (David Vernet) > > Signed-off-by: Dave Marchevsky Acked-by: David Vernet > --- > .../selftests/bpf/prog_tests/task_kfunc.c | 2 + > .../selftests/bpf/progs/task_kfunc_success.c | 51 +++++++++++++++++++ > 2 files changed, 53 insertions(+) > > diff --git a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c > index 740d5f644b40..d4579f735398 100644 > --- a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c > +++ b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c > @@ -79,6 +79,8 @@ static const char * const success_tests[] = { > "test_task_from_pid_current", > "test_task_from_pid_invalid", > "task_kfunc_acquire_trusted_walked", > + "test_task_kfunc_flavor_relo", > + "test_task_kfunc_flavor_relo_not_found", > }; > > void test_task_kfunc(void) > diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c > index b09371bba204..70df695312dc 100644 > --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c > +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c > @@ -18,6 +18,13 @@ int err, pid; > */ > > struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak; > + > +struct task_struct *bpf_task_acquire___one(struct task_struct *task) __ksym __weak; > +/* The two-param bpf_task_acquire doesn't exist */ > +struct task_struct *bpf_task_acquire___two(struct task_struct *p, void *ctx) __ksym __weak; > +/* Incorrect type for first param */ > +struct task_struct *bpf_task_acquire___three(void *ctx) __ksym __weak; > + > void invalid_kfunc(void) __ksym __weak; > void bpf_testmod_test_mod_kfunc(int i) __ksym __weak; > > @@ -55,6 +62,50 @@ static int test_acquire_release(struct task_struct *task) > return 0; > } > > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_kfunc_flavor_relo, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired = NULL; > + int fake_ctx = 42; > + > + if (bpf_ksym_exists(bpf_task_acquire___one)) { > + acquired = bpf_task_acquire___one(task); > + } else if (bpf_ksym_exists(bpf_task_acquire___two)) { > + /* Here, bpf_object__resolve_ksym_func_btf_id's find_ksym_btf_id > + * call will find vmlinux's bpf_task_acquire, but subsequent > + * bpf_core_types_are_compat will fail > + */ > + acquired = bpf_task_acquire___two(task, &fake_ctx); > + err = 3; > + return 0; > + } else if (bpf_ksym_exists(bpf_task_acquire___three)) { > + /* bpf_core_types_are_compat will fail similarly to above case */ > + acquired = bpf_task_acquire___three(&fake_ctx); > + err = 4; > + return 0; > + } > + > + if (acquired) > + bpf_task_release(acquired); > + else > + err = 5; > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_kfunc_flavor_relo_not_found, struct task_struct *task, u64 clone_flags) > +{ > + /* Neither symbol should successfully resolve. > + * Success or failure of one ___flavor should not affect others > + */ > + if (bpf_ksym_exists(bpf_task_acquire___two)) > + err = 1; > + else if (bpf_ksym_exists(bpf_task_acquire___three)) > + err = 2; > + > + return 0; > +} > + > SEC("tp_btf/task_newtask") > int BPF_PROG(test_task_acquire_release_argument, struct task_struct *task, u64 clone_flags) > { > -- > 2.34.1 > >