[RFC,v8,02/20] selftests/bpf: Test referenced kptr arguments of struct_ops programs

Message ID	20240510192412.3297104-3-amery.hung@bytedance.com (mailing list archive)
State	RFC
Delegated to:	BPF
Headers	show Received: from mail-qt1-f179.google.com (mail-qt1-f179.google.com [209.85.160.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6B3D175A6; Fri, 10 May 2024 19:24:15 +0000 (UTC) From: Amery Hung <ameryhung@gmail.com> To: netdev@vger.kernel.org Cc: bpf@vger.kernel.org, yangpeihao@sjtu.edu.cn, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, sinquersw@gmail.com, toke@redhat.com, jhs@mojatatu.com, jiri@resnulli.us, sdf@google.com, xiyou.wangcong@gmail.com, yepeilin.cs@gmail.com, ameryhung@gmail.com Subject: [RFC PATCH v8 02/20] selftests/bpf: Test referenced kptr arguments of struct_ops programs Date: Fri, 10 May 2024 19:23:54 +0000 Message-Id: <20240510192412.3297104-3-amery.hung@bytedance.com> In-Reply-To: <20240510192412.3297104-1-amery.hung@bytedance.com> References: <20240510192412.3297104-1-amery.hung@bytedance.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	bpf qdisc \| expand [RFC,v8,00/20] bpf qdisc [RFC,v8,01/20] bpf: Support passing referenced kptr to struct_ops programs [RFC,v8,02/20] selftests/bpf: Test referenced kptr arguments of struct_ops programs [RFC,v8,03/20] bpf: Allow struct_ops prog to return referenced kptr [RFC,v8,04/20] selftests/bpf: Test returning kptr from struct_ops programs [RFC,v8,05/20] bpf: Generate btf_struct_metas for kernel BTF [RFC,v8,06/20] bpf: Recognize kernel types as graph values [RFC,v8,07/20] bpf: Allow adding kernel objects to collections [RFC,v8,08/20] selftests/bpf: Test adding kernel object to bpf graph [RFC,v8,09/20] bpf: Find special BTF fields in union [RFC,v8,10/20] bpf: Introduce exclusive-ownership list and rbtree nodes [RFC,v8,11/20] bpf: Allow adding exclusive nodes to bpf list and rbtree [RFC,v8,12/20] selftests/bpf: Modify linked_list tests to work with macro-ified removes [RFC,v8,13/20] bpf: net_sched: Support implementation of Qdisc_ops in bpf [RFC,v8,14/20] bpf: net_sched: Add bpf qdisc kfuncs [RFC,v8,15/20] bpf: net_sched: Allow more optional methods in Qdisc_ops [RFC,v8,16/20] libbpf: Support creating and destroying qdisc [RFC,v8,17/20] selftests: Add a basic fifo qdisc test [RFC,v8,18/20] selftests: Add a bpf fq qdisc to selftest [RFC,v8,19/20] selftests: Add a bpf netem qdisc to selftest [RFC,v8,20/20] selftests: Add a prio bpf qdisc

Context	Check	Description
netdev/tree_selection	success	Guessing tree name failed - patch did not apply, async

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index 39ad96a18123..64dcab25b539 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -594,10 +594,17 @@ static int bpf_testmod_ops__test_maybe_null(int dummy, return 0; } +static int bpf_testmod_ops__test_ref_acquire(int dummy, + struct task_struct *task__ref_acquired) +{ + return 0; +} + static struct bpf_testmod_ops __bpf_testmod_ops = { .test_1 = bpf_testmod_test_1, .test_2 = bpf_testmod_test_2, .test_maybe_null = bpf_testmod_ops__test_maybe_null, + .test_ref_acquire = bpf_testmod_ops__test_ref_acquire, }; struct bpf_struct_ops bpf_bpf_testmod_ops = { diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h index 23fa1872ee67..a0233990fb0e 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h @@ -35,6 +35,8 @@ struct bpf_testmod_ops { void (*test_2)(int a, int b); /* Used to test nullable arguments. */ int (*test_maybe_null)(int dummy, struct task_struct *task); + /* Used to test ref_acquired arguments. */ + int (*test_ref_acquire)(int dummy, struct task_struct *task); /* The following fields are used to test shadow copies. */ char onebyte; diff --git a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_ref_acquire.c b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_ref_acquire.c new file mode 100644 index 000000000000..779287a00ed8 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_ref_acquire.c @@ -0,0 +1,58 @@ +#include <test_progs.h> + +#include "struct_ops_ref_acquire.skel.h" +#include "struct_ops_ref_acquire_ref_leak.skel.h" +#include "struct_ops_ref_acquire_dup_ref.skel.h" + +/* Test that the verifier accepts a program that acquires a referenced + * kptr and releases the reference + */ +static void ref_acquire(void) +{ + struct struct_ops_ref_acquire *skel; + + skel = struct_ops_ref_acquire__open_and_load(); + if (!ASSERT_OK_PTR(skel, "struct_ops_module_open_and_load")) + return; + + struct_ops_ref_acquire__destroy(skel); +} + +/* Test that the verifier rejects a program that acquires a referenced + * kptr without releasing the reference + */ +static void ref_acquire_ref_leak(void) +{ + struct struct_ops_ref_acquire_ref_leak *skel; + + skel = struct_ops_ref_acquire_ref_leak__open_and_load(); + if (ASSERT_ERR_PTR(skel, "struct_ops_module_fail__open_and_load")) + return; + + struct_ops_ref_acquire_ref_leak__destroy(skel); +} + +/* Test that the verifier rejects a program that tries to acquire a + * referenced twice + */ +static void ref_acquire_dup_ref(void) +{ + struct struct_ops_ref_acquire_dup_ref *skel; + + skel = struct_ops_ref_acquire_dup_ref__open_and_load(); + if (ASSERT_ERR_PTR(skel, "struct_ops_module_fail__open_and_load")) + return; + + struct_ops_ref_acquire_dup_ref__destroy(skel); +} + +void test_struct_ops_ref_acquire(void) +{ + if (test__start_subtest("ref_acquire")) + ref_acquire(); + if (test__start_subtest("ref_acquire_ref_leak")) + ref_acquire_ref_leak(); + if (test__start_subtest("ref_acquire_dup_ref")) + ref_acquire_dup_ref(); +} + diff --git a/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire.c b/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire.c new file mode 100644 index 000000000000..bae342db0fdb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire.c @@ -0,0 +1,27 @@ +#include <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include "../bpf_testmod/bpf_testmod.h" + +char _license[] SEC("license") = "GPL"; + +void bpf_task_release(struct task_struct *p) __ksym; + +/* This is a test BPF program that uses struct_ops to access a referenced + * kptr argument. This is a test for the verifier to ensure that it recongnizes + * the task as a referenced object (i.e., ref_obj_id > 0). + */ +SEC("struct_ops/test_ref_acquire") +int BPF_PROG(test_ref_acquire, int dummy, + struct task_struct *task) +{ + bpf_task_release(task); + + return 0; +} + +SEC(".struct_ops.link") +struct bpf_testmod_ops testmod_ref_acquire = { + .test_ref_acquire = (void *)test_ref_acquire, +}; + + diff --git a/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire_dup_ref.c b/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire_dup_ref.c new file mode 100644 index 000000000000..489db98a47fb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire_dup_ref.c @@ -0,0 +1,24 @@ +#include <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include "../bpf_testmod/bpf_testmod.h" + +char _license[] SEC("license") = "GPL"; + +void bpf_task_release(struct task_struct *p) __ksym; + +SEC("struct_ops/test_ref_acquire") +int BPF_PROG(test_ref_acquire, int dummy, + struct task_struct *task) +{ + bpf_task_release(task); + bpf_task_release(task); + + return 0; +} + +SEC(".struct_ops.link") +struct bpf_testmod_ops testmod_ref_acquire = { + .test_ref_acquire = (void *)test_ref_acquire, +}; + + diff --git a/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire_ref_leak.c b/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire_ref_leak.c new file mode 100644 index 000000000000..c5b9a1d748a1 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/struct_ops_ref_acquire_ref_leak.c @@ -0,0 +1,19 @@ +#include <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include "../bpf_testmod/bpf_testmod.h" + +char _license[] SEC("license") = "GPL"; + +SEC("struct_ops/test_ref_acquire") +int BPF_PROG(test_ref_acquire, int dummy, + struct task_struct *task) +{ + return 0; +} + +SEC(".struct_ops.link") +struct bpf_testmod_ops testmod_ref_acquire = { + .test_ref_acquire = (void *)test_ref_acquire, +}; + +

[RFC,v8,02/20] selftests/bpf: Test referenced kptr arguments of struct_ops programs

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