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Wed, 27 Mar 2024 05:00:12 -0700 (PDT) Received: from localhost.localdomain ([39.144.106.203]) by smtp.gmail.com with ESMTPSA id fa26-20020a056a002d1a00b006ea7b343877sm7675695pfb.9.2024.03.27.04.59.58 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Mar 2024 05:00:12 -0700 (PDT) From: Yafang Shao To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org Cc: bpf@vger.kernel.org, Yafang Shao Subject: [PATCH bpf-next v4 2/2] selftests/bpf: Add selftest for bits iter Date: Wed, 27 Mar 2024 19:58:48 +0800 Message-Id: <20240327115848.84695-3-laoar.shao@gmail.com> X-Mailer: git-send-email 2.30.1 (Apple Git-130) In-Reply-To: <20240327115848.84695-1-laoar.shao@gmail.com> References: <20240327115848.84695-1-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net Add selftests for the newly added bits iter. - bits_iter_success - percpu data extracted from the percpu struct should be expected - RCU lock is not required - It is fine without calling bpf_iter_cpumask_next() - It can work as expected when invalid arguments are passed - bits_iter_failure - bpf_iter_bits_destroy() is required after calling bpf_iter_bits_new() - bpf_iter_bits_destroy() can only destroy an initialized iter - bpf_iter_bits_next() must use an initialized iter Signed-off-by: Yafang Shao --- .../selftests/bpf/prog_tests/bits_iter.c | 139 +++++++++++++++++ .../bpf/progs/test_bits_iter_failure.c | 54 +++++++ .../bpf/progs/test_bits_iter_success.c | 146 ++++++++++++++++++ 3 files changed, 339 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/bits_iter.c create mode 100644 tools/testing/selftests/bpf/progs/test_bits_iter_failure.c create mode 100644 tools/testing/selftests/bpf/progs/test_bits_iter_success.c diff --git a/tools/testing/selftests/bpf/prog_tests/bits_iter.c b/tools/testing/selftests/bpf/prog_tests/bits_iter.c new file mode 100644 index 000000000000..0e2520a9dc62 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/bits_iter.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Yafang Shao */ + +#define _GNU_SOURCE +#include + +#include +#include "test_bits_iter_success.skel.h" +#include "test_bits_iter_failure.skel.h" +#include "cgroup_helpers.h" + +static const char * const positive_testcases[] = { + "cpumask_memalloc", + "cpumask_copy", +}; + +static const char * const negative_testcases[] = { + "null_pointer", + "zero_bit", + "no_mem", + "invalid_bits", +}; + +static int read_percpu_data(struct bpf_link *link) +{ + int iter_fd, len; + char buf[128]; + size_t left; + char *p; + + iter_fd = bpf_iter_create(bpf_link__fd(link)); + if (!ASSERT_GE(iter_fd, 0, "iter_fd")) + return -1; + + memset(buf, 0, sizeof(buf)); + left = ARRAY_SIZE(buf); + p = buf; + while ((len = read(iter_fd, p, left)) > 0) { + p += len; + left -= len; + } + + close(iter_fd); + return 0; +} + +static void verify_iter_success(const char *prog_name, bool negative) +{ + DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); + struct test_bits_iter_success *skel; + union bpf_iter_link_info linfo; + int cgrp_fd, err, i, nr_cpus; + struct bpf_program *prog; + struct bpf_link *link; + cpu_set_t set; + + if (setup_cgroup_environment()) + return; + + /* Utilize the cgroup iter */ + cgrp_fd = get_root_cgroup(); + if (!ASSERT_GE(cgrp_fd, 0, "create_cgrp")) + goto cleanup; + + skel = test_bits_iter_success__open(); + if (!ASSERT_OK_PTR(skel, "cpumask_iter_success__open")) + goto close_fd; + + skel->bss->pid = getpid(); + nr_cpus = libbpf_num_possible_cpus(); + skel->bss->total_nr_cpus = nr_cpus; + + err = test_bits_iter_success__load(skel); + if (!ASSERT_OK(err, "cpumask_iter_success__load")) + goto destroy; + + prog = bpf_object__find_program_by_name(skel->obj, prog_name); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto destroy; + + memset(&linfo, 0, sizeof(linfo)); + linfo.cgroup.cgroup_fd = cgrp_fd; + linfo.cgroup.order = BPF_CGROUP_ITER_SELF_ONLY; + opts.link_info = &linfo; + opts.link_info_len = sizeof(linfo); + link = bpf_program__attach_iter(prog, &opts); + if (!ASSERT_OK_PTR(link, "bpf_program__attach")) + goto destroy; + + if (negative) + goto negative; + + CPU_ZERO(&set); + /* To guarantee the success of "cpumask_copy" at all times */ + if (nr_cpus > 16) + nr_cpus = 16; + for (i = 0; i < nr_cpus; i++) + CPU_SET(i, &set); + err = sched_setaffinity(skel->bss->pid, sizeof(set), &set); + if (!ASSERT_OK(err, "setaffinity_all_cpus")) + goto free_link; + err = read_percpu_data(link); + if (!ASSERT_OK(err, "read_percpu_data")) + goto free_link; + +negative: + ASSERT_OK(skel->bss->err, "task_running"); + +free_link: + bpf_link__destroy(link); +destroy: + test_bits_iter_success__destroy(skel); +close_fd: + close(cgrp_fd); +cleanup: + cleanup_cgroup_environment(); +} + +void test_bits_iter(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(positive_testcases); i++) { + if (!test__start_subtest(positive_testcases[i])) + continue; + + verify_iter_success(positive_testcases[i], false); + } + + for (i = 0; i < ARRAY_SIZE(negative_testcases); i++) { + if (!test__start_subtest(negative_testcases[i])) + continue; + + verify_iter_success(negative_testcases[i], true); + } + + RUN_TESTS(test_bits_iter_success); + RUN_TESTS(test_bits_iter_failure); +} diff --git a/tools/testing/selftests/bpf/progs/test_bits_iter_failure.c b/tools/testing/selftests/bpf/progs/test_bits_iter_failure.c new file mode 100644 index 000000000000..974d0b7a540e --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_bits_iter_failure.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2024 Yafang Shao */ + +#include "vmlinux.h" +#include +#include + +#include "bpf_misc.h" +#include "task_kfunc_common.h" + +char _license[] SEC("license") = "GPL"; + +int bpf_iter_bits_new(struct bpf_iter_bits *it, const void *unsafe_ptr__ign, + u32 nr_bits) __ksym __weak; +int *bpf_iter_bits_next(struct bpf_iter_bits *it) __ksym __weak; +void bpf_iter_bits_destroy(struct bpf_iter_bits *it) __ksym __weak; + +SEC("iter.s/cgroup") +__failure __msg("Unreleased reference id=3 alloc_insn=10") +int BPF_PROG(no_destroy, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct bpf_iter_bits it; + struct task_struct *p; + + p = bpf_task_from_pid(1); + if (!p) + return 1; + + bpf_iter_bits_new(&it, p->cpus_ptr, 8192); + + bpf_iter_bits_next(&it); + bpf_task_release(p); + return 0; +} + +SEC("iter/cgroup") +__failure __msg("expected an initialized iter_bits as arg #1") +int BPF_PROG(next_uninit, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct bpf_iter_bits *it = NULL; + + bpf_iter_bits_next(it); + return 0; +} + +SEC("iter/cgroup") +__failure __msg("expected an initialized iter_bits as arg #1") +int BPF_PROG(destroy_uninit, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct bpf_iter_bits it = {}; + + bpf_iter_bits_destroy(&it); + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/test_bits_iter_success.c b/tools/testing/selftests/bpf/progs/test_bits_iter_success.c new file mode 100644 index 000000000000..67f4e810e1d2 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_bits_iter_success.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2024 Yafang Shao */ + +#include "vmlinux.h" +#include +#include +#include + +#include "task_kfunc_common.h" + +char _license[] SEC("license") = "GPL"; + +extern const struct rq runqueues __ksym __weak; + +int bpf_iter_bits_new(struct bpf_iter_bits *it, const void *unsafe_ptr__ign, + u32 nr_bits) __ksym __weak; +int *bpf_iter_bits_next(struct bpf_iter_bits *it) __ksym __weak; +void bpf_iter_bits_destroy(struct bpf_iter_bits *it) __ksym __weak; + +int pid, err, total_nr_cpus; + +static int cpumask_iter(struct bpf_iter_meta *meta, struct cgroup *cgrp, u32 nr_cpus) +{ + struct task_struct *p; + u32 nr_running = 0; + struct rq *rq; + int *cpu; + + /* epilogue */ + if (!cgrp) + return 0; + + p = bpf_task_from_pid(pid); + if (!p) + return 1; + + bpf_for_each(bits, cpu, p->cpus_ptr, nr_cpus) { + rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, *cpu); + /* Every valid CPU should possess a runqueue, even in the event of being offline */ + if (!rq) + break; + nr_running += rq->nr_running; + } + if (nr_running == 0) + err = 1; + bpf_task_release(p); + return 0; +} + +SEC("iter.s/cgroup") +int BPF_PROG(cpumask_memalloc, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + return cpumask_iter(meta, cgrp, 128); +} + +SEC("iter.s/cgroup") +int BPF_PROG(cpumask_copy, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + return cpumask_iter(meta, cgrp, 16); +} + +SEC("iter.s/cgroup") +int BPF_PROG(null_pointer, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + int *cpu; + + bpf_for_each(bits, cpu, NULL, 8192) + err++; + return 0; +} + +SEC("iter.s/cgroup") +int BPF_PROG(zero_bit, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct task_struct *p; + int *cpu; + + p = bpf_task_from_pid(pid); + if (!p) + return 1; + + bpf_for_each(bits, cpu, p->cpus_ptr, 0) + err++; + bpf_task_release(p); + return 0; +} + +SEC("iter.s/cgroup") +int BPF_PROG(no_mem, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct task_struct *p; + int *cpu; + + p = bpf_task_from_pid(pid); + if (!p) + return 1; + + /* The max number of memalloc is 4096, thus it will fail to allocate (8192 * 8) */ + bpf_for_each(bits, cpu, p->cpus_ptr, 8192 * 8) + err++; + bpf_task_release(p); + return 0; +} + +SEC("iter.s/cgroup") +int BPF_PROG(no_next, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct bpf_iter_bits it; + struct task_struct *p; + + p = bpf_task_from_pid(1); + if (!p) + return 1; + + bpf_iter_bits_new(&it, p->cpus_ptr, 8192); + + /* It functions properly without invoking bpf_iter_bits_next(). */ + + bpf_iter_bits_destroy(&it); + bpf_task_release(p); + return 0; +} + +SEC("iter.s/cgroup") +int BPF_PROG(invalid_bits, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct task_struct *p; + struct rq *rq; + int *cpu; + + p = bpf_task_from_pid(pid); + if (!p) + return 1; + + bpf_for_each(bits, cpu, p->cpus_ptr, 8192) { + rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, *cpu); + /* For invalid CPU IDs, the rq must be NULL. */ + if (!rq) + err++; + } + bpf_task_release(p); + + if (err) + err -= 8192 - total_nr_cpus; + return 0; +}