From patchwork Wed Mar 27 11:58:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13606301 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-oa1-f42.google.com (mail-oa1-f42.google.com [209.85.160.42]) (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 95ACC45954 for ; Wed, 27 Mar 2024 11:59:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.42 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711540800; cv=none; b=PW9KBWGoqNpeGLlz+wbcyr77kCufrJL8w0spByQmniDZvBOx6sS+cgpeBsTzKTJ/F7jflNvD2ocPX0j3j+EZe66tKOutlcBCxX0xPmF+gbXrYQoTcoDwhzM+UtbLrDETcEuj5w2nZSJ3/FA6g+3y76RAH42/AQOfVbVIL5CAUg0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711540800; c=relaxed/simple; bh=rjpdOrI7ow/nyOF4R2tJbHxSuseJLcU2SNV7gu1YB6s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hjQiqmJh2Eo8XmaVBnAMYGOIXHYec6ecNKIF1G+mRupg4KzFv9tRJ2xmkUrFeoUy3HhMXCf4nluhNKt1f6I75fnLAiSc0vvKOa3tEVe7UdHsypryXx7rNeka+hi3v+P+2aW4lCtgzV/1ljjMRofvJmtKOO163q7vx6Wj07R5yx4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=fhQdMNH/; arc=none smtp.client-ip=209.85.160.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fhQdMNH/" Received: by mail-oa1-f42.google.com with SMTP id 586e51a60fabf-22222357d76so2623089fac.2 for ; Wed, 27 Mar 2024 04:59:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1711540798; x=1712145598; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=hQShJgdiW/LpbqHpCbz1DV8sOZfoV/VXwPExK08qU9M=; b=fhQdMNH/QuNpNMUJjLaSk5T7Qq4dF0RcTOhYmv17jrgUZLOALjjbU4Wl/O8qFZBR8I AZGYkYNN00HwyxBRqzFGeXXRb7QfTvsNL2TaHnA9rqFmu1yjd1ESN1WJT+78nIRvwnFQ gRl/1y2yTvpJU3soBWPdVuyF6tp76t4+h9Hf16IoqEYWS5BEMBgfw2GL2N8swD3/CUZq lSYP0TkFyq38AsuGO8ch0FYQjfez00Ya0sOuc+N4o8PpaKS/CMA2HO+K8HnqV0TY7jFB sHLwn0Z75SP1184greNeczsLgv23XA6y3pmrLUyp7rianLePCKKMC80x4bz044J9kqcd hFRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711540798; x=1712145598; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=hQShJgdiW/LpbqHpCbz1DV8sOZfoV/VXwPExK08qU9M=; b=VPfgUnWuJmvuOiMmTORodMR7Na2G0Dv6yWPtwr3Zg0iD4ZiGW70YrzMp8DfutkLKo8 FyR4xiqh6Lhy3avL3LbSLd1k/0w9Ukwok+5LVCiKOQlX5+sBkAu1hN9eDHyacfpLm+5H slZoSF57O5e9uKqkAGDV4LPSG2uv7tyeiru012qDMSRljBXTaYfY/3B/GNX9IIlnawWF 8grlz7GT5HTT5nkdvwZkCRwZOyusx2+gS/Yj0xOzXfSFJfFRZ9LhpPWLzMi8rGjCKfa2 oriWG+IWFh94WWIyqUh4iG5+D51P7rCocSehq9MOTHFvAJsmHU3UE4MwQTj3dbPY5OJE MxQA== X-Gm-Message-State: AOJu0YzTh7H7ER5uYPESAKwgNGdjf0YhpY8A7wB98nOBU7NdcNER3TrI 4iuPSksvxcHjRPGdGRmPn8GJEku2HdhTVnxBiDS+SfYEfHneOrU0Ux2pgt7QcKVw7Q== X-Google-Smtp-Source: AGHT+IFmnLv3byYn5yXK39PbWazCHxfCgs63/BmCHiTVTDrJKZ2xRSnj9ekwdAiICrq22yS1p41jSQ== X-Received: by 2002:a05:6870:2317:b0:229:ec87:cc29 with SMTP id w23-20020a056870231700b00229ec87cc29mr2446719oao.49.1711540797722; Wed, 27 Mar 2024 04:59:57 -0700 (PDT) Received: from localhost.localdomain ([39.144.106.203]) by smtp.gmail.com with ESMTPSA id fa26-20020a056a002d1a00b006ea7b343877sm7675695pfb.9.2024.03.27.04.59.45 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Mar 2024 04:59:57 -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 1/2] bpf: Add bits iterator Date: Wed, 27 Mar 2024 19:58:47 +0800 Message-Id: <20240327115848.84695-2-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 three new kfuncs for the bits iterator: - bpf_iter_bits_new Initialize a new bits iterator for a given memory area. Due to the limitation of bpf memalloc, the max number of bits that can be iterated over is limited to (4096 * 8). - bpf_iter_bits_next Get the next bit in a bpf_iter_bits - bpf_iter_bits_destroy Destroy a bpf_iter_bits The bits iterator facilitates the iteration of the bits of a memory area, such as cpumask. It can be used in any context and on any address. Signed-off-by: Yafang Shao Acked-by: Andrii Nakryiko --- kernel/bpf/helpers.c | 120 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 9234174ccb21..35bd8dd08fb8 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2549,6 +2549,123 @@ __bpf_kfunc void bpf_throw(u64 cookie) WARN(1, "A call to BPF exception callback should never return\n"); } +struct bpf_iter_bits { + __u64 __opaque[2]; +} __aligned(8); + +struct bpf_iter_bits_kern { + union { + unsigned long *bits; + unsigned long bits_copy; + }; + u32 nr_bits; + int bit; +} __aligned(8); + +/** + * bpf_iter_bits_new() - Initialize a new bits iterator for a given memory area + * @it: The new bpf_iter_bits to be created + * @unsafe_ptr__ign: A ponter pointing to a memory area to be iterated over + * @nr_bits: The number of bits to be iterated over. Due to the limitation of + * memalloc, it can't greater than (4096 * 8). + * + * This function initializes a new bpf_iter_bits structure for iterating over + * a memory area which is specified by the @unsafe_ptr__ign and @nr_bits. It + * copy the data of the memory area to the newly created bpf_iter_bits @it for + * subsequent iteration operations. + * + * On success, 0 is returned. On failure, ERR is returned. + */ +__bpf_kfunc int +bpf_iter_bits_new(struct bpf_iter_bits *it, const void *unsafe_ptr__ign, u32 nr_bits) +{ + u32 size = BITS_TO_LONGS(nr_bits) * sizeof(unsigned long); + struct bpf_iter_bits_kern *kit = (void *)it; + int err; + + BUILD_BUG_ON(sizeof(struct bpf_iter_bits_kern) != sizeof(struct bpf_iter_bits)); + BUILD_BUG_ON(__alignof__(struct bpf_iter_bits_kern) != + __alignof__(struct bpf_iter_bits)); + + if (!unsafe_ptr__ign || !nr_bits) { + kit->bits = NULL; + return -EINVAL; + } + + kit->nr_bits = 0; + kit->bits_copy = 0; + /* Optimization for u64/u32 mask */ + if (nr_bits <= 64) { + err = bpf_probe_read_kernel_common(&kit->bits_copy, size, unsafe_ptr__ign); + if (err) + return -EFAULT; + + kit->nr_bits = nr_bits; + kit->bit = -1; + return 0; + } + + /* Fallback to memalloc */ + kit->bits = bpf_mem_alloc(&bpf_global_ma, size); + if (!kit->bits) + return -ENOMEM; + + err = bpf_probe_read_kernel_common(kit->bits, size, unsafe_ptr__ign); + if (err) { + bpf_mem_free(&bpf_global_ma, kit->bits); + return err; + } + + kit->nr_bits = nr_bits; + kit->bit = -1; + return 0; +} + +/** + * bpf_iter_bits_next() - Get the next bit in a bpf_iter_bits + * @it: The bpf_iter_bits to be checked + * + * This function returns a pointer to a number representing the value of the + * next bit in the bits. + * + * If there are no further bit available, it returns NULL. + */ +__bpf_kfunc int *bpf_iter_bits_next(struct bpf_iter_bits *it) +{ + struct bpf_iter_bits_kern *kit = (void *)it; + u32 nr_bits = kit->nr_bits; + const unsigned long *bits; + int bit; + + if (nr_bits == 0) + return NULL; + + bits = nr_bits <= 64 ? &kit->bits_copy : kit->bits; + bit = find_next_bit(bits, nr_bits, kit->bit + 1); + if (bit >= nr_bits) { + kit->nr_bits = 0; + return NULL; + } + + kit->bit = bit; + return &kit->bit; +} + +/** + * bpf_iter_bits_destroy() - Destroy a bpf_iter_bits + * @it: The bpf_iter_bits to be destroyed + * + * Destroy the resource associated with the bpf_iter_bits. + */ +__bpf_kfunc void bpf_iter_bits_destroy(struct bpf_iter_bits *it) +{ + struct bpf_iter_bits_kern *kit = (void *)it; + + if (kit->nr_bits <= 64) + return; + bpf_mem_free(&bpf_global_ma, kit->bits); +} + __bpf_kfunc_end_defs(); BTF_KFUNCS_START(generic_btf_ids) @@ -2625,6 +2742,9 @@ BTF_ID_FLAGS(func, bpf_dynptr_is_null) BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly) BTF_ID_FLAGS(func, bpf_dynptr_size) BTF_ID_FLAGS(func, bpf_dynptr_clone) +BTF_ID_FLAGS(func, bpf_iter_bits_new, KF_ITER_NEW) +BTF_ID_FLAGS(func, bpf_iter_bits_next, KF_ITER_NEXT | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_iter_bits_destroy, KF_ITER_DESTROY) BTF_KFUNCS_END(common_btf_ids) static const struct btf_kfunc_id_set common_kfunc_set = { From patchwork Wed Mar 27 11:58:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13606302 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-oa1-f44.google.com (mail-oa1-f44.google.com [209.85.160.44]) (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 D139F74BE8 for ; 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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; +}