From patchwork Tue Aug 22 13:38:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13360617 X-Patchwork-Delegate: bpf@iogearbox.net 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 2F17A1C9FF for ; Tue, 22 Aug 2023 13:06:16 +0000 (UTC) Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92810CDD for ; Tue, 22 Aug 2023 06:06:13 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.169]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4RVV325MxJz4f3mJy for ; Tue, 22 Aug 2023 21:06:06 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgBH16m+suRk0ldIBQ--.4082S7; Tue, 22 Aug 2023 21:06:09 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org Cc: Martin KaFai Lau , Alexei Starovoitov , Andrii Nakryiko , Song Liu , Hao Luo , Yonghong Song , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , houtao1@huawei.com Subject: [PATCH bpf-next 3/3] selftests/bpf: Test preemption between bpf_obj_new() and bpf_obj_drop() Date: Tue, 22 Aug 2023 21:38:07 +0800 Message-Id: <20230822133807.3198625-4-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20230822133807.3198625-1-houtao@huaweicloud.com> References: <20230822133807.3198625-1-houtao@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgBH16m+suRk0ldIBQ--.4082S7 X-Coremail-Antispam: 1UD129KBjvJXoWxKr47WFW7Xw1fGw4kXr4kXrb_yoWxWw1Upa yfAry0kwn2qw17G34Sqan7Cr4rtrW8X3W8JryfWFy5Zr17Wr95tr1xKFyYqF93KrWvqw4r uFn8tFWkArWkJaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBYb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU1c4S7UUUUU== X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,KHOP_HELO_FCRDNS, MAY_BE_FORGED,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao The test case creates 4 threads and then pins these 4 threads in CPU 0. These 4 threads will run different bpf program through bpf_prog_test_run_opts() and these bpf program will use bpf_obj_new() and bpf_obj_drop() to allocate and free local kptrs concurrently. Under preemptible kernel, bpf_obj_new() and bpf_obj_drop() may preempt each other, bpf_obj_new() may return NULL and the test will fail before the fixes are applied as shown below: test_preempted_bpf_ma_op:PASS:open_and_load 0 nsec test_preempted_bpf_ma_op:PASS:attach 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:no test prog 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:pthread_create 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:PASS:run prog err 0 nsec test_preempted_bpf_ma_op:FAIL:ENOMEM unexpected ENOMEM: got TRUE #168 preempted_bpf_ma_op:FAIL Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED Signed-off-by: Hou Tao --- .../bpf/prog_tests/preempted_bpf_ma_op.c | 89 +++++++++++++++ .../selftests/bpf/progs/preempted_bpf_ma_op.c | 106 ++++++++++++++++++ 2 files changed, 195 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/preempted_bpf_ma_op.c create mode 100644 tools/testing/selftests/bpf/progs/preempted_bpf_ma_op.c diff --git a/tools/testing/selftests/bpf/prog_tests/preempted_bpf_ma_op.c b/tools/testing/selftests/bpf/prog_tests/preempted_bpf_ma_op.c new file mode 100644 index 000000000000..9ac7210af4c9 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/preempted_bpf_ma_op.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023. Huawei Technologies Co., Ltd */ +#define _GNU_SOURCE +#include +#include +#include +#include + +#include "preempted_bpf_ma_op.skel.h" + +#define ALLOC_THREAD_NR 4 +#define ALLOC_LOOP_NR 512 + +struct alloc_ctx { + /* output */ + int run_err; + /* input */ + int fd; + bool *nomem_err; +}; + +static void *run_alloc_prog(void *data) +{ + struct alloc_ctx *ctx = data; + cpu_set_t cpu_set; + int i; + + CPU_ZERO(&cpu_set); + CPU_SET(0, &cpu_set); + pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set); + + for (i = 0; i < ALLOC_LOOP_NR && !*ctx->nomem_err; i++) { + LIBBPF_OPTS(bpf_test_run_opts, topts); + int err; + + err = bpf_prog_test_run_opts(ctx->fd, &topts); + ctx->run_err |= err | topts.retval; + } + + return NULL; +} + +void test_preempted_bpf_ma_op(void) +{ + struct alloc_ctx ctx[ALLOC_THREAD_NR]; + struct preempted_bpf_ma_op *skel; + pthread_t tid[ALLOC_THREAD_NR]; + int i, err; + + skel = preempted_bpf_ma_op__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open_and_load")) + return; + + err = preempted_bpf_ma_op__attach(skel); + if (!ASSERT_OK(err, "attach")) + goto out; + + for (i = 0; i < ARRAY_SIZE(ctx); i++) { + struct bpf_program *prog; + char name[8]; + + snprintf(name, sizeof(name), "test%d", i); + prog = bpf_object__find_program_by_name(skel->obj, name); + if (!ASSERT_OK_PTR(prog, "no test prog")) + goto out; + + ctx[i].run_err = 0; + ctx[i].fd = bpf_program__fd(prog); + ctx[i].nomem_err = &skel->bss->nomem_err; + } + + memset(tid, 0, sizeof(tid)); + for (i = 0; i < ARRAY_SIZE(tid); i++) { + err = pthread_create(&tid[i], NULL, run_alloc_prog, &ctx[i]); + if (!ASSERT_OK(err, "pthread_create")) + break; + } + + for (i = 0; i < ARRAY_SIZE(tid); i++) { + if (!tid[i]) + continue; + pthread_join(tid[i], NULL); + ASSERT_EQ(ctx[i].run_err, 0, "run prog err"); + } + + ASSERT_FALSE(skel->bss->nomem_err, "ENOMEM"); +out: + preempted_bpf_ma_op__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/preempted_bpf_ma_op.c b/tools/testing/selftests/bpf/progs/preempted_bpf_ma_op.c new file mode 100644 index 000000000000..55907ef961bf --- /dev/null +++ b/tools/testing/selftests/bpf/progs/preempted_bpf_ma_op.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023. Huawei Technologies Co., Ltd */ +#include +#include +#include + +#include "bpf_experimental.h" + +struct bin_data { + char data[256]; + struct bpf_spin_lock lock; +}; + +struct map_value { + struct bin_data __kptr * data; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, struct map_value); + __uint(max_entries, 2048); +} array SEC(".maps"); + +char _license[] SEC("license") = "GPL"; + +bool nomem_err = false; + +static int del_array(unsigned int i, int *from) +{ + struct map_value *value; + struct bin_data *old; + + value = bpf_map_lookup_elem(&array, from); + if (!value) + return 1; + + old = bpf_kptr_xchg(&value->data, NULL); + if (old) + bpf_obj_drop(old); + + (*from)++; + return 0; +} + +static int add_array(unsigned int i, int *from) +{ + struct bin_data *old, *new; + struct map_value *value; + + value = bpf_map_lookup_elem(&array, from); + if (!value) + return 1; + + new = bpf_obj_new(typeof(*new)); + if (!new) { + nomem_err = true; + return 1; + } + + old = bpf_kptr_xchg(&value->data, new); + if (old) + bpf_obj_drop(old); + + (*from)++; + return 0; +} + +static void del_then_add_array(int from) +{ + int i; + + i = from; + bpf_loop(512, del_array, &i, 0); + + i = from; + bpf_loop(512, add_array, &i, 0); +} + +SEC("fentry/bpf_fentry_test1") +int BPF_PROG2(test0, int, a) +{ + del_then_add_array(0); + return 0; +} + +SEC("fentry/bpf_fentry_test2") +int BPF_PROG2(test1, int, a, u64, b) +{ + del_then_add_array(512); + return 0; +} + +SEC("fentry/bpf_fentry_test3") +int BPF_PROG2(test2, char, a, int, b, u64, c) +{ + del_then_add_array(1024); + return 0; +} + +SEC("fentry/bpf_fentry_test4") +int BPF_PROG2(test3, void *, a, char, b, int, c, u64, d) +{ + del_then_add_array(1536); + return 0; +}