From patchwork Fri Jan 5 10:48:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13511950 X-Patchwork-Delegate: bpf@iogearbox.net Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (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 56397250ED for ; Fri, 5 Jan 2024 10:47:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4T60X43Wy2z4f3lW3 for ; Fri, 5 Jan 2024 18:47:16 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 3A6851A098C for ; Fri, 5 Jan 2024 18:47:22 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP1 (Coremail) with SMTP id cCh0CgAXZw013pdlA+1eFg--.49979S7; Fri, 05 Jan 2024 18:47:22 +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 , Eduard Zingerman , houtao1@huawei.com Subject: [PATCH bpf-next v3 3/3] selftests/bpf: Test the inlining of bpf_kptr_xchg() Date: Fri, 5 Jan 2024 18:48:19 +0800 Message-Id: <20240105104819.3916743-4-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20240105104819.3916743-1-houtao@huaweicloud.com> References: <20240105104819.3916743-1-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: cCh0CgAXZw013pdlA+1eFg--.49979S7 X-Coremail-Antispam: 1UD129KBjvJXoWxAw1xKw4xJr17Jw43CFWDCFg_yoWrGF45pa yrKry5Kr48J3WIk34fGF4UZFyfKan5urW5XrWfurWUZF1UZ34kXF18Kr1DtFnxXrW09ry5 ZF18trn8CFn8AFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBYb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV 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-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao The test uses bpf_prog_get_info_by_fd() to obtain the xlated instructions of the program first. Since these instructions have already been rewritten by the verifier, the tests then checks whether the rewritten instructions are as expected. And to ensure LLVM generates code exactly as expected, use inline assembly and a naked function. Suggested-by: Eduard Zingerman Signed-off-by: Hou Tao Acked-by: Eduard Zingerman --- .../bpf/prog_tests/kptr_xchg_inline.c | 51 +++++++++++++++++++ .../selftests/bpf/progs/kptr_xchg_inline.c | 48 +++++++++++++++++ 2 files changed, 99 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c create mode 100644 tools/testing/selftests/bpf/progs/kptr_xchg_inline.c diff --git a/tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c b/tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c new file mode 100644 index 0000000000000..5a4bee1cf9707 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/kptr_xchg_inline.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023. Huawei Technologies Co., Ltd */ +#include + +#include "linux/filter.h" +#include "kptr_xchg_inline.skel.h" + +void test_kptr_xchg_inline(void) +{ + struct kptr_xchg_inline *skel; + struct bpf_insn *insn = NULL; + struct bpf_insn exp; + unsigned int cnt; + int err; + +#if !defined(__x86_64__) + test__skip(); + return; +#endif + + skel = kptr_xchg_inline__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open_load")) + return; + + err = get_xlated_program(bpf_program__fd(skel->progs.kptr_xchg_inline), &insn, &cnt); + if (!ASSERT_OK(err, "prog insn")) + goto out; + + /* The original instructions are: + * r1 = map[id:xxx][0]+0 + * r2 = 0 + * call bpf_kptr_xchg#yyy + * + * call bpf_kptr_xchg#yyy will be inlined as: + * r0 = r2 + * r0 = atomic64_xchg((u64 *)(r1 +0), r0) + */ + if (!ASSERT_GT(cnt, 5, "insn cnt")) + goto out; + + exp = BPF_MOV64_REG(BPF_REG_0, BPF_REG_2); + if (!ASSERT_OK(memcmp(&insn[3], &exp, sizeof(exp)), "mov")) + goto out; + + exp = BPF_ATOMIC_OP(BPF_DW, BPF_XCHG, BPF_REG_1, BPF_REG_0, 0); + if (!ASSERT_OK(memcmp(&insn[4], &exp, sizeof(exp)), "xchg")) + goto out; +out: + free(insn); + kptr_xchg_inline__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/kptr_xchg_inline.c b/tools/testing/selftests/bpf/progs/kptr_xchg_inline.c new file mode 100644 index 0000000000000..2414ac20b6d50 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/kptr_xchg_inline.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023. Huawei Technologies Co., Ltd */ +#include +#include + +#include "bpf_experimental.h" +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +struct bin_data { + char blob[32]; +}; + +#define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8))) +private(kptr) struct bin_data __kptr * ptr; + +SEC("tc") +__naked int kptr_xchg_inline(void) +{ + asm volatile ( + "r1 = %[ptr] ll;" + "r2 = 0;" + "call %[bpf_kptr_xchg];" + "if r0 == 0 goto 1f;" + "r1 = r0;" + "r2 = 0;" + "call %[bpf_obj_drop_impl];" + "1:" + "r0 = 0;" + "exit;" + : + : __imm_addr(ptr), + __imm(bpf_kptr_xchg), + __imm(bpf_obj_drop_impl) + : __clobber_all + ); +} + +/* BTF FUNC records are not generated for kfuncs referenced + * from inline assembly. These records are necessary for + * libbpf to link the program. The function below is a hack + * to ensure that BTF FUNC records are generated. + */ +void __btf_root(void) +{ + bpf_obj_drop(NULL); +}