From patchwork Thu Jan 27 07:15:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12728130 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A42FFC43217 for ; Fri, 28 Jan 2022 08:41:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243172AbiA1Il6 (ORCPT ); Fri, 28 Jan 2022 03:41:58 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:17824 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243167AbiA1Ilz (ORCPT ); Fri, 28 Jan 2022 03:41:55 -0500 Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JlWB820s3z9sbl; Fri, 28 Jan 2022 16:40:32 +0800 (CST) Received: from huawei.com (10.175.124.27) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 28 Jan 2022 16:41:48 +0800 From: Hou Tao To: Daniel Borkmann CC: Alexei Starovoitov , Martin KaFai Lau , Yonghong Song , Andrii Nakryiko , "David S . Miller" , Jakub Kicinski , John Fastabend , , , , Zi Shen Lim , Catalin Marinas , Will Deacon , Ard Biesheuvel , Subject: [PATCH bpf-next v2 1/2] bpf, arm64: enable kfunc call Date: Thu, 27 Jan 2022 15:15:31 +0800 Message-ID: <20220127071532.384888-2-houtao1@huawei.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220127071532.384888-1-houtao1@huawei.com> References: <20220127071532.384888-1-houtao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Since commit b2eed9b58811 ("arm64/kernel: kaslr: reduce module randomization range to 2 GB"), for arm64 whether KASLR is enabled or not, the module is placed within 2GB of the kernel region, so s32 in bpf_kfunc_desc is sufficient to represente the offset of module function relative to __bpf_call_base. The only thing needed is to override bpf_jit_supports_kfunc_call(). Signed-off-by: Hou Tao --- arch/arm64/net/bpf_jit_comp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 6d92f363028c..e60c464004c2 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -1284,6 +1284,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) return prog; } +bool bpf_jit_supports_kfunc_call(void) +{ + return true; +} + u64 bpf_jit_alloc_exec_limit(void) { return VMALLOC_END - VMALLOC_START; From patchwork Thu Jan 27 07:15:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12728132 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DD65C43219 for ; Fri, 28 Jan 2022 08:42:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243260AbiA1Il7 (ORCPT ); Fri, 28 Jan 2022 03:41:59 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:17825 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231838AbiA1Il4 (ORCPT ); Fri, 28 Jan 2022 03:41:56 -0500 Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JlWB846Tyz9sbn; Fri, 28 Jan 2022 16:40:32 +0800 (CST) Received: from huawei.com (10.175.124.27) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 28 Jan 2022 16:41:49 +0800 From: Hou Tao To: Daniel Borkmann CC: Alexei Starovoitov , Martin KaFai Lau , Yonghong Song , Andrii Nakryiko , "David S . Miller" , Jakub Kicinski , John Fastabend , , , , Zi Shen Lim , Catalin Marinas , Will Deacon , Ard Biesheuvel , Subject: [PATCH bpf-next v2 2/2] selftests/bpf: check whether s32 is sufficient for kfunc offset Date: Thu, 27 Jan 2022 15:15:32 +0800 Message-ID: <20220127071532.384888-3-houtao1@huawei.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220127071532.384888-1-houtao1@huawei.com> References: <20220127071532.384888-1-houtao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net In add_kfunc_call(), bpf_kfunc_desc->imm with type s32 is used to represent the offset of called kfunc from __bpf_call_base, so add a test to ensure that the offset will not be overflowed. Signed-off-by: Hou Tao --- .../selftests/bpf/prog_tests/ksyms_module.c | 72 +++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c index d490ad80eccb..ce0cd3446931 100644 --- a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c +++ b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c @@ -6,6 +6,76 @@ #include "test_ksyms_module.lskel.h" #include "test_ksyms_module.skel.h" +/* Most logic comes from bpf_object__read_kallsyms_file() */ +static int test_find_func_in_kallsyms(const char *func, unsigned long *addr) +{ + /* Same as KSYM_NAME_LEN */ + char sym_name[128]; + char sym_type; + unsigned long sym_addr; + int ret, err; + FILE *f; + + f = fopen("/proc/kallsyms", "r"); + if (!f) + return -errno; + + err = -ENOENT; + while (true) { + ret = fscanf(f, "%lx %c %127s%*[^\n]\n", + &sym_addr, &sym_type, sym_name); + if (ret == EOF && feof(f)) + break; + + if (ret != 3) { + err = -EINVAL; + break; + } + + if ((sym_type == 't' || sym_type == 'T') && + !strcmp(sym_name, func)) { + *addr = sym_addr; + err = 0; + break; + } + } + + fclose(f); + return err; +} + +/* + * Check whether or not s32 in bpf_kfunc_desc is sufficient + * to represent the offset between bpf_testmod_test_mod_kfunc + * and __bpf_call_base. + */ +void test_ksyms_module_valid_offset(void) +{ + unsigned long kfunc_addr; + unsigned long base_addr; + int used_offset; + long actual_offset; + int err; + + if (!env.has_testmod) { + test__skip(); + return; + } + + err = test_find_func_in_kallsyms("bpf_testmod_test_mod_kfunc", + &kfunc_addr); + if (!ASSERT_OK(err, "find kfunc addr")) + return; + + err = test_find_func_in_kallsyms("__bpf_call_base", &base_addr); + if (!ASSERT_OK(err, "find base addr")) + return; + + used_offset = kfunc_addr - base_addr; + actual_offset = kfunc_addr - base_addr; + ASSERT_EQ((long)used_offset, actual_offset, "kfunc offset overflowed"); +} + void test_ksyms_module_lskel(void) { struct test_ksyms_module_lskel *skel; @@ -55,6 +125,8 @@ void test_ksyms_module_libbpf(void) void test_ksyms_module(void) { + if (test__start_subtest("valid_offset")) + test_ksyms_module_valid_offset(); if (test__start_subtest("lskel")) test_ksyms_module_lskel(); if (test__start_subtest("libbpf"))