From patchwork Tue Jul 13 12:42:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuyi Cheng X-Patchwork-Id: 477335 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D830BC07E96 for ; Tue, 13 Jul 2021 12:43:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFE7561289 for ; Tue, 13 Jul 2021 12:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236308AbhGMMq1 (ORCPT ); Tue, 13 Jul 2021 08:46:27 -0400 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]:40102 "EHLO out30-54.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236268AbhGMMq0 (ORCPT ); Tue, 13 Jul 2021 08:46:26 -0400 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R741e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04400; MF=chengshuyi@linux.alibaba.com; NM=1; PH=DS; RN=13; SR=0; TI=SMTPD_---0Ufgcb2l_1626180206; Received: from localhost(mailfrom:chengshuyi@linux.alibaba.com fp:SMTPD_---0Ufgcb2l_1626180206) by smtp.aliyun-inc.com(127.0.0.1); Tue, 13 Jul 2021 20:43:34 +0800 From: Shuyi Cheng To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Shuyi Cheng Subject: [PATCH bpf-next v4 1/3] libbpf: Introduce 'btf_custom_path' to 'bpf_obj_open_opts' Date: Tue, 13 Jul 2021 20:42:37 +0800 Message-Id: <1626180159-112996-2-git-send-email-chengshuyi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1626180159-112996-1-git-send-email-chengshuyi@linux.alibaba.com> References: <1626180159-112996-1-git-send-email-chengshuyi@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org btf_custom_path allows developers to load custom BTF, and subsequent CO-RE will use custom BTF for relocation. Learn from Andrii's comments in [0], add the btf_custom_path parameter to bpf_obj_open_opts, you can directly use the skeleton's _bpf__open_opts function to pass in the btf_custom_path parameter. Prior to this, there was also a developer who provided a patch with similar functions. It is a pity that the follow-up did not continue to advance. See [1]. [0]https://lore.kernel.org/bpf/CAEf4BzbJZLjNoiK8_VfeVg_Vrg=9iYFv+po-38SMe=UzwDKJ=Q@mail.gmail.com/#t [1]https://yhbt.net/lore/all/CAEf4Bzbgw49w2PtowsrzKQNcxD4fZRE6AKByX-5-dMo-+oWHHA@mail.gmail.com/ Signed-off-by: Shuyi Cheng --- tools/lib/bpf/libbpf.c | 36 ++++++++++++++++++++++++++++++------ tools/lib/bpf/libbpf.h | 9 ++++++++- 2 files changed, 38 insertions(+), 7 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 1e04ce7..6e11a7b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -498,6 +498,13 @@ struct bpf_object { * it at load time. */ struct btf *btf_vmlinux; + /* Path to the custom BTF to be used for BPF CO-RE relocations. + * This custom BTF completely replaces the use of vmlinux BTF + * for the purpose of CO-RE relocations. + * NOTE: any other BPF feature (e.g., fentry/fexit programs, + * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. + */ + char *btf_custom_path; /* vmlinux BTF override for CO-RE relocations */ struct btf *btf_vmlinux_override; /* Lazily initialized kernel module BTFs */ @@ -2645,10 +2652,6 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj) struct bpf_program *prog; int i; - /* CO-RE relocations need kernel BTF */ - if (obj->btf_ext && obj->btf_ext->core_relo_info.len) - return true; - /* Support for typed ksyms needs kernel BTF */ for (i = 0; i < obj->nr_extern; i++) { const struct extern_desc *ext; @@ -2665,6 +2668,13 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj) return true; } + /* CO-RE relocations need kernel BTF, only when btf_custom_path + * is not specified + */ + if (obj->btf_ext && obj->btf_ext->core_relo_info.len + && !obj->btf_custom_path) + return true; + return false; } @@ -7554,7 +7564,7 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver) __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, const struct bpf_object_open_opts *opts) { - const char *obj_name, *kconfig; + const char *obj_name, *kconfig, *btf_tmp_path; struct bpf_program *prog; struct bpf_object *obj; char tmp_name[64]; @@ -7584,6 +7594,19 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver) obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name); if (IS_ERR(obj)) return obj; + + btf_tmp_path = OPTS_GET(opts, btf_custom_path, NULL); + if (btf_tmp_path) { + if (strlen(btf_tmp_path) >= PATH_MAX) { + err = -ENAMETOOLONG; + goto out; + } + obj->btf_custom_path = strdup(btf_tmp_path); + if (!obj->btf_custom_path) { + err = -ENOMEM; + goto out; + } + } kconfig = OPTS_GET(opts, kconfig, NULL); if (kconfig) { @@ -8055,7 +8078,7 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr) err = err ? : bpf_object__sanitize_maps(obj); err = err ? : bpf_object__init_kern_struct_ops_maps(obj); err = err ? : bpf_object__create_maps(obj); - err = err ? : bpf_object__relocate(obj, attr->target_btf_path); + err = err ? : bpf_object__relocate(obj, obj->btf_custom_path ? : attr->target_btf_path); err = err ? : bpf_object__load_progs(obj, attr->log_level); if (obj->gen_loader) { @@ -8702,6 +8725,7 @@ void bpf_object__close(struct bpf_object *obj) for (i = 0; i < obj->nr_maps; i++) bpf_map__destroy(&obj->maps[i]); + zfree(&obj->btf_custom_path); zfree(&obj->kconfig); zfree(&obj->externs); obj->nr_extern = 0; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 6e61342..102ee8e 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -94,8 +94,15 @@ struct bpf_object_open_opts { * system Kconfig for CONFIG_xxx externs. */ const char *kconfig; + /* Path to the custom BTF to be used for BPF CO-RE relocations. + * This custom BTF completely replaces the use of vmlinux BTF + * for the purpose of CO-RE relocations. + * NOTE: any other BPF feature (e.g., fentry/fexit programs, + * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. + */ + char *btf_custom_path; }; -#define bpf_object_open_opts__last_field kconfig +#define bpf_object_open_opts__last_field btf_custom_path LIBBPF_API struct bpf_object *bpf_object__open(const char *path); LIBBPF_API struct bpf_object * From patchwork Tue Jul 13 12:42:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuyi Cheng X-Patchwork-Id: 477334 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB1E1C07E96 for ; Tue, 13 Jul 2021 12:43:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B34B161289 for ; Tue, 13 Jul 2021 12:43:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236376AbhGMMqh (ORCPT ); Tue, 13 Jul 2021 08:46:37 -0400 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:41288 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236167AbhGMMqg (ORCPT ); Tue, 13 Jul 2021 08:46:36 -0400 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R151e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04400; MF=chengshuyi@linux.alibaba.com; NM=1; PH=DS; RN=14; SR=0; TI=SMTPD_---0UfgxQcF_1626180215; Received: from localhost(mailfrom:chengshuyi@linux.alibaba.com fp:SMTPD_---0UfgxQcF_1626180215) by smtp.aliyun-inc.com(127.0.0.1); Tue, 13 Jul 2021 20:43:43 +0800 From: Shuyi Cheng To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Shuyi Cheng , Dan Carpenter Subject: [PATCH bpf-next v4 2/3] libbpf: Fix the possible memory leak on error Date: Tue, 13 Jul 2021 20:42:38 +0800 Message-Id: <1626180159-112996-3-git-send-email-chengshuyi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1626180159-112996-1-git-send-email-chengshuyi@linux.alibaba.com> References: <1626180159-112996-1-git-send-email-chengshuyi@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If the strdup() fails then we need to call bpf_object__close(obj) to avoid a resource leak. Fixes: 166750b ("libbpf: Support libbpf-provided extern variables") Cc: Dan Carpenter Signed-off-by: Shuyi Cheng --- tools/lib/bpf/libbpf.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6e11a7b..9d80794 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -7611,8 +7611,10 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver) kconfig = OPTS_GET(opts, kconfig, NULL); if (kconfig) { obj->kconfig = strdup(kconfig); - if (!obj->kconfig) - return ERR_PTR(-ENOMEM); + if (!obj->kconfig) { + err = -ENOMEM; + goto out; + } } err = bpf_object__elf_init(obj); From patchwork Tue Jul 13 12:42:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuyi Cheng X-Patchwork-Id: 475084 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D29CAC07E96 for ; Tue, 13 Jul 2021 12:43:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C030A611AB for ; Tue, 13 Jul 2021 12:43:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236372AbhGMMqs (ORCPT ); Tue, 13 Jul 2021 08:46:48 -0400 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:35786 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236167AbhGMMqq (ORCPT ); Tue, 13 Jul 2021 08:46:46 -0400 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R251e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04423; MF=chengshuyi@linux.alibaba.com; NM=1; PH=DS; RN=13; SR=0; TI=SMTPD_---0UfgRy8k_1626180226; Received: from localhost(mailfrom:chengshuyi@linux.alibaba.com fp:SMTPD_---0UfgRy8k_1626180226) by smtp.aliyun-inc.com(127.0.0.1); Tue, 13 Jul 2021 20:43:54 +0800 From: Shuyi Cheng To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Shuyi Cheng Subject: [PATCH bpf-next v4 3/3] selftests/bpf: Switches existing selftests to using open_opts for custom BTF Date: Tue, 13 Jul 2021 20:42:39 +0800 Message-Id: <1626180159-112996-4-git-send-email-chengshuyi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1626180159-112996-1-git-send-email-chengshuyi@linux.alibaba.com> References: <1626180159-112996-1-git-send-email-chengshuyi@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch mainly replaces the bpf_object_load_attr of the core_autosize.c and core_reloc.c files with bpf_object_open_opts. Signed-off-by: Shuyi Cheng --- .../selftests/bpf/prog_tests/core_autosize.c | 22 ++++++++--------- .../testing/selftests/bpf/prog_tests/core_reloc.c | 28 ++++++++++------------ 2 files changed, 24 insertions(+), 26 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/core_autosize.c b/tools/testing/selftests/bpf/prog_tests/core_autosize.c index 981c251..d163342 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_autosize.c +++ b/tools/testing/selftests/bpf/prog_tests/core_autosize.c @@ -54,7 +54,7 @@ void test_core_autosize(void) int err, fd = -1, zero = 0; int char_id, short_id, int_id, long_long_id, void_ptr_id, id; struct test_core_autosize* skel = NULL; - struct bpf_object_load_attr load_attr = {}; + struct bpf_object_open_opts open_opts = {}; struct bpf_program *prog; struct bpf_map *bss_map; struct btf *btf = NULL; @@ -125,9 +125,11 @@ void test_core_autosize(void) fd = -1; /* open and load BPF program with custom BTF as the kernel BTF */ - skel = test_core_autosize__open(); + open_opts.btf_custom_path = btf_file; + open_opts.sz = sizeof(struct bpf_object_open_opts); + skel = test_core_autosize__open_opts(&open_opts); if (!ASSERT_OK_PTR(skel, "skel_open")) - return; + goto cleanup; /* disable handle_signed() for now */ prog = bpf_object__find_program_by_name(skel->obj, "handle_signed"); @@ -135,9 +137,7 @@ void test_core_autosize(void) goto cleanup; bpf_program__set_autoload(prog, false); - load_attr.obj = skel->obj; - load_attr.target_btf_path = btf_file; - err = bpf_object__load_xattr(&load_attr); + err = bpf_object__load(skel->obj); if (!ASSERT_OK(err, "prog_load")) goto cleanup; @@ -204,13 +204,13 @@ void test_core_autosize(void) skel = NULL; /* now re-load with handle_signed() enabled, it should fail loading */ - skel = test_core_autosize__open(); + open_opts.btf_custom_path = btf_file; + open_opts.sz = sizeof(struct bpf_object_open_opts); + skel = test_core_autosize__open_opts(&opts); if (!ASSERT_OK_PTR(skel, "skel_open")) - return; + goto cleanup; - load_attr.obj = skel->obj; - load_attr.target_btf_path = btf_file; - err = bpf_object__load_xattr(&load_attr); + err = bpf_object__load(skel); if (!ASSERT_ERR(err, "bad_prog_load")) goto cleanup; diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c index d02e064..10eb2407 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c @@ -816,7 +816,7 @@ static size_t roundup_page(size_t sz) void test_core_reloc(void) { const size_t mmap_sz = roundup_page(sizeof(struct data)); - struct bpf_object_load_attr load_attr = {}; + struct bpf_object_open_opts open_opts = {}; struct core_reloc_test_case *test_case; const char *tp_name, *probe_name; int err, i, equal; @@ -846,9 +846,17 @@ void test_core_reloc(void) continue; } - obj = bpf_object__open_file(test_case->bpf_obj_file, NULL); + if (test_case->btf_src_file) { + err = access(test_case->btf_src_file, R_OK); + if (!ASSERT_OK(err, "btf_src_file")) + goto cleanup; + } + + open_opts.btf_custom_path = test_case->btf_src_file; + open_opts.sz = sizeof(struct bpf_object_open_opts); + obj = bpf_object__open_file(test_case->bpf_obj_file, &open_opts); if (!ASSERT_OK_PTR(obj, "obj_open")) - continue; + goto cleanup; probe_name = "raw_tracepoint/sys_enter"; tp_name = "sys_enter"; @@ -861,18 +869,8 @@ void test_core_reloc(void) if (CHECK(!prog, "find_probe", "prog '%s' not found\n", probe_name)) goto cleanup; - - - if (test_case->btf_src_file) { - err = access(test_case->btf_src_file, R_OK); - if (!ASSERT_OK(err, "btf_src_file")) - goto cleanup; - } - - load_attr.obj = obj; - load_attr.log_level = 0; - load_attr.target_btf_path = test_case->btf_src_file; - err = bpf_object__load_xattr(&load_attr); + + err = bpf_object__load(obj); if (err) { if (!test_case->fails) ASSERT_OK(err, "obj_load");