From patchwork Tue May 25 03:59:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 12277763 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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 C1E05C2B9F8 for ; Tue, 25 May 2021 03:59:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7F186141F for ; Tue, 25 May 2021 03:59:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230015AbhEYEBV convert rfc822-to-8bit (ORCPT ); Tue, 25 May 2021 00:01:21 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:63712 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230072AbhEYEBT (ORCPT ); Tue, 25 May 2021 00:01:19 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 14P3hwps031176 for ; Mon, 24 May 2021 20:59:50 -0700 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 38rr050f3s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 24 May 2021 20:59:50 -0700 Received: from intmgw001.05.ash7.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 24 May 2021 20:59:49 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id F33822EDBE05; Mon, 24 May 2021 20:59:44 -0700 (PDT) From: Andrii Nakryiko To: , , , CC: , , John Fastabend , =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?q?=C3=B8rgensen?= Subject: [PATCH v2 bpf-next 3/5] libbpf: streamline error reporting for low-level APIs Date: Mon, 24 May 2021 20:59:33 -0700 Message-ID: <20210525035935.1461796-4-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210525035935.1461796-1-andrii@kernel.org> References: <20210525035935.1461796-1-andrii@kernel.org> X-FB-Internal: Safe X-Proofpoint-GUID: LI5hpcL-__bEFMqEESArIrnp_1QDLU07 X-Proofpoint-ORIG-GUID: LI5hpcL-__bEFMqEESArIrnp_1QDLU07 X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-05-25_02:2021-05-24,2021-05-25 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 impostorscore=0 bulkscore=0 spamscore=0 adultscore=0 mlxlogscore=999 lowpriorityscore=0 phishscore=0 priorityscore=1501 clxscore=1015 suspectscore=0 malwarescore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105250024 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Ensure that low-level APIs behave uniformly across the libbpf as follows: - in case of an error, errno is always set to the correct error code; - when libbpf 1.0 mode is enabled with LIBBPF_STRICT_DIRECT_ERRS option to libbpf_set_strict_mode(), return -Exxx error value directly, instead of -1; - by default, until libbpf 1.0 is released, keep returning -1 directly. More context, justification, and discussion can be found in "Libbpf: the road to v1.0" document ([0]). [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY Acked-by: John Fastabend Acked-by: Toke Høiland-Jørgensen Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/bpf.c | 168 ++++++++++++++++++++++---------- tools/lib/bpf/libbpf_internal.h | 26 +++++ tools/lib/bpf/libbpf_legacy.h | 12 +++ 3 files changed, 156 insertions(+), 50 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index b7c2cc12034c..86dcac44f32f 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -80,6 +80,7 @@ static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size) int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) { union bpf_attr attr; + int fd; memset(&attr, '\0', sizeof(attr)); @@ -102,7 +103,8 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) else attr.inner_map_fd = create_attr->inner_map_fd; - return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); + fd = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_create_map_node(enum bpf_map_type map_type, const char *name, @@ -160,6 +162,7 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name, __u32 map_flags, int node) { union bpf_attr attr; + int fd; memset(&attr, '\0', sizeof(attr)); @@ -178,7 +181,8 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name, attr.numa_node = node; } - return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); + fd = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name, @@ -222,10 +226,10 @@ int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr) int fd; if (!load_attr->log_buf != !load_attr->log_buf_sz) - return -EINVAL; + return libbpf_err(-EINVAL); if (load_attr->log_level > (4 | 2 | 1) || (load_attr->log_level && !load_attr->log_buf)) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.prog_type = load_attr->prog_type; @@ -281,8 +285,10 @@ int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr) load_attr->func_info_cnt, load_attr->func_info_rec_size, attr.func_info_rec_size); - if (!finfo) + if (!finfo) { + errno = E2BIG; goto done; + } attr.func_info = ptr_to_u64(finfo); attr.func_info_rec_size = load_attr->func_info_rec_size; @@ -293,8 +299,10 @@ int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr) load_attr->line_info_cnt, load_attr->line_info_rec_size, attr.line_info_rec_size); - if (!linfo) + if (!linfo) { + errno = E2BIG; goto done; + } attr.line_info = ptr_to_u64(linfo); attr.line_info_rec_size = load_attr->line_info_rec_size; @@ -318,9 +326,10 @@ int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr) fd = sys_bpf_prog_load(&attr, sizeof(attr)); done: + /* free() doesn't affect errno, so we don't need to restore it */ free(finfo); free(linfo); - return fd; + return libbpf_err_errno(fd); } int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, @@ -329,7 +338,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, struct bpf_prog_load_params p = {}; if (!load_attr || !log_buf != !log_buf_sz) - return -EINVAL; + return libbpf_err(-EINVAL); p.prog_type = load_attr->prog_type; p.expected_attach_type = load_attr->expected_attach_type; @@ -391,6 +400,7 @@ int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, int log_level) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.prog_type = type; @@ -404,13 +414,15 @@ int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, attr.kern_version = kern_version; attr.prog_flags = prog_flags; - return sys_bpf_prog_load(&attr, sizeof(attr)); + fd = sys_bpf_prog_load(&attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_map_update_elem(int fd, const void *key, const void *value, __u64 flags) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; @@ -418,24 +430,28 @@ int bpf_map_update_elem(int fd, const void *key, const void *value, attr.value = ptr_to_u64(value); attr.flags = flags; - return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_map_lookup_elem(int fd, const void *key, void *value) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); - return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; @@ -443,19 +459,22 @@ int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) attr.value = ptr_to_u64(value); attr.flags = flags; - return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); - return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags) @@ -474,34 +493,40 @@ int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, _ int bpf_map_delete_elem(int fd, const void *key) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); - return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_map_get_next_key(int fd, const void *key, void *next_key) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.next_key = ptr_to_u64(next_key); - return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_map_freeze(int fd) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; - return sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } static int bpf_map_batch_common(int cmd, int fd, void *in_batch, @@ -513,7 +538,7 @@ static int bpf_map_batch_common(int cmd, int fd, void *in_batch, int ret; if (!OPTS_VALID(opts, bpf_map_batch_opts)) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.batch.map_fd = fd; @@ -528,7 +553,7 @@ static int bpf_map_batch_common(int cmd, int fd, void *in_batch, ret = sys_bpf(cmd, &attr, sizeof(attr)); *count = attr.batch.count; - return ret; + return libbpf_err_errno(ret); } int bpf_map_delete_batch(int fd, void *keys, __u32 *count, @@ -565,22 +590,26 @@ int bpf_map_update_batch(int fd, void *keys, void *values, __u32 *count, int bpf_obj_pin(int fd, const char *pathname) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.pathname = ptr_to_u64((void *)pathname); attr.bpf_fd = fd; - return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); + ret = sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_obj_get(const char *pathname) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.pathname = ptr_to_u64((void *)pathname); - return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); + fd = sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, @@ -598,9 +627,10 @@ int bpf_prog_attach_xattr(int prog_fd, int target_fd, const struct bpf_prog_attach_opts *opts) { union bpf_attr attr; + int ret; if (!OPTS_VALID(opts, bpf_prog_attach_opts)) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.target_fd = target_fd; @@ -609,30 +639,35 @@ int bpf_prog_attach_xattr(int prog_fd, int target_fd, attr.attach_flags = OPTS_GET(opts, flags, 0); attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0); - return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); + ret = sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_prog_detach(int target_fd, enum bpf_attach_type type) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.target_fd = target_fd; attr.attach_type = type; - return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); + ret = sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.target_fd = target_fd; attr.attach_bpf_fd = prog_fd; attr.attach_type = type; - return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); + ret = sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_link_create(int prog_fd, int target_fd, @@ -641,15 +676,16 @@ int bpf_link_create(int prog_fd, int target_fd, { __u32 target_btf_id, iter_info_len; union bpf_attr attr; + int fd; if (!OPTS_VALID(opts, bpf_link_create_opts)) - return -EINVAL; + return libbpf_err(-EINVAL); iter_info_len = OPTS_GET(opts, iter_info_len, 0); target_btf_id = OPTS_GET(opts, target_btf_id, 0); if (iter_info_len && target_btf_id) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.link_create.prog_fd = prog_fd; @@ -665,26 +701,30 @@ int bpf_link_create(int prog_fd, int target_fd, attr.link_create.target_btf_id = target_btf_id; } - return sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr)); + fd = sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_link_detach(int link_fd) { union bpf_attr attr; + int ret; memset(&attr, 0, sizeof(attr)); attr.link_detach.link_fd = link_fd; - return sys_bpf(BPF_LINK_DETACH, &attr, sizeof(attr)); + ret = sys_bpf(BPF_LINK_DETACH, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_link_update(int link_fd, int new_prog_fd, const struct bpf_link_update_opts *opts) { union bpf_attr attr; + int ret; if (!OPTS_VALID(opts, bpf_link_update_opts)) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.link_update.link_fd = link_fd; @@ -692,17 +732,20 @@ int bpf_link_update(int link_fd, int new_prog_fd, attr.link_update.flags = OPTS_GET(opts, flags, 0); attr.link_update.old_prog_fd = OPTS_GET(opts, old_prog_fd, 0); - return sys_bpf(BPF_LINK_UPDATE, &attr, sizeof(attr)); + ret = sys_bpf(BPF_LINK_UPDATE, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } int bpf_iter_create(int link_fd) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.iter_create.link_fd = link_fd; - return sys_bpf(BPF_ITER_CREATE, &attr, sizeof(attr)); + fd = sys_bpf(BPF_ITER_CREATE, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, @@ -719,10 +762,12 @@ int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, attr.query.prog_ids = ptr_to_u64(prog_ids); ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr)); + if (attach_flags) *attach_flags = attr.query.attach_flags; *prog_cnt = attr.query.prog_cnt; - return ret; + + return libbpf_err_errno(ret); } int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, @@ -740,13 +785,15 @@ int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, attr.test.repeat = repeat; ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); + if (size_out) *size_out = attr.test.data_size_out; if (retval) *retval = attr.test.retval; if (duration) *duration = attr.test.duration; - return ret; + + return libbpf_err_errno(ret); } int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr) @@ -755,7 +802,7 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr) int ret; if (!test_attr->data_out && test_attr->data_size_out > 0) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.test.prog_fd = test_attr->prog_fd; @@ -770,11 +817,13 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr) attr.test.repeat = test_attr->repeat; ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); + test_attr->data_size_out = attr.test.data_size_out; test_attr->ctx_size_out = attr.test.ctx_size_out; test_attr->retval = attr.test.retval; test_attr->duration = attr.test.duration; - return ret; + + return libbpf_err_errno(ret); } int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts) @@ -783,7 +832,7 @@ int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts) int ret; if (!OPTS_VALID(opts, bpf_test_run_opts)) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.test.prog_fd = prog_fd; @@ -801,11 +850,13 @@ int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts) attr.test.data_out = ptr_to_u64(OPTS_GET(opts, data_out, NULL)); ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); + OPTS_SET(opts, data_size_out, attr.test.data_size_out); OPTS_SET(opts, ctx_size_out, attr.test.ctx_size_out); OPTS_SET(opts, duration, attr.test.duration); OPTS_SET(opts, retval, attr.test.retval); - return ret; + + return libbpf_err_errno(ret); } static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd) @@ -820,7 +871,7 @@ static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd) if (!err) *next_id = attr.next_id; - return err; + return libbpf_err_errno(err); } int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) @@ -846,41 +897,49 @@ int bpf_link_get_next_id(__u32 start_id, __u32 *next_id) int bpf_prog_get_fd_by_id(__u32 id) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.prog_id = id; - return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); + fd = sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_map_get_fd_by_id(__u32 id) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.map_id = id; - return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); + fd = sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_btf_get_fd_by_id(__u32 id) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.btf_id = id; - return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr)); + fd = sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_link_get_fd_by_id(__u32 id) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.link_id = id; - return sys_bpf(BPF_LINK_GET_FD_BY_ID, &attr, sizeof(attr)); + fd = sys_bpf(BPF_LINK_GET_FD_BY_ID, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len) @@ -894,21 +953,24 @@ int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len) attr.info.info = ptr_to_u64(info); err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); + if (!err) *info_len = attr.info.info_len; - return err; + return libbpf_err_errno(err); } int bpf_raw_tracepoint_open(const char *name, int prog_fd) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.raw_tracepoint.name = ptr_to_u64(name); attr.raw_tracepoint.prog_fd = prog_fd; - return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr)); + fd = sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size, @@ -928,12 +990,13 @@ int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_s } fd = sys_bpf(BPF_BTF_LOAD, &attr, sizeof(attr)); - if (fd == -1 && !do_log && log_buf && log_buf_size) { + + if (fd < 0 && !do_log && log_buf && log_buf_size) { do_log = true; goto retry; } - return fd; + return libbpf_err_errno(fd); } int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, @@ -950,37 +1013,42 @@ int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, attr.task_fd_query.buf_len = *buf_len; err = sys_bpf(BPF_TASK_FD_QUERY, &attr, sizeof(attr)); + *buf_len = attr.task_fd_query.buf_len; *prog_id = attr.task_fd_query.prog_id; *fd_type = attr.task_fd_query.fd_type; *probe_offset = attr.task_fd_query.probe_offset; *probe_addr = attr.task_fd_query.probe_addr; - return err; + return libbpf_err_errno(err); } int bpf_enable_stats(enum bpf_stats_type type) { union bpf_attr attr; + int fd; memset(&attr, 0, sizeof(attr)); attr.enable_stats.type = type; - return sys_bpf(BPF_ENABLE_STATS, &attr, sizeof(attr)); + fd = sys_bpf(BPF_ENABLE_STATS, &attr, sizeof(attr)); + return libbpf_err_errno(fd); } int bpf_prog_bind_map(int prog_fd, int map_fd, const struct bpf_prog_bind_opts *opts) { union bpf_attr attr; + int ret; if (!OPTS_VALID(opts, bpf_prog_bind_opts)) - return -EINVAL; + return libbpf_err(-EINVAL); memset(&attr, 0, sizeof(attr)); attr.prog_bind_map.prog_fd = prog_fd; attr.prog_bind_map.map_fd = map_fd; attr.prog_bind_map.flags = OPTS_GET(opts, flags, 0); - return sys_bpf(BPF_PROG_BIND_MAP, &attr, sizeof(attr)); + ret = sys_bpf(BPF_PROG_BIND_MAP, &attr, sizeof(attr)); + return libbpf_err_errno(ret); } diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 55d9b4dca64f..04a0cc8da06e 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -11,6 +11,9 @@ #include #include +#include +#include +#include "libbpf_legacy.h" /* make sure libbpf doesn't use kernel-only integer typedefs */ #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 @@ -430,4 +433,27 @@ int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ct int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx); int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx); +extern enum libbpf_strict_mode libbpf_mode; + +/* handle direct returned errors */ +static inline int libbpf_err(int ret) +{ + if (ret < 0) + errno = -ret; + return ret; +} + +/* handle errno-based (e.g., syscall or libc) errors according to libbpf's + * strict mode settings + */ +static inline int libbpf_err_errno(int ret) +{ + if (libbpf_mode & LIBBPF_STRICT_DIRECT_ERRS) + /* errno is already assumed to be set on error */ + return ret < 0 ? -errno : ret; + + /* legacy: on error return -1 directly and don't touch errno */ + return ret; +} + #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h index 7482cfe22ab2..df0d03dcffab 100644 --- a/tools/lib/bpf/libbpf_legacy.h +++ b/tools/lib/bpf/libbpf_legacy.h @@ -33,6 +33,18 @@ enum libbpf_strict_mode { * code so that it handles LIBBPF_STRICT_ALL mode before libbpf v1.0. */ LIBBPF_STRICT_NONE = 0x00, + /* + * Return NULL pointers on error, not ERR_PTR(err). + * Additionally, libbpf also always sets errno to corresponding Exx + * (positive) error code. + */ + LIBBPF_STRICT_CLEAN_PTRS = 0x01, + /* + * Return actual error codes from low-level APIs directly, not just -1. + * Additionally, libbpf also always sets errno to corresponding Exx + * (positive) error code. + */ + LIBBPF_STRICT_DIRECT_ERRS = 0x02, __LIBBPF_STRICT_LAST, };