From patchwork Thu Aug 20 23:12:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 262170 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 BA98CC433DF for ; Thu, 20 Aug 2020 23:13:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8ADDD207DF for ; Thu, 20 Aug 2020 23:13:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="YQ0pyOoZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728706AbgHTXNI (ORCPT ); Thu, 20 Aug 2020 19:13:08 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:55968 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728661AbgHTXNB (ORCPT ); Thu, 20 Aug 2020 19:13:01 -0400 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 07KNA5Yg013971 for ; Thu, 20 Aug 2020 16:12:57 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=WDLoYgp0TrTLgFNM0lrYQP5548eLofctgWau85KDG44=; b=YQ0pyOoZCMHSqghqxu1KAZwpSfrp8wGwiepp6T4MHuKium3UcmKp+yzdwjbtzx0Przk4 qIRNvVHmqJ+bqaBrFQLYSdrH9BuvcyEeA96D9eGNySUrvcKzWYVW6pLp5zrAx0e5FFUd 2g00iIsg1RDCDX8PelzAFxydFySvIB7tP7g= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 3318g0qhyn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 20 Aug 2020 16:12:57 -0700 Received: from intmgw001.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Thu, 20 Aug 2020 16:12:56 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 6FF652EC5F42; Thu, 20 Aug 2020 16:12:56 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 02/16] libbpf: factor out common ELF operations and improve logging Date: Thu, 20 Aug 2020 16:12:36 -0700 Message-ID: <20200820231250.1293069-3-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200820231250.1293069-1-andriin@fb.com> References: <20200820231250.1293069-1-andriin@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-08-20_07:2020-08-19,2020-08-20 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 spamscore=0 lowpriorityscore=0 clxscore=1015 bulkscore=0 priorityscore=1501 mlxlogscore=999 suspectscore=9 mlxscore=0 adultscore=0 malwarescore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008200189 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Factor out common ELF operations done throughout the libbpf. This simplifies usage across multiple places in libbpf, as well as hide error reporting from higher-level functions and make error logging more consistent. Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 367 +++++++++++++++++++++++------------------ 1 file changed, 206 insertions(+), 161 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 0bc1fd813408..1f7e2ac0979e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -398,6 +398,7 @@ struct bpf_object { Elf_Data *rodata; Elf_Data *bss; Elf_Data *st_ops_data; + size_t shstrndx; /* section index for section name strings */ size_t strtabidx; struct { GElf_Shdr shdr; @@ -435,6 +436,14 @@ struct bpf_object { }; #define obj_elf_valid(o) ((o)->efile.elf) +static const char *elf_sym_str(const struct bpf_object *obj, size_t off); +static const char *elf_sec_str(const struct bpf_object *obj, size_t off); +static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx); +static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name); +static int elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn, GElf_Shdr *hdr); +static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn); +static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn); + void bpf_program__unload(struct bpf_program *prog) { int i; @@ -496,7 +505,7 @@ static char *__bpf_program__pin_name(struct bpf_program *prog) } static int -bpf_program__init(void *data, size_t size, char *section_name, int idx, +bpf_program__init(void *data, size_t size, const char *section_name, int idx, struct bpf_program *prog) { const size_t bpf_insn_sz = sizeof(struct bpf_insn); @@ -545,7 +554,7 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx, static int bpf_object__add_program(struct bpf_object *obj, void *data, size_t size, - char *section_name, int idx) + const char *section_name, int idx) { struct bpf_program prog, *progs; int nr_progs, err; @@ -570,7 +579,7 @@ bpf_object__add_program(struct bpf_object *obj, void *data, size_t size, return -ENOMEM; } - pr_debug("found program %s\n", prog.section_name); + pr_debug("elf: found program '%s'\n", prog.section_name); obj->programs = progs; obj->nr_programs = nr_progs + 1; prog.obj = obj; @@ -590,8 +599,7 @@ bpf_object__init_prog_names(struct bpf_object *obj) prog = &obj->programs[pi]; - for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name; - si++) { + for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name; si++) { GElf_Sym sym; if (!gelf_getsym(symbols, si, &sym)) @@ -601,11 +609,9 @@ bpf_object__init_prog_names(struct bpf_object *obj) if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL) continue; - name = elf_strptr(obj->efile.elf, - obj->efile.strtabidx, - sym.st_name); + name = elf_sym_str(obj, sym.st_name); if (!name) { - pr_warn("failed to get sym name string for prog %s\n", + pr_warn("prog '%s': failed to get symbol name\n", prog->section_name); return -LIBBPF_ERRNO__LIBELF; } @@ -615,17 +621,14 @@ bpf_object__init_prog_names(struct bpf_object *obj) name = ".text"; if (!name) { - pr_warn("failed to find sym for prog %s\n", + pr_warn("prog '%s': failed to find program symbol\n", prog->section_name); return -EINVAL; } prog->name = strdup(name); - if (!prog->name) { - pr_warn("failed to allocate memory for prog sym %s\n", - name); + if (!prog->name) return -ENOMEM; - } } return 0; @@ -1069,7 +1072,7 @@ static int bpf_object__elf_init(struct bpf_object *obj) GElf_Ehdr *ep; if (obj_elf_valid(obj)) { - pr_warn("elf init: internal error\n"); + pr_warn("elf: init internal error\n"); return -LIBBPF_ERRNO__LIBELF; } @@ -1087,7 +1090,7 @@ static int bpf_object__elf_init(struct bpf_object *obj) err = -errno; cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); - pr_warn("failed to open %s: %s\n", obj->path, cp); + pr_warn("elf: failed to open %s: %s\n", obj->path, cp); return err; } @@ -1095,22 +1098,36 @@ static int bpf_object__elf_init(struct bpf_object *obj) } if (!obj->efile.elf) { - pr_warn("failed to open %s as ELF file\n", obj->path); + pr_warn("elf: failed to open %s as ELF file: %s\n", obj->path, elf_errmsg(-1)); err = -LIBBPF_ERRNO__LIBELF; goto errout; } if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) { - pr_warn("failed to get EHDR from %s\n", obj->path); + pr_warn("elf: failed to get ELF header from %s: %s\n", obj->path, elf_errmsg(-1)); err = -LIBBPF_ERRNO__FORMAT; goto errout; } ep = &obj->efile.ehdr; + if (elf_getshdrstrndx(obj->efile.elf, &obj->efile.shstrndx)) { + pr_warn("elf: failed to get section names section index for %s: %s\n", + obj->path, elf_errmsg(-1)); + err = -LIBBPF_ERRNO__FORMAT; + goto errout; + } + + /* Elf is corrupted/truncated, avoid calling elf_strptr. */ + if (!elf_rawdata(elf_getscn(obj->efile.elf, obj->efile.shstrndx), NULL)) { + pr_warn("elf: failed to get section names strings from %s: %s\n", + obj->path, elf_errmsg(-1)); + return -LIBBPF_ERRNO__FORMAT; + } + /* Old LLVM set e_machine to EM_NONE */ if (ep->e_type != ET_REL || (ep->e_machine && ep->e_machine != EM_BPF)) { - pr_warn("%s is not an eBPF object file\n", obj->path); + pr_warn("elf: %s is not a valid eBPF object file\n", obj->path); err = -LIBBPF_ERRNO__FORMAT; goto errout; } @@ -1132,7 +1149,7 @@ static int bpf_object__check_endianness(struct bpf_object *obj) #else # error "Unrecognized __BYTE_ORDER__" #endif - pr_warn("endianness mismatch.\n"); + pr_warn("elf: endianness mismatch in %s.\n", obj->path); return -LIBBPF_ERRNO__ENDIAN; } @@ -1167,55 +1184,10 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type) return false; } -static int bpf_object_search_section_size(const struct bpf_object *obj, - const char *name, size_t *d_size) -{ - const GElf_Ehdr *ep = &obj->efile.ehdr; - Elf *elf = obj->efile.elf; - Elf_Scn *scn = NULL; - int idx = 0; - - while ((scn = elf_nextscn(elf, scn)) != NULL) { - const char *sec_name; - Elf_Data *data; - GElf_Shdr sh; - - idx++; - if (gelf_getshdr(scn, &sh) != &sh) { - pr_warn("failed to get section(%d) header from %s\n", - idx, obj->path); - return -EIO; - } - - sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); - if (!sec_name) { - pr_warn("failed to get section(%d) name from %s\n", - idx, obj->path); - return -EIO; - } - - if (strcmp(name, sec_name)) - continue; - - data = elf_getdata(scn, 0); - if (!data) { - pr_warn("failed to get section(%d) data from %s(%s)\n", - idx, name, obj->path); - return -EIO; - } - - *d_size = data->d_size; - return 0; - } - - return -ENOENT; -} - int bpf_object__section_size(const struct bpf_object *obj, const char *name, __u32 *size) { int ret = -ENOENT; - size_t d_size; *size = 0; if (!name) { @@ -1233,9 +1205,13 @@ int bpf_object__section_size(const struct bpf_object *obj, const char *name, if (obj->efile.st_ops_data) *size = obj->efile.st_ops_data->d_size; } else { - ret = bpf_object_search_section_size(obj, name, &d_size); - if (!ret) - *size = d_size; + Elf_Scn *scn = elf_sec_by_name(obj, name); + Elf_Data *data = elf_sec_data(obj, scn); + + if (data) { + ret = 0; /* found it */ + *size = data->d_size; + } } return *size ? 0 : ret; @@ -1260,8 +1236,7 @@ int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, GELF_ST_TYPE(sym.st_info) != STT_OBJECT) continue; - sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx, - sym.st_name); + sname = elf_sym_str(obj, sym.st_name); if (!sname) { pr_warn("failed to get sym name string for var %s\n", name); @@ -1738,12 +1713,12 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) if (!symbols) return -EINVAL; - scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); - if (scn) - data = elf_getdata(scn, NULL); + + scn = elf_sec_by_idx(obj, obj->efile.maps_shndx); + data = elf_sec_data(obj, scn); if (!scn || !data) { - pr_warn("failed to get Elf_Data from map section %d\n", - obj->efile.maps_shndx); + pr_warn("elf: failed to get legacy map definitions for %s\n", + obj->path); return -EINVAL; } @@ -1765,12 +1740,12 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) nr_maps++; } /* Assume equally sized map definitions */ - pr_debug("maps in %s: %d maps in %zd bytes\n", - obj->path, nr_maps, data->d_size); + pr_debug("elf: found %d legacy map definitions (%zd bytes) in %s\n", + nr_maps, data->d_size, obj->path); if (!data->d_size || nr_maps == 0 || (data->d_size % nr_maps) != 0) { - pr_warn("unable to determine map definition size section %s, %d maps in %zd bytes\n", - obj->path, nr_maps, data->d_size); + pr_warn("elf: unable to determine legacy map definition size in %s\n", + obj->path); return -EINVAL; } map_def_sz = data->d_size / nr_maps; @@ -1791,8 +1766,7 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) if (IS_ERR(map)) return PTR_ERR(map); - map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, - sym.st_name); + map_name = elf_sym_str(obj, sym.st_name); if (!map_name) { pr_warn("failed to get map #%d name sym string for obj %s\n", i, obj->path); @@ -2274,12 +2248,11 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict, if (obj->efile.btf_maps_shndx < 0) return 0; - scn = elf_getscn(obj->efile.elf, obj->efile.btf_maps_shndx); - if (scn) - data = elf_getdata(scn, NULL); + scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx); + data = elf_sec_data(obj, scn); if (!scn || !data) { - pr_warn("failed to get Elf_Data from map section %d (%s)\n", - obj->efile.maps_shndx, MAPS_ELF_SEC); + pr_warn("elf: failed to get %s map definitions for %s\n", + MAPS_ELF_SEC, obj->path); return -EINVAL; } @@ -2337,20 +2310,12 @@ static int bpf_object__init_maps(struct bpf_object *obj, static bool section_have_execinstr(struct bpf_object *obj, int idx) { - Elf_Scn *scn; GElf_Shdr sh; - scn = elf_getscn(obj->efile.elf, idx); - if (!scn) - return false; - - if (gelf_getshdr(scn, &sh) != &sh) + if (elf_sec_hdr(obj, elf_sec_by_idx(obj, idx), &sh)) return false; - if (sh.sh_flags & SHF_EXECINSTR) - return true; - - return false; + return sh.sh_flags & SHF_EXECINSTR; } static bool btf_needs_sanitization(struct bpf_object *obj) @@ -2594,61 +2559,156 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) return err; } +static const char *elf_sym_str(const struct bpf_object *obj, size_t off) +{ + const char *name; + + name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, off); + if (!name) { + pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n", + off, obj->path, elf_errmsg(-1)); + return NULL; + } + + return name; +} + +static const char *elf_sec_str(const struct bpf_object *obj, size_t off) +{ + const char *name; + + name = elf_strptr(obj->efile.elf, obj->efile.shstrndx, off); + if (!name) { + pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n", + off, obj->path, elf_errmsg(-1)); + return NULL; + } + + return name; +} + +static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx) +{ + Elf_Scn *scn; + + scn = elf_getscn(obj->efile.elf, idx); + if (!scn) { + pr_warn("elf: failed to get section(%zu) from %s: %s\n", + idx, obj->path, elf_errmsg(-1)); + return NULL; + } + return scn; +} + +static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name) +{ + Elf_Scn *scn = NULL; + Elf *elf = obj->efile.elf; + const char *sec_name; + + while ((scn = elf_nextscn(elf, scn)) != NULL) { + sec_name = elf_sec_name(obj, scn); + if (!sec_name) + return NULL; + + if (strcmp(sec_name, name) != 0) + continue; + + return scn; + } + return NULL; +} + +static int elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn, GElf_Shdr *hdr) +{ + if (!scn) + return -EINVAL; + + if (gelf_getshdr(scn, hdr) != hdr) { + pr_warn("elf: failed to get section(%zu) header from %s: %s\n", + elf_ndxscn(scn), obj->path, elf_errmsg(-1)); + return -EINVAL; + } + + return 0; +} + +static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn) +{ + const char *name; + GElf_Shdr sh; + + if (!scn) + return NULL; + + if (elf_sec_hdr(obj, scn, &sh)) + return NULL; + + name = elf_sec_str(obj, sh.sh_name); + if (!name) { + pr_warn("elf: failed to get section(%zu) name from %s: %s\n", + elf_ndxscn(scn), obj->path, elf_errmsg(-1)); + return NULL; + } + + return name; +} + +static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn) +{ + Elf_Data *data; + + if (!scn) + return NULL; + + data = elf_getdata(scn, 0); + if (!data) { + pr_warn("elf: failed to get section(%zu) %s data from %s: %s\n", + elf_ndxscn(scn), elf_sec_name(obj, scn) ?: "", + obj->path, elf_errmsg(-1)); + return NULL; + } + + return data; +} + static int bpf_object__elf_collect(struct bpf_object *obj) { Elf *elf = obj->efile.elf; - GElf_Ehdr *ep = &obj->efile.ehdr; Elf_Data *btf_ext_data = NULL; Elf_Data *btf_data = NULL; Elf_Scn *scn = NULL; int idx = 0, err = 0; - /* Elf is corrupted/truncated, avoid calling elf_strptr. */ - if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) { - pr_warn("failed to get e_shstrndx from %s\n", obj->path); - return -LIBBPF_ERRNO__FORMAT; - } - while ((scn = elf_nextscn(elf, scn)) != NULL) { - char *name; + const char *name; GElf_Shdr sh; Elf_Data *data; idx++; - if (gelf_getshdr(scn, &sh) != &sh) { - pr_warn("failed to get section(%d) header from %s\n", - idx, obj->path); + + if (elf_sec_hdr(obj, scn, &sh)) return -LIBBPF_ERRNO__FORMAT; - } - name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); - if (!name) { - pr_warn("failed to get section(%d) name from %s\n", - idx, obj->path); + name = elf_sec_str(obj, sh.sh_name); + if (!name) return -LIBBPF_ERRNO__FORMAT; - } - data = elf_getdata(scn, 0); - if (!data) { - pr_warn("failed to get section(%d) data from %s(%s)\n", - idx, name, obj->path); + data = elf_sec_data(obj, scn); + if (!data) return -LIBBPF_ERRNO__FORMAT; - } - pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", + + pr_debug("elf: section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", idx, name, (unsigned long)data->d_size, (int)sh.sh_link, (unsigned long)sh.sh_flags, (int)sh.sh_type); if (strcmp(name, "license") == 0) { - err = bpf_object__init_license(obj, - data->d_buf, - data->d_size); + err = bpf_object__init_license(obj, data->d_buf, data->d_size); if (err) return err; } else if (strcmp(name, "version") == 0) { - err = bpf_object__init_kversion(obj, - data->d_buf, - data->d_size); + err = bpf_object__init_kversion(obj, data->d_buf, data->d_size); if (err) return err; } else if (strcmp(name, "maps") == 0) { @@ -2661,8 +2721,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj) btf_ext_data = data; } else if (sh.sh_type == SHT_SYMTAB) { if (obj->efile.symbols) { - pr_warn("bpf: multiple SYMTAB in %s\n", - obj->path); + pr_warn("elf: multiple symbol tables in %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; } obj->efile.symbols = data; @@ -2675,16 +2734,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj) err = bpf_object__add_program(obj, data->d_buf, data->d_size, name, idx); - if (err) { - char errmsg[STRERR_BUFSIZE]; - char *cp; - - cp = libbpf_strerror_r(-err, errmsg, - sizeof(errmsg)); - pr_warn("failed to alloc program %s (%s): %s", - name, obj->path, cp); + if (err) return err; - } } else if (strcmp(name, DATA_SEC) == 0) { obj->efile.data = data; obj->efile.data_shndx = idx; @@ -2695,7 +2746,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj) obj->efile.st_ops_data = data; obj->efile.st_ops_shndx = idx; } else { - pr_debug("skip section(%d) %s\n", idx, name); + pr_debug("elf: skipping unrecognized data section(%d) %s\n", + idx, name); } } else if (sh.sh_type == SHT_REL) { int nr_sects = obj->efile.nr_reloc_sects; @@ -2706,34 +2758,32 @@ static int bpf_object__elf_collect(struct bpf_object *obj) if (!section_have_execinstr(obj, sec) && strcmp(name, ".rel" STRUCT_OPS_SEC) && strcmp(name, ".rel" MAPS_ELF_SEC)) { - pr_debug("skip relo %s(%d) for section(%d)\n", - name, idx, sec); + pr_debug("elf: skipping relo section(%d) %s for section(%d) %s\n", + idx, name, sec, + elf_sec_name(obj, elf_sec_by_idx(obj, sec)) ?: ""); continue; } sects = libbpf_reallocarray(sects, nr_sects + 1, sizeof(*obj->efile.reloc_sects)); - if (!sects) { - pr_warn("reloc_sects realloc failed\n"); + if (!sects) return -ENOMEM; - } obj->efile.reloc_sects = sects; obj->efile.nr_reloc_sects++; obj->efile.reloc_sects[nr_sects].shdr = sh; obj->efile.reloc_sects[nr_sects].data = data; - } else if (sh.sh_type == SHT_NOBITS && - strcmp(name, BSS_SEC) == 0) { + } else if (sh.sh_type == SHT_NOBITS && strcmp(name, BSS_SEC) == 0) { obj->efile.bss = data; obj->efile.bss_shndx = idx; } else { - pr_debug("skip section(%d) %s\n", idx, name); + pr_debug("elf: skipping section(%d) %s\n", idx, name); } } if (!obj->efile.strtabidx || obj->efile.strtabidx > idx) { - pr_warn("Corrupted ELF file: index of strtab invalid\n"); + pr_warn("elf: symbol strings section missing or invalid in %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; } return bpf_object__init_btf(obj, btf_data, btf_ext_data); @@ -2894,14 +2944,13 @@ static int bpf_object__collect_externs(struct bpf_object *obj) if (!obj->efile.symbols) return 0; - scn = elf_getscn(obj->efile.elf, obj->efile.symbols_shndx); - if (!scn) - return -LIBBPF_ERRNO__FORMAT; - if (gelf_getshdr(scn, &sh) != &sh) + scn = elf_sec_by_idx(obj, obj->efile.symbols_shndx); + if (elf_sec_hdr(obj, scn, &sh)) return -LIBBPF_ERRNO__FORMAT; - n = sh.sh_size / sh.sh_entsize; + n = sh.sh_size / sh.sh_entsize; pr_debug("looking for externs among %d symbols...\n", n); + for (i = 0; i < n; i++) { GElf_Sym sym; @@ -2909,8 +2958,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj) return -LIBBPF_ERRNO__FORMAT; if (!sym_is_extern(&sym)) continue; - ext_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, - sym.st_name); + ext_name = elf_sym_str(obj, sym.st_name); if (!ext_name || !ext_name[0]) continue; @@ -3289,16 +3337,15 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, return -LIBBPF_ERRNO__FORMAT; } if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) { - pr_warn("relocation: symbol %"PRIx64" not found\n", - GELF_R_SYM(rel.r_info)); + pr_warn("relocation: symbol %zx not found\n", + (size_t)GELF_R_SYM(rel.r_info)); return -LIBBPF_ERRNO__FORMAT; } if (rel.r_offset % sizeof(struct bpf_insn)) return -LIBBPF_ERRNO__FORMAT; insn_idx = rel.r_offset / sizeof(struct bpf_insn); - name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, - sym.st_name) ? : ""; + name = elf_sym_str(obj, sym.st_name) ?: ""; pr_debug("relo for shdr %u, symb %zu, value %zu, type %d, bind %d, name %d (\'%s\'), insn %u\n", (__u32)sym.st_shndx, (size_t)GELF_R_SYM(rel.r_info), @@ -5720,8 +5767,7 @@ static int bpf_object__collect_map_relos(struct bpf_object *obj, i, (size_t)GELF_R_SYM(rel.r_info)); return -LIBBPF_ERRNO__FORMAT; } - name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, - sym.st_name) ? : ""; + name = elf_sym_str(obj, sym.st_name) ?: ""; if (sym.st_shndx != obj->efile.btf_maps_shndx) { pr_warn(".maps relo #%d: '%s' isn't a BTF-defined map\n", i, name); @@ -7663,8 +7709,7 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, return -LIBBPF_ERRNO__FORMAT; } - name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, - sym.st_name) ? : ""; + name = elf_sym_str(obj, sym.st_name) ?: ""; map = find_struct_ops_map_by_offset(obj, rel.r_offset); if (!map) { pr_warn("struct_ops reloc: cannot find map at rel.r_offset %zu\n",