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[2620:137:e000::1:20]) by mx.google.com with ESMTP id z34-20020a630a62000000b004fba312c233si8461576pgk.413.2023.03.16.10.15.30; Thu, 16 Mar 2023 10:15:45 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=GGxc9yi2; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230478AbjCPRDp (ORCPT + 99 others); Thu, 16 Mar 2023 13:03:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229717AbjCPRDm (ORCPT ); Thu, 16 Mar 2023 13:03:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65D2DDC096; Thu, 16 Mar 2023 10:03:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7BFE7620B8; Thu, 16 Mar 2023 17:03:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84B9BC433EF; Thu, 16 Mar 2023 17:02:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678986180; bh=Rj6UdNWuOo8DkLviQii3I1+Tk2Kvc/67ARrHkQm/dfw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GGxc9yi28eFc9bY1ajwWe10NyIStMwt4YOzdhNM/wiX7yOjelaepeo5UXwJfAytWI lDik7EeGavF+ShDZ3r/gpO2e1n4/59BQSSW8iv6Z7JNAXcztJowDqIeD/qF/a5nuNf QtVkOWTQ+AKS6CyZBXVFQ7EsGqj70MeAYMnQIKquZwZBIZPDhvAblZJFyFBmKbUnJP rH/8mHFzO8LPJnWLCse6i6Z32V7YnpbZh4+vysz014gw+q2mzA7e0t0ec7lFSilRnj shtyTlk6ESVFdmTJGfIG5cKbon9GjIAevOi6p1Ee6Sq9SEUJ6lgRL/cKjUQpcFHlNO jrdFLxifXhH/A== From: Jiri Olsa To: Alexei Starovoitov , Andrii Nakryiko , Hao Luo , Andrew Morton , Alexander Viro , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Matthew Wilcox Cc: bpf@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-perf-users@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Daniel Borkmann , Namhyung Kim , Dave Chinner Subject: [PATCHv3 bpf-next 5/9] selftests/bpf: Add read_buildid function Date: Thu, 16 Mar 2023 18:01:45 +0100 Message-Id: <20230316170149.4106586-6-jolsa@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230316170149.4106586-1-jolsa@kernel.org> References: <20230316170149.4106586-1-jolsa@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1760545415667886776?= X-GMAIL-MSGID: =?utf-8?q?1760545415667886776?= Adding read_build_id function that parses out build id from specified binary. It will replace extract_build_id and also be used in following changes. Signed-off-by: Jiri Olsa --- tools/testing/selftests/bpf/trace_helpers.c | 86 +++++++++++++++++++++ tools/testing/selftests/bpf/trace_helpers.h | 5 ++ 2 files changed, 91 insertions(+) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 934bf28fc888..72b38a41f574 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -11,6 +11,9 @@ #include #include #include "trace_helpers.h" +#include +#include +#include #define TRACEFS_PIPE "/sys/kernel/tracing/trace_pipe" #define DEBUGFS_PIPE "/sys/kernel/debug/tracing/trace_pipe" @@ -234,3 +237,86 @@ ssize_t get_rel_offset(uintptr_t addr) fclose(f); return -EINVAL; } + +static int +parse_build_id_buf(const void *note_start, Elf32_Word note_size, + char *build_id) +{ + Elf32_Word note_offs = 0, new_offs; + + while (note_offs + sizeof(Elf32_Nhdr) < note_size) { + Elf32_Nhdr *nhdr = (Elf32_Nhdr *)(note_start + note_offs); + + if (nhdr->n_type == 3 && nhdr->n_namesz == sizeof("GNU") && + !strcmp((char *)(nhdr + 1), "GNU") && nhdr->n_descsz > 0 && + nhdr->n_descsz <= BPF_BUILD_ID_SIZE) { + memcpy(build_id, note_start + note_offs + + ALIGN(sizeof("GNU"), 4) + sizeof(Elf32_Nhdr), nhdr->n_descsz); + memset(build_id + nhdr->n_descsz, 0, BPF_BUILD_ID_SIZE - nhdr->n_descsz); + return (int) nhdr->n_descsz; + } + + new_offs = note_offs + sizeof(Elf32_Nhdr) + + ALIGN(nhdr->n_namesz, 4) + ALIGN(nhdr->n_descsz, 4); + if (new_offs >= note_size) + break; + note_offs = new_offs; + } + + return -EINVAL; +} + +/* Reads binary from *path* file and returns it in the *build_id* + * which is expected to be at least BPF_BUILD_ID_SIZE bytes. + * Returns size of build id on success. On error the error value + * is returned. + */ +int read_build_id(const char *path, char *build_id) +{ + int fd, err = -EINVAL; + Elf *elf = NULL; + GElf_Ehdr ehdr; + size_t max, i; + + fd = open(path, O_RDONLY | O_CLOEXEC); + if (fd < 0) + return -errno; + + (void)elf_version(EV_CURRENT); + + elf = elf_begin(fd, ELF_C_READ, NULL); + if (!elf) + goto out; + if (elf_kind(elf) != ELF_K_ELF) + goto out; + if (gelf_getehdr(elf, &ehdr) == NULL) + goto out; + if (ehdr.e_ident[EI_CLASS] != ELFCLASS64) + goto out; + + for (i = 0; i < ehdr.e_phnum; i++) { + GElf_Phdr mem, *phdr; + char *data; + + phdr = gelf_getphdr(elf, i, &mem); + if (!phdr) + goto out; + if (phdr->p_type != PT_NOTE) + continue; + data = elf_rawfile(elf, &max); + if (!data) + goto out; + if (phdr->p_offset >= max || (phdr->p_offset + phdr->p_memsz >= max)) + goto out; + err = parse_build_id_buf(data + phdr->p_offset, phdr->p_memsz, build_id); + if (err > 0) + goto out; + err = -EINVAL; + } + +out: + if (elf) + elf_end(elf); + close(fd); + return err; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index 53efde0e2998..bc3b92057033 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -4,6 +4,9 @@ #include +#define __ALIGN_MASK(x, mask) (((x)+(mask))&~(mask)) +#define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a)-1) + struct ksym { long addr; char *name; @@ -23,4 +26,6 @@ void read_trace_pipe(void); ssize_t get_uprobe_offset(const void *addr); ssize_t get_rel_offset(uintptr_t addr); +int read_build_id(const char *path, char *build_id); + #endif