From mboxrd@z Thu Jan 1 00:00:00 1970 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 45056C07E99 for ; Sat, 3 Jul 2021 15:35:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2FF9A61938 for ; Sat, 3 Jul 2021 15:35:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230091AbhGCPiE (ORCPT ); Sat, 3 Jul 2021 11:38:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:35994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229924AbhGCPiD (ORCPT ); Sat, 3 Jul 2021 11:38:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4D8EF6161E; Sat, 3 Jul 2021 15:35:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625326529; bh=tS9//WzT5l76oJrWdPtooZEXhKPrvqWOWetH8EF9ECc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cpHKUDThrbCuUMCLNDb18TdLCitqznqCEWjev58affhL+3L6HRJsK4S0JNte6yeDh wNm3SxPsTFwmXYnsMMC2GRiWe5YHNwwEi3cJNahgREclkJpr5h7oxHt5kI4EbQJ0Ea bI2tRfrMial9iBE9gwfm/yY9rIreEAf7SMTANasQdC8ckqfILG97Vsm0sbK2QEuaWp FR4bH5fj+pWHsUvFvwuriHJtV34g1TAIyE2zcZ+Al2Kgr0w6snUNeShrmLOJDH6AIX B7qlgkxOMVDa1hUnfQo+ZR6rkAONVt5uvooz9z3ybusL3E9mVEnZX8iGUqOGqWih9b Ki4HjqVJUFd5w== From: Masami Hiramatsu To: Arnaldo Carvalho de Melo Cc: linux-perf-users@vger.kernel.org, Masami Hiramatsu , Sven Schnelle , Heiko Carstens , Stefan Liebler , Thomas Richter , linux-kernel@vger.kernel.org Subject: [PATCH 2/3] perf symbol-elf: Decode dynsym even if symtab exists Date: Sun, 4 Jul 2021 00:35:27 +0900 Message-Id: <162532652681.393143.10163733179955267999.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162532651032.393143.4602033845482295575.stgit@devnote2> References: <162532651032.393143.4602033845482295575.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In Fedora34, libc-2.33.so has both .dynsym and .symtab sections and most of (not all) symbols moved to .dynsym. In this case, perf only decode the symbols in .symtab, and perf probe can not list up the functions in the library. To fix this issue, decode both .symtab and .dynsym sections. Without this fix, ----- $ ./perf probe -x /usr/lib64/libc-2.33.so -F @plt @plt calloc@plt free@plt malloc@plt memalign@plt realloc@plt ----- With this fix. ----- $ ./perf probe -x /usr/lib64/libc-2.33.so -F @plt @plt a64l abort abs accept accept4 access acct addmntent ----- Reported-by: Thomas Richter Signed-off-by: Masami Hiramatsu --- tools/perf/util/symbol-elf.c | 82 ++++++++++++++++++++++++++++-------------- 1 file changed, 54 insertions(+), 28 deletions(-) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index a73345730ba9..eb10b4e0d888 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1074,8 +1074,9 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map, return 0; } -int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, - struct symsrc *runtime_ss, int kmodule) +static int +dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss, + struct symsrc *runtime_ss, int kmodule, int dynsym) { struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL; struct maps *kmaps = kmap ? map__kmaps(map) : NULL; @@ -1098,34 +1099,15 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, if (kmap && !kmaps) return -1; - dso->symtab_type = syms_ss->type; - dso->is_64_bit = syms_ss->is_64_bit; - dso->rel = syms_ss->ehdr.e_type == ET_REL; - - /* - * Modules may already have symbols from kallsyms, but those symbols - * have the wrong values for the dso maps, so remove them. - */ - if (kmodule && syms_ss->symtab) - symbols__delete(&dso->symbols); - - if (!syms_ss->symtab) { - /* - * If the vmlinux is stripped, fail so we will fall back - * to using kallsyms. The vmlinux runtime symbols aren't - * of much use. - */ - if (dso->kernel) - goto out_elf_end; - - syms_ss->symtab = syms_ss->dynsym; - syms_ss->symshdr = syms_ss->dynshdr; - } - elf = syms_ss->elf; ehdr = syms_ss->ehdr; - sec = syms_ss->symtab; - shdr = syms_ss->symshdr; + if (dynsym) { + sec = syms_ss->dynsym; + shdr = syms_ss->dynshdr; + } else { + sec = syms_ss->symtab; + shdr = syms_ss->symshdr; + } if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr, ".text", NULL)) @@ -1312,6 +1294,50 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, return err; } +int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, + struct symsrc *runtime_ss, int kmodule) +{ + int nr = 0; + int err = -1; + + dso->symtab_type = syms_ss->type; + dso->is_64_bit = syms_ss->is_64_bit; + dso->rel = syms_ss->ehdr.e_type == ET_REL; + + /* + * Modules may already have symbols from kallsyms, but those symbols + * have the wrong values for the dso maps, so remove them. + */ + if (kmodule && syms_ss->symtab) + symbols__delete(&dso->symbols); + + if (!syms_ss->symtab) { + /* + * If the vmlinux is stripped, fail so we will fall back + * to using kallsyms. The vmlinux runtime symbols aren't + * of much use. + */ + if (dso->kernel) + return err; + } else { + err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss, + kmodule, 0); + if (err < 0) + return err; + nr = err; + } + + if (syms_ss->dynsym) { + err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss, + kmodule, 1); + if (err < 0) + return err; + err += nr; + } + + return err; +} + static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data) { GElf_Phdr phdr;