Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965686AbbD1MGd (ORCPT ); Tue, 28 Apr 2015 08:06:33 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:38958 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965614AbbD1MG1 (ORCPT ); Tue, 28 Apr 2015 08:06:27 -0400 From: "Naveen N. Rao" To: acme@kernel.org Cc: masami.hiramatsu.pt@hitachi.com, ananth@in.ibm.com, mpe@ellerman.id.au, sukadev@linux.vnet.ibm.com, srikar@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v3 2/7] perf probe/ppc: Fix symbol fixup issues due to ELF type Date: Tue, 28 Apr 2015 17:35:35 +0530 Message-Id: <41392bb856ef62d929995e0b61967689b7915207.1430217967.git.naveen.n.rao@linux.vnet.ibm.com> X-Mailer: git-send-email 2.3.5 In-Reply-To: References: In-Reply-To: References: X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15042812-0005-0000-0000-00000500CAAF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3682 Lines: 115 If using the symbol table, symbol addresses are not being fixed up properly, resulting in probes being placed at wrong addresses: # perf probe do_fork Added new event: probe:do_fork (on do_fork) You can now use it in all perf tools, such as: perf record -e probe:do_fork -aR sleep 1 # cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_fork _text+635952 # printf "%x" 635952 9b430 # grep do_fork /boot/System.map c0000000000ab430 T .do_fork Fix by checking for ELF type ET_DYN used by ppc64 kernels. Signed-off-by: Naveen N. Rao Reviewed-by: Srikar Dronamraju --- Changes: - Introduce arch helper to limit change to ppc. tools/perf/arch/powerpc/util/Build | 1 + tools/perf/arch/powerpc/util/sym-handling.c | 19 +++++++++++++++++++ tools/perf/util/symbol-elf.c | 8 ++++++-- tools/perf/util/symbol.h | 4 ++++ 4 files changed, 30 insertions(+), 2 deletions(-) create mode 100644 tools/perf/arch/powerpc/util/sym-handling.c diff --git a/tools/perf/arch/powerpc/util/Build b/tools/perf/arch/powerpc/util/Build index 0af6e9b..7b8b0d1 100644 --- a/tools/perf/arch/powerpc/util/Build +++ b/tools/perf/arch/powerpc/util/Build @@ -1,4 +1,5 @@ libperf-y += header.o +libperf-y += sym-handling.o libperf-$(CONFIG_DWARF) += dwarf-regs.o libperf-$(CONFIG_DWARF) += skip-callchain-idx.o diff --git a/tools/perf/arch/powerpc/util/sym-handling.c b/tools/perf/arch/powerpc/util/sym-handling.c new file mode 100644 index 0000000..c9de001 --- /dev/null +++ b/tools/perf/arch/powerpc/util/sym-handling.c @@ -0,0 +1,19 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * Copyright (C) 2015 Naveen N. Rao, IBM Corporation + */ + +#include "debug.h" +#include "symbol.h" + +#ifdef HAVE_LIBELF_SUPPORT +bool elf__needs_adjust_symbols(GElf_Ehdr ehdr) +{ + return ehdr.e_type == ET_EXEC || + ehdr.e_type == ET_REL || + ehdr.e_type == ET_DYN; +} +#endif diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index ac09c60..7f5d237 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -630,6 +630,11 @@ void symsrc__destroy(struct symsrc *ss) close(ss->fd); } +bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr) +{ + return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL; +} + int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, enum dso_binary_type type) { @@ -712,8 +717,7 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, ".gnu.prelink_undo", NULL) != NULL); } else { - ss->adjust_symbols = ehdr.e_type == ET_EXEC || - ehdr.e_type == ET_REL; + ss->adjust_symbols = elf__needs_adjust_symbols(ehdr); } ss->name = strdup(name); diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index 0956150..8cb0af4 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -303,4 +303,8 @@ int setup_list(struct strlist **list, const char *list_str, int setup_intlist(struct intlist **list, const char *list_str, const char *list_name); +#ifdef HAVE_LIBELF_SUPPORT +bool elf__needs_adjust_symbols(GElf_Ehdr ehdr); +#endif + #endif /* __PERF_SYMBOL */ -- 2.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/