From 414311960cbd9c5ea1e6adbd8a501ef8ec034819 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Tue, 28 Apr 2015 17:35:35 +0530 Subject: [PATCH 1/5] perf probe ppc: Fix symbol fixup issues due to ELF type 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 Cc: Ananth N Mavinakayanahalli Cc: Masami Hiramatsu Cc: Michael Ellerman Cc: Sukadev Bhattiprolu Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/41392bb856ef62d929995e0b61967689b7915207.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/arch/powerpc/Makefile | 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/Makefile b/tools/perf/arch/powerpc/Makefile index 6f7782b..85d2306 100644 --- a/tools/perf/arch/powerpc/Makefile +++ b/tools/perf/arch/powerpc/Makefile @@ -4,3 +4,4 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/skip-callchain-idx.o endif LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/header.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/sym-handling.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 eafee11..32de043 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -617,6 +617,11 @@ 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) { @@ -686,8 +691,7 @@ 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 1650dcb..35dc7b5 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -295,4 +295,8 @@ int compare_proc_modules(const char *from, const char *to); int setup_list(struct strlist **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 */ -- 2.4.0