From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752059AbbCMHDR (ORCPT ); Fri, 13 Mar 2015 03:03:17 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:51773 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751572AbbCMHDN (ORCPT ); Fri, 13 Mar 2015 03:03:13 -0400 Message-ID: <55028BA0.1030701@huawei.com> Date: Fri, 13 Mar 2015 15:02:56 +0800 From: Wang Nan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Namhyung Kim , Arnaldo Carvalho de Melo , Jiri Olsa , "linux-kernel@vger.kernel.org" CC: Ingo Molnar , Li Zefan Subject: [PATCH] perf callchain: separate eh/debug frame offset cache. Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.69.129] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit f1f13af99a90 ("perf callchain: Cache eh/debug frame offset for dwarf unwind") introduces a cache for .debug_frame and .eh_frame_hdr. Unfortunately, it makes them share a same cache (dso->frame_offset). Which causes unwind failure on ARM: $ perf test unwind Test dwarf unwind: FAILED! The reason is that, if a dso has '.debug_frame' but doesn't have '.eh_frame_hdr' (like ARM), dso->frame_offset will be filled by offset of '.debug_frame' during the first time calling of find_proc_info() -> read_unwind_spec_debug_frame(), and be regarded to '.eh_frame_hdr' when the second time calling of find_proc_info() -> read_unwind_spec_eh_frame(), since '.eh_frame_hdr' is checked prior to '.debug_frame'. This patch solves the problem by creating two cache fields for '.eh_frame_hdr' and '.debug_frame'. Signed-off-by: Wang Nan --- tools/perf/util/dso.h | 3 ++- tools/perf/util/unwind-libunwind.c | 8 ++++---- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index ced9284..408c65f 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -139,7 +139,8 @@ struct dso { u32 status_seen; size_t file_size; struct list_head open_entry; - u64 frame_offset; + u64 debug_frame_offset; + u64 eh_frame_hdr_offset; } data; union { /* Tool specific area */ diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c index e3c40a5..7b09a44 100644 --- a/tools/perf/util/unwind-libunwind.c +++ b/tools/perf/util/unwind-libunwind.c @@ -266,7 +266,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, u64 *fde_count) { int ret = -EINVAL, fd; - u64 offset = dso->data.frame_offset; + u64 offset = dso->data.eh_frame_hdr_offset; if (offset == 0) { fd = dso__data_fd(dso, machine); @@ -275,7 +275,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, /* Check the .eh_frame section for unwinding info */ offset = elf_section_offset(fd, ".eh_frame_hdr"); - dso->data.frame_offset = offset; + dso->data.eh_frame_hdr_offset = offset; } if (offset) @@ -291,7 +291,7 @@ static int read_unwind_spec_debug_frame(struct dso *dso, struct machine *machine, u64 *offset) { int fd; - u64 ofs = dso->data.frame_offset; + u64 ofs = dso->data.debug_frame_offset; if (ofs == 0) { fd = dso__data_fd(dso, machine); @@ -300,7 +300,7 @@ static int read_unwind_spec_debug_frame(struct dso *dso, /* Check the .debug_frame section for unwinding info */ ofs = elf_section_offset(fd, ".debug_frame"); - dso->data.frame_offset = ofs; + dso->data.debug_frame_offset = ofs; } *offset = ofs; -- 1.8.3.4