Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753448Ab3IEQbK (ORCPT ); Thu, 5 Sep 2013 12:31:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41789 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752241Ab3IEQbH (ORCPT ); Thu, 5 Sep 2013 12:31:07 -0400 Date: Thu, 5 Sep 2013 18:30:30 +0200 From: Jiri Olsa To: Jean Pihet Cc: Will Deacon , linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org Subject: Re: [PATCH 3/3] perf: parse the .debug_frame section in case .eh_frame is not present Message-ID: <20130905163030.GF1100@krava.brq.redhat.com> References: <1378317854-25965-1-git-send-email-jean.pihet@linaro.org> <1378317854-25965-4-git-send-email-jean.pihet@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1378317854-25965-4-git-send-email-jean.pihet@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5634 Lines: 183 On Wed, Sep 04, 2013 at 08:04:14PM +0200, Jean Pihet wrote: > On ARM the debug info is not present in the .eh_frame sections but > instead in .debug_frame. > Use libunwind to load and parse the debug info. hum, cannot make final link: $ make LIBUNWIND_DIR=/opt/libunwind/ CHK -fstack-protector-all CHK -Wstack-protector CHK -Wvolatile-register-var CHK -D_FORTIFY_SOURCE=2 CHK bionic CHK libelf CHK libdw CHK -DLIBELF_MMAP CHK -DLIBELF_MMAP CHK libunwind CHK libaudit ... make[1]: `liblk.a' is up to date. SUBDIR /home/jolsa/linux-perf/tools/lib/traceevent/ LINK perf libperf.a(unwind.o): In function `find_proc_info': /home/jolsa/linux-perf/tools/perf/util/unwind.c:339: undefined reference to `_Ux86_64_dwarf_find_debug_frame' collect2: ld returned 1 exit status make: *** [perf] Error 1 I'm using the latest code from git://git.sv.gnu.org/libunwind.git Looks like dwarf_find_debug_frame is not exported, although it looks like it is based on what I see in libunwind sources ;-) What did I miss? Also few typo comments below.. thanks, jirka > > Signed-off-by: Jean Pihet > --- > tools/perf/util/unwind.c | 70 +++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 54 insertions(+), 16 deletions(-) > > diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c > index 958723b..5353b32 100644 > --- a/tools/perf/util/unwind.c > +++ b/tools/perf/util/unwind.c > @@ -39,6 +39,14 @@ UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, > > #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) > > +extern int > +UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, > + unw_word_t ip, unw_word_t segbase, > + const char *obj_name, unw_word_t start, > + unw_word_t end); > + > +#define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame) > + > #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ > #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */ > > @@ -245,8 +253,9 @@ static int unwind_spec_ehframe(struct dso *dso, struct machine *machine, > return 0; > } > > -static int read_unwind_spec(struct dso *dso, struct machine *machine, > - u64 *table_data, u64 *segbase, u64 *fde_count) > +static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, > + u64 *table_data, u64 *segbase, > + u64 *fde_count) > { > int ret = -EINVAL, fd; > u64 offset; > @@ -255,6 +264,7 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine, > if (fd < 0) > return -EINVAL; > > + /* Check the .eh_frame section for unwinding info */ > offset = elf_section_offset(fd, ".eh_frame_hdr"); > close(fd); > > @@ -263,10 +273,27 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine, > table_data, segbase, > fde_count); > > - /* TODO .debug_frame check if eh_frame_hdr fails */ > return ret; > } > > +static int read_unwind_spec_debug_frame(struct dso *dso, > + struct machine *machine, u64 *offset) > +{ some strange formatting issue ^^^ ;-) > + int fd = dso__data_fd(dso, machine); > + > + if (fd < 0) > + return -EINVAL; > + > + /* Check the .debug_frame section for unwinding info */ > + *offset = elf_section_offset(fd, ".debug_frame"); > + close(fd); > + > + if (*offset) > + return 0; > + > + return -EINVAL; > +} > + > static struct map *find_map(unw_word_t ip, struct unwind_info *ui) > { > struct addr_location al; > @@ -291,20 +318,31 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, > > pr_debug("unwind: find_proc_info dso %s\n", map->dso->name); > > - if (read_unwind_spec(map->dso, ui->machine, > - &table_data, &segbase, &fde_count)) > - return -EINVAL; > + /* Check the .eh_frame section for unwinding info */ > + if (!read_unwind_spec_eh_frame(map->dso, ui->machine, > + &table_data, &segbase, &fde_count)) { ditto ^^^ > + memset(&di, 0, sizeof(di)); > + di.format = UNW_INFO_FORMAT_REMOTE_TABLE; > + di.start_ip = map->start; > + di.end_ip = map->end; > + di.u.rti.segbase = map->start + segbase; > + di.u.rti.table_data = map->start + table_data; > + di.u.rti.table_len = fde_count * sizeof(struct table_entry) > + / sizeof(unw_word_t); > + return dwarf_search_unwind_table(as, ip, &di, pi, > + need_unwind_info, arg); ditto ^^^ > + } > + > + /* Check the .debug_frame section for unwinding info */ > + if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { > + memset(&di, 0, sizeof(di)); > + dwarf_find_debug_frame(0, &di, ip, 0, map->dso->name, > + map->start, map->end); > + return dwarf_search_unwind_table(as, ip, &di, pi, > + need_unwind_info, arg); ditto ^^^ > + } > > - memset(&di, 0, sizeof(di)); > - di.format = UNW_INFO_FORMAT_REMOTE_TABLE; > - di.start_ip = map->start; > - di.end_ip = map->end; > - di.u.rti.segbase = map->start + segbase; > - di.u.rti.table_data = map->start + table_data; > - di.u.rti.table_len = fde_count * sizeof(struct table_entry) > - / sizeof(unw_word_t); > - return dwarf_search_unwind_table(as, ip, &di, pi, > - need_unwind_info, arg); > + return -EINVAL; > } > > static int access_fpreg(unw_addr_space_t __maybe_unused as, > -- > 1.7.11.7 > -- 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/