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 jean.pihet@linaro.org
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