@@ -39,6 +39,15 @@ 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 +254,9 @@ 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 +265,7 @@ 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 +274,27 @@ 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)
+{
+ 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 +319,31 @@ 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)) {
+ 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);
+ }
+
+ /* 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);
+ }
- 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,
On ARM the debug info is not present in the .eh_frame sections but in .debug_frame instead, in the dwarf format. Use libunwind to load and parse the debug info. Dependencies: . if present, libunwind >= 1.1 is needed to prevent a segfault when parsing the dwarf info, . libunwind needs to be configured with --enable-debug-frame to prevent a linkage error. Note: --enable-debug-frame is automatically selected on ARM). Signed-off-by: Jean Pihet <jean.pihet@linaro.org> --- tools/perf/config/Makefile | 2 +- tools/perf/util/unwind.c | 71 +++++++++++++++++++++++++++++++++++----------- 2 files changed, 56 insertions(+), 17 deletions(-)