Show appropriate symbol for _stext based kprobes instead
of _stext+offset when perf-probe -l runs without debuginfo.
Without this change:
# ./perf probe -l
probe:t_show (on _stext+889880 with m v)
probe:t_show_1 (on _stext+928568 with m v t)
probe:t_show_2 (on _stext+969512 with m v fmt)
probe:t_show_3 (on _stext+1001416 with m v file)
With this change:
# ./perf probe -l
probe:t_show (on t_show with m v)
probe:t_show_1 (on t_show with m v t)
probe:t_show_2 (on t_show with m v fmt)
probe:t_show_3 (on t_show with m v file)
Signed-off-by: Masami Hiramatsu <[email protected]>
---
tools/perf/util/probe-event.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index b35f047..8db172a 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -125,6 +125,11 @@ static struct symbol *__find_kernel_function_by_name(const
char *name,
NULL);
}
+static struct symbol *__find_kernel_function(u64 addr, struct map **mapp)
+{
+ return machine__find_kernel_function(host_machine, addr, mapp, NULL);
+}
+
static struct map *kernel_get_module_map(const char *module)
{
struct rb_node *nd;
@@ -220,12 +225,30 @@ out:
static int convert_to_perf_probe_point(struct probe_trace_point *tp,
struct perf_probe_point *pp)
{
- pp->function = strdup(tp->symbol);
+ struct symbol *sym;
+ struct map *map;
+ u64 addr;
+
+ /* _stext based probe point is solved to absolute address */
+ if (tp->symbol && strcmp(tp->symbol, "_stext") == 0) {
+ sym = __find_kernel_function_by_name(tp->symbol, &map);
+ if (!sym)
+ goto failed;
+ addr = map->unmap_ip(map, sym->start + tp->offset);
+ sym = __find_kernel_function(addr, &map);
+ if (!sym)
+ goto failed;
+ pp->function = strdup(sym->name);
+ pp->offset = addr - map->unmap_ip(map, sym->start);
+ } else {
+failed:
+ pp->function = strdup(tp->symbol);
+ pp->offset = tp->offset;
+ }
if (pp->function == NULL)
return -ENOMEM;
- pp->offset = tp->offset;
pp->retprobe = tp->retprobe;
return 0;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
