perf probe: Show accessible global variables
Add --externs for allowing --vars to show accessible global (externally
defined) variables from a given probe point too.
This will give you a hint which globals can be accessible from the probe point.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101335.3542.31003.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 83192a5..82b0976 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -379,7 +379,7 @@
}
static int show_available_vars_at(int fd, struct perf_probe_event *pev,
- int max_vls)
+ int max_vls, bool externs)
{
char *buf;
int ret, i;
@@ -391,7 +391,7 @@
return -EINVAL;
pr_debug("Searching variables at %s\n", buf);
- ret = find_available_vars_at(fd, pev, &vls, max_vls);
+ ret = find_available_vars_at(fd, pev, &vls, max_vls, externs);
if (ret > 0) {
/* Some variables were found */
fprintf(stdout, "Available variables at %s\n", buf);
@@ -421,7 +421,7 @@
/* Show available variables on given probe point */
int show_available_vars(struct perf_probe_event *pevs, int npevs,
- int max_vls)
+ int max_vls, bool externs)
{
int i, fd, ret = 0;
@@ -438,7 +438,7 @@
setup_pager();
for (i = 0; i < npevs && ret >= 0; i++)
- ret = show_available_vars_at(fd, &pevs[i], max_vls);
+ ret = show_available_vars_at(fd, &pevs[i], max_vls, externs);
close(fd);
return ret;
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 83130f6..c74b1fd 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -122,7 +122,7 @@
extern int show_perf_probe_events(void);
extern int show_line_range(struct line_range *lr);
extern int show_available_vars(struct perf_probe_event *pevs, int npevs,
- int max_probe_points);
+ int max_probe_points, bool externs);
/* Maximum index number of event-name postfix */
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 986027f..a274fd0 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1312,12 +1312,13 @@
af->pf.fb_ops, NULL);
if (ret == 0) {
ret = die_get_varname(die_mem, buf, MAX_VAR_LEN);
+ pr_debug2("Add new var: %s\n", buf);
if (ret > 0)
strlist__add(vl->vars, buf);
}
}
- if (dwarf_haspc(die_mem, af->pf.addr))
+ if (af->child && dwarf_haspc(die_mem, af->pf.addr))
return DIE_FIND_CB_CONTINUE;
else
return DIE_FIND_CB_SIBLING;
@@ -1329,8 +1330,8 @@
struct available_var_finder *af =
container_of(pf, struct available_var_finder, pf);
struct variable_list *vl;
- Dwarf_Die die_mem;
- int ret;
+ Dwarf_Die die_mem, *scopes = NULL;
+ int ret, nscopes;
/* Check number of tevs */
if (af->nvls == af->max_vls) {
@@ -1351,8 +1352,22 @@
vl->vars = strlist__new(true, NULL);
if (vl->vars == NULL)
return -ENOMEM;
+ af->child = true;
die_find_child(sp_die, collect_variables_cb, (void *)af, &die_mem);
+ /* Find external variables */
+ if (!af->externs)
+ goto out;
+ /* Don't need to search child DIE for externs. */
+ af->child = false;
+ nscopes = dwarf_getscopes_die(sp_die, &scopes);
+ while (nscopes-- > 1)
+ die_find_child(&scopes[nscopes], collect_variables_cb,
+ (void *)af, &die_mem);
+ if (scopes)
+ free(scopes);
+
+out:
if (strlist__empty(vl->vars)) {
strlist__delete(vl->vars);
vl->vars = NULL;
@@ -1363,11 +1378,12 @@
/* Find available variables at given probe point */
int find_available_vars_at(int fd, struct perf_probe_event *pev,
- struct variable_list **vls, int max_vls)
+ struct variable_list **vls, int max_vls,
+ bool externs)
{
struct available_var_finder af = {
.pf = {.pev = pev, .callback = add_available_vars},
- .max_vls = max_vls};
+ .max_vls = max_vls, .externs = externs};
int ret;
/* Allocate result vls array */
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index baffd25..516912a 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -30,7 +30,8 @@
/* Find available variables */
extern int find_available_vars_at(int fd, struct perf_probe_event *pev,
- struct variable_list **vls, int max_points);
+ struct variable_list **vls, int max_points,
+ bool externs);
#include <dwarf.h>
#include <libdw.h>
@@ -70,6 +71,8 @@
struct variable_list *vls; /* Found variable lists */
int nvls; /* Number of variable lists */
int max_vls; /* Max no. of variable lists */
+ bool externs; /* Find external vars too */
+ bool child; /* Search child scopes */
};
struct line_finder {