perf probe: Search concrete out-of-line instances

gcc 4.6 generates a concrete out-of-line instance when there is a function which is implicitly inlined somewhere but also has its own instance. The concrete out-of-line instance means that it has an abstract origin of the function which is referred by not only inlined-subroutines but also a concrete subprogram. Since current dwarf_func_inline_instances() can find only instances of inlined-subroutines, this introduces new die_walk_instances() to find both of subprogram and inlined-subroutines. e.g. without this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg perf probe failed to find actual subprogram instance of sched_group_rt_period(). With this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg @<sched_group_rt_period+0> struct task_group* tg Now it found the sched_group_rt_period() itself. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf probe: Search concrete out-of-line instances
gcc 4.6 generates a concrete out-of-line instance when there is a function which is implicitly inlined somewhere but also has its own instance. The concrete out-of-line instance means that it has an abstract origin of the function which is referred by not only inlined-subroutines but also a concrete subprogram. Since current dwarf_func_inline_instances() can find only instances of inlined-subroutines, this introduces new die_walk_instances() to find both of subprogram and inlined-subroutines. e.g. without this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg perf probe failed to find actual subprogram instance of sched_group_rt_period(). With this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg @<sched_group_rt_period+0> struct task_group* tg Now it found the sched_group_rt_period() itself. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Masami Hiramatsu · Arnaldo Carvalho de Melo
1 parent f182e3e13c
Showing 3 changed files with 83 additions and 35 deletions Side-by-side Diff
tools/perf/util/dwarf-aux.c
tools/perf/util/dwarf-aux.h
tools/perf/util/probe-finder.c
@@ -453,6 +453,64 @@
 	return die_mem;
 }
  
+struct __instance_walk_param {
+	void    *addr;
+	int	(*callback)(Dwarf_Die *, void *);
+	void    *data;
+	int	retval;
+};
+
+static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
+{
+	struct __instance_walk_param *iwp = data;
+	Dwarf_Attribute attr_mem;
+	Dwarf_Die origin_mem;
+	Dwarf_Attribute *attr;
+	Dwarf_Die *origin;
+
+	attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
+	if (attr == NULL)
+		return DIE_FIND_CB_CONTINUE;
+
+	origin = dwarf_formref_die(attr, &origin_mem);
+	if (origin == NULL || origin->addr != iwp->addr)
+		return DIE_FIND_CB_CONTINUE;
+
+	iwp->retval = iwp->callback(inst, iwp->data);
+
+	return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
+}
+
+/**
+ * die_walk_instances - Walk on instances of given DIE
+ * @or_die: an abstract original DIE
+ * @callback: a callback function which is called with instance DIE
+ * @data: user data
+ *
+ * Walk on the instances of give @in_die. @in_die must be an inlined function
+ * declartion. This returns the return value of @callback if it returns
+ * non-zero value, or -ENOENT if there is no instance.
+ */
+int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
+		       void *data)
+{
+	Dwarf_Die cu_die;
+	Dwarf_Die die_mem;
+	struct __instance_walk_param iwp = {
+		.addr = or_die->addr,
+		.callback = callback,
+		.data = data,
+		.retval = -ENOENT,
+	};
+
+	if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
+		return -ENOENT;
+
+	die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
+
+	return iwp.retval;
+}
+
 /* Line walker internal parameters */
 struct __line_walk_param {
 	bool recursive;
@@ -80,6 +80,10 @@
 extern Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
 				      Dwarf_Die *die_mem);
  
+/* Walk on the instances of given DIE */
+extern int die_walk_instances(Dwarf_Die *in_die,
+			      int (*callback)(Dwarf_Die *, void *), void *data);
+
 /* Walker on lines (Note: line number will not be sorted) */
 typedef int (* line_walk_callback_t) (const char *fname, int lineno,
 				      Dwarf_Addr addr, void *data);
@@ -924,42 +924,39 @@
 	return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
 }
  
-/* Callback parameter with return value */
-struct dwarf_callback_param {
-	void *data;
-	int retval;
-};
-
 static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
 {
-	struct dwarf_callback_param *param = data;
-	struct probe_finder *pf = param->data;
+	struct probe_finder *pf = data;
 	struct perf_probe_point *pp = &pf->pev->point;
 	Dwarf_Addr addr;
+	int ret;
  
 	if (pp->lazy_line)
-		param->retval = find_probe_point_lazy(in_die, pf);
+		ret = find_probe_point_lazy(in_die, pf);
 	else {
 		/* Get probe address */
 		if (dwarf_entrypc(in_die, &addr) != 0) {
 			pr_warning("Failed to get entry address of %s.\n",
 				   dwarf_diename(in_die));
-			param->retval = -ENOENT;
-			return DWARF_CB_ABORT;
+			return -ENOENT;
 		}
 		pf->addr = addr;
 		pf->addr += pp->offset;
 		pr_debug("found inline addr: 0x%jx\n",
 			 (uintmax_t)pf->addr);
  
-		param->retval = call_probe_finder(in_die, pf);
-		if (param->retval < 0)
-			return DWARF_CB_ABORT;
+		ret = call_probe_finder(in_die, pf);
 	}
  
-	return DWARF_CB_OK;
+	return ret;
 }
  
+/* Callback parameter with return value for libdw */
+struct dwarf_callback_param {
+	void *data;
+	int retval;
+};
+
 /* Search function from function name */
 static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
 {
  
@@ -996,14 +993,10 @@
 			/* TODO: Check the address in this function */
 			param->retval = call_probe_finder(sp_die, pf);
 		}
-	} else {
-		struct dwarf_callback_param _param = {.data = (void *)pf,
-						      .retval = 0};
+	} else
 		/* Inlined function: search instances */
-		dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
-					    &_param);
-		param->retval = _param.retval;
-	}
+		param->retval = die_walk_instances(sp_die,
+					probe_point_inline_cb, (void *)pf);
  
 	return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
 }
  
  
@@ -1452,16 +1445,14 @@
  
 static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
 {
-	struct dwarf_callback_param *param = data;
+	find_line_range_by_line(in_die, data);
  
-	param->retval = find_line_range_by_line(in_die, param->data);
-
 	/*
 	 * We have to check all instances of inlined function, because
 	 * some execution paths can be optimized out depends on the
 	 * function argument of instances
 	 */
-	return DWARF_CB_OK;
+	return 0;
 }
  
 /* Search function from function name */
@@ -1489,15 +1480,10 @@
 		pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
 		lr->start = lf->lno_s;
 		lr->end = lf->lno_e;
-		if (dwarf_func_inline(sp_die)) {
-			struct dwarf_callback_param _param;
-			_param.data = (void *)lf;
-			_param.retval = 0;
-			dwarf_func_inline_instances(sp_die,
-						    line_range_inline_cb,
-						    &_param);
-			param->retval = _param.retval;
-		} else
+		if (dwarf_func_inline(sp_die))
+			param->retval = die_walk_instances(sp_die,
+						line_range_inline_cb, lf);
+		else
 			param->retval = find_line_range_by_line(sp_die, lf);
 		return DWARF_CB_ABORT;
 	}
...	...	@@ -453,6 +453,64 @@
453	453	return die_mem;
454	454	}
455	455
	456	+struct __instance_walk_param {
	457	+ void *addr;
	458	+ int (callback)(Dwarf_Die , void *);
	459	+ void *data;
	460	+ int retval;
	461	+};
	462	+
	463	+static int __die_walk_instances_cb(Dwarf_Die inst, void data)
	464	+{
	465	+ struct __instance_walk_param *iwp = data;
	466	+ Dwarf_Attribute attr_mem;
	467	+ Dwarf_Die origin_mem;
	468	+ Dwarf_Attribute *attr;
	469	+ Dwarf_Die *origin;
	470	+
	471	+ attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
	472	+ if (attr == NULL)
	473	+ return DIE_FIND_CB_CONTINUE;
	474	+
	475	+ origin = dwarf_formref_die(attr, &origin_mem);
	476	+ if (origin == NULL \|\| origin->addr != iwp->addr)
	477	+ return DIE_FIND_CB_CONTINUE;
	478	+
	479	+ iwp->retval = iwp->callback(inst, iwp->data);
	480	+
	481	+ return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
	482	+}
	483	+
	484	+/**
	485	+ * die_walk_instances - Walk on instances of given DIE
	486	+ * @or_die: an abstract original DIE
	487	+ * @callback: a callback function which is called with instance DIE
	488	+ * @data: user data
	489	+ *
	490	+ * Walk on the instances of give @in_die. @in_die must be an inlined function
	491	+ * declartion. This returns the return value of @callback if it returns
	492	+ * non-zero value, or -ENOENT if there is no instance.
	493	+ */
	494	+int die_walk_instances(Dwarf_Die or_die, int (callback)(Dwarf_Die , void ),
	495	+ void *data)
	496	+{
	497	+ Dwarf_Die cu_die;
	498	+ Dwarf_Die die_mem;
	499	+ struct __instance_walk_param iwp = {
	500	+ .addr = or_die->addr,
	501	+ .callback = callback,
	502	+ .data = data,
	503	+ .retval = -ENOENT,
	504	+ };
	505	+
	506	+ if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
	507	+ return -ENOENT;
	508	+
	509	+ die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
	510	+
	511	+ return iwp.retval;
	512	+}
	513	+
456	514	/* Line walker internal parameters */
457	515	struct __line_walk_param {
458	516	bool recursive;
...	...	@@ -80,6 +80,10 @@
80	80	extern Dwarf_Die die_find_inlinefunc(Dwarf_Die sp_die, Dwarf_Addr addr,
81	81	Dwarf_Die *die_mem);
82	82
	83	+/* Walk on the instances of given DIE */
	84	+extern int die_walk_instances(Dwarf_Die *in_die,
	85	+ int (callback)(Dwarf_Die , void ), void data);
	86	+
83	87	/* Walker on lines (Note: line number will not be sorted) */
84	88	typedef int (* line_walk_callback_t) (const char *fname, int lineno,
85	89	Dwarf_Addr addr, void *data);
...	...	@@ -924,42 +924,39 @@
924	924	return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
925	925	}
926	926
927		-/* Callback parameter with return value */
928		-struct dwarf_callback_param {
929		- void *data;
930		- int retval;
931		-};
932		-
933	927	static int probe_point_inline_cb(Dwarf_Die in_die, void data)
934	928	{
935		- struct dwarf_callback_param *param = data;
936		- struct probe_finder *pf = param->data;
	929	+ struct probe_finder *pf = data;
937	930	struct perf_probe_point *pp = &pf->pev->point;
938	931	Dwarf_Addr addr;
	932	+ int ret;
939	933
940	934	if (pp->lazy_line)
941		- param->retval = find_probe_point_lazy(in_die, pf);
	935	+ ret = find_probe_point_lazy(in_die, pf);
942	936	else {
943	937	/* Get probe address */
944	938	if (dwarf_entrypc(in_die, &addr) != 0) {
945	939	pr_warning("Failed to get entry address of %s.\n",
946	940	dwarf_diename(in_die));
947		- param->retval = -ENOENT;
948		- return DWARF_CB_ABORT;
	941	+ return -ENOENT;
949	942	}
950	943	pf->addr = addr;
951	944	pf->addr += pp->offset;
952	945	pr_debug("found inline addr: 0x%jx\n",
953	946	(uintmax_t)pf->addr);
954	947
955		- param->retval = call_probe_finder(in_die, pf);
956		- if (param->retval < 0)
957		- return DWARF_CB_ABORT;
	948	+ ret = call_probe_finder(in_die, pf);
958	949	}
959	950
960		- return DWARF_CB_OK;
	951	+ return ret;
961	952	}
962	953
	954	+/* Callback parameter with return value for libdw */
	955	+struct dwarf_callback_param {
	956	+ void *data;
	957	+ int retval;
	958	+};
	959	+
963	960	/* Search function from function name */
964	961	static int probe_point_search_cb(Dwarf_Die sp_die, void data)
965	962	{
966	963
...	...	@@ -996,14 +993,10 @@
996	993	/* TODO: Check the address in this function */
997	994	param->retval = call_probe_finder(sp_die, pf);
998	995	}
999		- } else {
1000		- struct dwarf_callback_param _param = {.data = (void *)pf,
1001		- .retval = 0};
	996	+ } else
1002	997	/* Inlined function: search instances */
1003		- dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
1004		- &_param);
1005		- param->retval = _param.retval;
1006		- }
	998	+ param->retval = die_walk_instances(sp_die,
	999	+ probe_point_inline_cb, (void *)pf);
1007	1000
1008	1001	return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
1009	1002	}
1010	1003
1011	1004
...	...	@@ -1452,16 +1445,14 @@
1452	1445
1453	1446	static int line_range_inline_cb(Dwarf_Die in_die, void data)
1454	1447	{
1455		- struct dwarf_callback_param *param = data;
	1448	+ find_line_range_by_line(in_die, data);
1456	1449
1457		- param->retval = find_line_range_by_line(in_die, param->data);
1458		-
1459	1450	/*
1460	1451	* We have to check all instances of inlined function, because
1461	1452	* some execution paths can be optimized out depends on the
1462	1453	* function argument of instances
1463	1454	*/
1464		- return DWARF_CB_OK;
	1455	+ return 0;
1465	1456	}
1466	1457
1467	1458	/* Search function from function name */
...	...	@@ -1489,15 +1480,10 @@
1489	1480	pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
1490	1481	lr->start = lf->lno_s;
1491	1482	lr->end = lf->lno_e;
1492		- if (dwarf_func_inline(sp_die)) {
1493		- struct dwarf_callback_param _param;
1494		- _param.data = (void *)lf;
1495		- _param.retval = 0;
1496		- dwarf_func_inline_instances(sp_die,
1497		- line_range_inline_cb,
1498		- &_param);
1499		- param->retval = _param.retval;
1500		- } else
	1483	+ if (dwarf_func_inline(sp_die))
	1484	+ param->retval = die_walk_instances(sp_die,
	1485	+ line_range_inline_cb, lf);
	1486	+ else
1501	1487	param->retval = find_line_range_by_line(sp_die, lf);
1502	1488	return DWARF_CB_ABORT;
1503	1489	}