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Date: Thu, 21 Apr 2011 12:40:58 +0200
From: Jiri Olsa <jolsa@...hat.com>
To: rostedt@...dmis.org, fweisbec@...il.com, mingo@...hat.com,
a.p.zijlstra@...llo.nl
Cc: linux-kernel@...r.kernel.org
Subject: [RFC,PATCH 3/3] trace,perf: add filter support for ftrace/function tracepoint event
Added support to be able to pass "ip == glob" filter for the ftrace/function
tracepoint.
Respective functions are hot-patched/updated when the filter is set,
and the filter predicate is set to be allways true. Probably missing
several cases.. not sure this is the way.
wbr,
jirka
---
include/linux/ftrace_event.h | 3 ++
kernel/trace/ftrace.c | 35 ++++++++++++++++++++++++++++
kernel/trace/trace.h | 2 +
kernel/trace/trace_events_filter.c | 45 ++++++++++++++++++++++++++++++++---
kernel/trace/trace_export.c | 26 ++++++++++++++++----
5 files changed, 102 insertions(+), 9 deletions(-)
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 22b32af..bbf7cc6 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -144,6 +144,8 @@ struct ftrace_event_class {
struct list_head *(*get_fields)(struct ftrace_event_call *);
struct list_head fields;
int (*raw_init)(struct ftrace_event_call *);
+ void (*filter)(struct ftrace_event_call *call,
+ int enable);
};
extern int ftrace_event_reg(struct ftrace_event_call *event,
@@ -221,6 +223,7 @@ enum {
FILTER_STATIC_STRING,
FILTER_DYN_STRING,
FILTER_PTR_STRING,
+ FILTER_TRACE_FN,
};
#define EVENT_STORAGE_SIZE 128
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 49fbc8c..b52db6e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3285,6 +3285,41 @@ int ftrace_event_class_register(struct ftrace_event_call *call,
return -EINVAL;
}
+void ftrace_event_tracefn_filter(int enable)
+{
+ char *filter = event_function.data;
+
+ if (enable) {
+ WARN_ON(!filter);
+ if (filter)
+ ftrace_match_records(filter, strlen(filter), 1);
+ } else {
+ ftrace_filter_reset(1);
+ if (filter) {
+ kfree(filter);
+ event_function.data = NULL;
+ }
+ }
+
+ mutex_lock(&ftrace_lock);
+ if (ftrace_enabled)
+ ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+ mutex_unlock(&ftrace_lock);
+}
+
+void ftrace_event_class_filter(struct ftrace_event_call *call, int enable)
+{
+ int etype = call->event.type;
+
+ switch (etype) {
+ case TRACE_FN:
+ ftrace_event_tracefn_filter(enable);
+ break;
+ default:
+ break;
+ }
+}
+
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int ftrace_graph_active;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3298333..bc2537e 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -780,6 +780,8 @@ extern const char *__stop___trace_bprintk_fmt[];
extern int ftrace_event_class_register(struct ftrace_event_call *call,
enum trace_reg type);
+extern void ftrace_event_class_filter(struct ftrace_event_call *call,
+ int enable);
#undef FTRACE_ENTRY
#define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 8008ddc..5a847a5 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -238,6 +238,11 @@ static int filter_pred_none(struct filter_pred *pred, void *event)
return 0;
}
+static int filter_pred_all(struct filter_pred *pred, void *event)
+{
+ return 1;
+}
+
/*
* regex_match_foo - Basic regex callbacks
*
@@ -755,8 +760,23 @@ static void __free_preds(struct event_filter *filter)
filter->n_preds = 0;
}
+static void filter_enable(struct ftrace_event_call *call)
+{
+ struct ftrace_event_class *class = call->class;
+
+ call->flags |= TRACE_EVENT_FL_FILTERED;
+
+ if (class && class->filter)
+ class->filter(call, 1);
+}
+
static void filter_disable(struct ftrace_event_call *call)
{
+ struct ftrace_event_class *class = call->class;
+
+ if (class && class->filter)
+ class->filter(call, 0);
+
call->flags &= ~TRACE_EVENT_FL_FILTERED;
}
@@ -883,6 +903,11 @@ static bool is_string_field(struct ftrace_event_field *field)
field->filter_type == FILTER_PTR_STRING;
}
+static bool is_tracefn_field(struct ftrace_event_field *field)
+{
+ return field->filter_type == FILTER_TRACE_FN;
+}
+
static int is_legal_op(struct ftrace_event_field *field, int op)
{
if (is_string_field(field) &&
@@ -969,7 +994,15 @@ static int filter_add_pred(struct filter_parse_state *ps,
return -EINVAL;
}
- if (is_string_field(field)) {
+ if (is_tracefn_field(field)) {
+ /* allow only one function trace predicate */
+ if (call->data) {
+ parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0);
+ return -EINVAL;
+ }
+ fn = filter_pred_all;
+ call->data = kstrdup(pred->regex.pattern, GFP_KERNEL);
+ } else if (is_string_field(field)) {
filter_build_regex(pred);
if (field->filter_type == FILTER_STATIC_STRING) {
@@ -1760,7 +1793,7 @@ static int replace_system_preds(struct event_subsystem *system,
parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
append_filter_err(ps, filter);
} else
- call->flags |= TRACE_EVENT_FL_FILTERED;
+ filter_enable(call);
/*
* Regardless of if this returned an error, we still
* replace the filter for the call.
@@ -1853,7 +1886,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
filter_disable(call);
append_filter_err(ps, filter);
} else
- call->flags |= TRACE_EVENT_FL_FILTERED;
+ filter_enable(call);
out:
/*
* Always swap the call filter with the new filter
@@ -1965,6 +1998,8 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id,
if (&call->list == &ftrace_events)
goto out_unlock;
+ filter_disable(call);
+
err = -EEXIST;
if (event->filter)
goto out_unlock;
@@ -1986,8 +2021,10 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id,
goto free_ps;
err = replace_preds(call, filter, ps, filter_str, false);
- if (!err)
+ if (!err) {
+ filter_enable(call);
event->filter = filter;
+ }
free_ps:
filter_opstack_clear(ps);
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 0b0906a..b1d5301 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -67,7 +67,7 @@ static void __always_unused ____ftrace_check_##name(void) \
ret = trace_define_field(event_call, #type, #item, \
offsetof(typeof(field), item), \
sizeof(field.item), \
- is_signed_type(type), FILTER_OTHER); \
+ is_signed_type(type), filter_type); \
if (ret) \
return ret;
@@ -77,7 +77,7 @@ static void __always_unused ____ftrace_check_##name(void) \
offsetof(typeof(field), \
container.item), \
sizeof(field.container.item), \
- is_signed_type(type), FILTER_OTHER); \
+ is_signed_type(type), filter_type); \
if (ret) \
return ret;
@@ -91,7 +91,7 @@ static void __always_unused ____ftrace_check_##name(void) \
ret = trace_define_field(event_call, event_storage, #item, \
offsetof(typeof(field), item), \
sizeof(field.item), \
- is_signed_type(type), FILTER_OTHER); \
+ is_signed_type(type), filter_type); \
mutex_unlock(&event_storage_mutex); \
if (ret) \
return ret; \
@@ -104,7 +104,7 @@ static void __always_unused ____ftrace_check_##name(void) \
offsetof(typeof(field), \
container.item), \
sizeof(field.container.item), \
- is_signed_type(type), FILTER_OTHER); \
+ is_signed_type(type), filter_type); \
if (ret) \
return ret;
@@ -112,10 +112,24 @@ static void __always_unused ____ftrace_check_##name(void) \
#define __dynamic_array(type, item) \
ret = trace_define_field(event_call, #type, #item, \
offsetof(typeof(field), item), \
- 0, is_signed_type(type), FILTER_OTHER);\
+ 0, is_signed_type(type), filter_type); \
if (ret) \
return ret;
+#define FILTER_TYPE_TRACE_FN FILTER_TRACE_FN
+#define FILTER_TYPE_TRACE_GRAPH_ENT FILTER_OTHER
+#define FILTER_TYPE_TRACE_GRAPH_RET FILTER_OTHER
+#define FILTER_TYPE_TRACE_CTX FILTER_OTHER
+#define FILTER_TYPE_TRACE_WAKE FILTER_OTHER
+#define FILTER_TYPE_TRACE_STACK FILTER_OTHER
+#define FILTER_TYPE_TRACE_USER_STACK FILTER_OTHER
+#define FILTER_TYPE_TRACE_BPRINT FILTER_OTHER
+#define FILTER_TYPE_TRACE_PRINT FILTER_OTHER
+#define FILTER_TYPE_TRACE_MMIO_RW FILTER_OTHER
+#define FILTER_TYPE_TRACE_MMIO_MAP FILTER_OTHER
+#define FILTER_TYPE_TRACE_BRANCH FILTER_OTHER
+#define FILTER_TYPE(arg) FILTER_TYPE_##arg
+
#undef FTRACE_ENTRY
#define FTRACE_ENTRY(name, struct_name, id, tstruct, print) \
int \
@@ -123,6 +137,7 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call) \
{ \
struct struct_name field; \
int ret; \
+ int filter_type = FILTER_TYPE(id); \
\
tstruct; \
\
@@ -160,6 +175,7 @@ struct ftrace_event_class event_class_ftrace_##call = { \
.define_fields = ftrace_define_fields_##call, \
.fields = LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
.reg = ftrace_event_class_register, \
+ .filter = ftrace_event_class_filter, \
}; \
\
struct ftrace_event_call __used event_##call = { \
--
1.7.1
--
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