[for-next][PATCH 27/33] tracing: Pass the trace_array into ftrace_probe_ops functions

From: Steven Rostedt
Date: Fri Apr 21 2017 - 17:38:38 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

Pass the trace_array associated to a ftrace_probe_ops into the probe_ops
func(), init() and free() functions. The trace_array is the descriptor that
describes a tracing instance. This will help create the infrastructure that
will allow having function probes unique to tracing instances.

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 13 +++++++++----
kernel/trace/trace.c | 14 ++++++++------
kernel/trace/trace.h | 3 +++
kernel/trace/trace_events.c | 16 +++++++++-------
kernel/trace/trace_functions.c | 35 ++++++++++++++++++++++-------------
5 files changed, 51 insertions(+), 30 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index ea208e93f000..e51cd6b51253 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3791,6 +3791,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)
{
struct ftrace_probe_ops *probe_ops;
+ struct trace_array *tr = op->private;

probe_ops = container_of(op, struct ftrace_probe_ops, ops);

@@ -3800,7 +3801,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
* on the hash. rcu_read_lock is too dangerous here.
*/
preempt_disable_notrace();
- probe_ops->func(ip, parent_ip, probe_ops, NULL);
+ probe_ops->func(ip, parent_ip, tr, probe_ops, NULL);
preempt_enable_notrace();
}

@@ -3969,6 +3970,7 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
ops->ops.func = function_trace_probe_call;
ftrace_ops_init(&ops->ops);
INIT_LIST_HEAD(&ops->list);
+ ops->ops.private = tr;
}

mutex_lock(&ops->ops.func_hash->regex_lock);
@@ -3997,7 +3999,7 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
* to give the caller an opportunity to do so.
*/
if (ops->init) {
- ret = ops->init(ops, entry->ip, data);
+ ret = ops->init(ops, tr, entry->ip, data);
if (ret < 0)
goto out;
}
@@ -4038,7 +4040,7 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
if (ftrace_lookup_ip(old_hash, entry->ip))
continue;
- ops->free(ops, entry->ip, NULL);
+ ops->free(ops, tr, entry->ip, NULL);
}
}
goto out_unlock;
@@ -4055,6 +4057,7 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
struct ftrace_hash *hash = NULL;
struct hlist_node *tmp;
struct hlist_head hhd;
+ struct trace_array *tr;
char str[KSYM_SYMBOL_LEN];
int i, ret;
int size;
@@ -4062,6 +4065,8 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED))
return -EINVAL;

+ tr = ops->ops.private;
+
if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
func_g.search = NULL;
else if (glob) {
@@ -4139,7 +4144,7 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
hlist_del(&entry->hlist);
if (ops->free)
- ops->free(ops, entry->ip, NULL);
+ ops->free(ops, tr, entry->ip, NULL);
kfree(entry);
}
mutex_unlock(&ftrace_lock);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 86598293787a..368310e78d45 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6736,14 +6736,16 @@ static const struct file_operations tracing_dyn_info_fops = {
#if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE)
static void
ftrace_snapshot(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
tracing_snapshot();
}

static void
ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
struct ftrace_func_mapper *mapper = ops->private_data;
long *count = NULL;
@@ -6785,8 +6787,8 @@ ftrace_snapshot_print(struct seq_file *m, unsigned long ip,
}

static int
-ftrace_snapshot_init(struct ftrace_probe_ops *ops, unsigned long ip,
- void *data)
+ftrace_snapshot_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void *data)
{
struct ftrace_func_mapper *mapper = ops->private_data;

@@ -6794,8 +6796,8 @@ ftrace_snapshot_init(struct ftrace_probe_ops *ops, unsigned long ip,
}

static void
-ftrace_snapshot_free(struct ftrace_probe_ops *ops, unsigned long ip,
- void **_data)
+ftrace_snapshot_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void **data)
{
struct ftrace_func_mapper *mapper = ops->private_data;

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 68ff25e4cb19..390761804886 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -943,11 +943,14 @@ struct ftrace_probe_ops {
struct list_head list;
void (*func)(unsigned long ip,
unsigned long parent_ip,
+ struct trace_array *tr,
struct ftrace_probe_ops *ops,
void **data);
int (*init)(struct ftrace_probe_ops *ops,
+ struct trace_array *tr,
unsigned long ip, void *data);
void (*free)(struct ftrace_probe_ops *ops,
+ struct trace_array *tr,
unsigned long ip, void **data);
int (*print)(struct seq_file *m,
unsigned long ip,
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f0d6e5aef53e..713bec614312 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2470,7 +2470,8 @@ static void update_event_probe(struct event_probe_data *data)

static void
event_enable_probe(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **_data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **_data)
{
struct ftrace_func_mapper *mapper = ops->private_data;
struct event_probe_data *data;
@@ -2486,7 +2487,8 @@ event_enable_probe(unsigned long ip, unsigned long parent_ip,

static void
event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **_data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **_data)
{
struct ftrace_func_mapper *mapper = ops->private_data;
struct event_probe_data *data;
@@ -2513,7 +2515,7 @@ event_enable_count_probe(unsigned long ip, unsigned long parent_ip,

static int
event_enable_print(struct seq_file *m, unsigned long ip,
- struct ftrace_probe_ops *ops, void *_data)
+ struct ftrace_probe_ops *ops, void *_data)
{
struct ftrace_func_mapper *mapper = ops->private_data;
struct event_probe_data *data;
@@ -2542,8 +2544,8 @@ event_enable_print(struct seq_file *m, unsigned long ip,
}

static int
-event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
- void *_data)
+event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void *_data)
{
struct ftrace_func_mapper *mapper = ops->private_data;
struct event_probe_data *data = _data;
@@ -2559,8 +2561,8 @@ event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
}

static void
-event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
- void **_data)
+event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void **_data)
{
struct ftrace_func_mapper *mapper = ops->private_data;
struct event_probe_data *data;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 2c8961b35401..797f087183c5 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -328,21 +328,24 @@ static void update_traceon_count(struct ftrace_probe_ops *ops,

static void
ftrace_traceon_count(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
update_traceon_count(ops, ip, 1);
}

static void
ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
update_traceon_count(ops, ip, 0);
}

static void
ftrace_traceon(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
if (tracing_is_on())
return;
@@ -352,7 +355,8 @@ ftrace_traceon(unsigned long ip, unsigned long parent_ip,

static void
ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
if (!tracing_is_on())
return;
@@ -371,14 +375,16 @@ ftrace_traceoff(unsigned long ip, unsigned long parent_ip,

static void
ftrace_stacktrace(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
trace_dump_stack(STACK_SKIP);
}

static void
ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
struct ftrace_func_mapper *mapper = ops->private_data;
long *count;
@@ -436,7 +442,8 @@ static int update_count(struct ftrace_probe_ops *ops, unsigned long ip)

static void
ftrace_dump_probe(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
if (update_count(ops, ip))
ftrace_dump(DUMP_ALL);
@@ -445,7 +452,8 @@ ftrace_dump_probe(unsigned long ip, unsigned long parent_ip,
/* Only dump the current CPU buffer. */
static void
ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip,
- struct ftrace_probe_ops *ops, void **data)
+ struct trace_array *tr, struct ftrace_probe_ops *ops,
+ void **data)
{
if (update_count(ops, ip))
ftrace_dump(DUMP_ORIG);
@@ -473,7 +481,8 @@ ftrace_probe_print(const char *name, struct seq_file *m,

static int
ftrace_traceon_print(struct seq_file *m, unsigned long ip,
- struct ftrace_probe_ops *ops, void *data)
+ struct ftrace_probe_ops *ops,
+ void *data)
{
return ftrace_probe_print("traceon", m, ip, ops);
}
@@ -508,8 +517,8 @@ ftrace_cpudump_print(struct seq_file *m, unsigned long ip,


static int
-ftrace_count_init(struct ftrace_probe_ops *ops, unsigned long ip,
- void *data)
+ftrace_count_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void *data)
{
struct ftrace_func_mapper *mapper = ops->private_data;

@@ -517,8 +526,8 @@ ftrace_count_init(struct ftrace_probe_ops *ops, unsigned long ip,
}

static void
-ftrace_count_free(struct ftrace_probe_ops *ops, unsigned long ip,
- void **_data)
+ftrace_count_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+ unsigned long ip, void **_data)
{
struct ftrace_func_mapper *mapper = ops->private_data;

--
2.10.2