Commit 1ec3a81a authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
Browse files

ftrace: Have each function probe use its own ftrace_ops 



Have the function probes have their own ftrace_ops, and remove the
trace_probe_ops. This simplifies some of the ftrace infrastructure code.

Individual entries for each function is still allocated for the use of the
output for set_ftrace_filter, but they will be removed soon too.

Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent d3d532d7

kernel/trace/ftrace.c

+98 −148
Original line number Diff line number Diff line
@@ -3789,63 +3789,6 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, 
	preempt_enable_notrace();

}



static struct ftrace_ops trace_probe_ops __read_mostly =

{

	.func		= function_trace_probe_call,

	.flags		= FTRACE_OPS_FL_INITIALIZED,

	INIT_OPS_HASH(trace_probe_ops)

};



static int ftrace_probe_registered;



static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash)

{

	int ret;

	int i;



	if (ftrace_probe_registered) {

		/* still need to update the function call sites */

		if (ftrace_enabled)

			ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,

					       old_hash);

		return;

	}



	for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {

		struct hlist_head *hhd = &ftrace_func_hash[i];

		if (hhd->first)

			break;

	}

	/* Nothing registered? */

	if (i == FTRACE_FUNC_HASHSIZE)

		return;



	ret = ftrace_startup(&trace_probe_ops, 0);



	ftrace_probe_registered = 1;

}



static bool __disable_ftrace_function_probe(void)

{

	int i;



	if (!ftrace_probe_registered)

		return false;



	for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {

		struct hlist_head *hhd = &ftrace_func_hash[i];

		if (hhd->first)

			return false;

	}



	/* no more funcs left */

	ftrace_shutdown(&trace_probe_ops, 0);



	ftrace_probe_registered = 0;

	return true;

}





static void ftrace_free_entry(struct ftrace_func_probe *entry)

{

	if (entry->ops->free)
@@ -3998,108 +3941,108 @@ int 
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,

			       void *data)

{

	struct ftrace_ops_hash old_hash_ops;

	struct ftrace_func_probe *entry;

	struct ftrace_glob func_g;

	struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;

	struct ftrace_hash *old_hash = *orig_hash;

	struct ftrace_func_entry *entry;

	struct ftrace_func_probe *probe;

	struct ftrace_hash **orig_hash;

	struct ftrace_hash *old_hash;

	struct ftrace_hash *hash;

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	int not;

	struct hlist_head hl;

	struct hlist_node *n;

	unsigned long key;

	int count = 0;

	int size;

	int ret;

	int i;



	func_g.type = filter_parse_regex(glob, strlen(glob),

			&func_g.search, &not);

	func_g.len = strlen(func_g.search);



	/* we do not support '!' for function probes */

	if (WARN_ON(not))

	/* We do not support '!' for function probes */

	if (WARN_ON(glob[0] == '!'))

		return -EINVAL;



	mutex_lock(&trace_probe_ops.func_hash->regex_lock);

	if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED)) {

		ops->ops.func = function_trace_probe_call;

		ftrace_ops_init(&ops->ops);

	}



	old_hash_ops.filter_hash = old_hash;

	/* Probes only have filters */

	old_hash_ops.notrace_hash = NULL;

	mutex_lock(&ops->ops.func_hash->regex_lock);



	orig_hash = &ops->ops.func_hash->filter_hash;

	old_hash = *orig_hash;

	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);

	if (!hash) {

		count = -ENOMEM;

		goto out;

	}



	if (unlikely(ftrace_disabled)) {

		count = -ENODEV;

		goto out;

	}

	ret = ftrace_match_records(hash, glob, strlen(glob));



	mutex_lock(&ftrace_lock);

	/* Nothing found? */

	if (!ret)

		ret = -EINVAL;



	do_for_each_ftrace_rec(pg, rec) {

	if (ret < 0)

		goto out;



		if (rec->flags & FTRACE_FL_DISABLED)

			continue;

	INIT_HLIST_HEAD(&hl);



		if (!ftrace_match_record(rec, &func_g, NULL, 0))

	size = 1 << hash->size_bits;

	for (i = 0; i < size; i++) {

		hlist_for_each_entry(entry, &hash->buckets[i], hlist) {

			if (ftrace_lookup_ip(old_hash, entry->ip))

				continue;



		entry = kmalloc(sizeof(*entry), GFP_KERNEL);

		if (!entry) {

			/* If we did not process any, then return error */

			if (!count)

			probe = kmalloc(sizeof(*probe), GFP_KERNEL);

			if (!probe) {

				count = -ENOMEM;

			goto out_unlock;

				goto err_free;

			}



		count++;



			probe->ops = ops;

			probe->ip = entry->ip;

			/*

			 * The caller might want to do something special

			 * for each function we find. We call the callback

			 * to give the caller an opportunity to do so.

			 */

		if (ops->init) {

			if (ops->init(ops, rec->ip, data) < 0) {

				/* caller does not like this func */

				kfree(entry);

				continue;

			}

			if (ops->init && ops->init(ops, entry->ip, data) < 0) {

				kfree(probe);

				goto err_free;

			}

			hlist_add_head(&probe->node, &hl);



		ret = enter_record(hash, rec, 0);

		if (ret < 0) {

			kfree(entry);

			count = ret;

			goto out_unlock;

			count++;

		}

	}



		entry->ops = ops;

		entry->ip = rec->ip;

	mutex_lock(&ftrace_lock);



		key = hash_long(entry->ip, FTRACE_HASH_BITS);

		hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);

	ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash,

						      hash, 1);

	if (ret < 0)

		goto err_free_unlock;



	} while_for_each_ftrace_rec();

	hlist_for_each_entry_safe(probe, n, &hl, node) {

		hlist_del(&probe->node);

		key = hash_long(probe->ip, FTRACE_HASH_BITS);

		hlist_add_head_rcu(&probe->node, &ftrace_func_hash[key]);

	}



	ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);

	if (!(ops->ops.flags & FTRACE_OPS_FL_ENABLED))

		ret = ftrace_startup(&ops->ops, 0);



	__enable_ftrace_function_probe(&old_hash_ops);

	mutex_unlock(&ftrace_lock);



	if (!ret)

		free_ftrace_hash_rcu(old_hash);

	else

		count = ret;



 out_unlock:

	mutex_unlock(&ftrace_lock);

		ret = count;

 out:

	mutex_unlock(&trace_probe_ops.func_hash->regex_lock);

	mutex_unlock(&ops->ops.func_hash->regex_lock);

	free_ftrace_hash(hash);



	return count;

	return ret;



 err_free_unlock:

	mutex_unlock(&ftrace_lock);

 err_free:

	hlist_for_each_entry_safe(probe, n, &hl, node) {

		hlist_del(&probe->node);

		if (ops->free)

			ops->free(ops, probe->ip, NULL);

		kfree(probe);

	}

	goto out;

}



int
@@ -4110,14 +4053,16 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) 
	struct ftrace_func_probe *entry;

	struct ftrace_func_probe *p;

	struct ftrace_glob func_g;

	struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;

	struct ftrace_hash *old_hash = *orig_hash;

	struct ftrace_hash **orig_hash;

	struct ftrace_hash *old_hash;

	struct list_head free_list;

	struct ftrace_hash *hash;

	struct ftrace_hash *hash = NULL;

	struct hlist_node *tmp;

	char str[KSYM_SYMBOL_LEN];

	int i, ret;

	bool disabled;



	if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED))

		return -EINVAL;



	if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))

		func_g.search = NULL;
@@ -4134,14 +4079,21 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) 
			return -EINVAL;

	}



	mutex_lock(&trace_probe_ops.func_hash->regex_lock);

	mutex_lock(&ops->ops.func_hash->regex_lock);



	orig_hash = &ops->ops.func_hash->filter_hash;

	old_hash = *orig_hash;



	ret = -EINVAL;

	if (ftrace_hash_empty(old_hash))

		goto out_unlock;



	old_hash_ops.filter_hash = old_hash;

	/* Probes only have filters */

	old_hash_ops.notrace_hash = NULL;



	ret = -ENOMEM;

	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);

	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);

	if (!hash)

		goto out_unlock;
@@ -4181,20 +4133,18 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) 
	}



	mutex_lock(&ftrace_lock);

	disabled = __disable_ftrace_function_probe();

	/*

	 * Remove after the disable is called. Otherwise, if the last

	 * probe is removed, a null hash means *all enabled*.

	 */

	ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);



	if (ftrace_hash_empty(hash))

		ftrace_shutdown(&ops->ops, 0);



	ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash,

					      hash, 1);



	/* still need to update the function call sites */

	if (ftrace_enabled && !disabled)

		ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,

	if (ftrace_enabled && !ftrace_hash_empty(hash))

		ftrace_run_modify_code(&ops->ops, FTRACE_UPDATE_CALLS,

				       &old_hash_ops);

	synchronize_sched();

	if (!ret)

		free_ftrace_hash_rcu(old_hash);



	list_for_each_entry_safe(entry, p, &free_list, free_list) {

		list_del(&entry->free_list);
@@ -4203,7 +4153,7 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) 
	mutex_unlock(&ftrace_lock);



 out_unlock:

	mutex_unlock(&trace_probe_ops.func_hash->regex_lock);

	mutex_unlock(&ops->ops.func_hash->regex_lock);

	free_ftrace_hash(hash);

	return ret;

}

kernel/trace/trace.h

+1 −0
Original line number Diff line number Diff line
@@ -932,6 +932,7 @@ static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { 
#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)



struct ftrace_probe_ops {

	struct ftrace_ops	ops;

	void			(*func)(unsigned long ip,

					unsigned long parent_ip,

					struct ftrace_probe_ops *ops,

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