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Commit e16b35dd authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware)
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ftrace: Add helper function ftrace_hash_move_and_update_ops() 



The processes of updating a ops filter_hash is a bit complex, and requires
setting up an old hash to perform the update. This is done exactly the same
in two locations for the same reasons. Create a helper function that does it
in one place.

Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 1a48df00

kernel/trace/ftrace.c

+53 −52
Original line number Diff line number Diff line
@@ -3674,6 +3674,56 @@ ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) 
	return match_records(hash, buff, len, NULL);

}



static void ftrace_ops_update_code(struct ftrace_ops *ops,

				   struct ftrace_ops_hash *old_hash)

{

	struct ftrace_ops *op;



	if (!ftrace_enabled)

		return;



	if (ops->flags & FTRACE_OPS_FL_ENABLED) {

		ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);

		return;

	}



	/*

	 * If this is the shared global_ops filter, then we need to

	 * check if there is another ops that shares it, is enabled.

	 * If so, we still need to run the modify code.

	 */

	if (ops->func_hash != &global_ops.local_hash)

		return;



	do_for_each_ftrace_op(op, ftrace_ops_list) {

		if (op->func_hash == &global_ops.local_hash &&

		    op->flags & FTRACE_OPS_FL_ENABLED) {

			ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);

			/* Only need to do this once */

			return;

		}

	} while_for_each_ftrace_op(op);

}



static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,

					   struct ftrace_hash **orig_hash,

					   struct ftrace_hash *hash,

					   int enable)

{

	struct ftrace_ops_hash old_hash_ops;

	struct ftrace_hash *old_hash;

	int ret;



	old_hash = *orig_hash;

	old_hash_ops.filter_hash = ops->func_hash->filter_hash;

	old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;

	ret = ftrace_hash_move(ops, enable, orig_hash, hash);

	if (!ret) {

		ftrace_ops_update_code(ops, &old_hash_ops);

		free_ftrace_hash_rcu(old_hash);

	}

	return ret;

}



/*

 * We register the module command as a template to show others how
@@ -4306,44 +4356,11 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) 
	return add_hash_entry(hash, ip);

}



static void ftrace_ops_update_code(struct ftrace_ops *ops,

				   struct ftrace_ops_hash *old_hash)

{

	struct ftrace_ops *op;



	if (!ftrace_enabled)

		return;



	if (ops->flags & FTRACE_OPS_FL_ENABLED) {

		ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);

		return;

	}



	/*

	 * If this is the shared global_ops filter, then we need to

	 * check if there is another ops that shares it, is enabled.

	 * If so, we still need to run the modify code.

	 */

	if (ops->func_hash != &global_ops.local_hash)

		return;



	do_for_each_ftrace_op(op, ftrace_ops_list) {

		if (op->func_hash == &global_ops.local_hash &&

		    op->flags & FTRACE_OPS_FL_ENABLED) {

			ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);

			/* Only need to do this once */

			return;

		}

	} while_for_each_ftrace_op(op);

}



static int

ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,

		unsigned long ip, int remove, int reset, int enable)

{

	struct ftrace_hash **orig_hash;

	struct ftrace_ops_hash old_hash_ops;

	struct ftrace_hash *old_hash;

	struct ftrace_hash *hash;

	int ret;
@@ -4378,14 +4395,7 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, 
	}



	mutex_lock(&ftrace_lock);

	old_hash = *orig_hash;

	old_hash_ops.filter_hash = ops->func_hash->filter_hash;

	old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;

	ret = ftrace_hash_move(ops, enable, orig_hash, hash);

	if (!ret) {

		ftrace_ops_update_code(ops, &old_hash_ops);

		free_ftrace_hash_rcu(old_hash);

	}

	ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);

	mutex_unlock(&ftrace_lock);



 out_regex_unlock:
@@ -4624,10 +4634,8 @@ static void __init set_ftrace_early_filters(void) 
int ftrace_regex_release(struct inode *inode, struct file *file)

{

	struct seq_file *m = (struct seq_file *)file->private_data;

	struct ftrace_ops_hash old_hash_ops;

	struct ftrace_iterator *iter;

	struct ftrace_hash **orig_hash;

	struct ftrace_hash *old_hash;

	struct trace_parser *parser;

	int filter_hash;

	int ret;
@@ -4657,15 +4665,8 @@ int ftrace_regex_release(struct inode *inode, struct file *file) 
			orig_hash = &iter->ops->func_hash->notrace_hash;



		mutex_lock(&ftrace_lock);

		old_hash = *orig_hash;

		old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash;

		old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash;

		ret = ftrace_hash_move(iter->ops, filter_hash,

				       orig_hash, iter->hash);

		if (!ret) {

			ftrace_ops_update_code(iter->ops, &old_hash_ops);

			free_ftrace_hash_rcu(old_hash);

		}

		ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,

						      iter->hash, filter_hash);

		mutex_unlock(&ftrace_lock);

	} else {

		/* For read only, the hash is the ops hash */