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Commit 84261912 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
Browse files

ftrace: Update all ftrace_ops for a ftrace_hash_ops update 



When updating what an ftrace_ops traces, if it is registered (that is,
actively tracing), and that ftrace_ops uses the shared global_ops
local_hash, then we need to update all tracers that are active and
also share the global_ops' ftrace_hash_ops.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 33b7f99c

kernel/trace/ftrace.c

+39 −4
Original line number Diff line number Diff line
@@ -1292,9 +1292,9 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) 
}



static void

ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);

ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);

static void

ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);

ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);



static int

ftrace_hash_move(struct ftrace_ops *ops, int enable,
@@ -1346,13 +1346,13 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, 
	 * Remove the current set, update the hash and add

	 * them back.

	 */

	ftrace_hash_rec_disable(ops, enable);

	ftrace_hash_rec_disable_modify(ops, enable);



	old_hash = *dst;

	rcu_assign_pointer(*dst, new_hash);

	free_ftrace_hash_rcu(old_hash);



	ftrace_hash_rec_enable(ops, enable);

	ftrace_hash_rec_enable_modify(ops, enable);



	return 0;

}
@@ -1686,6 +1686,41 @@ static void ftrace_hash_rec_enable(struct ftrace_ops *ops, 
	__ftrace_hash_rec_update(ops, filter_hash, 1);

}



static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,

					  int filter_hash, int inc)

{

	struct ftrace_ops *op;



	__ftrace_hash_rec_update(ops, filter_hash, inc);



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

		return;



	/*

	 * If the ops shares the global_ops hash, then we need to update

	 * all ops that are enabled and use this hash.

	 */

	do_for_each_ftrace_op(op, ftrace_ops_list) {

		/* Already done */

		if (op == ops)

			continue;

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

			__ftrace_hash_rec_update(op, filter_hash, inc);

	} while_for_each_ftrace_op(op);

}



static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,

					   int filter_hash)

{

	ftrace_hash_rec_update_modify(ops, filter_hash, 0);

}



static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,

					  int filter_hash)

{

	ftrace_hash_rec_update_modify(ops, filter_hash, 1);

}



static void print_ip_ins(const char *fmt, unsigned char *p)

{

	int i;