Commit 7d5b7cad authored by Jiri Olsa's avatar Jiri Olsa Committed by Steven Rostedt (VMware)
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ftrace: Use direct_ops hash in unregister_ftrace_direct 

Now when we have *direct_multi interface the direct_functions
hash is no longer owned just by direct_ops. It's also used by
any other ftrace_ops passed to *direct_multi interface.

Thus to find out that we are unregistering the last function
from direct_ops, we need to check directly direct_ops's hash.

Link: https://lkml.kernel.org/r/20211206182032.87248-2-jolsa@kernel.org



Cc: Ingo Molnar <mingo@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Fixes: f64dd462 ("ftrace: Add multi direct register/unregister interface")
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 48b27b6b

kernel/trace/ftrace.c

+3 −1
Original line number Diff line number Diff line
@@ -5217,6 +5217,7 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 
{

	struct ftrace_direct_func *direct;

	struct ftrace_func_entry *entry;

	struct ftrace_hash *hash;

	int ret = -ENODEV;



	mutex_lock(&direct_mutex);
@@ -5225,7 +5226,8 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 
	if (!entry)

		goto out_unlock;



	if (direct_functions->count == 1)

	hash = direct_ops.func_hash->filter_hash;

	if (hash->count == 1)

		unregister_ftrace_function(&direct_ops);



	ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0);