Commit 600b18f8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing fixes from Steven Rostedt:
 "Two locking fixes:

   - Add mutex protection to ring_buffer_reset()

   - Fix deadlock in modify_ftrace_direct_multi()"

* tag 'trace-v5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/direct: Fix lockup in modify_ftrace_direct_multi
  ring-buffer: Protect ring_buffer_reset() from reentrancy
parents f54ca91f 2e6e9058

kernel/trace/ftrace.c

+2 −1
Original line number Diff line number Diff line
@@ -5602,10 +5602,11 @@ int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 
		}

	}



	mutex_unlock(&ftrace_lock);



	/* Removing the tmp_ops will add the updated direct callers to the functions */

	unregister_ftrace_function(&tmp_ops);



	mutex_unlock(&ftrace_lock);

 out_direct:

	mutex_unlock(&direct_mutex);

	return err;

kernel/trace/ring_buffer.c

+5 −0
Original line number Diff line number Diff line
@@ -5228,6 +5228,9 @@ void ring_buffer_reset(struct trace_buffer *buffer) 
	struct ring_buffer_per_cpu *cpu_buffer;

	int cpu;



	/* prevent another thread from changing buffer sizes */

	mutex_lock(&buffer->mutex);



	for_each_buffer_cpu(buffer, cpu) {

		cpu_buffer = buffer->buffers[cpu];
@@ -5246,6 +5249,8 @@ void ring_buffer_reset(struct trace_buffer *buffer) 
		atomic_dec(&cpu_buffer->record_disabled);

		atomic_dec(&cpu_buffer->resize_disabled);

	}



	mutex_unlock(&buffer->mutex);

}

EXPORT_SYMBOL_GPL(ring_buffer_reset);