Commit 60b8f711 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (Google)
Browse files

tracing: Have the error of __tracing_resize_ring_buffer() passed to user 

Currently if __tracing_resize_ring_buffer() returns an error, the
tracing_resize_ringbuffer() returns -ENOMEM. But it may not be a memory
issue that caused the function to fail. If the ring buffer is memory
mapped, then the resizing of the ring buffer will be disabled. But if the
user tries to resize the buffer, it will get an -ENOMEM returned, which is
confusing because there is plenty of memory. The actual error returned was
-EBUSY, which would make much more sense to the user.

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250213134132.7e4505d7@gandalf.local.home


Fixes: 117c3920 ("ring-buffer: Introducing ring-buffer mapping functions")
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
parent 9ba0e175

kernel/trace/trace.c

+1 −7
Original line number Diff line number Diff line
@@ -5977,8 +5977,6 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, 
ssize_t tracing_resize_ring_buffer(struct trace_array *tr,

				  unsigned long size, int cpu_id)

{

	int ret;



	guard(mutex)(&trace_types_lock);



	if (cpu_id != RING_BUFFER_ALL_CPUS) {
@@ -5987,11 +5985,7 @@ ssize_t tracing_resize_ring_buffer(struct trace_array *tr, 
			return -EINVAL;

	}



	ret = __tracing_resize_ring_buffer(tr, size, cpu_id);

	if (ret < 0)

		ret = -ENOMEM;



	return ret;

	return __tracing_resize_ring_buffer(tr, size, cpu_id);

}



static void update_last_data(struct trace_array *tr)