linux-kernel - [PATCH v2 5/5] ring-buffer: Convert ring_buffer_write() to use guard(preempt

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Message-ID: <20250801203858.205479143@kernel.org>
Date: Fri, 01 Aug 2025 16:37:27 -0400
From: Steven Rostedt <rostedt@...nel.org>
To: linux-kernel@...r.kernel.org,
 linux-trace-kernel@...r.kernel.org
Cc: Masami Hiramatsu <mhiramat@...nel.org>,
 Mark Rutland <mark.rutland@....com>,
 Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
 Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH v2 5/5] ring-buffer: Convert ring_buffer_write() to use
 guard(preempt_notrace)

From: Steven Rostedt <rostedt@...dmis.org>

The function ring_buffer_write() has a goto out to only do a
preempt_enable_notrace(). This can be replaced by a guard.

Signed-off-by: Steven Rostedt (Google) <rostedt@...dmis.org>
---
 kernel/trace/ring_buffer.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 00fc38d70e86..9d7bf17fbfba 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4714,26 +4714,26 @@ int ring_buffer_write(struct trace_buffer *buffer,
 	int ret = -EBUSY;
 	int cpu;
 
-	preempt_disable_notrace();
+	guard(preempt_notrace)();
 
 	if (atomic_read(&buffer->record_disabled))
-		goto out;
+		return -EBUSY;
 
 	cpu = raw_smp_processor_id();
 
 	if (!cpumask_test_cpu(cpu, buffer->cpumask))
-		goto out;
+		return -EBUSY;
 
 	cpu_buffer = buffer->buffers[cpu];
 
 	if (atomic_read(&cpu_buffer->record_disabled))
-		goto out;
+		return -EBUSY;
 
 	if (length > buffer->max_data_size)
-		goto out;
+		return -EBUSY;
 
 	if (unlikely(trace_recursive_lock(cpu_buffer)))
-		goto out;
+		return -EBUSY;
 
 	event = rb_reserve_next_event(buffer, cpu_buffer, length);
 	if (!event)
@@ -4751,10 +4751,6 @@ int ring_buffer_write(struct trace_buffer *buffer,
 
  out_unlock:
 	trace_recursive_unlock(cpu_buffer);
-
- out:
-	preempt_enable_notrace();
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(ring_buffer_write);
-- 
2.47.2