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authorSteven Rostedt <srostedt@redhat.com>2009-01-21 15:24:56 -0500
committerIngo Molnar <mingo@elte.hu>2009-01-22 10:27:16 +0100
commit97b17efe4537e11bf6669106cfe4ee2c5331b267 (patch)
tree46310b25ea38628fc631d4c4c248ebe66426036f /kernel
parent5bc4564b224c3d9fe6dddafa25f56059bd978231 (diff)
ring-buffer: do not swap if recording is disabled
If the ring buffer recording has been disabled. Do not let swapping of ring buffers occur. Simply return -EAGAIN. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/ring_buffer.c15
-rw-r--r--kernel/trace/trace.c2
2 files changed, 16 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 0b9de5a3d699..890020e28a35 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2266,9 +2266,24 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
if (buffer_a->pages != buffer_b->pages)
return -EINVAL;
+ if (ring_buffer_flags != RB_BUFFERS_ON)
+ return -EAGAIN;
+
+ if (atomic_read(&buffer_a->record_disabled))
+ return -EAGAIN;
+
+ if (atomic_read(&buffer_b->record_disabled))
+ return -EAGAIN;
+
cpu_buffer_a = buffer_a->buffers[cpu];
cpu_buffer_b = buffer_b->buffers[cpu];
+ if (atomic_read(&cpu_buffer_a->record_disabled))
+ return -EAGAIN;
+
+ if (atomic_read(&cpu_buffer_b->record_disabled))
+ return -EAGAIN;
+
/*
* We can't do a synchronize_sched here because this
* function can be called in atomic context.
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 220c264e3111..757ae6f7e648 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -415,7 +415,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
ftrace_enable_cpu();
- WARN_ON_ONCE(ret);
+ WARN_ON_ONCE(ret && ret != -EAGAIN);
__update_max_tr(tr, tsk, cpu);
__raw_spin_unlock(&ftrace_max_lock);