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-rw-r--r--kernel/trace/trace.c27
1 files changed, 25 insertions, 2 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 815c878..24c1f23 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1600,15 +1600,31 @@ void trace_buffer_unlock_commit(struct ring_buffer *buffer,
}
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit);
+static struct ring_buffer *temp_buffer;
+
struct ring_buffer_event *
trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
struct ftrace_event_file *ftrace_file,
int type, unsigned long len,
unsigned long flags, int pc)
{
+ struct ring_buffer_event *entry;
+
*current_rb = ftrace_file->tr->trace_buffer.buffer;
- return trace_buffer_lock_reserve(*current_rb,
+ entry = trace_buffer_lock_reserve(*current_rb,
type, len, flags, pc);
+ /*
+ * If tracing is off, but we have triggers enabled
+ * we still need to look at the event data. Use the temp_buffer
+ * to store the trace event for the tigger to use. It's recusive
+ * safe and will not be recorded anywhere.
+ */
+ if (!entry && ftrace_file->flags & FTRACE_EVENT_FL_TRIGGER_COND) {
+ *current_rb = temp_buffer;
+ entry = trace_buffer_lock_reserve(*current_rb,
+ type, len, flags, pc);
+ }
+ return entry;
}
EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
@@ -6494,11 +6510,16 @@ __init static int tracer_alloc_buffers(void)
raw_spin_lock_init(&global_trace.start_lock);
+ /* Used for event triggers */
+ temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
+ if (!temp_buffer)
+ goto out_free_cpumask;
+
/* TODO: make the number of buffers hot pluggable with CPUS */
if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
WARN_ON(1);
- goto out_free_cpumask;
+ goto out_free_temp_buffer;
}
if (global_trace.buffer_disabled)
@@ -6540,6 +6561,8 @@ __init static int tracer_alloc_buffers(void)
return 0;
+out_free_temp_buffer:
+ ring_buffer_free(temp_buffer);
out_free_cpumask:
free_percpu(global_trace.trace_buffer.data);
#ifdef CONFIG_TRACER_MAX_TRACE
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