tracing: pass around ring buffer instead of tracer
The latency tracers (irqsoff and wakeup) can swap trace buffers
on the fly. If an event is happening and has reserved data on one of
the buffers, and the latency tracer swaps the global buffer with the
max buffer, the result is that the event may commit the data to the
wrong buffer.
This patch changes the API to the trace recording to be recieve the
buffer that was used to reserve a commit. Then this buffer can be passed
in to the commit.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 3f4a251..b3749a2 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -173,19 +173,20 @@
{
struct ftrace_event_call *call = &event_funcgraph_entry;
struct ring_buffer_event *event;
+ struct ring_buffer *buffer = tr->buffer;
struct ftrace_graph_ent_entry *entry;
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
return 0;
- event = trace_buffer_lock_reserve(tr, TRACE_GRAPH_ENT,
+ event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
sizeof(*entry), flags, pc);
if (!event)
return 0;
entry = ring_buffer_event_data(event);
entry->graph_ent = *trace;
- if (!filter_current_check_discard(call, entry, event))
- ring_buffer_unlock_commit(tr->buffer, event);
+ if (!filter_current_check_discard(buffer, call, entry, event))
+ ring_buffer_unlock_commit(buffer, event);
return 1;
}
@@ -236,19 +237,20 @@
{
struct ftrace_event_call *call = &event_funcgraph_exit;
struct ring_buffer_event *event;
+ struct ring_buffer *buffer = tr->buffer;
struct ftrace_graph_ret_entry *entry;
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
return;
- event = trace_buffer_lock_reserve(tr, TRACE_GRAPH_RET,
+ event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
sizeof(*entry), flags, pc);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->ret = *trace;
- if (!filter_current_check_discard(call, entry, event))
- ring_buffer_unlock_commit(tr->buffer, event);
+ if (!filter_current_check_discard(buffer, call, entry, event))
+ ring_buffer_unlock_commit(buffer, event);
}
void trace_graph_return(struct ftrace_graph_ret *trace)
