Commit 6c34df6f authored by Pingfan Liu's avatar Pingfan Liu Committed by Steven Rostedt (VMware)
Browse files

tracing: Apply trace filters on all output channels 

The event filters are not applied on all of the output, which results in
the flood of printk when using tp_printk. Unfolding
event_trigger_unlock_commit_regs() into trace_event_buffer_commit(), so
the filters can be applied on every output.

Link: https://lkml.kernel.org/r/20210814034538.8428-1-kernelfans@gmail.com



Cc: stable@vger.kernel.org
Fixes: 0daa2302 ("tracing: Add tp_printk cmdline to have tracepoints go to printk()")
Signed-off-by: default avatarPingfan Liu <kernelfans@gmail.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 5acce0bf

kernel/trace/trace.c

+15 −3
Original line number Diff line number Diff line
@@ -2897,14 +2897,26 @@ int tracepoint_printk_sysctl(struct ctl_table *table, int write, 


void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)

{

	enum event_trigger_type tt = ETT_NONE;

	struct trace_event_file *file = fbuffer->trace_file;



	if (__event_trigger_test_discard(file, fbuffer->buffer, fbuffer->event,

			fbuffer->entry, &tt))

		goto discard;



	if (static_key_false(&tracepoint_printk_key.key))

		output_printk(fbuffer);



	if (static_branch_unlikely(&trace_event_exports_enabled))

		ftrace_exports(fbuffer->event, TRACE_EXPORT_EVENT);

	event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer,

				    fbuffer->event, fbuffer->entry,

				    fbuffer->trace_ctx, fbuffer->regs);



	trace_buffer_unlock_commit_regs(file->tr, fbuffer->buffer,

			fbuffer->event, fbuffer->trace_ctx, fbuffer->regs);



discard:

	if (tt)

		event_triggers_post_call(file, tt);



}

EXPORT_SYMBOL_GPL(trace_event_buffer_commit);

kernel/trace/trace.h

+0 −32
Original line number Diff line number Diff line
@@ -1389,38 +1389,6 @@ event_trigger_unlock_commit(struct trace_event_file *file, 
		event_triggers_post_call(file, tt);

}



/**

 * event_trigger_unlock_commit_regs - handle triggers and finish event commit

 * @file: The file pointer associated with the event

 * @buffer: The ring buffer that the event is being written to

 * @event: The event meta data in the ring buffer

 * @entry: The event itself

 * @trace_ctx: The tracing context flags.

 *

 * This is a helper function to handle triggers that require data

 * from the event itself. It also tests the event against filters and

 * if the event is soft disabled and should be discarded.

 *

 * Same as event_trigger_unlock_commit() but calls

 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().

 */

static inline void

event_trigger_unlock_commit_regs(struct trace_event_file *file,

				 struct trace_buffer *buffer,

				 struct ring_buffer_event *event,

				 void *entry, unsigned int trace_ctx,

				 struct pt_regs *regs)

{

	enum event_trigger_type tt = ETT_NONE;



	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))

		trace_buffer_unlock_commit_regs(file->tr, buffer, event,

						trace_ctx, regs);



	if (tt)

		event_triggers_post_call(file, tt);

}



#define FILTER_PRED_INVALID	((unsigned short)-1)

#define FILTER_PRED_IS_RIGHT	(1 << 15)

#define FILTER_PRED_FOLD	(1 << 15)