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Commit 1b22e382 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
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tracing: Let tracing_snapshot() be used by modules but not NMI 



Add EXPORT_SYMBOL_GPL() to let the tracing_snapshot() functions be
called from modules.

Also add a test to see if the snapshot was called from NMI context
and just warn in the tracing buffer if so, and return.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent ca268da6

kernel/trace/trace.c

+10 −0
Original line number Diff line number Diff line
@@ -442,6 +442,12 @@ void tracing_snapshot(void) 
	struct tracer *tracer = tr->current_trace;

	unsigned long flags;



	if (in_nmi()) {

		internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n");

		internal_trace_puts("*** snapshot is being ignored        ***\n");

		return;

	}



	if (!tr->allocated_snapshot) {

		internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n");

		internal_trace_puts("*** stopping trace here!   ***\n");
@@ -460,6 +466,7 @@ void tracing_snapshot(void) 
	update_max_tr(tr, current, smp_processor_id());

	local_irq_restore(flags);

}

EXPORT_SYMBOL_GPL(tracing_snapshot);



static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,

					struct trace_buffer *size_buf, int cpu_id);
@@ -493,16 +500,19 @@ void tracing_snapshot_alloc(void) 


	tracing_snapshot();

}

EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);

#else

void tracing_snapshot(void)

{

	WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");

}

EXPORT_SYMBOL_GPL(tracing_snapshot);

void tracing_snapshot_alloc(void)

{

	/* Give warning */

	tracing_snapshot();

}

EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);

#endif /* CONFIG_TRACER_SNAPSHOT */



/**