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: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d372c65..5c53e40 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -442,6 +442,12 @@
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 @@
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 @@
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 */
/**