arm64: lib: Add static tracepoint for memcpyarm64-memcpy-trace

To better gauge the memcpy usage across the kernel, this patch creates
a static ftrace probe for memcpy taking the src, dest, size and caller
pc.

TODO: this will add a function call overhead, we could inline the new
memcpy, that would need some thought on how to handle the trace point
logic.

Signed-off-by: Steve Capper <steve.capper@linaro.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/trace/events/string.h b/arch/arm64/include/asm/trace/events/string.h
new file mode 100644
index 00000000000..c3649d20003
--- /dev/null
+++ b/arch/arm64/include/asm/trace/events/string.h
@@ -0,0 +1,37 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM string
+
+#if !defined(_TRACE_STRING_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_STRING_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(memcpy,
+	TP_PROTO(void *dest, const void *src, size_t count, void *location),
+
+	TP_ARGS(dest, src, count, location),
+
+	TP_STRUCT__entry(
+		__field(void *, dest)
+		__field(const void *, src)
+		__field(size_t, count)
+		__field(void *, location)
+	),
+
+	TP_fast_assign(
+		__entry->dest = dest;
+		__entry->src = src;
+		__entry->count = count;
+		__entry->location = location;
+	),
+
+	TP_printk("dest=%p src=%p count=%ld location=%p",
+			__entry->dest, __entry->src,
+			__entry->count, __entry->location)
+);
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH asm/trace/events
+#endif /*_TRACE_STRING_H */
+
+#include <trace/define_trace.h>