Add new kernel probes instrumentation

[lttng-modules.git] / instrumentation / events / lttng-module / printk.h

diff --git a/instrumentation/events/lttng-module/printk.h b/instrumentation/events/lttng-module/printk.h
new file mode 100644 (file)
index 0000000..4c744f9
--- /dev/null
+++ b/instrumentation/events/lttng-module/printk.h
@@ -0,0 +1,64 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM printk
+
+#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PRINTK_H
+
+#include <linux/tracepoint.h>
+#include <linux/version.h>
+
+#define MSG_TRACE_MAX_LEN      2048
+
+TRACE_EVENT_CONDITION(console,
+       TP_PROTO(const char *log_buf, unsigned start, unsigned end,
+                unsigned log_buf_len),
+
+       TP_ARGS(log_buf, start, end, log_buf_len),
+
+       TP_CONDITION(start != end),
+
+       TP_STRUCT__entry(
+               __dynamic_array_text(char, msg,
+                       min_t(unsigned, end - start, MSG_TRACE_MAX_LEN) + 1)
+       ),
+
+       TP_fast_assign(
+               tp_memcpy_dyn(msg,
+                       ({
+                               char lmsg[MSG_TRACE_MAX_LEN + 1];
+
+                               if ((end - start) > MSG_TRACE_MAX_LEN)
+                                       start = end - MSG_TRACE_MAX_LEN;
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(3,5,0))
+                               if ((start & (log_buf_len - 1)) >
+                                       (end & (log_buf_len - 1))) {
+                                       memcpy(lmsg,
+                                               log_buf +
+                                               (start & (log_buf_len - 1)),
+                                               log_buf_len -
+                                               (start & (log_buf_len - 1)));
+                                       memcpy(lmsg + log_buf_len -
+                                               (start & (log_buf_len - 1)),
+                                               log_buf,
+                                               end & (log_buf_len - 1));
+                               } else
+                                       memcpy(lmsg,
+                                               log_buf +
+                                               (start & (log_buf_len - 1)),
+                                               end - start);
+#else
+                               memcpy(lmsg, log_buf + start, end - start);
+#endif
+                               lmsg[end - start] = 0;
+                               lmsg;
+                       })
+               )
+       ),
+
+       TP_printk("%s", __get_str(msg))
+)
+#endif /* _TRACE_PRINTK_H */
+
+/* This part must be outside protection */
+#include "../../../probes/define_trace.h"