diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index cbe1b0cc7a6a..7158421ac911 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -225,6 +225,11 @@ typedef struct siginfo {
 #define TRAP_HWBKPT     4	/* hardware breakpoint/watchpoint */
 #define NSIGTRAP	4
 
+/*
+ * There are an additional set of SIGTRAP si_codes used by ptrace
+ * that of the form: ((PTRACE_EVENT_XXX << 8) | SIGTRAP)
+ */
+
 /*
  * SIGCHLD si_codes
  */