Update Doku aus Driversourcen

Change-Id: I455f0813b970151089b3dc1b8d9407eea323cdd1
diff --git a/doc/master/valid_trace b/doc/master/valid_trace
new file mode 100644
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+++ b/doc/master/valid_trace
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+SYNOPSIS
+        int valid_trace(string what, int|string arg)
+
+DESCRIPTION
+        Check if the interactive user is allowed to use tracing.
+
+        The argument <what> denotes the action for which permission is to be
+        checked, <arg> is the argument given to the traceing efun:
+
+        "trace"        Is the user allowed to use tracing?
+                       <arg> is the tracelevel argument given.
+        "traceprefix"  Is the user allowed to set a traceprefix?
+                       <arg> is the prefix given.
+
+SEE ALSO
+        trace(E), showsmallnewmalloced(D), malloc(D), status(D), memory(C)