^^&&^^

Edit File: logging.stp

// logging tapset
// Copyright (C) 2005-2011 Red Hat Inc.
//
// This file is part of systemtap, and is free software.  You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.

/**
 * sfunction ftrace - Send a message to the ftrace ring-buffer
 *
 * @msg: The formatted message string
 *
 * Description: If the ftrace ring-buffer is configured & available,
 * see /debugfs/tracing/trace for the message.  Otherwise, the
 * message may be quietly dropped.  An implicit end-of-line is added.
 */
function ftrace (msg:string) %{ /* unmodified-fnargs */
#ifdef STAPCONF_TRACE_PRINTK
       static char *fmt = "%s\n";
       trace_printk (fmt, STAP_ARG_msg);

/* The "fmt" is designed to be non __builtin_constant_p(), so as
       to defeat trace_printk -> __trace_bprintk optimization.  That's
       because bprintk doesn't save the incoming strings, only their
       addresses. */
#else
  #error "trace_printk not supported"
#endif
%}

/**
 * sfunction printk - Send a message to the kernel trace buffer
 *
 * @level: an integer for the severity level (0=KERN_EMERG ... 7=KERN_DEBUG)
 * @msg: The formatted message string
 *
 * Description: Print a line of text to the kernel dmesg/console with the
 * given severity.  An implicit end-of-line is added.  This function may 
 * not be safely called from all kernel probe contexts, so is restricted
 * to guru mode only.
 */
function printk (level:long,msg:string) %{ /* guru */ /* unmodified-fnargs */
         printk (STAP_ARG_level == 0 ? KERN_EMERG "%s\n":
                 STAP_ARG_level == 1 ? KERN_ALERT "%s\n":
                 STAP_ARG_level == 2 ? KERN_CRIT "%s\n":
                 STAP_ARG_level == 3 ? KERN_ERR "%s\n":
                 STAP_ARG_level == 4 ? KERN_WARNING "%s\n":
                 STAP_ARG_level == 5 ? KERN_NOTICE "%s\n":
                 STAP_ARG_level == 6 ? KERN_INFO "%s\n":
                 STAP_ARG_level == 7 ? KERN_DEBUG "%s\n":
#ifdef KERN_DEFAULT
                 KERN_DEFAULT "%s\n"
#else
                 KERN_INFO "%s\n"
#endif
                 , STAP_ARG_msg);
%}