// target tapset
// Copyright (C) 2019 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.

// TODO: get 'call' instruction to handle the functions below

/**
 * function _set_procfs_value - Used to set the message 
 * from a procfs-like probe.
 *
 * Description: This function always returns 0.
 */

function _set_procfs_value:long (msg:string)
%{/* bpf */
   0xbf, 1, $msg, -, -;   /* mov r1, $msg */
   0x85, 0, 0, 0, -6;     /* call BPF_FUNC_SET_PROCFS_VALUE */
   0xbf, $$, 0, -, -;     /* return r0 */
%}

/**
 * function _append_procfs_value - Used to append to 
 * the message for a procfs-like probe.
 *
 * Description: This function always returns 0.
 */

function _append_procfs_value:long (append:string)
%{/* bpf */
   0xbf, 1, $append, -, -;    /* mov r1, $msg */
   0x85, 0, 0, 0, -7;         /* call BPF_FUNC_APPEND_PROCFS_VALUE */
   0xbf, $$, 0, -, -;         /* return r0 */
%}

/**
 * function _get_procfs_value - Used to get the message 
 * for a procfs-like probe.
 *
 * Description: This function returns a pointer to the 
 * message.
 */

function _get_procfs_value:string ()
%{/* bpf */
   0x85, 0, 0, 0, -8;   /* call BPF_FUNC_GET_PROCFS_VALUE */
   0xbf, $$, 0, -, -;   /* return r0 */ 
%}