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kern_sdt.c revision 1.1.24.1 
      1 /*	$NetBSD: kern_sdt.c,v 1.1.24.1 2017/12/03 11:38:44 jdolecek Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2010 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by CoyotePoint Systems, Inc. It was developed under contract to
      9  * CoyotePoint by Darran Hunt.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 /*-
     35  * Copyright 2006-2008 John Birrell <jb (at) FreeBSD.org>
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  *
     46  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     49  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
     50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     56  * SUCH DAMAGE.
     57  *
     58  * $FreeBSD: src/sys/kern/kern_sdt.c,v 1.1.4.1 2009/08/03 08:13:06 kensmith Exp $
     59  *
     60  * Backend for the Statically Defined Tracing (SDT) kernel support. This is
     61  * required to allow a module to load even though DTrace kernel support may
     62  * not be present. A module may be built with SDT probes in it.
     63  *
     64  */
     65 #ifdef _KERNEL_OPT
     66 #include "opt_dtrace.h"
     67 #endif
     68 
     69 #include <sys/cdefs.h>
     70 #include <sys/param.h>
     71 #include <sys/systm.h>
     72 #include <sys/sdt.h>
     73 
     74 SDT_PROVIDER_DEFINE(sdt);
     75 
     76 void sdt_probe_stub(u_int32_t, uintptr_t, uintptr_t,
     77 	uintptr_t, uintptr_t, uintptr_t);
     78 
     79 __link_set_decl(sdt_providers_set, struct sdt_provider);
     80 __link_set_decl(sdt_probes_set, struct sdt_probe);
     81 __link_set_decl(sdt_argtypes_set, struct sdt_argtype);
     82 
     83 /*
     84  * Hook for the DTrace probe function. The 'sdt' provider will set this
     85  * to dtrace_probe when it loads.
     86  */
     87 sdt_probe_func_t sdt_probe_func = sdt_probe_stub;
     88 
     89 /*
     90  * This is a stub for probe calls in case kernel DTrace support isn't
     91  * compiled in. It should never get called because there is no DTrace
     92  * support to enable it.
     93  */
     94 void
     95 sdt_probe_stub(u_int32_t id, uintptr_t arg0, uintptr_t arg1,
     96     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
     97 {
     98 	struct sdt_provider * const * provider;
     99 	struct sdt_probe * const * probe;
    100 	struct sdt_argtype * const * argtype;
    101 	printf("%s: XXX should not be called\n", __func__);
    102 	printf("providers: ");
    103 	__link_set_foreach(provider, sdt_providers_set)
    104 		printf("%s ", (*provider)->name);
    105 	printf("\nprobes: ");
    106 	__link_set_foreach(probe, sdt_probes_set)
    107 		printf("%s ", (*probe)->name);
    108 	printf("\nargtypes: ");
    109 	__link_set_foreach(argtype, sdt_argtypes_set)
    110 		printf("%s ", (*argtype)->type);
    111 	printf("\n");
    112 }
    113 
    114 /*
    115  * initialize the SDT dtrace probe function
    116  */
    117 void
    118 sdt_init(void *dtrace_probe)
    119 {
    120 
    121 	sdt_probe_func = dtrace_probe;
    122 }
    123 
    124 /*
    125  * Disable the SDT dtrace probe function
    126  */
    127 void
    128 sdt_exit(void)
    129 {
    130 
    131 	sdt_probe_func = sdt_probe_stub;
    132 }
    133