[src/trunk]: src/external/cddl/osnet/dev/sdt Adapt to NetBSD modules and link...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/5872dadf684f
branches:  trunk
changeset: 340799:5872dadf684f
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Oct 02 16:59:23 2015 +0000

description:
Adapt to NetBSD modules and link set access.
XXX: We don't have an event system so that we can issue callback that
     will be run on construction or destruction to enable and disable probes
XXX: We don't have a way to use link_sets across modules properly.

diffstat:

 external/cddl/osnet/dev/sdt/sdt.c |  703 ++++++++++++++++---------------------
 1 files changed, 312 insertions(+), 391 deletions(-)

diffs (truncated from 798 to 300 lines):

diff -r 1a2ed371ea03 -r 5872dadf684f external/cddl/osnet/dev/sdt/sdt.c
--- a/external/cddl/osnet/dev/sdt/sdt.c Fri Oct 02 16:54:15 2015 +0000
+++ b/external/cddl/osnet/dev/sdt/sdt.c Fri Oct 02 16:59:23 2015 +0000
@@ -1,74 +1,91 @@
-/*     $NetBSD: sdt.c,v 1.12 2015/09/30 20:59:44 christos Exp $        */
-
-/*-
- * Copyright (c) 2010 The NetBSD Foundation, Inc.
- * All rights reserved.
+/*
+ * CDDL HEADER START
  *
- * This code is derived from software contributed to The NetBSD Foundation
- * by CoyotePoint Systems, Inc. It was developed under contract to 
- * CoyotePoint by Darran Hunt.
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
  *
- * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
- * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
- * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
+ * CDDL HEADER END
+ *
+ * Portions Copyright 2006-2008 John Birrell jb%freebsd.org@localhost
+ *
+ * $FreeBSD: head/sys/cddl/dev/sdt/sdt.c 285703 2015-07-19 22:14:09Z markj $
+ *
  */
 
-#ifdef _KERNEL_OPT
-#include "opt_dtrace.h"
-#endif
+/*
+ * This file contains a reimplementation of the statically-defined tracing (SDT)
+ * framework for DTrace. Probes and SDT providers are defined using the macros
+ * in sys/sdt.h, which append all the needed structures to linker sets. When
+ * this module is loaded, it iterates over all of the loaded modules and
+ * registers probes and providers with the DTrace framework based on the
+ * contents of these linker sets.
+ *
+ * A list of SDT providers is maintained here since a provider may span multiple
+ * modules. When a kernel module is unloaded, a provider defined in that module
+ * is unregistered only if no other modules refer to it. The DTrace framework is
+ * responsible for destroying individual probes when a kernel module is
+ * unloaded; in particular, probes may not span multiple kernel modules.
+ */
 
 #include <sys/cdefs.h>
 #include <sys/param.h>
 #include <sys/systm.h>
+
 #include <sys/conf.h>
+#include <sys/eventhandler.h>
 #include <sys/kernel.h>
-#include <sys/kmem.h>
+#include <sys/limits.h>
+#include <sys/linker.h>
+#include <sys/linker_set.h>
+#include <sys/lock.h>
+#include <sys/lockstat.h>
+#include <sys/malloc.h>
 #include <sys/module.h>
 #include <sys/mutex.h>
-
-#include <sys/dtrace.h>
-
-#define KDTRACE_HOOKS
+#include <sys/queue.h>
 #include <sys/sdt.h>
 
-#undef SDT_DEBUG
-
-static dev_type_open(sdt_open);
+#include <sys/dtrace.h>
+#include <sys/dtrace_bsd.h>
 
-static int     sdt_unload(void);
+/* DTrace methods. */
 static void    sdt_getargdesc(void *, dtrace_id_t, void *, dtrace_argdesc_t *);
-static void    sdt_provide(void *, const dtrace_probedesc_t *);
+static void    sdt_provide_probes(void *, dtrace_probedesc_t *);
 static void    sdt_destroy(void *, dtrace_id_t, void *);
-static int     sdt_enable(void *, dtrace_id_t, void *);
+static void    sdt_enable(void *, dtrace_id_t, void *);
 static void    sdt_disable(void *, dtrace_id_t, void *);
-static void    sdt_load(void *);
 
-static const struct cdevsw sdt_cdevsw = {
-       sdt_open, noclose, noread, nowrite, noioctl,
-       nostop, notty, nopoll, nommap, nokqfilter, nodiscard,
-       D_OTHER
+static void    sdt_load(void);
+static int     sdt_unload(void);
+static void    sdt_create_provider(struct sdt_provider *);
+static void    sdt_create_probe(struct sdt_probe *);
+static void    sdt_kld_load(void *, struct linker_file *);
+static void    sdt_kld_unload_try(void *, struct linker_file *, int *);
+
+static MALLOC_DEFINE(M_SDT, "SDT", "DTrace SDT providers");
+
+static dtrace_pattr_t sdt_attr = {
+{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
+{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
+{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
+{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
+{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
 };
 
 static dtrace_pops_t sdt_pops = {
-       sdt_provide,
+       sdt_provide_probes,
        NULL,
        sdt_enable,
        sdt_disable,
@@ -77,407 +94,311 @@
        sdt_getargdesc,
        NULL,
        NULL,
-       sdt_destroy
+       sdt_destroy,
 };
 
-#ifdef notyet
-static struct cdev             *sdt_cdev;
-#endif
+static TAILQ_HEAD(, sdt_provider) sdt_prov_list;
+
+eventhandler_tag       sdt_kld_load_tag;
+eventhandler_tag       sdt_kld_unload_try_tag;
+
+static void
+sdt_create_provider(struct sdt_provider *prov)
+{
+       struct sdt_provider *curr, *newprov;
+
+       TAILQ_FOREACH(curr, &sdt_prov_list, prov_entry)
+               if (strcmp(prov->name, curr->name) == 0) {
+                       /* The provider has already been defined. */
+                       curr->sdt_refs++;
+                       return;
+               }
+
+       /*
+        * Make a copy of prov so that we don't lose fields if its module is
+        * unloaded but the provider isn't destroyed. This could happen with
+        * a provider that spans multiple modules.
+        */
+       newprov = malloc(sizeof(*newprov), M_SDT, M_WAITOK | M_ZERO);
+       newprov->name = strdup(prov->name, M_SDT);
+       prov->sdt_refs = newprov->sdt_refs = 1;
+
+       TAILQ_INSERT_TAIL(&sdt_prov_list, newprov, prov_entry);
+
+       (void)dtrace_register(newprov->name, &sdt_attr, DTRACE_PRIV_USER, NULL,
+           &sdt_pops, NULL, (dtrace_provider_id_t *)&newprov->id);
+       prov->id = newprov->id;
+}
 
-/*
- * Provider and probe definitions 
- */
+static void
+sdt_create_probe(struct sdt_probe *probe)
+{
+       struct sdt_provider *prov;
+       char mod[DTRACE_MODNAMELEN];
+       char func[DTRACE_FUNCNAMELEN];
+       char name[DTRACE_NAMELEN];
+       const char *from;
+       char *to;
+       size_t len;
+
+       TAILQ_FOREACH(prov, &sdt_prov_list, prov_entry)
+               if (strcmp(prov->name, probe->prov->name) == 0)
+                       break;
+
+       KASSERT(prov != NULL, ("probe defined without a provider"));
+
+       /* If no module name was specified, use the module filename. */
+       if (*probe->mod == 0) {
+               len = strlcpy(mod, probe->sdtp_lf->filename, sizeof(mod));
+               if (len > 3 && strcmp(mod + len - 3, ".ko") == 0)
+                       mod[len - 3] = '\0';
+       } else
+               strlcpy(mod, probe->mod, sizeof(mod));
+
+       /*
+        * Unfortunately this is necessary because the Solaris DTrace
+        * code mixes consts and non-consts with casts to override
+        * the incompatibilies. On FreeBSD, we use strict warnings
+        * in the C compiler, so we have to respect const vs non-const.
+        */
+       strlcpy(func, probe->func, sizeof(func));
+
+       from = probe->name;
+       to = name;
+       for (len = 0; len < (sizeof(name) - 1) && *from != '\0';
+           len++, from++, to++) {
+               if (from[0] == '_' && from[1] == '_') {
+                       *to = '-';
+                       from++;
+               } else
+                       *to = *from;
+       }
+       *to = '\0';
+
+       if (dtrace_probe_lookup(prov->id, mod, func, name) != DTRACE_IDNONE)
+               return;
+
+       (void)dtrace_probe_create(prov->id, mod, func, name, 1, probe);
+}
 
 /*
- * proc provider
+ * Probes are created through the SDT module load/unload hook, so this function
+ * has nothing to do. It only exists because the DTrace provider framework
+ * requires one of provide_probes and provide_module to be defined.
  */
+static void
+sdt_provide_probes(void *arg, dtrace_probedesc_t *desc)
+{
+}
 
-/* declare all probes belonging to the provider */
-SDT_PROBE_DECLARE(proc,,,create);
-SDT_PROBE_DECLARE(proc,,,exec);
-SDT_PROBE_DECLARE(proc,,,exit);
-SDT_PROBE_DECLARE(proc,,,exec_success);
-SDT_PROBE_DECLARE(proc,,,exec_failure);
-SDT_PROBE_DECLARE(proc,,,signal_send);
-SDT_PROBE_DECLARE(proc,,,signal_discard);
-SDT_PROBE_DECLARE(proc,,,signal_clear);
-SDT_PROBE_DECLARE(proc,,,signal_handle);
-SDT_PROBE_DECLARE(proc,,,lwp_create);
-SDT_PROBE_DECLARE(proc,,,lwp_start);
-SDT_PROBE_DECLARE(proc,,,lwp_exit);
+static void
+sdt_enable(void *arg __unused, dtrace_id_t id, void *parg)
+{
+       struct sdt_probe *probe = parg;
 
-/* define the provider */
-static sdt_provider_t proc_provider = {
-       "proc",         /* provider name */
-       0,              /* registered ID - leave as 0 */
-       {
-               { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
-               { DTRACE_STABILITY_PRIVATE,  DTRACE_STABILITY_PRIVATE,  DTRACE_CLASS_UNKNOWN },
-               { DTRACE_STABILITY_PRIVATE,  DTRACE_STABILITY_PRIVATE,  DTRACE_CLASS_ISA },
-               { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
-               { DTRACE_STABILITY_PRIVATE,  DTRACE_STABILITY_PRIVATE,  DTRACE_CLASS_ISA },
-       },
+       probe->id = id;
+       probe->sdtp_lf->nenabled++;
+       if (strcmp(probe->prov->name, "lockstat") == 0)
+               lockstat_enabled++;
+}
 
-       /* list all probes belonging to the provider */
-       { 
-               &SDT_NAME(proc,,,create),
-               &SDT_NAME(proc,,,exec),
-               &SDT_NAME(proc,,,exit),
-               &SDT_NAME(proc,,,exec_success),
-               &SDT_NAME(proc,,,exec_failure),
-               &SDT_NAME(proc,,,signal_send),
-               &SDT_NAME(proc,,,signal_discard),
-               &SDT_NAME(proc,,,signal_clear),
-               &SDT_NAME(proc,,,signal_handle),
-               &SDT_NAME(proc,,,lwp_create),
-               &SDT_NAME(proc,,,lwp_start),