sys/cddl/dev/dtrace/dtrace_unload.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  *
  21  * $FreeBSD$
  22  *
  23  */
  24
  25 static int
  26 dtrace_unload()
  27 {
  28         dtrace_state_t *state;
  29         int error = 0;
  30
  31         destroy_dev(dtrace_dev);
  32         destroy_dev(helper_dev);
  33
  34         mutex_enter(&dtrace_provider_lock);
  35         mutex_enter(&dtrace_lock);
  36         mutex_enter(&cpu_lock);
  37
  38         ASSERT(dtrace_opens == 0);
  39
  40         if (dtrace_helpers > 0) {
  41                 mutex_exit(&cpu_lock);
  42                 mutex_exit(&dtrace_lock);
  43                 mutex_exit(&dtrace_provider_lock);
  44                 return (EBUSY);
  45         }
  46
  47         if (dtrace_unregister((dtrace_provider_id_t)dtrace_provider) != 0) {
  48                 mutex_exit(&cpu_lock);
  49                 mutex_exit(&dtrace_lock);
  50                 mutex_exit(&dtrace_provider_lock);
  51                 return (EBUSY);
  52         }
  53
  54         dtrace_provider = NULL;
  55         EVENTHANDLER_DEREGISTER(kld_load, dtrace_kld_load_tag);
  56         EVENTHANDLER_DEREGISTER(kld_unload_try, dtrace_kld_unload_try_tag);
  57
  58         if ((state = dtrace_anon_grab()) != NULL) {
  59                 /*
  60                  * If there were ECBs on this state, the provider should
  61                  * have not been allowed to detach; assert that there is
  62                  * none.
  63                  */
  64                 ASSERT(state->dts_necbs == 0);
  65                 dtrace_state_destroy(state);
  66         }
  67
  68         bzero(&dtrace_anon, sizeof (dtrace_anon_t));
  69
  70         mutex_exit(&cpu_lock);
  71
  72         if (dtrace_probes != NULL) {
  73                 kmem_free(dtrace_probes, 0);
  74                 dtrace_probes = NULL;
  75                 dtrace_nprobes = 0;
  76         }
  77
  78         dtrace_hash_destroy(dtrace_bymod);
  79         dtrace_hash_destroy(dtrace_byfunc);
  80         dtrace_hash_destroy(dtrace_byname);
  81         dtrace_bymod = NULL;
  82         dtrace_byfunc = NULL;
  83         dtrace_byname = NULL;
  84
  85         kmem_cache_destroy(dtrace_state_cache);
  86
  87         delete_unrhdr(dtrace_arena);
  88
  89         if (dtrace_toxrange != NULL) {
  90                 kmem_free(dtrace_toxrange, 0);
  91                 dtrace_toxrange = NULL;
  92                 dtrace_toxranges = 0;
  93                 dtrace_toxranges_max = 0;
  94         }
  95
  96         ASSERT(dtrace_vtime_references == 0);
  97         ASSERT(dtrace_opens == 0);
  98         ASSERT(dtrace_retained == NULL);
  99
 100         mutex_exit(&dtrace_lock);
 101         mutex_exit(&dtrace_provider_lock);
 102
 103         mutex_destroy(&dtrace_meta_lock);
 104         mutex_destroy(&dtrace_provider_lock);
 105         mutex_destroy(&dtrace_lock);
 106 #ifdef DEBUG
 107         mutex_destroy(&dtrace_errlock);
 108 #endif
 109
 110         taskq_destroy(dtrace_taskq);
 111
 112         /* Reset our hook for exceptions. */
 113         dtrace_invop_uninit();
 114
 115         /*
 116          * Reset our hook for thread switches, but ensure that vtime isn't
 117          * active first.
 118          */
 119         dtrace_vtime_active = 0;
 120         dtrace_vtime_switch_func = NULL;
 121
 122         /* Unhook from the trap handler. */
 123         dtrace_trap_func = NULL;
 124
 125         return (error);
 126 }