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 #if __FreeBSD_version < 800039
  32         /*
  33          * Check if there is still an event handler callback
  34          * registered.
  35          */
  36         if (eh_tag != 0) {
  37                 /* De-register the device cloning event handler. */
  38                 EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
  39                 eh_tag = 0;
  40
  41                 /* Stop device cloning. */
  42                 clone_cleanup(&dtrace_clones);
  43         }
  44 #else
  45         destroy_dev(dtrace_dev);
  46         destroy_dev(helper_dev);
  47 #endif
  48
  49         mutex_enter(&dtrace_provider_lock);
  50         mutex_enter(&dtrace_lock);
  51         mutex_enter(&cpu_lock);
  52
  53         ASSERT(dtrace_opens == 0);
  54
  55         if (dtrace_helpers > 0) {
  56                 mutex_exit(&cpu_lock);
  57                 mutex_exit(&dtrace_lock);
  58                 mutex_exit(&dtrace_provider_lock);
  59                 return (EBUSY);
  60         }
  61
  62         if (dtrace_unregister((dtrace_provider_id_t)dtrace_provider) != 0) {
  63                 mutex_exit(&cpu_lock);
  64                 mutex_exit(&dtrace_lock);
  65                 mutex_exit(&dtrace_provider_lock);
  66                 return (EBUSY);
  67         }
  68
  69         dtrace_provider = NULL;
  70         EVENTHANDLER_DEREGISTER(kld_load, dtrace_kld_load_tag);
  71         EVENTHANDLER_DEREGISTER(kld_unload_try, dtrace_kld_unload_try_tag);
  72
  73         if ((state = dtrace_anon_grab()) != NULL) {
  74                 /*
  75                  * If there were ECBs on this state, the provider should
  76                  * have not been allowed to detach; assert that there is
  77                  * none.
  78                  */
  79                 ASSERT(state->dts_necbs == 0);
  80                 dtrace_state_destroy(state);
  81         }
  82
  83         bzero(&dtrace_anon, sizeof (dtrace_anon_t));
  84
  85         mutex_exit(&cpu_lock);
  86
  87         if (dtrace_helptrace_enabled) {
  88                 kmem_free(dtrace_helptrace_buffer, 0);
  89                 dtrace_helptrace_buffer = NULL;
  90         }
  91
  92         if (dtrace_probes != NULL) {
  93                 kmem_free(dtrace_probes, 0);
  94                 dtrace_probes = NULL;
  95                 dtrace_nprobes = 0;
  96         }
  97
  98         dtrace_hash_destroy(dtrace_bymod);
  99         dtrace_hash_destroy(dtrace_byfunc);
 100         dtrace_hash_destroy(dtrace_byname);
 101         dtrace_bymod = NULL;
 102         dtrace_byfunc = NULL;
 103         dtrace_byname = NULL;
 104
 105         kmem_cache_destroy(dtrace_state_cache);
 106
 107         delete_unrhdr(dtrace_arena);
 108
 109         if (dtrace_toxrange != NULL) {
 110                 kmem_free(dtrace_toxrange, 0);
 111                 dtrace_toxrange = NULL;
 112                 dtrace_toxranges = 0;
 113                 dtrace_toxranges_max = 0;
 114         }
 115
 116         ASSERT(dtrace_vtime_references == 0);
 117         ASSERT(dtrace_opens == 0);
 118         ASSERT(dtrace_retained == NULL);
 119
 120         mutex_exit(&dtrace_lock);
 121         mutex_exit(&dtrace_provider_lock);
 122
 123         mutex_destroy(&dtrace_meta_lock);
 124         mutex_destroy(&dtrace_provider_lock);
 125         mutex_destroy(&dtrace_lock);
 126 #ifdef DEBUG
 127         mutex_destroy(&dtrace_errlock);
 128 #endif
 129
 130         taskq_destroy(dtrace_taskq);
 131
 132         /* Reset our hook for exceptions. */
 133         dtrace_invop_uninit();
 134
 135         /*
 136          * Reset our hook for thread switches, but ensure that vtime isn't
 137          * active first.
 138          */
 139         dtrace_vtime_active = 0;
 140         dtrace_vtime_switch_func = NULL;
 141
 142         /* Unhook from the trap handler. */
 143         dtrace_trap_func = NULL;
 144
 145         return (error);
 146 }