sys/sys/eventhandler.h

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #ifndef _SYS_EVENTHANDLER_H_
  30 #define _SYS_EVENTHANDLER_H_
  31
  32 #include <sys/_eventhandler.h>
  33 #include <sys/lock.h>
  34 #include <sys/ktr.h>
  35 #include <sys/mutex.h>
  36 #include <sys/queue.h>
  37
  38 #ifdef VIMAGE
  39 struct eventhandler_entry_vimage {
  40         void    (* func)(void);         /* Original function registered. */
  41         void    *ee_arg;                /* Original argument registered. */
  42         void    *sparep[2];
  43 };
  44 #endif
  45
  46 struct eventhandler_list {
  47         char                            *el_name;
  48         int                             el_flags;       /* Unused. */
  49         u_int                           el_runcount;
  50         struct mtx                      el_lock;
  51         TAILQ_ENTRY(eventhandler_list)  el_link;
  52         TAILQ_HEAD(,eventhandler_entry) el_entries;
  53 };
  54
  55 #define EHL_LOCK(p)             mtx_lock(&(p)->el_lock)
  56 #define EHL_UNLOCK(p)           mtx_unlock(&(p)->el_lock)
  57 #define EHL_LOCK_ASSERT(p, x)   mtx_assert(&(p)->el_lock, x)
  58
  59 /*
  60  * Macro to invoke the handlers for a given event.
  61  */
  62 #define _EVENTHANDLER_INVOKE(name, list, ...) do {                      \
  63         struct eventhandler_entry *_ep;                                 \
  64         struct eventhandler_entry_ ## name *_t;                         \
  65                                                                         \
  66         EHL_LOCK_ASSERT((list), MA_OWNED);                              \
  67         (list)->el_runcount++;                                          \
  68         KASSERT((list)->el_runcount > 0,                                \
  69             ("eventhandler_invoke: runcount overflow"));                \
  70         CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");   \
  71         TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {            \
  72                 if (_ep->ee_priority != EHE_DEAD_PRIORITY) {            \
  73                         EHL_UNLOCK((list));                             \
  74                         _t = (struct eventhandler_entry_ ## name *)_ep; \
  75                         CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
  76                             (void *)_t->eh_func);                       \
  77                         _t->eh_func(_ep->ee_arg , ## __VA_ARGS__);      \
  78                         EHL_LOCK((list));                               \
  79                 }                                                       \
  80         }                                                               \
  81         KASSERT((list)->el_runcount > 0,                                \
  82             ("eventhandler_invoke: runcount underflow"));               \
  83         (list)->el_runcount--;                                          \
  84         if ((list)->el_runcount == 0)                                   \
  85                 eventhandler_prune_list(list);                          \
  86         EHL_UNLOCK((list));                                             \
  87 } while (0)
  88
  89 /*
  90  * You can optionally use the EVENTHANDLER_LIST and EVENTHANDLER_DIRECT macros
  91  * to pre-define a symbol for the eventhandler list. This symbol can be used by
  92  * EVENTHANDLER_DIRECT_INVOKE, which has the advantage of not needing to do a
  93  * locked search of the global list of eventhandler lists. At least
  94  * EVENTHANDLER_LIST_DEFINE must be used for EVENTHANDLER_DIRECT_INVOKE to
  95  * work. EVENTHANDLER_LIST_DECLARE is only needed if the call to
  96  * EVENTHANDLER_DIRECT_INVOKE is in a different compilation unit from
  97  * EVENTHANDLER_LIST_DEFINE. If the events are even relatively high frequency
  98  * it is suggested that you directly define a list for them.
  99  */
 100 #define EVENTHANDLER_LIST_DEFINE(name)                                  \
 101 struct eventhandler_list *_eventhandler_list_ ## name ;                 \
 102 static void _ehl_init_ ## name (void * ctx __unused)                    \
 103 {                                                                       \
 104         _eventhandler_list_ ## name = eventhandler_create_list(#name);  \
 105 }                                                                       \
 106 SYSINIT(name ## _ehl_init, SI_SUB_EVENTHANDLER, SI_ORDER_ANY,           \
 107             _ehl_init_ ## name, NULL);                                  \
 108         struct __hack
 109
 110 #define EVENTHANDLER_DIRECT_INVOKE(name, ...) do {                      \
 111         struct eventhandler_list *_el;                                  \
 112                                                                         \
 113         _el = _eventhandler_list_ ## name ;                             \
 114         if (!TAILQ_EMPTY(&_el->el_entries)) {                           \
 115                 EHL_LOCK(_el);                                          \
 116                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 117         }                                                               \
 118 } while (0)
 119
 120 #define EVENTHANDLER_DEFINE(name, func, arg, priority)                  \
 121         static eventhandler_tag name ## _tag;                           \
 122         static void name ## _evh_init(void *ctx)                        \
 123         {                                                               \
 124                 name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,   \
 125                     priority);                                          \
 126         }                                                               \
 127         SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,      \
 128             name ## _evh_init, arg);                                    \
 129         struct __hack
 130
 131 #define EVENTHANDLER_INVOKE(name, ...)                                  \
 132 do {                                                                    \
 133         struct eventhandler_list *_el;                                  \
 134                                                                         \
 135         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 136                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 137 } while (0)
 138
 139 #define EVENTHANDLER_REGISTER(name, func, arg, priority)                \
 140         eventhandler_register(NULL, #name, func, arg, priority)
 141
 142 #define EVENTHANDLER_DEREGISTER(name, tag)                              \
 143 do {                                                                    \
 144         struct eventhandler_list *_el;                                  \
 145                                                                         \
 146         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 147                 eventhandler_deregister(_el, tag);                      \
 148 } while (0)
 149
 150 #define EVENTHANDLER_DEREGISTER_NOWAIT(name, tag)                       \
 151 do {                                                                    \
 152         struct eventhandler_list *_el;                                  \
 153                                                                         \
 154         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 155                 eventhandler_deregister_nowait(_el, tag);               \
 156 } while (0)
 157
 158 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
 159             const char *name, void *func, void *arg, int priority);
 160 void    eventhandler_deregister(struct eventhandler_list *list,
 161             eventhandler_tag tag);
 162 void    eventhandler_deregister_nowait(struct eventhandler_list *list,
 163             eventhandler_tag tag);
 164 struct eventhandler_list *eventhandler_find_list(const char *name);
 165 void    eventhandler_prune_list(struct eventhandler_list *list);
 166 struct eventhandler_list *eventhandler_create_list(const char *name);
 167
 168 #ifdef VIMAGE
 169 typedef void (*vimage_iterator_func_t)(void *, ...);
 170
 171 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
 172             const char *name, void *func, void *arg, int priority,
 173             vimage_iterator_func_t);
 174 #endif
 175
 176 /*
 177  * Standard system event queues.
 178  */
 179
 180 /* Generic priority levels */
 181 #define EVENTHANDLER_PRI_FIRST  0
 182 #define EVENTHANDLER_PRI_ANY    10000
 183 #define EVENTHANDLER_PRI_LAST   20000
 184
 185 /*
 186  * Successive shutdown events invoked by kern_reboot(9).
 187  *
 188  * Handlers will receive the 'howto' value as their second argument.
 189  *
 190  * All handlers must be prepared to be executed from a panic/debugger context;
 191  * see the man page for details.
 192  */
 193 typedef void (*shutdown_fn)(void *, int);
 194
 195 #define SHUTDOWN_PRI_FIRST      EVENTHANDLER_PRI_FIRST
 196 #define SHUTDOWN_PRI_DEFAULT    EVENTHANDLER_PRI_ANY
 197 #define SHUTDOWN_PRI_LAST       EVENTHANDLER_PRI_LAST
 198
 199 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);   /* before fs sync */
 200 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);  /* after fs sync */
 201 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
 202
 203 /* Power state change events */
 204 typedef void (*power_change_fn)(void *);
 205 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
 206 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
 207 EVENTHANDLER_DECLARE(power_suspend_early, power_change_fn);
 208
 209 /* Low memory event */
 210 typedef void (*vm_lowmem_handler_t)(void *, int);
 211 #define LOWMEM_PRI_DEFAULT      EVENTHANDLER_PRI_FIRST
 212 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
 213 /* Some of mbuf(9) zones reached maximum */
 214 EVENTHANDLER_DECLARE(mbuf_lowmem, vm_lowmem_handler_t);
 215
 216 /* Root mounted event */
 217 typedef void (*mountroot_handler_t)(void *);
 218 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
 219
 220 /* File system mount events */
 221 struct mount;
 222 struct vnode;
 223 struct thread;
 224 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
 225     struct thread *);
 226 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
 227     struct thread *);
 228 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
 229 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
 230
 231 /*
 232  * Process events
 233  * process_fork and exit handlers are called without Giant.
 234  * exec handlers are called with Giant, but that is by accident.
 235  */
 236 struct proc;
 237 struct image_params;
 238
 239 typedef void (*exitlist_fn)(void *, struct proc *);
 240 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
 241 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
 242 typedef void (*proc_ctor_fn)(void *, struct proc *);
 243 typedef void (*proc_dtor_fn)(void *, struct proc *);
 244 typedef void (*proc_init_fn)(void *, struct proc *);
 245 typedef void (*proc_fini_fn)(void *, struct proc *);
 246 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
 247 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
 248 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
 249 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
 250 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
 251 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
 252 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
 253
 254 /*
 255  * application dump event
 256  */
 257 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
 258 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
 259 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
 260 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
 261
 262 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
 263 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
 264 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
 265 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
 266
 267 typedef void (*thread_ctor_fn)(void *, struct thread *);
 268 typedef void (*thread_dtor_fn)(void *, struct thread *);
 269 typedef void (*thread_fini_fn)(void *, struct thread *);
 270 typedef void (*thread_init_fn)(void *, struct thread *);
 271 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
 272 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
 273 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
 274 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
 275
 276 typedef void (*uma_zone_chfn)(void *);
 277 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
 278 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
 279 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
 280
 281 /* Kernel linker file load and unload events */
 282 struct linker_file;
 283 typedef void (*kld_load_fn)(void *, struct linker_file *);
 284 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
 285 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
 286 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
 287 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
 288 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
 289
 290 /* Generic graphics framebuffer interface */
 291 struct fb_info;
 292 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
 293 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
 294 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
 295 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
 296
 297 /* Veto ada attachment */
 298 struct cam_path;
 299 struct ata_params;
 300 typedef void (*ada_probe_veto_fn)(void *, struct cam_path *,
 301     struct ata_params *, int *);
 302 EVENTHANDLER_DECLARE(ada_probe_veto, ada_probe_veto_fn);
 303
 304 /* Swap device events */
 305 struct swdevt;
 306 typedef void (*swapon_fn)(void *, struct swdevt *);
 307 typedef void (*swapoff_fn)(void *, struct swdevt *);
 308 EVENTHANDLER_DECLARE(swapon, swapon_fn);
 309 EVENTHANDLER_DECLARE(swapoff, swapoff_fn);
 310
 311 /* newbus device events */
 312 enum evhdev_detach {
 313         EVHDEV_DETACH_BEGIN,    /* Before detach() is called */
 314         EVHDEV_DETACH_COMPLETE, /* After detach() returns 0 */
 315         EVHDEV_DETACH_FAILED    /* After detach() returns err */
 316 };
 317 typedef void (*device_attach_fn)(void *, device_t);
 318 typedef void (*device_detach_fn)(void *, device_t, enum evhdev_detach);
 319 typedef void (*device_nomatch_fn)(void *, device_t);
 320 EVENTHANDLER_DECLARE(device_attach, device_attach_fn);
 321 EVENTHANDLER_DECLARE(device_detach, device_detach_fn);
 322 EVENTHANDLER_DECLARE(device_nomatch, device_nomatch_fn);
 323
 324 /* Interface address addition and removal event */
 325 struct ifaddr;
 326 typedef void (*rt_addrmsg_fn)(void *, struct ifaddr *, int);
 327 EVENTHANDLER_DECLARE(rt_addrmsg, rt_addrmsg_fn);
 328
 329 /* Kernel environment variable change event */
 330 typedef void (*env_change_fn)(void *, const char *);
 331 EVENTHANDLER_DECLARE(setenv, env_change_fn);
 332 EVENTHANDLER_DECLARE(unsetenv, env_change_fn);
 333
 334 #endif /* _SYS_EVENTHANDLER_H_ */