xref: /minix/minix/lib/libsys/sef.c (revision 03de4d97)
1 #include "syslib.h"
2 #include <assert.h>
3 #include <minix/sysutil.h>
4 #include <minix/rs.h>
5 #include <minix/timers.h>
6 #include <minix/endpoint.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <unistd.h>
10 #include <string.h>
11 
12 /* Self variables. */
13 #define SEF_SELF_NAME_MAXLEN 20
14 char sef_self_name[SEF_SELF_NAME_MAXLEN];
15 endpoint_t sef_self_endpoint = NONE;
16 endpoint_t sef_self_proc_nr;
17 int sef_self_priv_flags;
18 int sef_self_init_flags;
19 int sef_self_receiving;
20 int sef_controlled_crash;
21 
22 /* Extern variables. */
23 EXTERN int sef_lu_state;
24 EXTERN int __sef_st_before_receive_enabled;
25 EXTERN __attribute__((weak)) int __vm_init_fresh;
26 
27 /* Debug. */
28 #if SEF_INIT_DEBUG || SEF_LU_DEBUG || SEF_PING_DEBUG || SEF_SIGNAL_DEBUG
29 #define SEF_DEBUG_HEADER_MAXLEN 50
30 static int sef_debug_init = 0;
31 static time_t sef_debug_boottime = 0;
32 static u32_t sef_debug_system_hz = 0;
33 static time_t sef_debug_time_sec = 0;
34 static time_t sef_debug_time_us = 0;
35 static char sef_debug_header_buff[SEF_DEBUG_HEADER_MAXLEN];
36 static void sef_debug_refresh_params(void);
37 char* sef_debug_header(void);
38 #endif
39 
40 /* SEF Init prototypes. */
41 EXTERN int do_sef_rs_init(endpoint_t old_endpoint);
42 EXTERN int do_sef_init_request(message *m_ptr);
43 
44 /* SEF Ping prototypes. */
45 EXTERN int do_sef_ping_request(message *m_ptr);
46 
47 /* SEF Live update prototypes. */
48 EXTERN void do_sef_lu_before_receive(void);
49 EXTERN int do_sef_lu_request(message *m_ptr);
50 
51 /* SEF Signal prototypes. */
52 EXTERN int do_sef_signal_request(message *m_ptr);
53 
54 /* State transfer prototypes. */
55 EXTERN void do_sef_st_before_receive(void);
56 
57 /* SEF GCOV prototypes. */
58 #ifdef USE_COVERAGE
59 EXTERN int do_sef_gcov_request(message *m_ptr);
60 #endif
61 
62 /* SEF Fault Injection prototypes. */
63 EXTERN int do_sef_fi_request(message *m_ptr);
64 
65 /*===========================================================================*
66  *				sef_startup				     *
67  *===========================================================================*/
68 void sef_startup()
69 {
70 /* SEF startup interface for system services. */
71   int r, status;
72   endpoint_t old_endpoint;
73   int priv_flags;
74   int init_flags;
75   int sys_upd_flags = 0;
76 
77   /* Get information about self. */
78   r = sys_whoami(&sef_self_endpoint, sef_self_name, SEF_SELF_NAME_MAXLEN,
79       &priv_flags, &init_flags);
80   if ( r != OK) {
81       panic("sef_startup: sys_whoami failed: %d\n", r);
82   }
83 
84   sef_self_proc_nr = _ENDPOINT_P(sef_self_endpoint);
85   sef_self_priv_flags = priv_flags;
86   sef_self_init_flags = init_flags;
87   sef_lu_state = SEF_LU_STATE_NULL;
88   sef_controlled_crash = FALSE;
89   old_endpoint = NONE;
90   if(init_flags & SEF_LU_NOMMAP) {
91       sys_upd_flags |= SF_VM_NOMMAP;
92   }
93 
94 #if USE_LIVEUPDATE
95   /* RS may wake up with the wrong endpoint, perfom the update in that case. */
96   if((sef_self_priv_flags & ROOT_SYS_PROC) && sef_self_endpoint != RS_PROC_NR) {
97       r = vm_update(RS_PROC_NR, sef_self_endpoint, sys_upd_flags);
98       if(r != OK) {
99           panic("unable to update RS from instance %d to %d: %d",
100               RS_PROC_NR, sef_self_endpoint, r);
101       }
102       old_endpoint = sef_self_endpoint;
103       sef_self_endpoint = RS_PROC_NR;
104   }
105 #endif /* USE_LIVEUPDATE */
106 
107 #if INTERCEPT_SEF_INIT_REQUESTS
108   /* Intercept SEF Init requests. */
109   if(sef_self_priv_flags & ROOT_SYS_PROC) {
110       /* RS initialization is special. */
111       if((r = do_sef_rs_init(old_endpoint)) != OK) {
112           panic("RS unable to complete init: %d", r);
113       }
114   }
115   else if(sef_self_endpoint == VM_PROC_NR && __vm_init_fresh) {
116       /* VM handles fresh initialization by RS later */
117   } else {
118       message m;
119 
120       /* Wait for an initialization message from RS. We need this to learn the
121        * initialization type and parameters. When restarting after a crash, we
122        * may get some spurious IPC messages from RS (e.g. update request) that
123        * were originally meant to be delivered to the old instance. We discard
124        * these messages and block till a proper initialization request arrives.
125        */
126       do {
127           r = ipc_receive(RS_PROC_NR, &m, &status);
128           if(r != OK) {
129               panic("unable to ipc_receive from RS: %d", r);
130           }
131       } while(!IS_SEF_INIT_REQUEST(&m, status));
132 
133       /* Process initialization request for this system service. */
134       if((r = do_sef_init_request(&m)) != OK) {
135           panic("unable to process init request: %d", r);
136       }
137   }
138 #endif
139 
140   /* (Re)initialize SEF variables. */
141   sef_self_priv_flags = priv_flags;
142   sef_self_init_flags = init_flags;
143   sef_lu_state = SEF_LU_STATE_NULL;
144   sef_controlled_crash = FALSE;
145 }
146 
147 /*===========================================================================*
148  *				sef_receive_status			     *
149  *===========================================================================*/
150 int sef_receive_status(endpoint_t src, message *m_ptr, int *status_ptr)
151 {
152 /* SEF receive() interface for system services. */
153   int r, status, m_type;
154 
155   sef_self_receiving = TRUE;
156 
157   while(TRUE) {
158       /* If the caller indicated that it no longer wants to receive a message,
159        * return now.
160        */
161       if (!sef_self_receiving)
162           return EINTR;
163 
164 #if INTERCEPT_SEF_LU_REQUESTS
165       /* Handle SEF Live update before receive events. */
166       if(sef_lu_state != SEF_LU_STATE_NULL) {
167           do_sef_lu_before_receive();
168       }
169 
170       /* Handle State transfer before receive events. */
171       if(__sef_st_before_receive_enabled) {
172           do_sef_st_before_receive();
173       }
174 #endif
175 
176       /* Receive and return in case of error. */
177       r = ipc_receive(src, m_ptr, &status);
178       if(status_ptr) *status_ptr = status;
179       if(r != OK) {
180           return r;
181       }
182 
183       m_type = m_ptr->m_type;
184       if (is_ipc_notify(status)) {
185           switch (m_ptr->m_source) {
186               case SYSTEM:
187                   m_type = SEF_SIGNAL_REQUEST_TYPE;
188               break;
189               case RS_PROC_NR:
190                   m_type = SEF_PING_REQUEST_TYPE;
191               break;
192           }
193       }
194       switch(m_type) {
195 
196 #if INTERCEPT_SEF_INIT_REQUESTS
197       case SEF_INIT_REQUEST_TYPE:
198           /* Intercept SEF Init requests. */
199           if(IS_SEF_INIT_REQUEST(m_ptr, status)) {
200               /* Ignore spurious init requests. */
201               if (m_ptr->m_rs_init.type != SEF_INIT_FRESH
202                   || sef_self_endpoint != VM_PROC_NR)
203               continue;
204           }
205       break;
206 #endif
207 
208 #if INTERCEPT_SEF_PING_REQUESTS
209       case SEF_PING_REQUEST_TYPE:
210           /* Intercept SEF Ping requests. */
211           if(IS_SEF_PING_REQUEST(m_ptr, status)) {
212               if(do_sef_ping_request(m_ptr) == OK) {
213                   continue;
214               }
215           }
216       break;
217 #endif
218 
219 #if INTERCEPT_SEF_LU_REQUESTS
220       case SEF_LU_REQUEST_TYPE:
221           /* Intercept SEF Live update requests. */
222           if(IS_SEF_LU_REQUEST(m_ptr, status)) {
223               if(do_sef_lu_request(m_ptr) == OK) {
224                   continue;
225               }
226           }
227       break;
228 #endif
229 
230 #if INTERCEPT_SEF_SIGNAL_REQUESTS
231       case SEF_SIGNAL_REQUEST_TYPE:
232           /* Intercept SEF Signal requests. */
233           if(IS_SEF_SIGNAL_REQUEST(m_ptr, status)) {
234               if(do_sef_signal_request(m_ptr) == OK) {
235                   continue;
236               }
237           }
238       break;
239 #endif
240 
241 #if INTERCEPT_SEF_GCOV_REQUESTS && USE_COVERAGE
242       case SEF_GCOV_REQUEST_TYPE:
243           /* Intercept GCOV data requests (sent by VFS in vfs/gcov.c). */
244           if(IS_SEF_GCOV_REQUEST(m_ptr, status)) {
245               if(do_sef_gcov_request(m_ptr) == OK) {
246                   continue;
247               }
248           }
249       break;
250 #endif
251 
252 #if INTERCEPT_SEF_FI_REQUESTS
253       case SEF_FI_REQUEST_TYPE:
254           /* Intercept SEF Fault Injection requests. */
255           if(IS_SEF_FI_REQUEST(m_ptr, status)) {
256               if(do_sef_fi_request(m_ptr) == OK) {
257                   continue;
258               }
259           }
260       break;
261 #endif
262 
263       default:
264       break;
265       }
266 
267       /* If we get this far, this is not a valid SEF request, return and
268        * let the caller deal with that.
269        */
270       break;
271   }
272 
273   return r;
274 }
275 
276 /*===========================================================================*
277  *				sef_self				     *
278  *===========================================================================*/
279 endpoint_t sef_self(void)
280 {
281 /* Return the process's own endpoint number. */
282 
283   if (sef_self_endpoint == NONE)
284 	panic("sef_self called before initialization");
285 
286   return sef_self_endpoint;
287 }
288 
289 /*===========================================================================*
290  *				sef_cancel				     *
291  *===========================================================================*/
292 void sef_cancel(void)
293 {
294 /* Cancel receiving a message. This function be called from a callback invoked
295  * from within sef_receive_status(), which will then return an EINTR error
296  * code. In particular, this function can be used to exit from the main receive
297  * loop when a signal handler causes the process to want to shut down.
298  */
299 
300   sef_self_receiving = FALSE;
301 }
302 
303 /*===========================================================================*
304  *                              sef_getrndseed              		     *
305  *===========================================================================*/
306 int sef_getrndseed(void)
307 {
308     return (int)getticks();
309 }
310 
311 /*===========================================================================*
312  *      	                  sef_exit                                   *
313  *===========================================================================*/
314 void sef_exit(int status)
315 {
316 /* System services use a special version of exit() that generates a
317  * self-termination signal.
318  */
319 
320   /* Ask the kernel to exit. */
321   sys_exit();
322 
323   /* If everything else fails, hang. */
324   printf("Warning: system service %d couldn't exit\n", sef_self_endpoint);
325   for(;;) { }
326 }
327 
328 #ifdef __weak_alias
329 __weak_alias(_exit, sef_exit);
330 __weak_alias(__exit, sef_exit);
331 #endif
332 
333 /*===========================================================================*
334  *                                sef_munmap                                 *
335  *===========================================================================*/
336 int sef_munmap(void *addrstart, vir_bytes len, int type)
337 {
338 /* System services use a special version of munmap() to control implicit
339  * munmaps as startup and allow for asynchronous mnmap for VM.
340  */
341   message m;
342   m.m_type = type;
343   m.VMUM_ADDR = addrstart;
344   m.VMUM_LEN = len;
345   if(sef_self_endpoint == VM_PROC_NR) {
346       return asynsend3(SELF, &m, AMF_NOREPLY);
347   }
348   return _syscall(VM_PROC_NR, type, &m);
349 }
350 
351 #if SEF_INIT_DEBUG || SEF_LU_DEBUG || SEF_PING_DEBUG || SEF_SIGNAL_DEBUG
352 /*===========================================================================*
353  *                         sef_debug_refresh_params              	     *
354  *===========================================================================*/
355 static void sef_debug_refresh_params(void)
356 {
357 /* Refresh SEF debug params. */
358   clock_t uptime;
359 
360   /* Get boottime and system hz the first time. */
361   if(!sef_debug_init) {
362       if (sys_times(NONE, NULL, NULL, NULL, &sef_debug_boottime) != OK)
363 	  sef_debug_init = -1;
364       else if (sys_getinfo(GET_HZ, &sef_debug_system_hz,
365         sizeof(sef_debug_system_hz), 0, 0) != OK)
366 	  sef_debug_init = -1;
367       else
368 	  sef_debug_init = 1;
369   }
370 
371   /* Get uptime. */
372   uptime = -1;
373   if (sef_debug_init < 1 || sys_times(NONE, NULL, NULL, &uptime, NULL) != OK) {
374       sef_debug_time_sec = 0;
375       sef_debug_time_us = 0;
376   }
377   else {
378       /* Compute current time. */
379       sef_debug_time_sec = (time_t) (sef_debug_boottime
380           + (uptime/sef_debug_system_hz));
381       sef_debug_time_us = (uptime%sef_debug_system_hz)
382           * 1000000/sef_debug_system_hz;
383   }
384 }
385 
386 /*===========================================================================*
387  *                              sef_debug_header              		     *
388  *===========================================================================*/
389 char* sef_debug_header(void)
390 {
391 /* Build and return a SEF debug header. */
392   sef_debug_refresh_params();
393   snprintf(sef_debug_header_buff, sizeof(sef_debug_header_buff),
394       "%s: time = %ds %06dus", sef_self_name, (int) sef_debug_time_sec,
395       (int) sef_debug_time_us);
396 
397   return sef_debug_header_buff;
398 }
399 #endif /*SEF_INIT_DEBUG || SEF_LU_DEBUG || SEF_PING_DEBUG || SEF_SIGNAL_DEBUG*/
400 
401