xref: /redis-3.2.3/src/debug.c (revision fc00042e)
1 /*
2  * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  *   * Redistributions of source code must retain the above copyright notice,
9  *     this list of conditions and the following disclaimer.
10  *   * Redistributions in binary form must reproduce the above copyright
11  *     notice, this list of conditions and the following disclaimer in the
12  *     documentation and/or other materials provided with the distribution.
13  *   * Neither the name of Redis nor the names of its contributors may be used
14  *     to endorse or promote products derived from this software without
15  *     specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "server.h"
31 #include "sha1.h"   /* SHA1 is used for DEBUG DIGEST */
32 #include "crc64.h"
33 
34 #include <arpa/inet.h>
35 #include <signal.h>
36 
37 #ifdef HAVE_BACKTRACE
38 #include <execinfo.h>
39 #include <ucontext.h>
40 #include <fcntl.h>
41 #include "bio.h"
42 #endif /* HAVE_BACKTRACE */
43 
44 #ifdef __CYGWIN__
45 #ifndef SA_ONSTACK
46 #define SA_ONSTACK 0x08000000
47 #endif
48 #endif
49 
50 /* ================================= Debugging ============================== */
51 
52 /* Compute the sha1 of string at 's' with 'len' bytes long.
53  * The SHA1 is then xored against the string pointed by digest.
54  * Since xor is commutative, this operation is used in order to
55  * "add" digests relative to unordered elements.
56  *
57  * So digest(a,b,c,d) will be the same of digest(b,a,c,d) */
58 void xorDigest(unsigned char *digest, void *ptr, size_t len) {
59     SHA1_CTX ctx;
60     unsigned char hash[20], *s = ptr;
61     int j;
62 
63     SHA1Init(&ctx);
64     SHA1Update(&ctx,s,len);
65     SHA1Final(hash,&ctx);
66 
67     for (j = 0; j < 20; j++)
68         digest[j] ^= hash[j];
69 }
70 
71 void xorObjectDigest(unsigned char *digest, robj *o) {
72     o = getDecodedObject(o);
73     xorDigest(digest,o->ptr,sdslen(o->ptr));
74     decrRefCount(o);
75 }
76 
77 /* This function instead of just computing the SHA1 and xoring it
78  * against digest, also perform the digest of "digest" itself and
79  * replace the old value with the new one.
80  *
81  * So the final digest will be:
82  *
83  * digest = SHA1(digest xor SHA1(data))
84  *
85  * This function is used every time we want to preserve the order so
86  * that digest(a,b,c,d) will be different than digest(b,c,d,a)
87  *
88  * Also note that mixdigest("foo") followed by mixdigest("bar")
89  * will lead to a different digest compared to "fo", "obar".
90  */
91 void mixDigest(unsigned char *digest, void *ptr, size_t len) {
92     SHA1_CTX ctx;
93     char *s = ptr;
94 
95     xorDigest(digest,s,len);
96     SHA1Init(&ctx);
97     SHA1Update(&ctx,digest,20);
98     SHA1Final(digest,&ctx);
99 }
100 
101 void mixObjectDigest(unsigned char *digest, robj *o) {
102     o = getDecodedObject(o);
103     mixDigest(digest,o->ptr,sdslen(o->ptr));
104     decrRefCount(o);
105 }
106 
107 /* Compute the dataset digest. Since keys, sets elements, hashes elements
108  * are not ordered, we use a trick: every aggregate digest is the xor
109  * of the digests of their elements. This way the order will not change
110  * the result. For list instead we use a feedback entering the output digest
111  * as input in order to ensure that a different ordered list will result in
112  * a different digest. */
113 void computeDatasetDigest(unsigned char *final) {
114     unsigned char digest[20];
115     char buf[128];
116     dictIterator *di = NULL;
117     dictEntry *de;
118     int j;
119     uint32_t aux;
120 
121     memset(final,0,20); /* Start with a clean result */
122 
123     for (j = 0; j < server.dbnum; j++) {
124         redisDb *db = server.db+j;
125 
126         if (dictSize(db->dict) == 0) continue;
127         di = dictGetIterator(db->dict);
128 
129         /* hash the DB id, so the same dataset moved in a different
130          * DB will lead to a different digest */
131         aux = htonl(j);
132         mixDigest(final,&aux,sizeof(aux));
133 
134         /* Iterate this DB writing every entry */
135         while((de = dictNext(di)) != NULL) {
136             sds key;
137             robj *keyobj, *o;
138             long long expiretime;
139 
140             memset(digest,0,20); /* This key-val digest */
141             key = dictGetKey(de);
142             keyobj = createStringObject(key,sdslen(key));
143 
144             mixDigest(digest,key,sdslen(key));
145 
146             o = dictGetVal(de);
147 
148             aux = htonl(o->type);
149             mixDigest(digest,&aux,sizeof(aux));
150             expiretime = getExpire(db,keyobj);
151 
152             /* Save the key and associated value */
153             if (o->type == OBJ_STRING) {
154                 mixObjectDigest(digest,o);
155             } else if (o->type == OBJ_LIST) {
156                 listTypeIterator *li = listTypeInitIterator(o,0,LIST_TAIL);
157                 listTypeEntry entry;
158                 while(listTypeNext(li,&entry)) {
159                     robj *eleobj = listTypeGet(&entry);
160                     mixObjectDigest(digest,eleobj);
161                     decrRefCount(eleobj);
162                 }
163                 listTypeReleaseIterator(li);
164             } else if (o->type == OBJ_SET) {
165                 setTypeIterator *si = setTypeInitIterator(o);
166                 robj *ele;
167                 while((ele = setTypeNextObject(si)) != NULL) {
168                     xorObjectDigest(digest,ele);
169                     decrRefCount(ele);
170                 }
171                 setTypeReleaseIterator(si);
172             } else if (o->type == OBJ_ZSET) {
173                 unsigned char eledigest[20];
174 
175                 if (o->encoding == OBJ_ENCODING_ZIPLIST) {
176                     unsigned char *zl = o->ptr;
177                     unsigned char *eptr, *sptr;
178                     unsigned char *vstr;
179                     unsigned int vlen;
180                     long long vll;
181                     double score;
182 
183                     eptr = ziplistIndex(zl,0);
184                     serverAssert(eptr != NULL);
185                     sptr = ziplistNext(zl,eptr);
186                     serverAssert(sptr != NULL);
187 
188                     while (eptr != NULL) {
189                         serverAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
190                         score = zzlGetScore(sptr);
191 
192                         memset(eledigest,0,20);
193                         if (vstr != NULL) {
194                             mixDigest(eledigest,vstr,vlen);
195                         } else {
196                             ll2string(buf,sizeof(buf),vll);
197                             mixDigest(eledigest,buf,strlen(buf));
198                         }
199 
200                         snprintf(buf,sizeof(buf),"%.17g",score);
201                         mixDigest(eledigest,buf,strlen(buf));
202                         xorDigest(digest,eledigest,20);
203                         zzlNext(zl,&eptr,&sptr);
204                     }
205                 } else if (o->encoding == OBJ_ENCODING_SKIPLIST) {
206                     zset *zs = o->ptr;
207                     dictIterator *di = dictGetIterator(zs->dict);
208                     dictEntry *de;
209 
210                     while((de = dictNext(di)) != NULL) {
211                         robj *eleobj = dictGetKey(de);
212                         double *score = dictGetVal(de);
213 
214                         snprintf(buf,sizeof(buf),"%.17g",*score);
215                         memset(eledigest,0,20);
216                         mixObjectDigest(eledigest,eleobj);
217                         mixDigest(eledigest,buf,strlen(buf));
218                         xorDigest(digest,eledigest,20);
219                     }
220                     dictReleaseIterator(di);
221                 } else {
222                     serverPanic("Unknown sorted set encoding");
223                 }
224             } else if (o->type == OBJ_HASH) {
225                 hashTypeIterator *hi;
226                 robj *obj;
227 
228                 hi = hashTypeInitIterator(o);
229                 while (hashTypeNext(hi) != C_ERR) {
230                     unsigned char eledigest[20];
231 
232                     memset(eledigest,0,20);
233                     obj = hashTypeCurrentObject(hi,OBJ_HASH_KEY);
234                     mixObjectDigest(eledigest,obj);
235                     decrRefCount(obj);
236                     obj = hashTypeCurrentObject(hi,OBJ_HASH_VALUE);
237                     mixObjectDigest(eledigest,obj);
238                     decrRefCount(obj);
239                     xorDigest(digest,eledigest,20);
240                 }
241                 hashTypeReleaseIterator(hi);
242             } else {
243                 serverPanic("Unknown object type");
244             }
245             /* If the key has an expire, add it to the mix */
246             if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
247             /* We can finally xor the key-val digest to the final digest */
248             xorDigest(final,digest,20);
249             decrRefCount(keyobj);
250         }
251         dictReleaseIterator(di);
252     }
253 }
254 
255 void inputCatSds(void *result, const char *str) {
256     /* result is actually a (sds *), so re-cast it here */
257     sds *info = (sds *)result;
258     *info = sdscat(*info, str);
259 }
260 
261 void debugCommand(client *c) {
262     if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
263         *((char*)-1) = 'x';
264     } else if (!strcasecmp(c->argv[1]->ptr,"restart") ||
265                !strcasecmp(c->argv[1]->ptr,"crash-and-recover"))
266     {
267         long long delay = 0;
268         if (c->argc >= 3) {
269             if (getLongLongFromObjectOrReply(c, c->argv[2], &delay, NULL)
270                 != C_OK) return;
271             if (delay < 0) delay = 0;
272         }
273         int flags = !strcasecmp(c->argv[1]->ptr,"restart") ?
274             (RESTART_SERVER_GRACEFULLY|RESTART_SERVER_CONFIG_REWRITE) :
275              RESTART_SERVER_NONE;
276         restartServer(flags,delay);
277         addReplyError(c,"failed to restart the server. Check server logs.");
278     } else if (!strcasecmp(c->argv[1]->ptr,"oom")) {
279         void *ptr = zmalloc(ULONG_MAX); /* Should trigger an out of memory. */
280         zfree(ptr);
281         addReply(c,shared.ok);
282     } else if (!strcasecmp(c->argv[1]->ptr,"assert")) {
283         if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
284         serverAssertWithInfo(c,c->argv[0],1 == 2);
285     } else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
286         if (rdbSave(server.rdb_filename) != C_OK) {
287             addReply(c,shared.err);
288             return;
289         }
290         emptyDb(NULL);
291         if (rdbLoad(server.rdb_filename) != C_OK) {
292             addReplyError(c,"Error trying to load the RDB dump");
293             return;
294         }
295         serverLog(LL_WARNING,"DB reloaded by DEBUG RELOAD");
296         addReply(c,shared.ok);
297     } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
298         if (server.aof_state == AOF_ON) flushAppendOnlyFile(1);
299         emptyDb(NULL);
300         if (loadAppendOnlyFile(server.aof_filename) != C_OK) {
301             addReply(c,shared.err);
302             return;
303         }
304         server.dirty = 0; /* Prevent AOF / replication */
305         serverLog(LL_WARNING,"Append Only File loaded by DEBUG LOADAOF");
306         addReply(c,shared.ok);
307     } else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) {
308         dictEntry *de;
309         robj *val;
310         char *strenc;
311 
312         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
313             addReply(c,shared.nokeyerr);
314             return;
315         }
316         val = dictGetVal(de);
317         strenc = strEncoding(val->encoding);
318 
319         char extra[128] = {0};
320         if (val->encoding == OBJ_ENCODING_QUICKLIST) {
321             char *nextra = extra;
322             int remaining = sizeof(extra);
323             quicklist *ql = val->ptr;
324             /* Add number of quicklist nodes */
325             int used = snprintf(nextra, remaining, " ql_nodes:%u", ql->len);
326             nextra += used;
327             remaining -= used;
328             /* Add average quicklist fill factor */
329             double avg = (double)ql->count/ql->len;
330             used = snprintf(nextra, remaining, " ql_avg_node:%.2f", avg);
331             nextra += used;
332             remaining -= used;
333             /* Add quicklist fill level / max ziplist size */
334             used = snprintf(nextra, remaining, " ql_ziplist_max:%d", ql->fill);
335             nextra += used;
336             remaining -= used;
337             /* Add isCompressed? */
338             int compressed = ql->compress != 0;
339             used = snprintf(nextra, remaining, " ql_compressed:%d", compressed);
340             nextra += used;
341             remaining -= used;
342             /* Add total uncompressed size */
343             unsigned long sz = 0;
344             for (quicklistNode *node = ql->head; node; node = node->next) {
345                 sz += node->sz;
346             }
347             used = snprintf(nextra, remaining, " ql_uncompressed_size:%lu", sz);
348             nextra += used;
349             remaining -= used;
350         }
351 
352         addReplyStatusFormat(c,
353             "Value at:%p refcount:%d "
354             "encoding:%s serializedlength:%zu "
355             "lru:%d lru_seconds_idle:%llu%s",
356             (void*)val, val->refcount,
357             strenc, rdbSavedObjectLen(val),
358             val->lru, estimateObjectIdleTime(val)/1000, extra);
359     } else if (!strcasecmp(c->argv[1]->ptr,"sdslen") && c->argc == 3) {
360         dictEntry *de;
361         robj *val;
362         sds key;
363 
364         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
365             addReply(c,shared.nokeyerr);
366             return;
367         }
368         val = dictGetVal(de);
369         key = dictGetKey(de);
370 
371         if (val->type != OBJ_STRING || !sdsEncodedObject(val)) {
372             addReplyError(c,"Not an sds encoded string.");
373         } else {
374             addReplyStatusFormat(c,
375                 "key_sds_len:%lld, key_sds_avail:%lld, "
376                 "val_sds_len:%lld, val_sds_avail:%lld",
377                 (long long) sdslen(key),
378                 (long long) sdsavail(key),
379                 (long long) sdslen(val->ptr),
380                 (long long) sdsavail(val->ptr));
381         }
382     } else if (!strcasecmp(c->argv[1]->ptr,"populate") &&
383                (c->argc == 3 || c->argc == 4)) {
384         long keys, j;
385         robj *key, *val;
386         char buf[128];
387 
388         if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != C_OK)
389             return;
390         dictExpand(c->db->dict,keys);
391         for (j = 0; j < keys; j++) {
392             snprintf(buf,sizeof(buf),"%s:%lu",
393                 (c->argc == 3) ? "key" : (char*)c->argv[3]->ptr, j);
394             key = createStringObject(buf,strlen(buf));
395             if (lookupKeyWrite(c->db,key) != NULL) {
396                 decrRefCount(key);
397                 continue;
398             }
399             snprintf(buf,sizeof(buf),"value:%lu",j);
400             val = createStringObject(buf,strlen(buf));
401             dbAdd(c->db,key,val);
402             decrRefCount(key);
403         }
404         addReply(c,shared.ok);
405     } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
406         unsigned char digest[20];
407         sds d = sdsempty();
408         int j;
409 
410         computeDatasetDigest(digest);
411         for (j = 0; j < 20; j++)
412             d = sdscatprintf(d, "%02x",digest[j]);
413         addReplyStatus(c,d);
414         sdsfree(d);
415     } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
416         double dtime = strtod(c->argv[2]->ptr,NULL);
417         long long utime = dtime*1000000;
418         struct timespec tv;
419 
420         tv.tv_sec = utime / 1000000;
421         tv.tv_nsec = (utime % 1000000) * 1000;
422         nanosleep(&tv, NULL);
423         addReply(c,shared.ok);
424     } else if (!strcasecmp(c->argv[1]->ptr,"set-active-expire") &&
425                c->argc == 3)
426     {
427         server.active_expire_enabled = atoi(c->argv[2]->ptr);
428         addReply(c,shared.ok);
429     } else if (!strcasecmp(c->argv[1]->ptr,"lua-always-replicate-commands") &&
430                c->argc == 3)
431     {
432         server.lua_always_replicate_commands = atoi(c->argv[2]->ptr);
433         addReply(c,shared.ok);
434     } else if (!strcasecmp(c->argv[1]->ptr,"error") && c->argc == 3) {
435         sds errstr = sdsnewlen("-",1);
436 
437         errstr = sdscatsds(errstr,c->argv[2]->ptr);
438         errstr = sdsmapchars(errstr,"\n\r","  ",2); /* no newlines in errors. */
439         errstr = sdscatlen(errstr,"\r\n",2);
440         addReplySds(c,errstr);
441     } else if (!strcasecmp(c->argv[1]->ptr,"structsize") && c->argc == 2) {
442         sds sizes = sdsempty();
443         sizes = sdscatprintf(sizes,"bits:%d ",(sizeof(void*) == 8)?64:32);
444         sizes = sdscatprintf(sizes,"robj:%d ",(int)sizeof(robj));
445         sizes = sdscatprintf(sizes,"dictentry:%d ",(int)sizeof(dictEntry));
446         sizes = sdscatprintf(sizes,"sdshdr5:%d ",(int)sizeof(struct sdshdr5));
447         sizes = sdscatprintf(sizes,"sdshdr8:%d ",(int)sizeof(struct sdshdr8));
448         sizes = sdscatprintf(sizes,"sdshdr16:%d ",(int)sizeof(struct sdshdr16));
449         sizes = sdscatprintf(sizes,"sdshdr32:%d ",(int)sizeof(struct sdshdr32));
450         sizes = sdscatprintf(sizes,"sdshdr64:%d ",(int)sizeof(struct sdshdr64));
451         addReplyBulkSds(c,sizes);
452     } else if (!strcasecmp(c->argv[1]->ptr,"htstats") && c->argc == 3) {
453         long dbid;
454         sds stats = sdsempty();
455         char buf[4096];
456 
457         if (getLongFromObjectOrReply(c, c->argv[2], &dbid, NULL) != C_OK)
458             return;
459         if (dbid < 0 || dbid >= server.dbnum) {
460             addReplyError(c,"Out of range database");
461             return;
462         }
463 
464         stats = sdscatprintf(stats,"[Dictionary HT]\n");
465         dictGetStats(buf,sizeof(buf),server.db[dbid].dict);
466         stats = sdscat(stats,buf);
467 
468         stats = sdscatprintf(stats,"[Expires HT]\n");
469         dictGetStats(buf,sizeof(buf),server.db[dbid].expires);
470         stats = sdscat(stats,buf);
471 
472         addReplyBulkSds(c,stats);
473     } else if (!strcasecmp(c->argv[1]->ptr,"jemalloc") && c->argc == 3) {
474 #if defined(USE_JEMALLOC)
475         if (!strcasecmp(c->argv[2]->ptr, "info")) {
476             sds info = sdsempty();
477             je_malloc_stats_print(inputCatSds, &info, NULL);
478             addReplyBulkSds(c, info);
479         } else {
480             addReplyErrorFormat(c, "Valid jemalloc debug fields: info");
481         }
482 #else
483         addReplyErrorFormat(c, "jemalloc support not available");
484 #endif
485     } else {
486         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
487             (char*)c->argv[1]->ptr);
488     }
489 }
490 
491 /* =========================== Crash handling  ============================== */
492 
493 void _serverAssert(char *estr, char *file, int line) {
494     bugReportStart();
495     serverLog(LL_WARNING,"=== ASSERTION FAILED ===");
496     serverLog(LL_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
497 #ifdef HAVE_BACKTRACE
498     server.assert_failed = estr;
499     server.assert_file = file;
500     server.assert_line = line;
501     serverLog(LL_WARNING,"(forcing SIGSEGV to print the bug report.)");
502 #endif
503     *((char*)-1) = 'x';
504 }
505 
506 void _serverAssertPrintClientInfo(client *c) {
507     int j;
508 
509     bugReportStart();
510     serverLog(LL_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
511     serverLog(LL_WARNING,"client->flags = %d", c->flags);
512     serverLog(LL_WARNING,"client->fd = %d", c->fd);
513     serverLog(LL_WARNING,"client->argc = %d", c->argc);
514     for (j=0; j < c->argc; j++) {
515         char buf[128];
516         char *arg;
517 
518         if (c->argv[j]->type == OBJ_STRING && sdsEncodedObject(c->argv[j])) {
519             arg = (char*) c->argv[j]->ptr;
520         } else {
521             snprintf(buf,sizeof(buf),"Object type: %u, encoding: %u",
522                 c->argv[j]->type, c->argv[j]->encoding);
523             arg = buf;
524         }
525         serverLog(LL_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
526             j, arg, c->argv[j]->refcount);
527     }
528 }
529 
530 void serverLogObjectDebugInfo(robj *o) {
531     serverLog(LL_WARNING,"Object type: %d", o->type);
532     serverLog(LL_WARNING,"Object encoding: %d", o->encoding);
533     serverLog(LL_WARNING,"Object refcount: %d", o->refcount);
534     if (o->type == OBJ_STRING && sdsEncodedObject(o)) {
535         serverLog(LL_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
536         if (sdslen(o->ptr) < 4096) {
537             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
538             serverLog(LL_WARNING,"Object raw string content: %s", repr);
539             sdsfree(repr);
540         }
541     } else if (o->type == OBJ_LIST) {
542         serverLog(LL_WARNING,"List length: %d", (int) listTypeLength(o));
543     } else if (o->type == OBJ_SET) {
544         serverLog(LL_WARNING,"Set size: %d", (int) setTypeSize(o));
545     } else if (o->type == OBJ_HASH) {
546         serverLog(LL_WARNING,"Hash size: %d", (int) hashTypeLength(o));
547     } else if (o->type == OBJ_ZSET) {
548         serverLog(LL_WARNING,"Sorted set size: %d", (int) zsetLength(o));
549         if (o->encoding == OBJ_ENCODING_SKIPLIST)
550             serverLog(LL_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
551     }
552 }
553 
554 void _serverAssertPrintObject(robj *o) {
555     bugReportStart();
556     serverLog(LL_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
557     serverLogObjectDebugInfo(o);
558 }
559 
560 void _serverAssertWithInfo(client *c, robj *o, char *estr, char *file, int line) {
561     if (c) _serverAssertPrintClientInfo(c);
562     if (o) _serverAssertPrintObject(o);
563     _serverAssert(estr,file,line);
564 }
565 
566 void _serverPanic(char *msg, char *file, int line) {
567     bugReportStart();
568     serverLog(LL_WARNING,"------------------------------------------------");
569     serverLog(LL_WARNING,"!!! Software Failure. Press left mouse button to continue");
570     serverLog(LL_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
571 #ifdef HAVE_BACKTRACE
572     serverLog(LL_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
573 #endif
574     serverLog(LL_WARNING,"------------------------------------------------");
575     *((char*)-1) = 'x';
576 }
577 
578 void bugReportStart(void) {
579     if (server.bug_report_start == 0) {
580         serverLogRaw(LL_WARNING|LL_RAW,
581         "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===\n");
582         server.bug_report_start = 1;
583     }
584 }
585 
586 #ifdef HAVE_BACKTRACE
587 static void *getMcontextEip(ucontext_t *uc) {
588 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
589     /* OSX < 10.6 */
590     #if defined(__x86_64__)
591     return (void*) uc->uc_mcontext->__ss.__rip;
592     #elif defined(__i386__)
593     return (void*) uc->uc_mcontext->__ss.__eip;
594     #else
595     return (void*) uc->uc_mcontext->__ss.__srr0;
596     #endif
597 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
598     /* OSX >= 10.6 */
599     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
600     return (void*) uc->uc_mcontext->__ss.__rip;
601     #else
602     return (void*) uc->uc_mcontext->__ss.__eip;
603     #endif
604 #elif defined(__linux__)
605     /* Linux */
606     #if defined(__i386__)
607     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
608     #elif defined(__X86_64__) || defined(__x86_64__)
609     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
610     #elif defined(__ia64__) /* Linux IA64 */
611     return (void*) uc->uc_mcontext.sc_ip;
612     #endif
613 #else
614     return NULL;
615 #endif
616 }
617 
618 void logStackContent(void **sp) {
619     int i;
620     for (i = 15; i >= 0; i--) {
621         unsigned long addr = (unsigned long) sp+i;
622         unsigned long val = (unsigned long) sp[i];
623 
624         if (sizeof(long) == 4)
625             serverLog(LL_WARNING, "(%08lx) -> %08lx", addr, val);
626         else
627             serverLog(LL_WARNING, "(%016lx) -> %016lx", addr, val);
628     }
629 }
630 
631 void logRegisters(ucontext_t *uc) {
632     serverLog(LL_WARNING|LL_RAW, "\n------ REGISTERS ------\n");
633 
634 /* OSX */
635 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
636   /* OSX AMD64 */
637     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
638     serverLog(LL_WARNING,
639     "\n"
640     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
641     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
642     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
643     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
644     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
645         (unsigned long) uc->uc_mcontext->__ss.__rax,
646         (unsigned long) uc->uc_mcontext->__ss.__rbx,
647         (unsigned long) uc->uc_mcontext->__ss.__rcx,
648         (unsigned long) uc->uc_mcontext->__ss.__rdx,
649         (unsigned long) uc->uc_mcontext->__ss.__rdi,
650         (unsigned long) uc->uc_mcontext->__ss.__rsi,
651         (unsigned long) uc->uc_mcontext->__ss.__rbp,
652         (unsigned long) uc->uc_mcontext->__ss.__rsp,
653         (unsigned long) uc->uc_mcontext->__ss.__r8,
654         (unsigned long) uc->uc_mcontext->__ss.__r9,
655         (unsigned long) uc->uc_mcontext->__ss.__r10,
656         (unsigned long) uc->uc_mcontext->__ss.__r11,
657         (unsigned long) uc->uc_mcontext->__ss.__r12,
658         (unsigned long) uc->uc_mcontext->__ss.__r13,
659         (unsigned long) uc->uc_mcontext->__ss.__r14,
660         (unsigned long) uc->uc_mcontext->__ss.__r15,
661         (unsigned long) uc->uc_mcontext->__ss.__rip,
662         (unsigned long) uc->uc_mcontext->__ss.__rflags,
663         (unsigned long) uc->uc_mcontext->__ss.__cs,
664         (unsigned long) uc->uc_mcontext->__ss.__fs,
665         (unsigned long) uc->uc_mcontext->__ss.__gs
666     );
667     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
668     #else
669     /* OSX x86 */
670     serverLog(LL_WARNING,
671     "\n"
672     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
673     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
674     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
675     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
676         (unsigned long) uc->uc_mcontext->__ss.__eax,
677         (unsigned long) uc->uc_mcontext->__ss.__ebx,
678         (unsigned long) uc->uc_mcontext->__ss.__ecx,
679         (unsigned long) uc->uc_mcontext->__ss.__edx,
680         (unsigned long) uc->uc_mcontext->__ss.__edi,
681         (unsigned long) uc->uc_mcontext->__ss.__esi,
682         (unsigned long) uc->uc_mcontext->__ss.__ebp,
683         (unsigned long) uc->uc_mcontext->__ss.__esp,
684         (unsigned long) uc->uc_mcontext->__ss.__ss,
685         (unsigned long) uc->uc_mcontext->__ss.__eflags,
686         (unsigned long) uc->uc_mcontext->__ss.__eip,
687         (unsigned long) uc->uc_mcontext->__ss.__cs,
688         (unsigned long) uc->uc_mcontext->__ss.__ds,
689         (unsigned long) uc->uc_mcontext->__ss.__es,
690         (unsigned long) uc->uc_mcontext->__ss.__fs,
691         (unsigned long) uc->uc_mcontext->__ss.__gs
692     );
693     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
694     #endif
695 /* Linux */
696 #elif defined(__linux__)
697     /* Linux x86 */
698     #if defined(__i386__)
699     serverLog(LL_WARNING,
700     "\n"
701     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
702     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
703     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
704     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
705         (unsigned long) uc->uc_mcontext.gregs[11],
706         (unsigned long) uc->uc_mcontext.gregs[8],
707         (unsigned long) uc->uc_mcontext.gregs[10],
708         (unsigned long) uc->uc_mcontext.gregs[9],
709         (unsigned long) uc->uc_mcontext.gregs[4],
710         (unsigned long) uc->uc_mcontext.gregs[5],
711         (unsigned long) uc->uc_mcontext.gregs[6],
712         (unsigned long) uc->uc_mcontext.gregs[7],
713         (unsigned long) uc->uc_mcontext.gregs[18],
714         (unsigned long) uc->uc_mcontext.gregs[17],
715         (unsigned long) uc->uc_mcontext.gregs[14],
716         (unsigned long) uc->uc_mcontext.gregs[15],
717         (unsigned long) uc->uc_mcontext.gregs[3],
718         (unsigned long) uc->uc_mcontext.gregs[2],
719         (unsigned long) uc->uc_mcontext.gregs[1],
720         (unsigned long) uc->uc_mcontext.gregs[0]
721     );
722     logStackContent((void**)uc->uc_mcontext.gregs[7]);
723     #elif defined(__X86_64__) || defined(__x86_64__)
724     /* Linux AMD64 */
725     serverLog(LL_WARNING,
726     "\n"
727     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
728     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
729     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
730     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
731     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
732         (unsigned long) uc->uc_mcontext.gregs[13],
733         (unsigned long) uc->uc_mcontext.gregs[11],
734         (unsigned long) uc->uc_mcontext.gregs[14],
735         (unsigned long) uc->uc_mcontext.gregs[12],
736         (unsigned long) uc->uc_mcontext.gregs[8],
737         (unsigned long) uc->uc_mcontext.gregs[9],
738         (unsigned long) uc->uc_mcontext.gregs[10],
739         (unsigned long) uc->uc_mcontext.gregs[15],
740         (unsigned long) uc->uc_mcontext.gregs[0],
741         (unsigned long) uc->uc_mcontext.gregs[1],
742         (unsigned long) uc->uc_mcontext.gregs[2],
743         (unsigned long) uc->uc_mcontext.gregs[3],
744         (unsigned long) uc->uc_mcontext.gregs[4],
745         (unsigned long) uc->uc_mcontext.gregs[5],
746         (unsigned long) uc->uc_mcontext.gregs[6],
747         (unsigned long) uc->uc_mcontext.gregs[7],
748         (unsigned long) uc->uc_mcontext.gregs[16],
749         (unsigned long) uc->uc_mcontext.gregs[17],
750         (unsigned long) uc->uc_mcontext.gregs[18]
751     );
752     logStackContent((void**)uc->uc_mcontext.gregs[15]);
753     #endif
754 #else
755     serverLog(LL_WARNING,
756         "  Dumping of registers not supported for this OS/arch");
757 #endif
758 }
759 
760 /* Return a file descriptor to write directly to the Redis log with the
761  * write(2) syscall, that can be used in critical sections of the code
762  * where the rest of Redis can't be trusted (for example during the memory
763  * test) or when an API call requires a raw fd.
764  *
765  * Close it with closeDirectLogFiledes(). */
766 int openDirectLogFiledes(void) {
767     int log_to_stdout = server.logfile[0] == '\0';
768     int fd = log_to_stdout ?
769         STDOUT_FILENO :
770         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
771     return fd;
772 }
773 
774 /* Used to close what closeDirectLogFiledes() returns. */
775 void closeDirectLogFiledes(int fd) {
776     int log_to_stdout = server.logfile[0] == '\0';
777     if (!log_to_stdout) close(fd);
778 }
779 
780 /* Logs the stack trace using the backtrace() call. This function is designed
781  * to be called from signal handlers safely. */
782 void logStackTrace(ucontext_t *uc) {
783     void *trace[101];
784     int trace_size = 0, fd = openDirectLogFiledes();
785 
786     if (fd == -1) return; /* If we can't log there is anything to do. */
787 
788     /* Generate the stack trace */
789     trace_size = backtrace(trace+1, 100);
790 
791     if (getMcontextEip(uc) != NULL) {
792         char *msg1 = "EIP:\n";
793         char *msg2 = "\nBacktrace:\n";
794         if (write(fd,msg1,strlen(msg1)) == -1) {/* Avoid warning. */};
795         trace[0] = getMcontextEip(uc);
796         backtrace_symbols_fd(trace, 1, fd);
797         if (write(fd,msg2,strlen(msg2)) == -1) {/* Avoid warning. */};
798     }
799 
800     /* Write symbols to log file */
801     backtrace_symbols_fd(trace+1, trace_size, fd);
802 
803     /* Cleanup */
804     closeDirectLogFiledes(fd);
805 }
806 
807 /* Log information about the "current" client, that is, the client that is
808  * currently being served by Redis. May be NULL if Redis is not serving a
809  * client right now. */
810 void logCurrentClient(void) {
811     if (server.current_client == NULL) return;
812 
813     client *cc = server.current_client;
814     sds client;
815     int j;
816 
817     serverLogRaw(LL_WARNING|LL_RAW, "\n------ CURRENT CLIENT INFO ------\n");
818     client = catClientInfoString(sdsempty(),cc);
819     serverLog(LL_WARNING|LL_RAW,"%s\n", client);
820     sdsfree(client);
821     for (j = 0; j < cc->argc; j++) {
822         robj *decoded;
823 
824         decoded = getDecodedObject(cc->argv[j]);
825         serverLog(LL_WARNING|LL_RAW,"argv[%d]: '%s'\n", j,
826             (char*)decoded->ptr);
827         decrRefCount(decoded);
828     }
829     /* Check if the first argument, usually a key, is found inside the
830      * selected DB, and if so print info about the associated object. */
831     if (cc->argc >= 1) {
832         robj *val, *key;
833         dictEntry *de;
834 
835         key = getDecodedObject(cc->argv[1]);
836         de = dictFind(cc->db->dict, key->ptr);
837         if (de) {
838             val = dictGetVal(de);
839             serverLog(LL_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
840             serverLogObjectDebugInfo(val);
841         }
842         decrRefCount(key);
843     }
844 }
845 
846 #if defined(HAVE_PROC_MAPS)
847 
848 #define MEMTEST_MAX_REGIONS 128
849 
850 /* A non destructive memory test executed during segfauls. */
851 int memtest_test_linux_anonymous_maps(void) {
852     FILE *fp;
853     char line[1024];
854     char logbuf[1024];
855     size_t start_addr, end_addr, size;
856     size_t start_vect[MEMTEST_MAX_REGIONS];
857     size_t size_vect[MEMTEST_MAX_REGIONS];
858     int regions = 0, j;
859 
860     int fd = openDirectLogFiledes();
861     if (!fd) return 0;
862 
863     fp = fopen("/proc/self/maps","r");
864     if (!fp) return 0;
865     while(fgets(line,sizeof(line),fp) != NULL) {
866         char *start, *end, *p = line;
867 
868         start = p;
869         p = strchr(p,'-');
870         if (!p) continue;
871         *p++ = '\0';
872         end = p;
873         p = strchr(p,' ');
874         if (!p) continue;
875         *p++ = '\0';
876         if (strstr(p,"stack") ||
877             strstr(p,"vdso") ||
878             strstr(p,"vsyscall")) continue;
879         if (!strstr(p,"00:00")) continue;
880         if (!strstr(p,"rw")) continue;
881 
882         start_addr = strtoul(start,NULL,16);
883         end_addr = strtoul(end,NULL,16);
884         size = end_addr-start_addr;
885 
886         start_vect[regions] = start_addr;
887         size_vect[regions] = size;
888         snprintf(logbuf,sizeof(logbuf),
889             "*** Preparing to test memory region %lx (%lu bytes)\n",
890                 (unsigned long) start_vect[regions],
891                 (unsigned long) size_vect[regions]);
892         if (write(fd,logbuf,strlen(logbuf)) == -1) { /* Nothing to do. */ }
893         regions++;
894     }
895 
896     int errors = 0;
897     for (j = 0; j < regions; j++) {
898         if (write(fd,".",1) == -1) { /* Nothing to do. */ }
899         errors += memtest_preserving_test((void*)start_vect[j],size_vect[j],1);
900         if (write(fd, errors ? "E" : "O",1) == -1) { /* Nothing to do. */ }
901     }
902     if (write(fd,"\n",1) == -1) { /* Nothing to do. */ }
903 
904     /* NOTE: It is very important to close the file descriptor only now
905      * because closing it before may result into unmapping of some memory
906      * region that we are testing. */
907     fclose(fp);
908     closeDirectLogFiledes(fd);
909     return errors;
910 }
911 #endif
912 
913 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
914     ucontext_t *uc = (ucontext_t*) secret;
915     void *eip = getMcontextEip(uc);
916     sds infostring, clients;
917     struct sigaction act;
918     UNUSED(info);
919 
920     bugReportStart();
921     serverLog(LL_WARNING,
922         "Redis %s crashed by signal: %d", REDIS_VERSION, sig);
923     if (eip != NULL) {
924         serverLog(LL_WARNING,
925         "Crashed running the instuction at: %p", eip);
926     }
927     if (sig == SIGSEGV || sig == SIGBUS) {
928         serverLog(LL_WARNING,
929         "Accessing address: %p", (void*)info->si_addr);
930     }
931     serverLog(LL_WARNING,
932         "Failed assertion: %s (%s:%d)", server.assert_failed,
933                         server.assert_file, server.assert_line);
934 
935     /* Log the stack trace */
936     serverLogRaw(LL_WARNING|LL_RAW, "\n------ STACK TRACE ------\n");
937     logStackTrace(uc);
938 
939     /* Log INFO and CLIENT LIST */
940     serverLogRaw(LL_WARNING|LL_RAW, "\n------ INFO OUTPUT ------\n");
941     infostring = genRedisInfoString("all");
942     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
943         dictGetHashFunctionSeed());
944     serverLogRaw(LL_WARNING|LL_RAW, infostring);
945     serverLogRaw(LL_WARNING|LL_RAW, "\n------ CLIENT LIST OUTPUT ------\n");
946     clients = getAllClientsInfoString();
947     serverLogRaw(LL_WARNING|LL_RAW, clients);
948     sdsfree(infostring);
949     sdsfree(clients);
950 
951     /* Log the current client */
952     logCurrentClient();
953 
954     /* Log dump of processor registers */
955     logRegisters(uc);
956 
957 #if defined(HAVE_PROC_MAPS)
958     /* Test memory */
959     serverLogRaw(LL_WARNING|LL_RAW, "\n------ FAST MEMORY TEST ------\n");
960     bioKillThreads();
961     if (memtest_test_linux_anonymous_maps()) {
962         serverLogRaw(LL_WARNING|LL_RAW,
963             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
964     } else {
965         serverLogRaw(LL_WARNING|LL_RAW,
966             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
967     }
968 #endif
969 
970     serverLogRaw(LL_WARNING|LL_RAW,
971 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
972 "       Please report the crash by opening an issue on github:\n\n"
973 "           http://github.com/antirez/redis/issues\n\n"
974 "  Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
975 );
976     /* free(messages); Don't call free() with possibly corrupted memory. */
977     if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
978 
979     /* Make sure we exit with the right signal at the end. So for instance
980      * the core will be dumped if enabled. */
981     sigemptyset (&act.sa_mask);
982     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
983     act.sa_handler = SIG_DFL;
984     sigaction (sig, &act, NULL);
985     kill(getpid(),sig);
986 }
987 #endif /* HAVE_BACKTRACE */
988 
989 /* ==================== Logging functions for debugging ===================== */
990 
991 void serverLogHexDump(int level, char *descr, void *value, size_t len) {
992     char buf[65], *b;
993     unsigned char *v = value;
994     char charset[] = "0123456789abcdef";
995 
996     serverLog(level,"%s (hexdump):", descr);
997     b = buf;
998     while(len) {
999         b[0] = charset[(*v)>>4];
1000         b[1] = charset[(*v)&0xf];
1001         b[2] = '\0';
1002         b += 2;
1003         len--;
1004         v++;
1005         if (b-buf == 64 || len == 0) {
1006             serverLogRaw(level|LL_RAW,buf);
1007             b = buf;
1008         }
1009     }
1010     serverLogRaw(level|LL_RAW,"\n");
1011 }
1012 
1013 /* =========================== Software Watchdog ============================ */
1014 #include <sys/time.h>
1015 
1016 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
1017 #ifdef HAVE_BACKTRACE
1018     ucontext_t *uc = (ucontext_t*) secret;
1019 #endif
1020     UNUSED(info);
1021     UNUSED(sig);
1022 
1023     serverLogFromHandler(LL_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
1024 #ifdef HAVE_BACKTRACE
1025     logStackTrace(uc);
1026 #else
1027     serverLogFromHandler(LL_WARNING,"Sorry: no support for backtrace().");
1028 #endif
1029     serverLogFromHandler(LL_WARNING,"--------\n");
1030 }
1031 
1032 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
1033  * If a timer is already scheduled, this function will re-schedule it to the
1034  * specified time. If period is 0 the current timer is disabled. */
1035 void watchdogScheduleSignal(int period) {
1036     struct itimerval it;
1037 
1038     /* Will stop the timer if period is 0. */
1039     it.it_value.tv_sec = period/1000;
1040     it.it_value.tv_usec = (period%1000)*1000;
1041     /* Don't automatically restart. */
1042     it.it_interval.tv_sec = 0;
1043     it.it_interval.tv_usec = 0;
1044     setitimer(ITIMER_REAL, &it, NULL);
1045 }
1046 
1047 /* Enable the software watchdog with the specified period in milliseconds. */
1048 void enableWatchdog(int period) {
1049     int min_period;
1050 
1051     if (server.watchdog_period == 0) {
1052         struct sigaction act;
1053 
1054         /* Watchdog was actually disabled, so we have to setup the signal
1055          * handler. */
1056         sigemptyset(&act.sa_mask);
1057         act.sa_flags = SA_ONSTACK | SA_SIGINFO;
1058         act.sa_sigaction = watchdogSignalHandler;
1059         sigaction(SIGALRM, &act, NULL);
1060     }
1061     /* If the configured period is smaller than twice the timer period, it is
1062      * too short for the software watchdog to work reliably. Fix it now
1063      * if needed. */
1064     min_period = (1000/server.hz)*2;
1065     if (period < min_period) period = min_period;
1066     watchdogScheduleSignal(period); /* Adjust the current timer. */
1067     server.watchdog_period = period;
1068 }
1069 
1070 /* Disable the software watchdog. */
1071 void disableWatchdog(void) {
1072     struct sigaction act;
1073     if (server.watchdog_period == 0) return; /* Already disabled. */
1074     watchdogScheduleSignal(0); /* Stop the current timer. */
1075 
1076     /* Set the signal handler to SIG_IGN, this will also remove pending
1077      * signals from the queue. */
1078     sigemptyset(&act.sa_mask);
1079     act.sa_flags = 0;
1080     act.sa_handler = SIG_IGN;
1081     sigaction(SIGALRM, &act, NULL);
1082     server.watchdog_period = 0;
1083 }
1084