xref: /redis-3.2.3/src/debug.c (revision f15df8ba)
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 "redis.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 == REDIS_STRING) {
154                 mixObjectDigest(digest,o);
155             } else if (o->type == REDIS_LIST) {
156                 listTypeIterator *li = listTypeInitIterator(o,0,REDIS_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 == REDIS_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 == REDIS_ZSET) {
173                 unsigned char eledigest[20];
174 
175                 if (o->encoding == REDIS_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                     redisAssert(eptr != NULL);
185                     sptr = ziplistNext(zl,eptr);
186                     redisAssert(sptr != NULL);
187 
188                     while (eptr != NULL) {
189                         redisAssert(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 == REDIS_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                     redisPanic("Unknown sorted set encoding");
223                 }
224             } else if (o->type == REDIS_HASH) {
225                 hashTypeIterator *hi;
226                 robj *obj;
227 
228                 hi = hashTypeInitIterator(o);
229                 while (hashTypeNext(hi) != REDIS_ERR) {
230                     unsigned char eledigest[20];
231 
232                     memset(eledigest,0,20);
233                     obj = hashTypeCurrentObject(hi,REDIS_HASH_KEY);
234                     mixObjectDigest(eledigest,obj);
235                     decrRefCount(obj);
236                     obj = hashTypeCurrentObject(hi,REDIS_HASH_VALUE);
237                     mixObjectDigest(eledigest,obj);
238                     decrRefCount(obj);
239                     xorDigest(digest,eledigest,20);
240                 }
241                 hashTypeReleaseIterator(hi);
242             } else {
243                 redisPanic("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(redisClient *c) {
262     if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
263         *((char*)-1) = 'x';
264     } else if (!strcasecmp(c->argv[1]->ptr,"oom")) {
265         void *ptr = zmalloc(ULONG_MAX); /* Should trigger an out of memory. */
266         zfree(ptr);
267         addReply(c,shared.ok);
268     } else if (!strcasecmp(c->argv[1]->ptr,"assert")) {
269         if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
270         redisAssertWithInfo(c,c->argv[0],1 == 2);
271     } else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
272         if (rdbSave(server.rdb_filename) != REDIS_OK) {
273             addReply(c,shared.err);
274             return;
275         }
276         emptyDb(NULL);
277         if (rdbLoad(server.rdb_filename) != REDIS_OK) {
278             addReplyError(c,"Error trying to load the RDB dump");
279             return;
280         }
281         redisLog(REDIS_WARNING,"DB reloaded by DEBUG RELOAD");
282         addReply(c,shared.ok);
283     } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
284         emptyDb(NULL);
285         if (loadAppendOnlyFile(server.aof_filename) != REDIS_OK) {
286             addReply(c,shared.err);
287             return;
288         }
289         server.dirty = 0; /* Prevent AOF / replication */
290         redisLog(REDIS_WARNING,"Append Only File loaded by DEBUG LOADAOF");
291         addReply(c,shared.ok);
292     } else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) {
293         dictEntry *de;
294         robj *val;
295         char *strenc;
296 
297         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
298             addReply(c,shared.nokeyerr);
299             return;
300         }
301         val = dictGetVal(de);
302         strenc = strEncoding(val->encoding);
303 
304         char extra[128] = {0};
305         if (val->encoding == REDIS_ENCODING_QUICKLIST) {
306             char *nextra = extra;
307             int remaining = sizeof(extra);
308             quicklist *ql = val->ptr;
309             /* Add number of quicklist nodes */
310             int used = snprintf(nextra, remaining, " ql_nodes:%u", ql->len);
311             nextra += used;
312             remaining -= used;
313             /* Add average quicklist fill factor */
314             double avg = (double)ql->count/ql->len;
315             used = snprintf(nextra, remaining, " ql_avg_node:%.2f", avg);
316             nextra += used;
317             remaining -= used;
318             /* Add quicklist fill level / max ziplist size */
319             used = snprintf(nextra, remaining, " ql_ziplist_max:%d", ql->fill);
320             nextra += used;
321             remaining -= used;
322             /* Add isCompressed? */
323             int compressed = ql->compress != 0;
324             used = snprintf(nextra, remaining, " ql_compressed:%d", compressed);
325             nextra += used;
326             remaining -= used;
327             /* Add total uncompressed size */
328             unsigned long sz = 0;
329             for (quicklistNode *node = ql->head; node; node = node->next) {
330                 sz += node->sz;
331             }
332             used = snprintf(nextra, remaining, " ql_uncompressed_size:%lu", sz);
333             nextra += used;
334             remaining -= used;
335         }
336 
337         addReplyStatusFormat(c,
338             "Value at:%p refcount:%d "
339             "encoding:%s serializedlength:%zu "
340             "lru:%d lru_seconds_idle:%llu%s",
341             (void*)val, val->refcount,
342             strenc, rdbSavedObjectLen(val),
343             val->lru, estimateObjectIdleTime(val)/1000, extra);
344     } else if (!strcasecmp(c->argv[1]->ptr,"sdslen") && c->argc == 3) {
345         dictEntry *de;
346         robj *val;
347         sds key;
348 
349         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
350             addReply(c,shared.nokeyerr);
351             return;
352         }
353         val = dictGetVal(de);
354         key = dictGetKey(de);
355 
356         if (val->type != REDIS_STRING || !sdsEncodedObject(val)) {
357             addReplyError(c,"Not an sds encoded string.");
358         } else {
359             addReplyStatusFormat(c,
360                 "key_sds_len:%lld, key_sds_avail:%lld, "
361                 "val_sds_len:%lld, val_sds_avail:%lld",
362                 (long long) sdslen(key),
363                 (long long) sdsavail(key),
364                 (long long) sdslen(val->ptr),
365                 (long long) sdsavail(val->ptr));
366         }
367     } else if (!strcasecmp(c->argv[1]->ptr,"populate") &&
368                (c->argc == 3 || c->argc == 4)) {
369         long keys, j;
370         robj *key, *val;
371         char buf[128];
372 
373         if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK)
374             return;
375         dictExpand(c->db->dict,keys);
376         for (j = 0; j < keys; j++) {
377             snprintf(buf,sizeof(buf),"%s:%lu",
378                 (c->argc == 3) ? "key" : (char*)c->argv[3]->ptr, j);
379             key = createStringObject(buf,strlen(buf));
380             if (lookupKeyWrite(c->db,key) != NULL) {
381                 decrRefCount(key);
382                 continue;
383             }
384             snprintf(buf,sizeof(buf),"value:%lu",j);
385             val = createStringObject(buf,strlen(buf));
386             dbAdd(c->db,key,val);
387             decrRefCount(key);
388         }
389         addReply(c,shared.ok);
390     } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
391         unsigned char digest[20];
392         sds d = sdsempty();
393         int j;
394 
395         computeDatasetDigest(digest);
396         for (j = 0; j < 20; j++)
397             d = sdscatprintf(d, "%02x",digest[j]);
398         addReplyStatus(c,d);
399         sdsfree(d);
400     } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
401         double dtime = strtod(c->argv[2]->ptr,NULL);
402         long long utime = dtime*1000000;
403         struct timespec tv;
404 
405         tv.tv_sec = utime / 1000000;
406         tv.tv_nsec = (utime % 1000000) * 1000;
407         nanosleep(&tv, NULL);
408         addReply(c,shared.ok);
409     } else if (!strcasecmp(c->argv[1]->ptr,"set-active-expire") &&
410                c->argc == 3)
411     {
412         server.active_expire_enabled = atoi(c->argv[2]->ptr);
413         addReply(c,shared.ok);
414     } else if (!strcasecmp(c->argv[1]->ptr,"error") && c->argc == 3) {
415         sds errstr = sdsnewlen("-",1);
416 
417         errstr = sdscatsds(errstr,c->argv[2]->ptr);
418         errstr = sdsmapchars(errstr,"\n\r","  ",2); /* no newlines in errors. */
419         errstr = sdscatlen(errstr,"\r\n",2);
420         addReplySds(c,errstr);
421     } else if (!strcasecmp(c->argv[1]->ptr,"structsize") && c->argc == 2) {
422         sds sizes = sdsempty();
423         sizes = sdscatprintf(sizes,"bits:%d ", (sizeof(void*) == 8)?64:32);
424         sizes = sdscatprintf(sizes,"robj:%d ", (int)sizeof(robj));
425         sizes = sdscatprintf(sizes,"dictentry:%d ", (int)sizeof(dictEntry));
426         sizes = sdscatprintf(sizes,"sdshdr8:%d", (int)sizeof(struct sdshdr8));
427         sizes = sdscatprintf(sizes,"sdshdr16:%d", (int)sizeof(struct sdshdr16));
428         sizes = sdscatprintf(sizes,"sdshdr32:%d", (int)sizeof(struct sdshdr32));
429         sizes = sdscatprintf(sizes,"sdshdr64:%d", (int)sizeof(struct sdshdr64));
430         addReplyBulkSds(c,sizes);
431     } else if (!strcasecmp(c->argv[1]->ptr,"htstats") && c->argc == 3) {
432         long dbid;
433         sds stats = sdsempty();
434         char buf[4096];
435 
436         if (getLongFromObjectOrReply(c, c->argv[2], &dbid, NULL) != REDIS_OK)
437             return;
438         if (dbid < 0 || dbid >= server.dbnum) {
439             addReplyError(c,"Out of range database");
440             return;
441         }
442 
443         stats = sdscatprintf(stats,"[Dictionary HT]\n");
444         dictGetStats(buf,sizeof(buf),server.db[dbid].dict);
445         stats = sdscat(stats,buf);
446 
447         stats = sdscatprintf(stats,"[Expires HT]\n");
448         dictGetStats(buf,sizeof(buf),server.db[dbid].expires);
449         stats = sdscat(stats,buf);
450 
451         addReplyBulkSds(c,stats);
452     } else if (!strcasecmp(c->argv[1]->ptr,"jemalloc") && c->argc == 3) {
453 #if defined(USE_JEMALLOC)
454         if (!strcasecmp(c->argv[2]->ptr, "info")) {
455             sds info = sdsempty();
456             je_malloc_stats_print(inputCatSds, &info, NULL);
457             addReplyBulkSds(c, info);
458         } else {
459             addReplyErrorFormat(c, "Valid jemalloc debug fields: info");
460         }
461 #else
462         addReplyErrorFormat(c, "jemalloc support not available");
463 #endif
464     } else {
465         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
466             (char*)c->argv[1]->ptr);
467     }
468 }
469 
470 /* =========================== Crash handling  ============================== */
471 
472 void _redisAssert(char *estr, char *file, int line) {
473     bugReportStart();
474     redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
475     redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
476 #ifdef HAVE_BACKTRACE
477     server.assert_failed = estr;
478     server.assert_file = file;
479     server.assert_line = line;
480     redisLog(REDIS_WARNING,"(forcing SIGSEGV to print the bug report.)");
481 #endif
482     *((char*)-1) = 'x';
483 }
484 
485 void _redisAssertPrintClientInfo(redisClient *c) {
486     int j;
487 
488     bugReportStart();
489     redisLog(REDIS_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
490     redisLog(REDIS_WARNING,"client->flags = %d", c->flags);
491     redisLog(REDIS_WARNING,"client->fd = %d", c->fd);
492     redisLog(REDIS_WARNING,"client->argc = %d", c->argc);
493     for (j=0; j < c->argc; j++) {
494         char buf[128];
495         char *arg;
496 
497         if (c->argv[j]->type == REDIS_STRING && sdsEncodedObject(c->argv[j])) {
498             arg = (char*) c->argv[j]->ptr;
499         } else {
500             snprintf(buf,sizeof(buf),"Object type: %d, encoding: %d",
501                 c->argv[j]->type, c->argv[j]->encoding);
502             arg = buf;
503         }
504         redisLog(REDIS_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
505             j, arg, c->argv[j]->refcount);
506     }
507 }
508 
509 void redisLogObjectDebugInfo(robj *o) {
510     redisLog(REDIS_WARNING,"Object type: %d", o->type);
511     redisLog(REDIS_WARNING,"Object encoding: %d", o->encoding);
512     redisLog(REDIS_WARNING,"Object refcount: %d", o->refcount);
513     if (o->type == REDIS_STRING && sdsEncodedObject(o)) {
514         redisLog(REDIS_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
515         if (sdslen(o->ptr) < 4096) {
516             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
517             redisLog(REDIS_WARNING,"Object raw string content: %s", repr);
518             sdsfree(repr);
519         }
520     } else if (o->type == REDIS_LIST) {
521         redisLog(REDIS_WARNING,"List length: %d", (int) listTypeLength(o));
522     } else if (o->type == REDIS_SET) {
523         redisLog(REDIS_WARNING,"Set size: %d", (int) setTypeSize(o));
524     } else if (o->type == REDIS_HASH) {
525         redisLog(REDIS_WARNING,"Hash size: %d", (int) hashTypeLength(o));
526     } else if (o->type == REDIS_ZSET) {
527         redisLog(REDIS_WARNING,"Sorted set size: %d", (int) zsetLength(o));
528         if (o->encoding == REDIS_ENCODING_SKIPLIST)
529             redisLog(REDIS_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
530     }
531 }
532 
533 void _redisAssertPrintObject(robj *o) {
534     bugReportStart();
535     redisLog(REDIS_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
536     redisLogObjectDebugInfo(o);
537 }
538 
539 void _redisAssertWithInfo(redisClient *c, robj *o, char *estr, char *file, int line) {
540     if (c) _redisAssertPrintClientInfo(c);
541     if (o) _redisAssertPrintObject(o);
542     _redisAssert(estr,file,line);
543 }
544 
545 void _redisPanic(char *msg, char *file, int line) {
546     bugReportStart();
547     redisLog(REDIS_WARNING,"------------------------------------------------");
548     redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
549     redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
550 #ifdef HAVE_BACKTRACE
551     redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
552 #endif
553     redisLog(REDIS_WARNING,"------------------------------------------------");
554     *((char*)-1) = 'x';
555 }
556 
557 void bugReportStart(void) {
558     if (server.bug_report_start == 0) {
559         redisLog(REDIS_WARNING,
560             "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===");
561         server.bug_report_start = 1;
562     }
563 }
564 
565 #ifdef HAVE_BACKTRACE
566 static void *getMcontextEip(ucontext_t *uc) {
567 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
568     /* OSX < 10.6 */
569     #if defined(__x86_64__)
570     return (void*) uc->uc_mcontext->__ss.__rip;
571     #elif defined(__i386__)
572     return (void*) uc->uc_mcontext->__ss.__eip;
573     #else
574     return (void*) uc->uc_mcontext->__ss.__srr0;
575     #endif
576 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
577     /* OSX >= 10.6 */
578     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
579     return (void*) uc->uc_mcontext->__ss.__rip;
580     #else
581     return (void*) uc->uc_mcontext->__ss.__eip;
582     #endif
583 #elif defined(__linux__)
584     /* Linux */
585     #if defined(__i386__)
586     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
587     #elif defined(__X86_64__) || defined(__x86_64__)
588     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
589     #elif defined(__ia64__) /* Linux IA64 */
590     return (void*) uc->uc_mcontext.sc_ip;
591     #endif
592 #else
593     return NULL;
594 #endif
595 }
596 
597 void logStackContent(void **sp) {
598     int i;
599     for (i = 15; i >= 0; i--) {
600         unsigned long addr = (unsigned long) sp+i;
601         unsigned long val = (unsigned long) sp[i];
602 
603         if (sizeof(long) == 4)
604             redisLog(REDIS_WARNING, "(%08lx) -> %08lx", addr, val);
605         else
606             redisLog(REDIS_WARNING, "(%016lx) -> %016lx", addr, val);
607     }
608 }
609 
610 void logRegisters(ucontext_t *uc) {
611     redisLog(REDIS_WARNING, "--- REGISTERS");
612 
613 /* OSX */
614 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
615   /* OSX AMD64 */
616     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
617     redisLog(REDIS_WARNING,
618     "\n"
619     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
620     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
621     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
622     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
623     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
624         (unsigned long) uc->uc_mcontext->__ss.__rax,
625         (unsigned long) uc->uc_mcontext->__ss.__rbx,
626         (unsigned long) uc->uc_mcontext->__ss.__rcx,
627         (unsigned long) uc->uc_mcontext->__ss.__rdx,
628         (unsigned long) uc->uc_mcontext->__ss.__rdi,
629         (unsigned long) uc->uc_mcontext->__ss.__rsi,
630         (unsigned long) uc->uc_mcontext->__ss.__rbp,
631         (unsigned long) uc->uc_mcontext->__ss.__rsp,
632         (unsigned long) uc->uc_mcontext->__ss.__r8,
633         (unsigned long) uc->uc_mcontext->__ss.__r9,
634         (unsigned long) uc->uc_mcontext->__ss.__r10,
635         (unsigned long) uc->uc_mcontext->__ss.__r11,
636         (unsigned long) uc->uc_mcontext->__ss.__r12,
637         (unsigned long) uc->uc_mcontext->__ss.__r13,
638         (unsigned long) uc->uc_mcontext->__ss.__r14,
639         (unsigned long) uc->uc_mcontext->__ss.__r15,
640         (unsigned long) uc->uc_mcontext->__ss.__rip,
641         (unsigned long) uc->uc_mcontext->__ss.__rflags,
642         (unsigned long) uc->uc_mcontext->__ss.__cs,
643         (unsigned long) uc->uc_mcontext->__ss.__fs,
644         (unsigned long) uc->uc_mcontext->__ss.__gs
645     );
646     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
647     #else
648     /* OSX x86 */
649     redisLog(REDIS_WARNING,
650     "\n"
651     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
652     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
653     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
654     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
655         (unsigned long) uc->uc_mcontext->__ss.__eax,
656         (unsigned long) uc->uc_mcontext->__ss.__ebx,
657         (unsigned long) uc->uc_mcontext->__ss.__ecx,
658         (unsigned long) uc->uc_mcontext->__ss.__edx,
659         (unsigned long) uc->uc_mcontext->__ss.__edi,
660         (unsigned long) uc->uc_mcontext->__ss.__esi,
661         (unsigned long) uc->uc_mcontext->__ss.__ebp,
662         (unsigned long) uc->uc_mcontext->__ss.__esp,
663         (unsigned long) uc->uc_mcontext->__ss.__ss,
664         (unsigned long) uc->uc_mcontext->__ss.__eflags,
665         (unsigned long) uc->uc_mcontext->__ss.__eip,
666         (unsigned long) uc->uc_mcontext->__ss.__cs,
667         (unsigned long) uc->uc_mcontext->__ss.__ds,
668         (unsigned long) uc->uc_mcontext->__ss.__es,
669         (unsigned long) uc->uc_mcontext->__ss.__fs,
670         (unsigned long) uc->uc_mcontext->__ss.__gs
671     );
672     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
673     #endif
674 /* Linux */
675 #elif defined(__linux__)
676     /* Linux x86 */
677     #if defined(__i386__)
678     redisLog(REDIS_WARNING,
679     "\n"
680     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
681     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
682     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
683     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
684         (unsigned long) uc->uc_mcontext.gregs[11],
685         (unsigned long) uc->uc_mcontext.gregs[8],
686         (unsigned long) uc->uc_mcontext.gregs[10],
687         (unsigned long) uc->uc_mcontext.gregs[9],
688         (unsigned long) uc->uc_mcontext.gregs[4],
689         (unsigned long) uc->uc_mcontext.gregs[5],
690         (unsigned long) uc->uc_mcontext.gregs[6],
691         (unsigned long) uc->uc_mcontext.gregs[7],
692         (unsigned long) uc->uc_mcontext.gregs[18],
693         (unsigned long) uc->uc_mcontext.gregs[17],
694         (unsigned long) uc->uc_mcontext.gregs[14],
695         (unsigned long) uc->uc_mcontext.gregs[15],
696         (unsigned long) uc->uc_mcontext.gregs[3],
697         (unsigned long) uc->uc_mcontext.gregs[2],
698         (unsigned long) uc->uc_mcontext.gregs[1],
699         (unsigned long) uc->uc_mcontext.gregs[0]
700     );
701     logStackContent((void**)uc->uc_mcontext.gregs[7]);
702     #elif defined(__X86_64__) || defined(__x86_64__)
703     /* Linux AMD64 */
704     redisLog(REDIS_WARNING,
705     "\n"
706     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
707     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
708     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
709     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
710     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
711         (unsigned long) uc->uc_mcontext.gregs[13],
712         (unsigned long) uc->uc_mcontext.gregs[11],
713         (unsigned long) uc->uc_mcontext.gregs[14],
714         (unsigned long) uc->uc_mcontext.gregs[12],
715         (unsigned long) uc->uc_mcontext.gregs[8],
716         (unsigned long) uc->uc_mcontext.gregs[9],
717         (unsigned long) uc->uc_mcontext.gregs[10],
718         (unsigned long) uc->uc_mcontext.gregs[15],
719         (unsigned long) uc->uc_mcontext.gregs[0],
720         (unsigned long) uc->uc_mcontext.gregs[1],
721         (unsigned long) uc->uc_mcontext.gregs[2],
722         (unsigned long) uc->uc_mcontext.gregs[3],
723         (unsigned long) uc->uc_mcontext.gregs[4],
724         (unsigned long) uc->uc_mcontext.gregs[5],
725         (unsigned long) uc->uc_mcontext.gregs[6],
726         (unsigned long) uc->uc_mcontext.gregs[7],
727         (unsigned long) uc->uc_mcontext.gregs[16],
728         (unsigned long) uc->uc_mcontext.gregs[17],
729         (unsigned long) uc->uc_mcontext.gregs[18]
730     );
731     logStackContent((void**)uc->uc_mcontext.gregs[15]);
732     #endif
733 #else
734     redisLog(REDIS_WARNING,
735         "  Dumping of registers not supported for this OS/arch");
736 #endif
737 }
738 
739 /* Logs the stack trace using the backtrace() call. This function is designed
740  * to be called from signal handlers safely. */
741 void logStackTrace(ucontext_t *uc) {
742     void *trace[100];
743     int trace_size = 0, fd;
744     int log_to_stdout = server.logfile[0] == '\0';
745 
746     /* Open the log file in append mode. */
747     fd = log_to_stdout ?
748         STDOUT_FILENO :
749         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
750     if (fd == -1) return;
751 
752     /* Generate the stack trace */
753     trace_size = backtrace(trace, 100);
754 
755     /* overwrite sigaction with caller's address */
756     if (getMcontextEip(uc) != NULL)
757         trace[1] = getMcontextEip(uc);
758 
759     /* Write symbols to log file */
760     backtrace_symbols_fd(trace, trace_size, fd);
761 
762     /* Cleanup */
763     if (!log_to_stdout) close(fd);
764 }
765 
766 /* Log information about the "current" client, that is, the client that is
767  * currently being served by Redis. May be NULL if Redis is not serving a
768  * client right now. */
769 void logCurrentClient(void) {
770     if (server.current_client == NULL) return;
771 
772     redisClient *cc = server.current_client;
773     sds client;
774     int j;
775 
776     redisLog(REDIS_WARNING, "--- CURRENT CLIENT INFO");
777     client = catClientInfoString(sdsempty(),cc);
778     redisLog(REDIS_WARNING,"client: %s", client);
779     sdsfree(client);
780     for (j = 0; j < cc->argc; j++) {
781         robj *decoded;
782 
783         decoded = getDecodedObject(cc->argv[j]);
784         redisLog(REDIS_WARNING,"argv[%d]: '%s'", j, (char*)decoded->ptr);
785         decrRefCount(decoded);
786     }
787     /* Check if the first argument, usually a key, is found inside the
788      * selected DB, and if so print info about the associated object. */
789     if (cc->argc >= 1) {
790         robj *val, *key;
791         dictEntry *de;
792 
793         key = getDecodedObject(cc->argv[1]);
794         de = dictFind(cc->db->dict, key->ptr);
795         if (de) {
796             val = dictGetVal(de);
797             redisLog(REDIS_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
798             redisLogObjectDebugInfo(val);
799         }
800         decrRefCount(key);
801     }
802 }
803 
804 #if defined(HAVE_PROC_MAPS)
805 void memtest_non_destructive_invert(void *addr, size_t size);
806 void memtest_non_destructive_swap(void *addr, size_t size);
807 #define MEMTEST_MAX_REGIONS 128
808 
809 int memtest_test_linux_anonymous_maps(void) {
810     FILE *fp = fopen("/proc/self/maps","r");
811     char line[1024];
812     size_t start_addr, end_addr, size;
813     size_t start_vect[MEMTEST_MAX_REGIONS];
814     size_t size_vect[MEMTEST_MAX_REGIONS];
815     int regions = 0, j;
816     uint64_t crc1 = 0, crc2 = 0, crc3 = 0;
817 
818     while(fgets(line,sizeof(line),fp) != NULL) {
819         char *start, *end, *p = line;
820 
821         start = p;
822         p = strchr(p,'-');
823         if (!p) continue;
824         *p++ = '\0';
825         end = p;
826         p = strchr(p,' ');
827         if (!p) continue;
828         *p++ = '\0';
829         if (strstr(p,"stack") ||
830             strstr(p,"vdso") ||
831             strstr(p,"vsyscall")) continue;
832         if (!strstr(p,"00:00")) continue;
833         if (!strstr(p,"rw")) continue;
834 
835         start_addr = strtoul(start,NULL,16);
836         end_addr = strtoul(end,NULL,16);
837         size = end_addr-start_addr;
838 
839         start_vect[regions] = start_addr;
840         size_vect[regions] = size;
841         printf("Testing %lx %lu\n", (unsigned long) start_vect[regions],
842                                     (unsigned long) size_vect[regions]);
843         regions++;
844     }
845 
846     /* Test all the regions as an unique sequential region.
847      * 1) Take the CRC64 of the memory region. */
848     for (j = 0; j < regions; j++) {
849         crc1 = crc64(crc1,(void*)start_vect[j],size_vect[j]);
850     }
851 
852     /* 2) Invert bits, swap adjacent words, swap again, invert bits.
853      * This is the error amplification step. */
854     for (j = 0; j < regions; j++)
855         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
856     for (j = 0; j < regions; j++)
857         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
858     for (j = 0; j < regions; j++)
859         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
860     for (j = 0; j < regions; j++)
861         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
862 
863     /* 3) Take the CRC64 sum again. */
864     for (j = 0; j < regions; j++)
865         crc2 = crc64(crc2,(void*)start_vect[j],size_vect[j]);
866 
867     /* 4) Swap + Swap again */
868     for (j = 0; j < regions; j++)
869         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
870     for (j = 0; j < regions; j++)
871         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
872 
873     /* 5) Take the CRC64 sum again. */
874     for (j = 0; j < regions; j++)
875         crc3 = crc64(crc3,(void*)start_vect[j],size_vect[j]);
876 
877     /* NOTE: It is very important to close the file descriptor only now
878      * because closing it before may result into unmapping of some memory
879      * region that we are testing. */
880     fclose(fp);
881 
882     /* If the two CRC are not the same, we trapped a memory error. */
883     return crc1 != crc2 || crc2 != crc3;
884 }
885 #endif
886 
887 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
888     ucontext_t *uc = (ucontext_t*) secret;
889     sds infostring, clients;
890     struct sigaction act;
891     REDIS_NOTUSED(info);
892 
893     bugReportStart();
894     redisLog(REDIS_WARNING,
895         "    Redis %s crashed by signal: %d", REDIS_VERSION, sig);
896     redisLog(REDIS_WARNING,
897         "    Failed assertion: %s (%s:%d)", server.assert_failed,
898                         server.assert_file, server.assert_line);
899 
900     /* Log the stack trace */
901     redisLog(REDIS_WARNING, "--- STACK TRACE");
902     logStackTrace(uc);
903 
904     /* Log INFO and CLIENT LIST */
905     redisLog(REDIS_WARNING, "--- INFO OUTPUT");
906     infostring = genRedisInfoString("all");
907     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
908         dictGetHashFunctionSeed());
909     redisLogRaw(REDIS_WARNING, infostring);
910     redisLog(REDIS_WARNING, "--- CLIENT LIST OUTPUT");
911     clients = getAllClientsInfoString();
912     redisLogRaw(REDIS_WARNING, clients);
913     sdsfree(infostring);
914     sdsfree(clients);
915 
916     /* Log the current client */
917     logCurrentClient();
918 
919     /* Log dump of processor registers */
920     logRegisters(uc);
921 
922 #if defined(HAVE_PROC_MAPS)
923     /* Test memory */
924     redisLog(REDIS_WARNING, "--- FAST MEMORY TEST");
925     bioKillThreads();
926     if (memtest_test_linux_anonymous_maps()) {
927         redisLog(REDIS_WARNING,
928             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
929     } else {
930         redisLog(REDIS_WARNING,
931             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
932     }
933 #endif
934 
935     redisLog(REDIS_WARNING,
936 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
937 "       Please report the crash by opening an issue on github:\n\n"
938 "           http://github.com/antirez/redis/issues\n\n"
939 "  Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
940 );
941     /* free(messages); Don't call free() with possibly corrupted memory. */
942     if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
943 
944     /* Make sure we exit with the right signal at the end. So for instance
945      * the core will be dumped if enabled. */
946     sigemptyset (&act.sa_mask);
947     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
948     act.sa_handler = SIG_DFL;
949     sigaction (sig, &act, NULL);
950     kill(getpid(),sig);
951 }
952 #endif /* HAVE_BACKTRACE */
953 
954 /* ==================== Logging functions for debugging ===================== */
955 
956 void redisLogHexDump(int level, char *descr, void *value, size_t len) {
957     char buf[65], *b;
958     unsigned char *v = value;
959     char charset[] = "0123456789abcdef";
960 
961     redisLog(level,"%s (hexdump):", descr);
962     b = buf;
963     while(len) {
964         b[0] = charset[(*v)>>4];
965         b[1] = charset[(*v)&0xf];
966         b[2] = '\0';
967         b += 2;
968         len--;
969         v++;
970         if (b-buf == 64 || len == 0) {
971             redisLogRaw(level|REDIS_LOG_RAW,buf);
972             b = buf;
973         }
974     }
975     redisLogRaw(level|REDIS_LOG_RAW,"\n");
976 }
977 
978 /* =========================== Software Watchdog ============================ */
979 #include <sys/time.h>
980 
981 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
982 #ifdef HAVE_BACKTRACE
983     ucontext_t *uc = (ucontext_t*) secret;
984 #endif
985     REDIS_NOTUSED(info);
986     REDIS_NOTUSED(sig);
987 
988     redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
989 #ifdef HAVE_BACKTRACE
990     logStackTrace(uc);
991 #else
992     redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
993 #endif
994     redisLogFromHandler(REDIS_WARNING,"--------\n");
995 }
996 
997 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
998  * If a timer is already scheduled, this function will re-schedule it to the
999  * specified time. If period is 0 the current timer is disabled. */
1000 void watchdogScheduleSignal(int period) {
1001     struct itimerval it;
1002 
1003     /* Will stop the timer if period is 0. */
1004     it.it_value.tv_sec = period/1000;
1005     it.it_value.tv_usec = (period%1000)*1000;
1006     /* Don't automatically restart. */
1007     it.it_interval.tv_sec = 0;
1008     it.it_interval.tv_usec = 0;
1009     setitimer(ITIMER_REAL, &it, NULL);
1010 }
1011 
1012 /* Enable the software watchdog with the specified period in milliseconds. */
1013 void enableWatchdog(int period) {
1014     int min_period;
1015 
1016     if (server.watchdog_period == 0) {
1017         struct sigaction act;
1018 
1019         /* Watchdog was actually disabled, so we have to setup the signal
1020          * handler. */
1021         sigemptyset(&act.sa_mask);
1022         act.sa_flags = SA_ONSTACK | SA_SIGINFO;
1023         act.sa_sigaction = watchdogSignalHandler;
1024         sigaction(SIGALRM, &act, NULL);
1025     }
1026     /* If the configured period is smaller than twice the timer period, it is
1027      * too short for the software watchdog to work reliably. Fix it now
1028      * if needed. */
1029     min_period = (1000/server.hz)*2;
1030     if (period < min_period) period = min_period;
1031     watchdogScheduleSignal(period); /* Adjust the current timer. */
1032     server.watchdog_period = period;
1033 }
1034 
1035 /* Disable the software watchdog. */
1036 void disableWatchdog(void) {
1037     struct sigaction act;
1038     if (server.watchdog_period == 0) return; /* Already disabled. */
1039     watchdogScheduleSignal(0); /* Stop the current timer. */
1040 
1041     /* Set the signal handler to SIG_IGN, this will also remove pending
1042      * signals from the queue. */
1043     sigemptyset(&act.sa_mask);
1044     act.sa_flags = 0;
1045     act.sa_handler = SIG_IGN;
1046     sigaction(SIGALRM, &act, NULL);
1047     server.watchdog_period = 0;
1048 }
1049