xref: /redis-3.2.3/src/debug.c (revision 0f64080d)
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,"sdshdr:%d", (int)sizeof(struct sdshdr));
427         addReplyBulkSds(c,sizes);
428     } else if (!strcasecmp(c->argv[1]->ptr,"htstats") && c->argc == 3) {
429         long dbid;
430         sds stats = sdsempty();
431         char buf[4096];
432 
433         if (getLongFromObjectOrReply(c, c->argv[2], &dbid, NULL) != REDIS_OK)
434             return;
435         if (dbid < 0 || dbid >= server.dbnum) {
436             addReplyError(c,"Out of range database");
437             return;
438         }
439 
440         stats = sdscatprintf(stats,"[Dictionary HT]\n");
441         dictGetStats(buf,sizeof(buf),server.db[dbid].dict);
442         stats = sdscat(stats,buf);
443 
444         stats = sdscatprintf(stats,"[Expires HT]\n");
445         dictGetStats(buf,sizeof(buf),server.db[dbid].expires);
446         stats = sdscat(stats,buf);
447 
448         addReplyBulkSds(c,stats);
449     } else if (!strcasecmp(c->argv[1]->ptr,"jemalloc") && c->argc == 3) {
450 #if defined(USE_JEMALLOC)
451         if (!strcasecmp(c->argv[2]->ptr, "info")) {
452             sds info = sdsempty();
453             je_malloc_stats_print(inputCatSds, &info, NULL);
454             addReplyBulkSds(c, info);
455         } else {
456             addReplyErrorFormat(c, "Valid jemalloc debug fields: info");
457         }
458 #else
459         addReplyErrorFormat(c, "jemalloc support not available");
460 #endif
461     } else {
462         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
463             (char*)c->argv[1]->ptr);
464     }
465 }
466 
467 /* =========================== Crash handling  ============================== */
468 
469 void _redisAssert(char *estr, char *file, int line) {
470     bugReportStart();
471     redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
472     redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
473 #ifdef HAVE_BACKTRACE
474     server.assert_failed = estr;
475     server.assert_file = file;
476     server.assert_line = line;
477     redisLog(REDIS_WARNING,"(forcing SIGSEGV to print the bug report.)");
478 #endif
479     *((char*)-1) = 'x';
480 }
481 
482 void _redisAssertPrintClientInfo(redisClient *c) {
483     int j;
484 
485     bugReportStart();
486     redisLog(REDIS_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
487     redisLog(REDIS_WARNING,"client->flags = %d", c->flags);
488     redisLog(REDIS_WARNING,"client->fd = %d", c->fd);
489     redisLog(REDIS_WARNING,"client->argc = %d", c->argc);
490     for (j=0; j < c->argc; j++) {
491         char buf[128];
492         char *arg;
493 
494         if (c->argv[j]->type == REDIS_STRING && sdsEncodedObject(c->argv[j])) {
495             arg = (char*) c->argv[j]->ptr;
496         } else {
497             snprintf(buf,sizeof(buf),"Object type: %d, encoding: %d",
498                 c->argv[j]->type, c->argv[j]->encoding);
499             arg = buf;
500         }
501         redisLog(REDIS_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
502             j, arg, c->argv[j]->refcount);
503     }
504 }
505 
506 void redisLogObjectDebugInfo(robj *o) {
507     redisLog(REDIS_WARNING,"Object type: %d", o->type);
508     redisLog(REDIS_WARNING,"Object encoding: %d", o->encoding);
509     redisLog(REDIS_WARNING,"Object refcount: %d", o->refcount);
510     if (o->type == REDIS_STRING && sdsEncodedObject(o)) {
511         redisLog(REDIS_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
512         if (sdslen(o->ptr) < 4096) {
513             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
514             redisLog(REDIS_WARNING,"Object raw string content: %s", repr);
515             sdsfree(repr);
516         }
517     } else if (o->type == REDIS_LIST) {
518         redisLog(REDIS_WARNING,"List length: %d", (int) listTypeLength(o));
519     } else if (o->type == REDIS_SET) {
520         redisLog(REDIS_WARNING,"Set size: %d", (int) setTypeSize(o));
521     } else if (o->type == REDIS_HASH) {
522         redisLog(REDIS_WARNING,"Hash size: %d", (int) hashTypeLength(o));
523     } else if (o->type == REDIS_ZSET) {
524         redisLog(REDIS_WARNING,"Sorted set size: %d", (int) zsetLength(o));
525         if (o->encoding == REDIS_ENCODING_SKIPLIST)
526             redisLog(REDIS_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
527     }
528 }
529 
530 void _redisAssertPrintObject(robj *o) {
531     bugReportStart();
532     redisLog(REDIS_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
533     redisLogObjectDebugInfo(o);
534 }
535 
536 void _redisAssertWithInfo(redisClient *c, robj *o, char *estr, char *file, int line) {
537     if (c) _redisAssertPrintClientInfo(c);
538     if (o) _redisAssertPrintObject(o);
539     _redisAssert(estr,file,line);
540 }
541 
542 void _redisPanic(char *msg, char *file, int line) {
543     bugReportStart();
544     redisLog(REDIS_WARNING,"------------------------------------------------");
545     redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
546     redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
547 #ifdef HAVE_BACKTRACE
548     redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
549 #endif
550     redisLog(REDIS_WARNING,"------------------------------------------------");
551     *((char*)-1) = 'x';
552 }
553 
554 void bugReportStart(void) {
555     if (server.bug_report_start == 0) {
556         redisLog(REDIS_WARNING,
557             "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===");
558         server.bug_report_start = 1;
559     }
560 }
561 
562 #ifdef HAVE_BACKTRACE
563 static void *getMcontextEip(ucontext_t *uc) {
564 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
565     /* OSX < 10.6 */
566     #if defined(__x86_64__)
567     return (void*) uc->uc_mcontext->__ss.__rip;
568     #elif defined(__i386__)
569     return (void*) uc->uc_mcontext->__ss.__eip;
570     #else
571     return (void*) uc->uc_mcontext->__ss.__srr0;
572     #endif
573 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
574     /* OSX >= 10.6 */
575     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
576     return (void*) uc->uc_mcontext->__ss.__rip;
577     #else
578     return (void*) uc->uc_mcontext->__ss.__eip;
579     #endif
580 #elif defined(__linux__)
581     /* Linux */
582     #if defined(__i386__)
583     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
584     #elif defined(__X86_64__) || defined(__x86_64__)
585     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
586     #elif defined(__ia64__) /* Linux IA64 */
587     return (void*) uc->uc_mcontext.sc_ip;
588     #endif
589 #else
590     return NULL;
591 #endif
592 }
593 
594 void logStackContent(void **sp) {
595     int i;
596     for (i = 15; i >= 0; i--) {
597         unsigned long addr = (unsigned long) sp+i;
598         unsigned long val = (unsigned long) sp[i];
599 
600         if (sizeof(long) == 4)
601             redisLog(REDIS_WARNING, "(%08lx) -> %08lx", addr, val);
602         else
603             redisLog(REDIS_WARNING, "(%016lx) -> %016lx", addr, val);
604     }
605 }
606 
607 void logRegisters(ucontext_t *uc) {
608     redisLog(REDIS_WARNING, "--- REGISTERS");
609 
610 /* OSX */
611 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
612   /* OSX AMD64 */
613     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
614     redisLog(REDIS_WARNING,
615     "\n"
616     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
617     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
618     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
619     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
620     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
621         (unsigned long) uc->uc_mcontext->__ss.__rax,
622         (unsigned long) uc->uc_mcontext->__ss.__rbx,
623         (unsigned long) uc->uc_mcontext->__ss.__rcx,
624         (unsigned long) uc->uc_mcontext->__ss.__rdx,
625         (unsigned long) uc->uc_mcontext->__ss.__rdi,
626         (unsigned long) uc->uc_mcontext->__ss.__rsi,
627         (unsigned long) uc->uc_mcontext->__ss.__rbp,
628         (unsigned long) uc->uc_mcontext->__ss.__rsp,
629         (unsigned long) uc->uc_mcontext->__ss.__r8,
630         (unsigned long) uc->uc_mcontext->__ss.__r9,
631         (unsigned long) uc->uc_mcontext->__ss.__r10,
632         (unsigned long) uc->uc_mcontext->__ss.__r11,
633         (unsigned long) uc->uc_mcontext->__ss.__r12,
634         (unsigned long) uc->uc_mcontext->__ss.__r13,
635         (unsigned long) uc->uc_mcontext->__ss.__r14,
636         (unsigned long) uc->uc_mcontext->__ss.__r15,
637         (unsigned long) uc->uc_mcontext->__ss.__rip,
638         (unsigned long) uc->uc_mcontext->__ss.__rflags,
639         (unsigned long) uc->uc_mcontext->__ss.__cs,
640         (unsigned long) uc->uc_mcontext->__ss.__fs,
641         (unsigned long) uc->uc_mcontext->__ss.__gs
642     );
643     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
644     #else
645     /* OSX x86 */
646     redisLog(REDIS_WARNING,
647     "\n"
648     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
649     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
650     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
651     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
652         (unsigned long) uc->uc_mcontext->__ss.__eax,
653         (unsigned long) uc->uc_mcontext->__ss.__ebx,
654         (unsigned long) uc->uc_mcontext->__ss.__ecx,
655         (unsigned long) uc->uc_mcontext->__ss.__edx,
656         (unsigned long) uc->uc_mcontext->__ss.__edi,
657         (unsigned long) uc->uc_mcontext->__ss.__esi,
658         (unsigned long) uc->uc_mcontext->__ss.__ebp,
659         (unsigned long) uc->uc_mcontext->__ss.__esp,
660         (unsigned long) uc->uc_mcontext->__ss.__ss,
661         (unsigned long) uc->uc_mcontext->__ss.__eflags,
662         (unsigned long) uc->uc_mcontext->__ss.__eip,
663         (unsigned long) uc->uc_mcontext->__ss.__cs,
664         (unsigned long) uc->uc_mcontext->__ss.__ds,
665         (unsigned long) uc->uc_mcontext->__ss.__es,
666         (unsigned long) uc->uc_mcontext->__ss.__fs,
667         (unsigned long) uc->uc_mcontext->__ss.__gs
668     );
669     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
670     #endif
671 /* Linux */
672 #elif defined(__linux__)
673     /* Linux x86 */
674     #if defined(__i386__)
675     redisLog(REDIS_WARNING,
676     "\n"
677     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
678     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
679     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
680     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
681         (unsigned long) uc->uc_mcontext.gregs[11],
682         (unsigned long) uc->uc_mcontext.gregs[8],
683         (unsigned long) uc->uc_mcontext.gregs[10],
684         (unsigned long) uc->uc_mcontext.gregs[9],
685         (unsigned long) uc->uc_mcontext.gregs[4],
686         (unsigned long) uc->uc_mcontext.gregs[5],
687         (unsigned long) uc->uc_mcontext.gregs[6],
688         (unsigned long) uc->uc_mcontext.gregs[7],
689         (unsigned long) uc->uc_mcontext.gregs[18],
690         (unsigned long) uc->uc_mcontext.gregs[17],
691         (unsigned long) uc->uc_mcontext.gregs[14],
692         (unsigned long) uc->uc_mcontext.gregs[15],
693         (unsigned long) uc->uc_mcontext.gregs[3],
694         (unsigned long) uc->uc_mcontext.gregs[2],
695         (unsigned long) uc->uc_mcontext.gregs[1],
696         (unsigned long) uc->uc_mcontext.gregs[0]
697     );
698     logStackContent((void**)uc->uc_mcontext.gregs[7]);
699     #elif defined(__X86_64__) || defined(__x86_64__)
700     /* Linux AMD64 */
701     redisLog(REDIS_WARNING,
702     "\n"
703     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
704     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
705     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
706     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
707     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
708         (unsigned long) uc->uc_mcontext.gregs[13],
709         (unsigned long) uc->uc_mcontext.gregs[11],
710         (unsigned long) uc->uc_mcontext.gregs[14],
711         (unsigned long) uc->uc_mcontext.gregs[12],
712         (unsigned long) uc->uc_mcontext.gregs[8],
713         (unsigned long) uc->uc_mcontext.gregs[9],
714         (unsigned long) uc->uc_mcontext.gregs[10],
715         (unsigned long) uc->uc_mcontext.gregs[15],
716         (unsigned long) uc->uc_mcontext.gregs[0],
717         (unsigned long) uc->uc_mcontext.gregs[1],
718         (unsigned long) uc->uc_mcontext.gregs[2],
719         (unsigned long) uc->uc_mcontext.gregs[3],
720         (unsigned long) uc->uc_mcontext.gregs[4],
721         (unsigned long) uc->uc_mcontext.gregs[5],
722         (unsigned long) uc->uc_mcontext.gregs[6],
723         (unsigned long) uc->uc_mcontext.gregs[7],
724         (unsigned long) uc->uc_mcontext.gregs[16],
725         (unsigned long) uc->uc_mcontext.gregs[17],
726         (unsigned long) uc->uc_mcontext.gregs[18]
727     );
728     logStackContent((void**)uc->uc_mcontext.gregs[15]);
729     #endif
730 #else
731     redisLog(REDIS_WARNING,
732         "  Dumping of registers not supported for this OS/arch");
733 #endif
734 }
735 
736 /* Logs the stack trace using the backtrace() call. This function is designed
737  * to be called from signal handlers safely. */
738 void logStackTrace(ucontext_t *uc) {
739     void *trace[100];
740     int trace_size = 0, fd;
741     int log_to_stdout = server.logfile[0] == '\0';
742 
743     /* Open the log file in append mode. */
744     fd = log_to_stdout ?
745         STDOUT_FILENO :
746         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
747     if (fd == -1) return;
748 
749     /* Generate the stack trace */
750     trace_size = backtrace(trace, 100);
751 
752     /* overwrite sigaction with caller's address */
753     if (getMcontextEip(uc) != NULL)
754         trace[1] = getMcontextEip(uc);
755 
756     /* Write symbols to log file */
757     backtrace_symbols_fd(trace, trace_size, fd);
758 
759     /* Cleanup */
760     if (!log_to_stdout) close(fd);
761 }
762 
763 /* Log information about the "current" client, that is, the client that is
764  * currently being served by Redis. May be NULL if Redis is not serving a
765  * client right now. */
766 void logCurrentClient(void) {
767     if (server.current_client == NULL) return;
768 
769     redisClient *cc = server.current_client;
770     sds client;
771     int j;
772 
773     redisLog(REDIS_WARNING, "--- CURRENT CLIENT INFO");
774     client = catClientInfoString(sdsempty(),cc);
775     redisLog(REDIS_WARNING,"client: %s", client);
776     sdsfree(client);
777     for (j = 0; j < cc->argc; j++) {
778         robj *decoded;
779 
780         decoded = getDecodedObject(cc->argv[j]);
781         redisLog(REDIS_WARNING,"argv[%d]: '%s'", j, (char*)decoded->ptr);
782         decrRefCount(decoded);
783     }
784     /* Check if the first argument, usually a key, is found inside the
785      * selected DB, and if so print info about the associated object. */
786     if (cc->argc >= 1) {
787         robj *val, *key;
788         dictEntry *de;
789 
790         key = getDecodedObject(cc->argv[1]);
791         de = dictFind(cc->db->dict, key->ptr);
792         if (de) {
793             val = dictGetVal(de);
794             redisLog(REDIS_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
795             redisLogObjectDebugInfo(val);
796         }
797         decrRefCount(key);
798     }
799 }
800 
801 #if defined(HAVE_PROC_MAPS)
802 void memtest_non_destructive_invert(void *addr, size_t size);
803 void memtest_non_destructive_swap(void *addr, size_t size);
804 #define MEMTEST_MAX_REGIONS 128
805 
806 int memtest_test_linux_anonymous_maps(void) {
807     FILE *fp = fopen("/proc/self/maps","r");
808     char line[1024];
809     size_t start_addr, end_addr, size;
810     size_t start_vect[MEMTEST_MAX_REGIONS];
811     size_t size_vect[MEMTEST_MAX_REGIONS];
812     int regions = 0, j;
813     uint64_t crc1 = 0, crc2 = 0, crc3 = 0;
814 
815     while(fgets(line,sizeof(line),fp) != NULL) {
816         char *start, *end, *p = line;
817 
818         start = p;
819         p = strchr(p,'-');
820         if (!p) continue;
821         *p++ = '\0';
822         end = p;
823         p = strchr(p,' ');
824         if (!p) continue;
825         *p++ = '\0';
826         if (strstr(p,"stack") ||
827             strstr(p,"vdso") ||
828             strstr(p,"vsyscall")) continue;
829         if (!strstr(p,"00:00")) continue;
830         if (!strstr(p,"rw")) continue;
831 
832         start_addr = strtoul(start,NULL,16);
833         end_addr = strtoul(end,NULL,16);
834         size = end_addr-start_addr;
835 
836         start_vect[regions] = start_addr;
837         size_vect[regions] = size;
838         printf("Testing %lx %lu\n", (unsigned long) start_vect[regions],
839                                     (unsigned long) size_vect[regions]);
840         regions++;
841     }
842 
843     /* Test all the regions as an unique sequential region.
844      * 1) Take the CRC64 of the memory region. */
845     for (j = 0; j < regions; j++) {
846         crc1 = crc64(crc1,(void*)start_vect[j],size_vect[j]);
847     }
848 
849     /* 2) Invert bits, swap adjacent words, swap again, invert bits.
850      * This is the error amplification step. */
851     for (j = 0; j < regions; j++)
852         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
853     for (j = 0; j < regions; j++)
854         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
855     for (j = 0; j < regions; j++)
856         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
857     for (j = 0; j < regions; j++)
858         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
859 
860     /* 3) Take the CRC64 sum again. */
861     for (j = 0; j < regions; j++)
862         crc2 = crc64(crc2,(void*)start_vect[j],size_vect[j]);
863 
864     /* 4) Swap + Swap again */
865     for (j = 0; j < regions; j++)
866         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
867     for (j = 0; j < regions; j++)
868         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
869 
870     /* 5) Take the CRC64 sum again. */
871     for (j = 0; j < regions; j++)
872         crc3 = crc64(crc3,(void*)start_vect[j],size_vect[j]);
873 
874     /* NOTE: It is very important to close the file descriptor only now
875      * because closing it before may result into unmapping of some memory
876      * region that we are testing. */
877     fclose(fp);
878 
879     /* If the two CRC are not the same, we trapped a memory error. */
880     return crc1 != crc2 || crc2 != crc3;
881 }
882 #endif
883 
884 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
885     ucontext_t *uc = (ucontext_t*) secret;
886     sds infostring, clients;
887     struct sigaction act;
888     REDIS_NOTUSED(info);
889 
890     bugReportStart();
891     redisLog(REDIS_WARNING,
892         "    Redis %s crashed by signal: %d", REDIS_VERSION, sig);
893     redisLog(REDIS_WARNING,
894         "    Failed assertion: %s (%s:%d)", server.assert_failed,
895                         server.assert_file, server.assert_line);
896 
897     /* Log the stack trace */
898     redisLog(REDIS_WARNING, "--- STACK TRACE");
899     logStackTrace(uc);
900 
901     /* Log INFO and CLIENT LIST */
902     redisLog(REDIS_WARNING, "--- INFO OUTPUT");
903     infostring = genRedisInfoString("all");
904     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
905         dictGetHashFunctionSeed());
906     redisLogRaw(REDIS_WARNING, infostring);
907     redisLog(REDIS_WARNING, "--- CLIENT LIST OUTPUT");
908     clients = getAllClientsInfoString();
909     redisLogRaw(REDIS_WARNING, clients);
910     sdsfree(infostring);
911     sdsfree(clients);
912 
913     /* Log the current client */
914     logCurrentClient();
915 
916     /* Log dump of processor registers */
917     logRegisters(uc);
918 
919 #if defined(HAVE_PROC_MAPS)
920     /* Test memory */
921     redisLog(REDIS_WARNING, "--- FAST MEMORY TEST");
922     bioKillThreads();
923     if (memtest_test_linux_anonymous_maps()) {
924         redisLog(REDIS_WARNING,
925             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
926     } else {
927         redisLog(REDIS_WARNING,
928             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
929     }
930 #endif
931 
932     redisLog(REDIS_WARNING,
933 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
934 "       Please report the crash by opening an issue on github:\n\n"
935 "           http://github.com/antirez/redis/issues\n\n"
936 "  Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
937 );
938     /* free(messages); Don't call free() with possibly corrupted memory. */
939     if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
940 
941     /* Make sure we exit with the right signal at the end. So for instance
942      * the core will be dumped if enabled. */
943     sigemptyset (&act.sa_mask);
944     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
945     act.sa_handler = SIG_DFL;
946     sigaction (sig, &act, NULL);
947     kill(getpid(),sig);
948 }
949 #endif /* HAVE_BACKTRACE */
950 
951 /* ==================== Logging functions for debugging ===================== */
952 
953 void redisLogHexDump(int level, char *descr, void *value, size_t len) {
954     char buf[65], *b;
955     unsigned char *v = value;
956     char charset[] = "0123456789abcdef";
957 
958     redisLog(level,"%s (hexdump):", descr);
959     b = buf;
960     while(len) {
961         b[0] = charset[(*v)>>4];
962         b[1] = charset[(*v)&0xf];
963         b[2] = '\0';
964         b += 2;
965         len--;
966         v++;
967         if (b-buf == 64 || len == 0) {
968             redisLogRaw(level|REDIS_LOG_RAW,buf);
969             b = buf;
970         }
971     }
972     redisLogRaw(level|REDIS_LOG_RAW,"\n");
973 }
974 
975 /* =========================== Software Watchdog ============================ */
976 #include <sys/time.h>
977 
978 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
979 #ifdef HAVE_BACKTRACE
980     ucontext_t *uc = (ucontext_t*) secret;
981 #endif
982     REDIS_NOTUSED(info);
983     REDIS_NOTUSED(sig);
984 
985     redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
986 #ifdef HAVE_BACKTRACE
987     logStackTrace(uc);
988 #else
989     redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
990 #endif
991     redisLogFromHandler(REDIS_WARNING,"--------\n");
992 }
993 
994 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
995  * If a timer is already scheduled, this function will re-schedule it to the
996  * specified time. If period is 0 the current timer is disabled. */
997 void watchdogScheduleSignal(int period) {
998     struct itimerval it;
999 
1000     /* Will stop the timer if period is 0. */
1001     it.it_value.tv_sec = period/1000;
1002     it.it_value.tv_usec = (period%1000)*1000;
1003     /* Don't automatically restart. */
1004     it.it_interval.tv_sec = 0;
1005     it.it_interval.tv_usec = 0;
1006     setitimer(ITIMER_REAL, &it, NULL);
1007 }
1008 
1009 /* Enable the software watchdog with the specified period in milliseconds. */
1010 void enableWatchdog(int period) {
1011     int min_period;
1012 
1013     if (server.watchdog_period == 0) {
1014         struct sigaction act;
1015 
1016         /* Watchdog was actually disabled, so we have to setup the signal
1017          * handler. */
1018         sigemptyset(&act.sa_mask);
1019         act.sa_flags = SA_ONSTACK | SA_SIGINFO;
1020         act.sa_sigaction = watchdogSignalHandler;
1021         sigaction(SIGALRM, &act, NULL);
1022     }
1023     /* If the configured period is smaller than twice the timer period, it is
1024      * too short for the software watchdog to work reliably. Fix it now
1025      * if needed. */
1026     min_period = (1000/server.hz)*2;
1027     if (period < min_period) period = min_period;
1028     watchdogScheduleSignal(period); /* Adjust the current timer. */
1029     server.watchdog_period = period;
1030 }
1031 
1032 /* Disable the software watchdog. */
1033 void disableWatchdog(void) {
1034     struct sigaction act;
1035     if (server.watchdog_period == 0) return; /* Already disabled. */
1036     watchdogScheduleSignal(0); /* Stop the current timer. */
1037 
1038     /* Set the signal handler to SIG_IGN, this will also remove pending
1039      * signals from the queue. */
1040     sigemptyset(&act.sa_mask);
1041     act.sa_flags = 0;
1042     act.sa_handler = SIG_IGN;
1043     sigaction(SIGALRM, &act, NULL);
1044     server.watchdog_period = 0;
1045 }
1046