xref: /redis-3.2.3/src/debug.c (revision cc0d339b)
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,"jemalloc") && c->argc == 3) {
429 #if defined(USE_JEMALLOC)
430         if (!strcasecmp(c->argv[2]->ptr, "info")) {
431             sds info = sdsempty();
432             je_malloc_stats_print(inputCatSds, &info, NULL);
433             addReplyBulkSds(c, info);
434         } else {
435             addReplyErrorFormat(c, "Valid jemalloc debug fields: info");
436         }
437 #else
438         addReplyErrorFormat(c, "jemalloc support not available");
439 #endif
440     } else {
441         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
442             (char*)c->argv[1]->ptr);
443     }
444 }
445 
446 /* =========================== Crash handling  ============================== */
447 
448 void _redisAssert(char *estr, char *file, int line) {
449     bugReportStart();
450     redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
451     redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
452 #ifdef HAVE_BACKTRACE
453     server.assert_failed = estr;
454     server.assert_file = file;
455     server.assert_line = line;
456     redisLog(REDIS_WARNING,"(forcing SIGSEGV to print the bug report.)");
457 #endif
458     *((char*)-1) = 'x';
459 }
460 
461 void _redisAssertPrintClientInfo(redisClient *c) {
462     int j;
463 
464     bugReportStart();
465     redisLog(REDIS_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
466     redisLog(REDIS_WARNING,"client->flags = %d", c->flags);
467     redisLog(REDIS_WARNING,"client->fd = %d", c->fd);
468     redisLog(REDIS_WARNING,"client->argc = %d", c->argc);
469     for (j=0; j < c->argc; j++) {
470         char buf[128];
471         char *arg;
472 
473         if (c->argv[j]->type == REDIS_STRING && sdsEncodedObject(c->argv[j])) {
474             arg = (char*) c->argv[j]->ptr;
475         } else {
476             snprintf(buf,sizeof(buf),"Object type: %d, encoding: %d",
477                 c->argv[j]->type, c->argv[j]->encoding);
478             arg = buf;
479         }
480         redisLog(REDIS_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
481             j, arg, c->argv[j]->refcount);
482     }
483 }
484 
485 void redisLogObjectDebugInfo(robj *o) {
486     redisLog(REDIS_WARNING,"Object type: %d", o->type);
487     redisLog(REDIS_WARNING,"Object encoding: %d", o->encoding);
488     redisLog(REDIS_WARNING,"Object refcount: %d", o->refcount);
489     if (o->type == REDIS_STRING && sdsEncodedObject(o)) {
490         redisLog(REDIS_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
491         if (sdslen(o->ptr) < 4096) {
492             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
493             redisLog(REDIS_WARNING,"Object raw string content: %s", repr);
494             sdsfree(repr);
495         }
496     } else if (o->type == REDIS_LIST) {
497         redisLog(REDIS_WARNING,"List length: %d", (int) listTypeLength(o));
498     } else if (o->type == REDIS_SET) {
499         redisLog(REDIS_WARNING,"Set size: %d", (int) setTypeSize(o));
500     } else if (o->type == REDIS_HASH) {
501         redisLog(REDIS_WARNING,"Hash size: %d", (int) hashTypeLength(o));
502     } else if (o->type == REDIS_ZSET) {
503         redisLog(REDIS_WARNING,"Sorted set size: %d", (int) zsetLength(o));
504         if (o->encoding == REDIS_ENCODING_SKIPLIST)
505             redisLog(REDIS_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
506     }
507 }
508 
509 void _redisAssertPrintObject(robj *o) {
510     bugReportStart();
511     redisLog(REDIS_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
512     redisLogObjectDebugInfo(o);
513 }
514 
515 void _redisAssertWithInfo(redisClient *c, robj *o, char *estr, char *file, int line) {
516     if (c) _redisAssertPrintClientInfo(c);
517     if (o) _redisAssertPrintObject(o);
518     _redisAssert(estr,file,line);
519 }
520 
521 void _redisPanic(char *msg, char *file, int line) {
522     bugReportStart();
523     redisLog(REDIS_WARNING,"------------------------------------------------");
524     redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
525     redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
526 #ifdef HAVE_BACKTRACE
527     redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
528 #endif
529     redisLog(REDIS_WARNING,"------------------------------------------------");
530     *((char*)-1) = 'x';
531 }
532 
533 void bugReportStart(void) {
534     if (server.bug_report_start == 0) {
535         redisLog(REDIS_WARNING,
536             "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===");
537         server.bug_report_start = 1;
538     }
539 }
540 
541 #ifdef HAVE_BACKTRACE
542 static void *getMcontextEip(ucontext_t *uc) {
543 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
544     /* OSX < 10.6 */
545     #if defined(__x86_64__)
546     return (void*) uc->uc_mcontext->__ss.__rip;
547     #elif defined(__i386__)
548     return (void*) uc->uc_mcontext->__ss.__eip;
549     #else
550     return (void*) uc->uc_mcontext->__ss.__srr0;
551     #endif
552 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
553     /* OSX >= 10.6 */
554     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
555     return (void*) uc->uc_mcontext->__ss.__rip;
556     #else
557     return (void*) uc->uc_mcontext->__ss.__eip;
558     #endif
559 #elif defined(__linux__)
560     /* Linux */
561     #if defined(__i386__)
562     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
563     #elif defined(__X86_64__) || defined(__x86_64__)
564     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
565     #elif defined(__ia64__) /* Linux IA64 */
566     return (void*) uc->uc_mcontext.sc_ip;
567     #endif
568 #else
569     return NULL;
570 #endif
571 }
572 
573 void logStackContent(void **sp) {
574     int i;
575     for (i = 15; i >= 0; i--) {
576         unsigned long addr = (unsigned long) sp+i;
577         unsigned long val = (unsigned long) sp[i];
578 
579         if (sizeof(long) == 4)
580             redisLog(REDIS_WARNING, "(%08lx) -> %08lx", addr, val);
581         else
582             redisLog(REDIS_WARNING, "(%016lx) -> %016lx", addr, val);
583     }
584 }
585 
586 void logRegisters(ucontext_t *uc) {
587     redisLog(REDIS_WARNING, "--- REGISTERS");
588 
589 /* OSX */
590 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
591   /* OSX AMD64 */
592     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
593     redisLog(REDIS_WARNING,
594     "\n"
595     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
596     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
597     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
598     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
599     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
600         (unsigned long) uc->uc_mcontext->__ss.__rax,
601         (unsigned long) uc->uc_mcontext->__ss.__rbx,
602         (unsigned long) uc->uc_mcontext->__ss.__rcx,
603         (unsigned long) uc->uc_mcontext->__ss.__rdx,
604         (unsigned long) uc->uc_mcontext->__ss.__rdi,
605         (unsigned long) uc->uc_mcontext->__ss.__rsi,
606         (unsigned long) uc->uc_mcontext->__ss.__rbp,
607         (unsigned long) uc->uc_mcontext->__ss.__rsp,
608         (unsigned long) uc->uc_mcontext->__ss.__r8,
609         (unsigned long) uc->uc_mcontext->__ss.__r9,
610         (unsigned long) uc->uc_mcontext->__ss.__r10,
611         (unsigned long) uc->uc_mcontext->__ss.__r11,
612         (unsigned long) uc->uc_mcontext->__ss.__r12,
613         (unsigned long) uc->uc_mcontext->__ss.__r13,
614         (unsigned long) uc->uc_mcontext->__ss.__r14,
615         (unsigned long) uc->uc_mcontext->__ss.__r15,
616         (unsigned long) uc->uc_mcontext->__ss.__rip,
617         (unsigned long) uc->uc_mcontext->__ss.__rflags,
618         (unsigned long) uc->uc_mcontext->__ss.__cs,
619         (unsigned long) uc->uc_mcontext->__ss.__fs,
620         (unsigned long) uc->uc_mcontext->__ss.__gs
621     );
622     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
623     #else
624     /* OSX x86 */
625     redisLog(REDIS_WARNING,
626     "\n"
627     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
628     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
629     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
630     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
631         (unsigned long) uc->uc_mcontext->__ss.__eax,
632         (unsigned long) uc->uc_mcontext->__ss.__ebx,
633         (unsigned long) uc->uc_mcontext->__ss.__ecx,
634         (unsigned long) uc->uc_mcontext->__ss.__edx,
635         (unsigned long) uc->uc_mcontext->__ss.__edi,
636         (unsigned long) uc->uc_mcontext->__ss.__esi,
637         (unsigned long) uc->uc_mcontext->__ss.__ebp,
638         (unsigned long) uc->uc_mcontext->__ss.__esp,
639         (unsigned long) uc->uc_mcontext->__ss.__ss,
640         (unsigned long) uc->uc_mcontext->__ss.__eflags,
641         (unsigned long) uc->uc_mcontext->__ss.__eip,
642         (unsigned long) uc->uc_mcontext->__ss.__cs,
643         (unsigned long) uc->uc_mcontext->__ss.__ds,
644         (unsigned long) uc->uc_mcontext->__ss.__es,
645         (unsigned long) uc->uc_mcontext->__ss.__fs,
646         (unsigned long) uc->uc_mcontext->__ss.__gs
647     );
648     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
649     #endif
650 /* Linux */
651 #elif defined(__linux__)
652     /* Linux x86 */
653     #if defined(__i386__)
654     redisLog(REDIS_WARNING,
655     "\n"
656     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
657     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
658     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
659     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
660         (unsigned long) uc->uc_mcontext.gregs[11],
661         (unsigned long) uc->uc_mcontext.gregs[8],
662         (unsigned long) uc->uc_mcontext.gregs[10],
663         (unsigned long) uc->uc_mcontext.gregs[9],
664         (unsigned long) uc->uc_mcontext.gregs[4],
665         (unsigned long) uc->uc_mcontext.gregs[5],
666         (unsigned long) uc->uc_mcontext.gregs[6],
667         (unsigned long) uc->uc_mcontext.gregs[7],
668         (unsigned long) uc->uc_mcontext.gregs[18],
669         (unsigned long) uc->uc_mcontext.gregs[17],
670         (unsigned long) uc->uc_mcontext.gregs[14],
671         (unsigned long) uc->uc_mcontext.gregs[15],
672         (unsigned long) uc->uc_mcontext.gregs[3],
673         (unsigned long) uc->uc_mcontext.gregs[2],
674         (unsigned long) uc->uc_mcontext.gregs[1],
675         (unsigned long) uc->uc_mcontext.gregs[0]
676     );
677     logStackContent((void**)uc->uc_mcontext.gregs[7]);
678     #elif defined(__X86_64__) || defined(__x86_64__)
679     /* Linux AMD64 */
680     redisLog(REDIS_WARNING,
681     "\n"
682     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
683     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
684     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
685     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
686     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
687         (unsigned long) uc->uc_mcontext.gregs[13],
688         (unsigned long) uc->uc_mcontext.gregs[11],
689         (unsigned long) uc->uc_mcontext.gregs[14],
690         (unsigned long) uc->uc_mcontext.gregs[12],
691         (unsigned long) uc->uc_mcontext.gregs[8],
692         (unsigned long) uc->uc_mcontext.gregs[9],
693         (unsigned long) uc->uc_mcontext.gregs[10],
694         (unsigned long) uc->uc_mcontext.gregs[15],
695         (unsigned long) uc->uc_mcontext.gregs[0],
696         (unsigned long) uc->uc_mcontext.gregs[1],
697         (unsigned long) uc->uc_mcontext.gregs[2],
698         (unsigned long) uc->uc_mcontext.gregs[3],
699         (unsigned long) uc->uc_mcontext.gregs[4],
700         (unsigned long) uc->uc_mcontext.gregs[5],
701         (unsigned long) uc->uc_mcontext.gregs[6],
702         (unsigned long) uc->uc_mcontext.gregs[7],
703         (unsigned long) uc->uc_mcontext.gregs[16],
704         (unsigned long) uc->uc_mcontext.gregs[17],
705         (unsigned long) uc->uc_mcontext.gregs[18]
706     );
707     logStackContent((void**)uc->uc_mcontext.gregs[15]);
708     #endif
709 #else
710     redisLog(REDIS_WARNING,
711         "  Dumping of registers not supported for this OS/arch");
712 #endif
713 }
714 
715 /* Logs the stack trace using the backtrace() call. This function is designed
716  * to be called from signal handlers safely. */
717 void logStackTrace(ucontext_t *uc) {
718     void *trace[100];
719     int trace_size = 0, fd;
720     int log_to_stdout = server.logfile[0] == '\0';
721 
722     /* Open the log file in append mode. */
723     fd = log_to_stdout ?
724         STDOUT_FILENO :
725         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
726     if (fd == -1) return;
727 
728     /* Generate the stack trace */
729     trace_size = backtrace(trace, 100);
730 
731     /* overwrite sigaction with caller's address */
732     if (getMcontextEip(uc) != NULL)
733         trace[1] = getMcontextEip(uc);
734 
735     /* Write symbols to log file */
736     backtrace_symbols_fd(trace, trace_size, fd);
737 
738     /* Cleanup */
739     if (!log_to_stdout) close(fd);
740 }
741 
742 /* Log information about the "current" client, that is, the client that is
743  * currently being served by Redis. May be NULL if Redis is not serving a
744  * client right now. */
745 void logCurrentClient(void) {
746     if (server.current_client == NULL) return;
747 
748     redisClient *cc = server.current_client;
749     sds client;
750     int j;
751 
752     redisLog(REDIS_WARNING, "--- CURRENT CLIENT INFO");
753     client = catClientInfoString(sdsempty(),cc);
754     redisLog(REDIS_WARNING,"client: %s", client);
755     sdsfree(client);
756     for (j = 0; j < cc->argc; j++) {
757         robj *decoded;
758 
759         decoded = getDecodedObject(cc->argv[j]);
760         redisLog(REDIS_WARNING,"argv[%d]: '%s'", j, (char*)decoded->ptr);
761         decrRefCount(decoded);
762     }
763     /* Check if the first argument, usually a key, is found inside the
764      * selected DB, and if so print info about the associated object. */
765     if (cc->argc >= 1) {
766         robj *val, *key;
767         dictEntry *de;
768 
769         key = getDecodedObject(cc->argv[1]);
770         de = dictFind(cc->db->dict, key->ptr);
771         if (de) {
772             val = dictGetVal(de);
773             redisLog(REDIS_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
774             redisLogObjectDebugInfo(val);
775         }
776         decrRefCount(key);
777     }
778 }
779 
780 #if defined(HAVE_PROC_MAPS)
781 void memtest_non_destructive_invert(void *addr, size_t size);
782 void memtest_non_destructive_swap(void *addr, size_t size);
783 #define MEMTEST_MAX_REGIONS 128
784 
785 int memtest_test_linux_anonymous_maps(void) {
786     FILE *fp = fopen("/proc/self/maps","r");
787     char line[1024];
788     size_t start_addr, end_addr, size;
789     size_t start_vect[MEMTEST_MAX_REGIONS];
790     size_t size_vect[MEMTEST_MAX_REGIONS];
791     int regions = 0, j;
792     uint64_t crc1 = 0, crc2 = 0, crc3 = 0;
793 
794     while(fgets(line,sizeof(line),fp) != NULL) {
795         char *start, *end, *p = line;
796 
797         start = p;
798         p = strchr(p,'-');
799         if (!p) continue;
800         *p++ = '\0';
801         end = p;
802         p = strchr(p,' ');
803         if (!p) continue;
804         *p++ = '\0';
805         if (strstr(p,"stack") ||
806             strstr(p,"vdso") ||
807             strstr(p,"vsyscall")) continue;
808         if (!strstr(p,"00:00")) continue;
809         if (!strstr(p,"rw")) continue;
810 
811         start_addr = strtoul(start,NULL,16);
812         end_addr = strtoul(end,NULL,16);
813         size = end_addr-start_addr;
814 
815         start_vect[regions] = start_addr;
816         size_vect[regions] = size;
817         printf("Testing %lx %lu\n", (unsigned long) start_vect[regions],
818                                     (unsigned long) size_vect[regions]);
819         regions++;
820     }
821 
822     /* Test all the regions as an unique sequential region.
823      * 1) Take the CRC64 of the memory region. */
824     for (j = 0; j < regions; j++) {
825         crc1 = crc64(crc1,(void*)start_vect[j],size_vect[j]);
826     }
827 
828     /* 2) Invert bits, swap adjacent words, swap again, invert bits.
829      * This is the error amplification step. */
830     for (j = 0; j < regions; j++)
831         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
832     for (j = 0; j < regions; j++)
833         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
834     for (j = 0; j < regions; j++)
835         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
836     for (j = 0; j < regions; j++)
837         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
838 
839     /* 3) Take the CRC64 sum again. */
840     for (j = 0; j < regions; j++)
841         crc2 = crc64(crc2,(void*)start_vect[j],size_vect[j]);
842 
843     /* 4) Swap + Swap again */
844     for (j = 0; j < regions; j++)
845         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
846     for (j = 0; j < regions; j++)
847         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
848 
849     /* 5) Take the CRC64 sum again. */
850     for (j = 0; j < regions; j++)
851         crc3 = crc64(crc3,(void*)start_vect[j],size_vect[j]);
852 
853     /* NOTE: It is very important to close the file descriptor only now
854      * because closing it before may result into unmapping of some memory
855      * region that we are testing. */
856     fclose(fp);
857 
858     /* If the two CRC are not the same, we trapped a memory error. */
859     return crc1 != crc2 || crc2 != crc3;
860 }
861 #endif
862 
863 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
864     ucontext_t *uc = (ucontext_t*) secret;
865     sds infostring, clients;
866     struct sigaction act;
867     REDIS_NOTUSED(info);
868 
869     bugReportStart();
870     redisLog(REDIS_WARNING,
871         "    Redis %s crashed by signal: %d", REDIS_VERSION, sig);
872     redisLog(REDIS_WARNING,
873         "    Failed assertion: %s (%s:%d)", server.assert_failed,
874                         server.assert_file, server.assert_line);
875 
876     /* Log the stack trace */
877     redisLog(REDIS_WARNING, "--- STACK TRACE");
878     logStackTrace(uc);
879 
880     /* Log INFO and CLIENT LIST */
881     redisLog(REDIS_WARNING, "--- INFO OUTPUT");
882     infostring = genRedisInfoString("all");
883     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
884         dictGetHashFunctionSeed());
885     redisLogRaw(REDIS_WARNING, infostring);
886     redisLog(REDIS_WARNING, "--- CLIENT LIST OUTPUT");
887     clients = getAllClientsInfoString();
888     redisLogRaw(REDIS_WARNING, clients);
889     sdsfree(infostring);
890     sdsfree(clients);
891 
892     /* Log the current client */
893     logCurrentClient();
894 
895     /* Log dump of processor registers */
896     logRegisters(uc);
897 
898 #if defined(HAVE_PROC_MAPS)
899     /* Test memory */
900     redisLog(REDIS_WARNING, "--- FAST MEMORY TEST");
901     bioKillThreads();
902     if (memtest_test_linux_anonymous_maps()) {
903         redisLog(REDIS_WARNING,
904             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
905     } else {
906         redisLog(REDIS_WARNING,
907             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
908     }
909 #endif
910 
911     redisLog(REDIS_WARNING,
912 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
913 "       Please report the crash by opening an issue on github:\n\n"
914 "           http://github.com/antirez/redis/issues\n\n"
915 "  Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
916 );
917     /* free(messages); Don't call free() with possibly corrupted memory. */
918     if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
919 
920     /* Make sure we exit with the right signal at the end. So for instance
921      * the core will be dumped if enabled. */
922     sigemptyset (&act.sa_mask);
923     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
924     act.sa_handler = SIG_DFL;
925     sigaction (sig, &act, NULL);
926     kill(getpid(),sig);
927 }
928 #endif /* HAVE_BACKTRACE */
929 
930 /* ==================== Logging functions for debugging ===================== */
931 
932 void redisLogHexDump(int level, char *descr, void *value, size_t len) {
933     char buf[65], *b;
934     unsigned char *v = value;
935     char charset[] = "0123456789abcdef";
936 
937     redisLog(level,"%s (hexdump):", descr);
938     b = buf;
939     while(len) {
940         b[0] = charset[(*v)>>4];
941         b[1] = charset[(*v)&0xf];
942         b[2] = '\0';
943         b += 2;
944         len--;
945         v++;
946         if (b-buf == 64 || len == 0) {
947             redisLogRaw(level|REDIS_LOG_RAW,buf);
948             b = buf;
949         }
950     }
951     redisLogRaw(level|REDIS_LOG_RAW,"\n");
952 }
953 
954 /* =========================== Software Watchdog ============================ */
955 #include <sys/time.h>
956 
957 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
958 #ifdef HAVE_BACKTRACE
959     ucontext_t *uc = (ucontext_t*) secret;
960 #endif
961     REDIS_NOTUSED(info);
962     REDIS_NOTUSED(sig);
963 
964     redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
965 #ifdef HAVE_BACKTRACE
966     logStackTrace(uc);
967 #else
968     redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
969 #endif
970     redisLogFromHandler(REDIS_WARNING,"--------\n");
971 }
972 
973 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
974  * If a timer is already scheduled, this function will re-schedule it to the
975  * specified time. If period is 0 the current timer is disabled. */
976 void watchdogScheduleSignal(int period) {
977     struct itimerval it;
978 
979     /* Will stop the timer if period is 0. */
980     it.it_value.tv_sec = period/1000;
981     it.it_value.tv_usec = (period%1000)*1000;
982     /* Don't automatically restart. */
983     it.it_interval.tv_sec = 0;
984     it.it_interval.tv_usec = 0;
985     setitimer(ITIMER_REAL, &it, NULL);
986 }
987 
988 /* Enable the software watchdog with the specified period in milliseconds. */
989 void enableWatchdog(int period) {
990     int min_period;
991 
992     if (server.watchdog_period == 0) {
993         struct sigaction act;
994 
995         /* Watchdog was actually disabled, so we have to setup the signal
996          * handler. */
997         sigemptyset(&act.sa_mask);
998         act.sa_flags = SA_ONSTACK | SA_SIGINFO;
999         act.sa_sigaction = watchdogSignalHandler;
1000         sigaction(SIGALRM, &act, NULL);
1001     }
1002     /* If the configured period is smaller than twice the timer period, it is
1003      * too short for the software watchdog to work reliably. Fix it now
1004      * if needed. */
1005     min_period = (1000/server.hz)*2;
1006     if (period < min_period) period = min_period;
1007     watchdogScheduleSignal(period); /* Adjust the current timer. */
1008     server.watchdog_period = period;
1009 }
1010 
1011 /* Disable the software watchdog. */
1012 void disableWatchdog(void) {
1013     struct sigaction act;
1014     if (server.watchdog_period == 0) return; /* Already disabled. */
1015     watchdogScheduleSignal(0); /* Stop the current timer. */
1016 
1017     /* Set the signal handler to SIG_IGN, this will also remove pending
1018      * signals from the queue. */
1019     sigemptyset(&act.sa_mask);
1020     act.sa_flags = 0;
1021     act.sa_handler = SIG_IGN;
1022     sigaction(SIGALRM, &act, NULL);
1023     server.watchdog_period = 0;
1024 }
1025