xref: /redis-3.2.3/src/debug.c (revision f3fd58eb)
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:%lld "
340             "lru:%d lru_seconds_idle:%llu%s",
341             (void*)val, val->refcount,
342             strenc, (long long) 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,"jemalloc") && c->argc == 3) {
422 #if defined(USE_JEMALLOC)
423         if (!strcasecmp(c->argv[2]->ptr, "info")) {
424             sds info = sdsempty();
425             je_malloc_stats_print(inputCatSds, &info, NULL);
426             addReplyBulkSds(c, info);
427         } else {
428             addReplyErrorFormat(c, "Valid jemalloc debug fields: info");
429         }
430 #else
431         addReplyErrorFormat(c, "jemalloc support not available");
432 #endif
433     } else {
434         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
435             (char*)c->argv[1]->ptr);
436     }
437 }
438 
439 /* =========================== Crash handling  ============================== */
440 
441 void _redisAssert(char *estr, char *file, int line) {
442     bugReportStart();
443     redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
444     redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
445 #ifdef HAVE_BACKTRACE
446     server.assert_failed = estr;
447     server.assert_file = file;
448     server.assert_line = line;
449     redisLog(REDIS_WARNING,"(forcing SIGSEGV to print the bug report.)");
450 #endif
451     *((char*)-1) = 'x';
452 }
453 
454 void _redisAssertPrintClientInfo(redisClient *c) {
455     int j;
456 
457     bugReportStart();
458     redisLog(REDIS_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
459     redisLog(REDIS_WARNING,"client->flags = %d", c->flags);
460     redisLog(REDIS_WARNING,"client->fd = %d", c->fd);
461     redisLog(REDIS_WARNING,"client->argc = %d", c->argc);
462     for (j=0; j < c->argc; j++) {
463         char buf[128];
464         char *arg;
465 
466         if (c->argv[j]->type == REDIS_STRING && sdsEncodedObject(c->argv[j])) {
467             arg = (char*) c->argv[j]->ptr;
468         } else {
469             snprintf(buf,sizeof(buf),"Object type: %d, encoding: %d",
470                 c->argv[j]->type, c->argv[j]->encoding);
471             arg = buf;
472         }
473         redisLog(REDIS_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
474             j, arg, c->argv[j]->refcount);
475     }
476 }
477 
478 void redisLogObjectDebugInfo(robj *o) {
479     redisLog(REDIS_WARNING,"Object type: %d", o->type);
480     redisLog(REDIS_WARNING,"Object encoding: %d", o->encoding);
481     redisLog(REDIS_WARNING,"Object refcount: %d", o->refcount);
482     if (o->type == REDIS_STRING && sdsEncodedObject(o)) {
483         redisLog(REDIS_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
484         if (sdslen(o->ptr) < 4096) {
485             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
486             redisLog(REDIS_WARNING,"Object raw string content: %s", repr);
487             sdsfree(repr);
488         }
489     } else if (o->type == REDIS_LIST) {
490         redisLog(REDIS_WARNING,"List length: %d", (int) listTypeLength(o));
491     } else if (o->type == REDIS_SET) {
492         redisLog(REDIS_WARNING,"Set size: %d", (int) setTypeSize(o));
493     } else if (o->type == REDIS_HASH) {
494         redisLog(REDIS_WARNING,"Hash size: %d", (int) hashTypeLength(o));
495     } else if (o->type == REDIS_ZSET) {
496         redisLog(REDIS_WARNING,"Sorted set size: %d", (int) zsetLength(o));
497         if (o->encoding == REDIS_ENCODING_SKIPLIST)
498             redisLog(REDIS_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
499     }
500 }
501 
502 void _redisAssertPrintObject(robj *o) {
503     bugReportStart();
504     redisLog(REDIS_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
505     redisLogObjectDebugInfo(o);
506 }
507 
508 void _redisAssertWithInfo(redisClient *c, robj *o, char *estr, char *file, int line) {
509     if (c) _redisAssertPrintClientInfo(c);
510     if (o) _redisAssertPrintObject(o);
511     _redisAssert(estr,file,line);
512 }
513 
514 void _redisPanic(char *msg, char *file, int line) {
515     bugReportStart();
516     redisLog(REDIS_WARNING,"------------------------------------------------");
517     redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
518     redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
519 #ifdef HAVE_BACKTRACE
520     redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
521 #endif
522     redisLog(REDIS_WARNING,"------------------------------------------------");
523     *((char*)-1) = 'x';
524 }
525 
526 void bugReportStart(void) {
527     if (server.bug_report_start == 0) {
528         redisLog(REDIS_WARNING,
529             "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===");
530         server.bug_report_start = 1;
531     }
532 }
533 
534 #ifdef HAVE_BACKTRACE
535 static void *getMcontextEip(ucontext_t *uc) {
536 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
537     /* OSX < 10.6 */
538     #if defined(__x86_64__)
539     return (void*) uc->uc_mcontext->__ss.__rip;
540     #elif defined(__i386__)
541     return (void*) uc->uc_mcontext->__ss.__eip;
542     #else
543     return (void*) uc->uc_mcontext->__ss.__srr0;
544     #endif
545 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
546     /* OSX >= 10.6 */
547     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
548     return (void*) uc->uc_mcontext->__ss.__rip;
549     #else
550     return (void*) uc->uc_mcontext->__ss.__eip;
551     #endif
552 #elif defined(__linux__)
553     /* Linux */
554     #if defined(__i386__)
555     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
556     #elif defined(__X86_64__) || defined(__x86_64__)
557     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
558     #elif defined(__ia64__) /* Linux IA64 */
559     return (void*) uc->uc_mcontext.sc_ip;
560     #endif
561 #else
562     return NULL;
563 #endif
564 }
565 
566 void logStackContent(void **sp) {
567     int i;
568     for (i = 15; i >= 0; i--) {
569         unsigned long addr = (unsigned long) sp+i;
570         unsigned long val = (unsigned long) sp[i];
571 
572         if (sizeof(long) == 4)
573             redisLog(REDIS_WARNING, "(%08lx) -> %08lx", addr, val);
574         else
575             redisLog(REDIS_WARNING, "(%016lx) -> %016lx", addr, val);
576     }
577 }
578 
579 void logRegisters(ucontext_t *uc) {
580     redisLog(REDIS_WARNING, "--- REGISTERS");
581 
582 /* OSX */
583 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
584   /* OSX AMD64 */
585     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
586     redisLog(REDIS_WARNING,
587     "\n"
588     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
589     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
590     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
591     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
592     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
593         (unsigned long) uc->uc_mcontext->__ss.__rax,
594         (unsigned long) uc->uc_mcontext->__ss.__rbx,
595         (unsigned long) uc->uc_mcontext->__ss.__rcx,
596         (unsigned long) uc->uc_mcontext->__ss.__rdx,
597         (unsigned long) uc->uc_mcontext->__ss.__rdi,
598         (unsigned long) uc->uc_mcontext->__ss.__rsi,
599         (unsigned long) uc->uc_mcontext->__ss.__rbp,
600         (unsigned long) uc->uc_mcontext->__ss.__rsp,
601         (unsigned long) uc->uc_mcontext->__ss.__r8,
602         (unsigned long) uc->uc_mcontext->__ss.__r9,
603         (unsigned long) uc->uc_mcontext->__ss.__r10,
604         (unsigned long) uc->uc_mcontext->__ss.__r11,
605         (unsigned long) uc->uc_mcontext->__ss.__r12,
606         (unsigned long) uc->uc_mcontext->__ss.__r13,
607         (unsigned long) uc->uc_mcontext->__ss.__r14,
608         (unsigned long) uc->uc_mcontext->__ss.__r15,
609         (unsigned long) uc->uc_mcontext->__ss.__rip,
610         (unsigned long) uc->uc_mcontext->__ss.__rflags,
611         (unsigned long) uc->uc_mcontext->__ss.__cs,
612         (unsigned long) uc->uc_mcontext->__ss.__fs,
613         (unsigned long) uc->uc_mcontext->__ss.__gs
614     );
615     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
616     #else
617     /* OSX x86 */
618     redisLog(REDIS_WARNING,
619     "\n"
620     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
621     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
622     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
623     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
624         (unsigned long) uc->uc_mcontext->__ss.__eax,
625         (unsigned long) uc->uc_mcontext->__ss.__ebx,
626         (unsigned long) uc->uc_mcontext->__ss.__ecx,
627         (unsigned long) uc->uc_mcontext->__ss.__edx,
628         (unsigned long) uc->uc_mcontext->__ss.__edi,
629         (unsigned long) uc->uc_mcontext->__ss.__esi,
630         (unsigned long) uc->uc_mcontext->__ss.__ebp,
631         (unsigned long) uc->uc_mcontext->__ss.__esp,
632         (unsigned long) uc->uc_mcontext->__ss.__ss,
633         (unsigned long) uc->uc_mcontext->__ss.__eflags,
634         (unsigned long) uc->uc_mcontext->__ss.__eip,
635         (unsigned long) uc->uc_mcontext->__ss.__cs,
636         (unsigned long) uc->uc_mcontext->__ss.__ds,
637         (unsigned long) uc->uc_mcontext->__ss.__es,
638         (unsigned long) uc->uc_mcontext->__ss.__fs,
639         (unsigned long) uc->uc_mcontext->__ss.__gs
640     );
641     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
642     #endif
643 /* Linux */
644 #elif defined(__linux__)
645     /* Linux x86 */
646     #if defined(__i386__)
647     redisLog(REDIS_WARNING,
648     "\n"
649     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
650     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
651     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
652     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
653         (unsigned long) uc->uc_mcontext.gregs[11],
654         (unsigned long) uc->uc_mcontext.gregs[8],
655         (unsigned long) uc->uc_mcontext.gregs[10],
656         (unsigned long) uc->uc_mcontext.gregs[9],
657         (unsigned long) uc->uc_mcontext.gregs[4],
658         (unsigned long) uc->uc_mcontext.gregs[5],
659         (unsigned long) uc->uc_mcontext.gregs[6],
660         (unsigned long) uc->uc_mcontext.gregs[7],
661         (unsigned long) uc->uc_mcontext.gregs[18],
662         (unsigned long) uc->uc_mcontext.gregs[17],
663         (unsigned long) uc->uc_mcontext.gregs[14],
664         (unsigned long) uc->uc_mcontext.gregs[15],
665         (unsigned long) uc->uc_mcontext.gregs[3],
666         (unsigned long) uc->uc_mcontext.gregs[2],
667         (unsigned long) uc->uc_mcontext.gregs[1],
668         (unsigned long) uc->uc_mcontext.gregs[0]
669     );
670     logStackContent((void**)uc->uc_mcontext.gregs[7]);
671     #elif defined(__X86_64__) || defined(__x86_64__)
672     /* Linux AMD64 */
673     redisLog(REDIS_WARNING,
674     "\n"
675     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
676     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
677     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
678     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
679     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
680         (unsigned long) uc->uc_mcontext.gregs[13],
681         (unsigned long) uc->uc_mcontext.gregs[11],
682         (unsigned long) uc->uc_mcontext.gregs[14],
683         (unsigned long) uc->uc_mcontext.gregs[12],
684         (unsigned long) uc->uc_mcontext.gregs[8],
685         (unsigned long) uc->uc_mcontext.gregs[9],
686         (unsigned long) uc->uc_mcontext.gregs[10],
687         (unsigned long) uc->uc_mcontext.gregs[15],
688         (unsigned long) uc->uc_mcontext.gregs[0],
689         (unsigned long) uc->uc_mcontext.gregs[1],
690         (unsigned long) uc->uc_mcontext.gregs[2],
691         (unsigned long) uc->uc_mcontext.gregs[3],
692         (unsigned long) uc->uc_mcontext.gregs[4],
693         (unsigned long) uc->uc_mcontext.gregs[5],
694         (unsigned long) uc->uc_mcontext.gregs[6],
695         (unsigned long) uc->uc_mcontext.gregs[7],
696         (unsigned long) uc->uc_mcontext.gregs[16],
697         (unsigned long) uc->uc_mcontext.gregs[17],
698         (unsigned long) uc->uc_mcontext.gregs[18]
699     );
700     logStackContent((void**)uc->uc_mcontext.gregs[15]);
701     #endif
702 #else
703     redisLog(REDIS_WARNING,
704         "  Dumping of registers not supported for this OS/arch");
705 #endif
706 }
707 
708 /* Logs the stack trace using the backtrace() call. This function is designed
709  * to be called from signal handlers safely. */
710 void logStackTrace(ucontext_t *uc) {
711     void *trace[100];
712     int trace_size = 0, fd;
713     int log_to_stdout = server.logfile[0] == '\0';
714 
715     /* Open the log file in append mode. */
716     fd = log_to_stdout ?
717         STDOUT_FILENO :
718         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
719     if (fd == -1) return;
720 
721     /* Generate the stack trace */
722     trace_size = backtrace(trace, 100);
723 
724     /* overwrite sigaction with caller's address */
725     if (getMcontextEip(uc) != NULL)
726         trace[1] = getMcontextEip(uc);
727 
728     /* Write symbols to log file */
729     backtrace_symbols_fd(trace, trace_size, fd);
730 
731     /* Cleanup */
732     if (!log_to_stdout) close(fd);
733 }
734 
735 /* Log information about the "current" client, that is, the client that is
736  * currently being served by Redis. May be NULL if Redis is not serving a
737  * client right now. */
738 void logCurrentClient(void) {
739     if (server.current_client == NULL) return;
740 
741     redisClient *cc = server.current_client;
742     sds client;
743     int j;
744 
745     redisLog(REDIS_WARNING, "--- CURRENT CLIENT INFO");
746     client = catClientInfoString(sdsempty(),cc);
747     redisLog(REDIS_WARNING,"client: %s", client);
748     sdsfree(client);
749     for (j = 0; j < cc->argc; j++) {
750         robj *decoded;
751 
752         decoded = getDecodedObject(cc->argv[j]);
753         redisLog(REDIS_WARNING,"argv[%d]: '%s'", j, (char*)decoded->ptr);
754         decrRefCount(decoded);
755     }
756     /* Check if the first argument, usually a key, is found inside the
757      * selected DB, and if so print info about the associated object. */
758     if (cc->argc >= 1) {
759         robj *val, *key;
760         dictEntry *de;
761 
762         key = getDecodedObject(cc->argv[1]);
763         de = dictFind(cc->db->dict, key->ptr);
764         if (de) {
765             val = dictGetVal(de);
766             redisLog(REDIS_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
767             redisLogObjectDebugInfo(val);
768         }
769         decrRefCount(key);
770     }
771 }
772 
773 #if defined(HAVE_PROC_MAPS)
774 void memtest_non_destructive_invert(void *addr, size_t size);
775 void memtest_non_destructive_swap(void *addr, size_t size);
776 #define MEMTEST_MAX_REGIONS 128
777 
778 int memtest_test_linux_anonymous_maps(void) {
779     FILE *fp = fopen("/proc/self/maps","r");
780     char line[1024];
781     size_t start_addr, end_addr, size;
782     size_t start_vect[MEMTEST_MAX_REGIONS];
783     size_t size_vect[MEMTEST_MAX_REGIONS];
784     int regions = 0, j;
785     uint64_t crc1 = 0, crc2 = 0, crc3 = 0;
786 
787     while(fgets(line,sizeof(line),fp) != NULL) {
788         char *start, *end, *p = line;
789 
790         start = p;
791         p = strchr(p,'-');
792         if (!p) continue;
793         *p++ = '\0';
794         end = p;
795         p = strchr(p,' ');
796         if (!p) continue;
797         *p++ = '\0';
798         if (strstr(p,"stack") ||
799             strstr(p,"vdso") ||
800             strstr(p,"vsyscall")) continue;
801         if (!strstr(p,"00:00")) continue;
802         if (!strstr(p,"rw")) continue;
803 
804         start_addr = strtoul(start,NULL,16);
805         end_addr = strtoul(end,NULL,16);
806         size = end_addr-start_addr;
807 
808         start_vect[regions] = start_addr;
809         size_vect[regions] = size;
810         printf("Testing %lx %lu\n", (unsigned long) start_vect[regions],
811                                     (unsigned long) size_vect[regions]);
812         regions++;
813     }
814 
815     /* Test all the regions as an unique sequential region.
816      * 1) Take the CRC64 of the memory region. */
817     for (j = 0; j < regions; j++) {
818         crc1 = crc64(crc1,(void*)start_vect[j],size_vect[j]);
819     }
820 
821     /* 2) Invert bits, swap adjacent words, swap again, invert bits.
822      * This is the error amplification step. */
823     for (j = 0; j < regions; j++)
824         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
825     for (j = 0; j < regions; j++)
826         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
827     for (j = 0; j < regions; j++)
828         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
829     for (j = 0; j < regions; j++)
830         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
831 
832     /* 3) Take the CRC64 sum again. */
833     for (j = 0; j < regions; j++)
834         crc2 = crc64(crc2,(void*)start_vect[j],size_vect[j]);
835 
836     /* 4) Swap + Swap again */
837     for (j = 0; j < regions; j++)
838         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
839     for (j = 0; j < regions; j++)
840         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
841 
842     /* 5) Take the CRC64 sum again. */
843     for (j = 0; j < regions; j++)
844         crc3 = crc64(crc3,(void*)start_vect[j],size_vect[j]);
845 
846     /* NOTE: It is very important to close the file descriptor only now
847      * because closing it before may result into unmapping of some memory
848      * region that we are testing. */
849     fclose(fp);
850 
851     /* If the two CRC are not the same, we trapped a memory error. */
852     return crc1 != crc2 || crc2 != crc3;
853 }
854 #endif
855 
856 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
857     ucontext_t *uc = (ucontext_t*) secret;
858     sds infostring, clients;
859     struct sigaction act;
860     REDIS_NOTUSED(info);
861 
862     bugReportStart();
863     redisLog(REDIS_WARNING,
864         "    Redis %s crashed by signal: %d", REDIS_VERSION, sig);
865     redisLog(REDIS_WARNING,
866         "    Failed assertion: %s (%s:%d)", server.assert_failed,
867                         server.assert_file, server.assert_line);
868 
869     /* Log the stack trace */
870     redisLog(REDIS_WARNING, "--- STACK TRACE");
871     logStackTrace(uc);
872 
873     /* Log INFO and CLIENT LIST */
874     redisLog(REDIS_WARNING, "--- INFO OUTPUT");
875     infostring = genRedisInfoString("all");
876     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
877         dictGetHashFunctionSeed());
878     redisLogRaw(REDIS_WARNING, infostring);
879     redisLog(REDIS_WARNING, "--- CLIENT LIST OUTPUT");
880     clients = getAllClientsInfoString();
881     redisLogRaw(REDIS_WARNING, clients);
882     sdsfree(infostring);
883     sdsfree(clients);
884 
885     /* Log the current client */
886     logCurrentClient();
887 
888     /* Log dump of processor registers */
889     logRegisters(uc);
890 
891 #if defined(HAVE_PROC_MAPS)
892     /* Test memory */
893     redisLog(REDIS_WARNING, "--- FAST MEMORY TEST");
894     bioKillThreads();
895     if (memtest_test_linux_anonymous_maps()) {
896         redisLog(REDIS_WARNING,
897             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
898     } else {
899         redisLog(REDIS_WARNING,
900             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
901     }
902 #endif
903 
904     redisLog(REDIS_WARNING,
905 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
906 "       Please report the crash by opening an issue on github:\n\n"
907 "           http://github.com/antirez/redis/issues\n\n"
908 "  Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
909 );
910     /* free(messages); Don't call free() with possibly corrupted memory. */
911     if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
912 
913     /* Make sure we exit with the right signal at the end. So for instance
914      * the core will be dumped if enabled. */
915     sigemptyset (&act.sa_mask);
916     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
917     act.sa_handler = SIG_DFL;
918     sigaction (sig, &act, NULL);
919     kill(getpid(),sig);
920 }
921 #endif /* HAVE_BACKTRACE */
922 
923 /* ==================== Logging functions for debugging ===================== */
924 
925 void redisLogHexDump(int level, char *descr, void *value, size_t len) {
926     char buf[65], *b;
927     unsigned char *v = value;
928     char charset[] = "0123456789abcdef";
929 
930     redisLog(level,"%s (hexdump):", descr);
931     b = buf;
932     while(len) {
933         b[0] = charset[(*v)>>4];
934         b[1] = charset[(*v)&0xf];
935         b[2] = '\0';
936         b += 2;
937         len--;
938         v++;
939         if (b-buf == 64 || len == 0) {
940             redisLogRaw(level|REDIS_LOG_RAW,buf);
941             b = buf;
942         }
943     }
944     redisLogRaw(level|REDIS_LOG_RAW,"\n");
945 }
946 
947 /* =========================== Software Watchdog ============================ */
948 #include <sys/time.h>
949 
950 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
951 #ifdef HAVE_BACKTRACE
952     ucontext_t *uc = (ucontext_t*) secret;
953 #endif
954     REDIS_NOTUSED(info);
955     REDIS_NOTUSED(sig);
956 
957     redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
958 #ifdef HAVE_BACKTRACE
959     logStackTrace(uc);
960 #else
961     redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
962 #endif
963     redisLogFromHandler(REDIS_WARNING,"--------\n");
964 }
965 
966 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
967  * If a timer is already scheduled, this function will re-schedule it to the
968  * specified time. If period is 0 the current timer is disabled. */
969 void watchdogScheduleSignal(int period) {
970     struct itimerval it;
971 
972     /* Will stop the timer if period is 0. */
973     it.it_value.tv_sec = period/1000;
974     it.it_value.tv_usec = (period%1000)*1000;
975     /* Don't automatically restart. */
976     it.it_interval.tv_sec = 0;
977     it.it_interval.tv_usec = 0;
978     setitimer(ITIMER_REAL, &it, NULL);
979 }
980 
981 /* Enable the software watchdog with the specified period in milliseconds. */
982 void enableWatchdog(int period) {
983     int min_period;
984 
985     if (server.watchdog_period == 0) {
986         struct sigaction act;
987 
988         /* Watchdog was actually disabled, so we have to setup the signal
989          * handler. */
990         sigemptyset(&act.sa_mask);
991         act.sa_flags = SA_ONSTACK | SA_SIGINFO;
992         act.sa_sigaction = watchdogSignalHandler;
993         sigaction(SIGALRM, &act, NULL);
994     }
995     /* If the configured period is smaller than twice the timer period, it is
996      * too short for the software watchdog to work reliably. Fix it now
997      * if needed. */
998     min_period = (1000/server.hz)*2;
999     if (period < min_period) period = min_period;
1000     watchdogScheduleSignal(period); /* Adjust the current timer. */
1001     server.watchdog_period = period;
1002 }
1003 
1004 /* Disable the software watchdog. */
1005 void disableWatchdog(void) {
1006     struct sigaction act;
1007     if (server.watchdog_period == 0) return; /* Already disabled. */
1008     watchdogScheduleSignal(0); /* Stop the current timer. */
1009 
1010     /* Set the signal handler to SIG_IGN, this will also remove pending
1011      * signals from the queue. */
1012     sigemptyset(&act.sa_mask);
1013     act.sa_flags = 0;
1014     act.sa_handler = SIG_IGN;
1015     sigaction(SIGALRM, &act, NULL);
1016     server.watchdog_period = 0;
1017 }
1018