xref: /redis-3.2.3/src/debug.c (revision 02bb515a)
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             double avg = (double)ql->count/ql->len;
310             int used = snprintf(nextra, remaining, " ql_nodes:%u", ql->len);
311             nextra += used;
312             remaining -= used;
313             snprintf(nextra, remaining, " ql_avg_node:%.2f", avg);
314         }
315 
316         addReplyStatusFormat(c,
317             "Value at:%p refcount:%d "
318             "encoding:%s serializedlength:%lld "
319             "lru:%d lru_seconds_idle:%llu%s",
320             (void*)val, val->refcount,
321             strenc, (long long) rdbSavedObjectLen(val),
322             val->lru, estimateObjectIdleTime(val)/1000, extra);
323     } else if (!strcasecmp(c->argv[1]->ptr,"sdslen") && c->argc == 3) {
324         dictEntry *de;
325         robj *val;
326         sds key;
327 
328         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
329             addReply(c,shared.nokeyerr);
330             return;
331         }
332         val = dictGetVal(de);
333         key = dictGetKey(de);
334 
335         if (val->type != REDIS_STRING || !sdsEncodedObject(val)) {
336             addReplyError(c,"Not an sds encoded string.");
337         } else {
338             addReplyStatusFormat(c,
339                 "key_sds_len:%lld, key_sds_avail:%lld, "
340                 "val_sds_len:%lld, val_sds_avail:%lld",
341                 (long long) sdslen(key),
342                 (long long) sdsavail(key),
343                 (long long) sdslen(val->ptr),
344                 (long long) sdsavail(val->ptr));
345         }
346     } else if (!strcasecmp(c->argv[1]->ptr,"populate") &&
347                (c->argc == 3 || c->argc == 4)) {
348         long keys, j;
349         robj *key, *val;
350         char buf[128];
351 
352         if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK)
353             return;
354         dictExpand(c->db->dict,keys);
355         for (j = 0; j < keys; j++) {
356             snprintf(buf,sizeof(buf),"%s:%lu",
357                 (c->argc == 3) ? "key" : (char*)c->argv[3]->ptr, j);
358             key = createStringObject(buf,strlen(buf));
359             if (lookupKeyWrite(c->db,key) != NULL) {
360                 decrRefCount(key);
361                 continue;
362             }
363             snprintf(buf,sizeof(buf),"value:%lu",j);
364             val = createStringObject(buf,strlen(buf));
365             dbAdd(c->db,key,val);
366             decrRefCount(key);
367         }
368         addReply(c,shared.ok);
369     } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
370         unsigned char digest[20];
371         sds d = sdsempty();
372         int j;
373 
374         computeDatasetDigest(digest);
375         for (j = 0; j < 20; j++)
376             d = sdscatprintf(d, "%02x",digest[j]);
377         addReplyStatus(c,d);
378         sdsfree(d);
379     } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
380         double dtime = strtod(c->argv[2]->ptr,NULL);
381         long long utime = dtime*1000000;
382         struct timespec tv;
383 
384         tv.tv_sec = utime / 1000000;
385         tv.tv_nsec = (utime % 1000000) * 1000;
386         nanosleep(&tv, NULL);
387         addReply(c,shared.ok);
388     } else if (!strcasecmp(c->argv[1]->ptr,"set-active-expire") &&
389                c->argc == 3)
390     {
391         server.active_expire_enabled = atoi(c->argv[2]->ptr);
392         addReply(c,shared.ok);
393     } else if (!strcasecmp(c->argv[1]->ptr,"error") && c->argc == 3) {
394         sds errstr = sdsnewlen("-",1);
395 
396         errstr = sdscatsds(errstr,c->argv[2]->ptr);
397         errstr = sdsmapchars(errstr,"\n\r","  ",2); /* no newlines in errors. */
398         errstr = sdscatlen(errstr,"\r\n",2);
399         addReplySds(c,errstr);
400     } else if (!strcasecmp(c->argv[1]->ptr,"jemalloc") && c->argc == 3) {
401 #if defined(USE_JEMALLOC)
402         if (!strcasecmp(c->argv[2]->ptr, "info")) {
403             sds info = sdsempty();
404             je_malloc_stats_print(inputCatSds, &info, NULL);
405             addReplyBulkSds(c, info);
406         } else {
407             addReplyErrorFormat(c, "Valid jemalloc debug fields: info");
408         }
409 #else
410         addReplyErrorFormat(c, "jemalloc support not available");
411 #endif
412     } else {
413         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
414             (char*)c->argv[1]->ptr);
415     }
416 }
417 
418 /* =========================== Crash handling  ============================== */
419 
420 void _redisAssert(char *estr, char *file, int line) {
421     bugReportStart();
422     redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
423     redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
424 #ifdef HAVE_BACKTRACE
425     server.assert_failed = estr;
426     server.assert_file = file;
427     server.assert_line = line;
428     redisLog(REDIS_WARNING,"(forcing SIGSEGV to print the bug report.)");
429 #endif
430     *((char*)-1) = 'x';
431 }
432 
433 void _redisAssertPrintClientInfo(redisClient *c) {
434     int j;
435 
436     bugReportStart();
437     redisLog(REDIS_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
438     redisLog(REDIS_WARNING,"client->flags = %d", c->flags);
439     redisLog(REDIS_WARNING,"client->fd = %d", c->fd);
440     redisLog(REDIS_WARNING,"client->argc = %d", c->argc);
441     for (j=0; j < c->argc; j++) {
442         char buf[128];
443         char *arg;
444 
445         if (c->argv[j]->type == REDIS_STRING && sdsEncodedObject(c->argv[j])) {
446             arg = (char*) c->argv[j]->ptr;
447         } else {
448             snprintf(buf,sizeof(buf),"Object type: %d, encoding: %d",
449                 c->argv[j]->type, c->argv[j]->encoding);
450             arg = buf;
451         }
452         redisLog(REDIS_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
453             j, arg, c->argv[j]->refcount);
454     }
455 }
456 
457 void redisLogObjectDebugInfo(robj *o) {
458     redisLog(REDIS_WARNING,"Object type: %d", o->type);
459     redisLog(REDIS_WARNING,"Object encoding: %d", o->encoding);
460     redisLog(REDIS_WARNING,"Object refcount: %d", o->refcount);
461     if (o->type == REDIS_STRING && sdsEncodedObject(o)) {
462         redisLog(REDIS_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
463         if (sdslen(o->ptr) < 4096) {
464             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
465             redisLog(REDIS_WARNING,"Object raw string content: %s", repr);
466             sdsfree(repr);
467         }
468     } else if (o->type == REDIS_LIST) {
469         redisLog(REDIS_WARNING,"List length: %d", (int) listTypeLength(o));
470     } else if (o->type == REDIS_SET) {
471         redisLog(REDIS_WARNING,"Set size: %d", (int) setTypeSize(o));
472     } else if (o->type == REDIS_HASH) {
473         redisLog(REDIS_WARNING,"Hash size: %d", (int) hashTypeLength(o));
474     } else if (o->type == REDIS_ZSET) {
475         redisLog(REDIS_WARNING,"Sorted set size: %d", (int) zsetLength(o));
476         if (o->encoding == REDIS_ENCODING_SKIPLIST)
477             redisLog(REDIS_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
478     }
479 }
480 
481 void _redisAssertPrintObject(robj *o) {
482     bugReportStart();
483     redisLog(REDIS_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
484     redisLogObjectDebugInfo(o);
485 }
486 
487 void _redisAssertWithInfo(redisClient *c, robj *o, char *estr, char *file, int line) {
488     if (c) _redisAssertPrintClientInfo(c);
489     if (o) _redisAssertPrintObject(o);
490     _redisAssert(estr,file,line);
491 }
492 
493 void _redisPanic(char *msg, char *file, int line) {
494     bugReportStart();
495     redisLog(REDIS_WARNING,"------------------------------------------------");
496     redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
497     redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
498 #ifdef HAVE_BACKTRACE
499     redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
500 #endif
501     redisLog(REDIS_WARNING,"------------------------------------------------");
502     *((char*)-1) = 'x';
503 }
504 
505 void bugReportStart(void) {
506     if (server.bug_report_start == 0) {
507         redisLog(REDIS_WARNING,
508             "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===");
509         server.bug_report_start = 1;
510     }
511 }
512 
513 #ifdef HAVE_BACKTRACE
514 static void *getMcontextEip(ucontext_t *uc) {
515 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
516     /* OSX < 10.6 */
517     #if defined(__x86_64__)
518     return (void*) uc->uc_mcontext->__ss.__rip;
519     #elif defined(__i386__)
520     return (void*) uc->uc_mcontext->__ss.__eip;
521     #else
522     return (void*) uc->uc_mcontext->__ss.__srr0;
523     #endif
524 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
525     /* OSX >= 10.6 */
526     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
527     return (void*) uc->uc_mcontext->__ss.__rip;
528     #else
529     return (void*) uc->uc_mcontext->__ss.__eip;
530     #endif
531 #elif defined(__linux__)
532     /* Linux */
533     #if defined(__i386__)
534     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
535     #elif defined(__X86_64__) || defined(__x86_64__)
536     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
537     #elif defined(__ia64__) /* Linux IA64 */
538     return (void*) uc->uc_mcontext.sc_ip;
539     #endif
540 #else
541     return NULL;
542 #endif
543 }
544 
545 void logStackContent(void **sp) {
546     int i;
547     for (i = 15; i >= 0; i--) {
548         unsigned long addr = (unsigned long) sp+i;
549         unsigned long val = (unsigned long) sp[i];
550 
551         if (sizeof(long) == 4)
552             redisLog(REDIS_WARNING, "(%08lx) -> %08lx", addr, val);
553         else
554             redisLog(REDIS_WARNING, "(%016lx) -> %016lx", addr, val);
555     }
556 }
557 
558 void logRegisters(ucontext_t *uc) {
559     redisLog(REDIS_WARNING, "--- REGISTERS");
560 
561 /* OSX */
562 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
563   /* OSX AMD64 */
564     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
565     redisLog(REDIS_WARNING,
566     "\n"
567     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
568     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
569     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
570     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
571     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
572         (unsigned long) uc->uc_mcontext->__ss.__rax,
573         (unsigned long) uc->uc_mcontext->__ss.__rbx,
574         (unsigned long) uc->uc_mcontext->__ss.__rcx,
575         (unsigned long) uc->uc_mcontext->__ss.__rdx,
576         (unsigned long) uc->uc_mcontext->__ss.__rdi,
577         (unsigned long) uc->uc_mcontext->__ss.__rsi,
578         (unsigned long) uc->uc_mcontext->__ss.__rbp,
579         (unsigned long) uc->uc_mcontext->__ss.__rsp,
580         (unsigned long) uc->uc_mcontext->__ss.__r8,
581         (unsigned long) uc->uc_mcontext->__ss.__r9,
582         (unsigned long) uc->uc_mcontext->__ss.__r10,
583         (unsigned long) uc->uc_mcontext->__ss.__r11,
584         (unsigned long) uc->uc_mcontext->__ss.__r12,
585         (unsigned long) uc->uc_mcontext->__ss.__r13,
586         (unsigned long) uc->uc_mcontext->__ss.__r14,
587         (unsigned long) uc->uc_mcontext->__ss.__r15,
588         (unsigned long) uc->uc_mcontext->__ss.__rip,
589         (unsigned long) uc->uc_mcontext->__ss.__rflags,
590         (unsigned long) uc->uc_mcontext->__ss.__cs,
591         (unsigned long) uc->uc_mcontext->__ss.__fs,
592         (unsigned long) uc->uc_mcontext->__ss.__gs
593     );
594     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
595     #else
596     /* OSX x86 */
597     redisLog(REDIS_WARNING,
598     "\n"
599     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
600     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
601     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
602     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
603         (unsigned long) uc->uc_mcontext->__ss.__eax,
604         (unsigned long) uc->uc_mcontext->__ss.__ebx,
605         (unsigned long) uc->uc_mcontext->__ss.__ecx,
606         (unsigned long) uc->uc_mcontext->__ss.__edx,
607         (unsigned long) uc->uc_mcontext->__ss.__edi,
608         (unsigned long) uc->uc_mcontext->__ss.__esi,
609         (unsigned long) uc->uc_mcontext->__ss.__ebp,
610         (unsigned long) uc->uc_mcontext->__ss.__esp,
611         (unsigned long) uc->uc_mcontext->__ss.__ss,
612         (unsigned long) uc->uc_mcontext->__ss.__eflags,
613         (unsigned long) uc->uc_mcontext->__ss.__eip,
614         (unsigned long) uc->uc_mcontext->__ss.__cs,
615         (unsigned long) uc->uc_mcontext->__ss.__ds,
616         (unsigned long) uc->uc_mcontext->__ss.__es,
617         (unsigned long) uc->uc_mcontext->__ss.__fs,
618         (unsigned long) uc->uc_mcontext->__ss.__gs
619     );
620     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
621     #endif
622 /* Linux */
623 #elif defined(__linux__)
624     /* Linux x86 */
625     #if defined(__i386__)
626     redisLog(REDIS_WARNING,
627     "\n"
628     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
629     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
630     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
631     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
632         (unsigned long) uc->uc_mcontext.gregs[11],
633         (unsigned long) uc->uc_mcontext.gregs[8],
634         (unsigned long) uc->uc_mcontext.gregs[10],
635         (unsigned long) uc->uc_mcontext.gregs[9],
636         (unsigned long) uc->uc_mcontext.gregs[4],
637         (unsigned long) uc->uc_mcontext.gregs[5],
638         (unsigned long) uc->uc_mcontext.gregs[6],
639         (unsigned long) uc->uc_mcontext.gregs[7],
640         (unsigned long) uc->uc_mcontext.gregs[18],
641         (unsigned long) uc->uc_mcontext.gregs[17],
642         (unsigned long) uc->uc_mcontext.gregs[14],
643         (unsigned long) uc->uc_mcontext.gregs[15],
644         (unsigned long) uc->uc_mcontext.gregs[3],
645         (unsigned long) uc->uc_mcontext.gregs[2],
646         (unsigned long) uc->uc_mcontext.gregs[1],
647         (unsigned long) uc->uc_mcontext.gregs[0]
648     );
649     logStackContent((void**)uc->uc_mcontext.gregs[7]);
650     #elif defined(__X86_64__) || defined(__x86_64__)
651     /* Linux AMD64 */
652     redisLog(REDIS_WARNING,
653     "\n"
654     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
655     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
656     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
657     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
658     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
659         (unsigned long) uc->uc_mcontext.gregs[13],
660         (unsigned long) uc->uc_mcontext.gregs[11],
661         (unsigned long) uc->uc_mcontext.gregs[14],
662         (unsigned long) uc->uc_mcontext.gregs[12],
663         (unsigned long) uc->uc_mcontext.gregs[8],
664         (unsigned long) uc->uc_mcontext.gregs[9],
665         (unsigned long) uc->uc_mcontext.gregs[10],
666         (unsigned long) uc->uc_mcontext.gregs[15],
667         (unsigned long) uc->uc_mcontext.gregs[0],
668         (unsigned long) uc->uc_mcontext.gregs[1],
669         (unsigned long) uc->uc_mcontext.gregs[2],
670         (unsigned long) uc->uc_mcontext.gregs[3],
671         (unsigned long) uc->uc_mcontext.gregs[4],
672         (unsigned long) uc->uc_mcontext.gregs[5],
673         (unsigned long) uc->uc_mcontext.gregs[6],
674         (unsigned long) uc->uc_mcontext.gregs[7],
675         (unsigned long) uc->uc_mcontext.gregs[16],
676         (unsigned long) uc->uc_mcontext.gregs[17],
677         (unsigned long) uc->uc_mcontext.gregs[18]
678     );
679     logStackContent((void**)uc->uc_mcontext.gregs[15]);
680     #endif
681 #else
682     redisLog(REDIS_WARNING,
683         "  Dumping of registers not supported for this OS/arch");
684 #endif
685 }
686 
687 /* Logs the stack trace using the backtrace() call. This function is designed
688  * to be called from signal handlers safely. */
689 void logStackTrace(ucontext_t *uc) {
690     void *trace[100];
691     int trace_size = 0, fd;
692     int log_to_stdout = server.logfile[0] == '\0';
693 
694     /* Open the log file in append mode. */
695     fd = log_to_stdout ?
696         STDOUT_FILENO :
697         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
698     if (fd == -1) return;
699 
700     /* Generate the stack trace */
701     trace_size = backtrace(trace, 100);
702 
703     /* overwrite sigaction with caller's address */
704     if (getMcontextEip(uc) != NULL)
705         trace[1] = getMcontextEip(uc);
706 
707     /* Write symbols to log file */
708     backtrace_symbols_fd(trace, trace_size, fd);
709 
710     /* Cleanup */
711     if (!log_to_stdout) close(fd);
712 }
713 
714 /* Log information about the "current" client, that is, the client that is
715  * currently being served by Redis. May be NULL if Redis is not serving a
716  * client right now. */
717 void logCurrentClient(void) {
718     if (server.current_client == NULL) return;
719 
720     redisClient *cc = server.current_client;
721     sds client;
722     int j;
723 
724     redisLog(REDIS_WARNING, "--- CURRENT CLIENT INFO");
725     client = catClientInfoString(sdsempty(),cc);
726     redisLog(REDIS_WARNING,"client: %s", client);
727     sdsfree(client);
728     for (j = 0; j < cc->argc; j++) {
729         robj *decoded;
730 
731         decoded = getDecodedObject(cc->argv[j]);
732         redisLog(REDIS_WARNING,"argv[%d]: '%s'", j, (char*)decoded->ptr);
733         decrRefCount(decoded);
734     }
735     /* Check if the first argument, usually a key, is found inside the
736      * selected DB, and if so print info about the associated object. */
737     if (cc->argc >= 1) {
738         robj *val, *key;
739         dictEntry *de;
740 
741         key = getDecodedObject(cc->argv[1]);
742         de = dictFind(cc->db->dict, key->ptr);
743         if (de) {
744             val = dictGetVal(de);
745             redisLog(REDIS_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
746             redisLogObjectDebugInfo(val);
747         }
748         decrRefCount(key);
749     }
750 }
751 
752 #if defined(HAVE_PROC_MAPS)
753 void memtest_non_destructive_invert(void *addr, size_t size);
754 void memtest_non_destructive_swap(void *addr, size_t size);
755 #define MEMTEST_MAX_REGIONS 128
756 
757 int memtest_test_linux_anonymous_maps(void) {
758     FILE *fp = fopen("/proc/self/maps","r");
759     char line[1024];
760     size_t start_addr, end_addr, size;
761     size_t start_vect[MEMTEST_MAX_REGIONS];
762     size_t size_vect[MEMTEST_MAX_REGIONS];
763     int regions = 0, j;
764     uint64_t crc1 = 0, crc2 = 0, crc3 = 0;
765 
766     while(fgets(line,sizeof(line),fp) != NULL) {
767         char *start, *end, *p = line;
768 
769         start = p;
770         p = strchr(p,'-');
771         if (!p) continue;
772         *p++ = '\0';
773         end = p;
774         p = strchr(p,' ');
775         if (!p) continue;
776         *p++ = '\0';
777         if (strstr(p,"stack") ||
778             strstr(p,"vdso") ||
779             strstr(p,"vsyscall")) continue;
780         if (!strstr(p,"00:00")) continue;
781         if (!strstr(p,"rw")) continue;
782 
783         start_addr = strtoul(start,NULL,16);
784         end_addr = strtoul(end,NULL,16);
785         size = end_addr-start_addr;
786 
787         start_vect[regions] = start_addr;
788         size_vect[regions] = size;
789         printf("Testing %lx %lu\n", (unsigned long) start_vect[regions],
790                                     (unsigned long) size_vect[regions]);
791         regions++;
792     }
793 
794     /* Test all the regions as an unique sequential region.
795      * 1) Take the CRC64 of the memory region. */
796     for (j = 0; j < regions; j++) {
797         crc1 = crc64(crc1,(void*)start_vect[j],size_vect[j]);
798     }
799 
800     /* 2) Invert bits, swap adjacent words, swap again, invert bits.
801      * This is the error amplification step. */
802     for (j = 0; j < regions; j++)
803         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
804     for (j = 0; j < regions; j++)
805         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
806     for (j = 0; j < regions; j++)
807         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
808     for (j = 0; j < regions; j++)
809         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
810 
811     /* 3) Take the CRC64 sum again. */
812     for (j = 0; j < regions; j++)
813         crc2 = crc64(crc2,(void*)start_vect[j],size_vect[j]);
814 
815     /* 4) Swap + Swap again */
816     for (j = 0; j < regions; j++)
817         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
818     for (j = 0; j < regions; j++)
819         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
820 
821     /* 5) Take the CRC64 sum again. */
822     for (j = 0; j < regions; j++)
823         crc3 = crc64(crc3,(void*)start_vect[j],size_vect[j]);
824 
825     /* NOTE: It is very important to close the file descriptor only now
826      * because closing it before may result into unmapping of some memory
827      * region that we are testing. */
828     fclose(fp);
829 
830     /* If the two CRC are not the same, we trapped a memory error. */
831     return crc1 != crc2 || crc2 != crc3;
832 }
833 #endif
834 
835 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
836     ucontext_t *uc = (ucontext_t*) secret;
837     sds infostring, clients;
838     struct sigaction act;
839     REDIS_NOTUSED(info);
840 
841     bugReportStart();
842     redisLog(REDIS_WARNING,
843         "    Redis %s crashed by signal: %d", REDIS_VERSION, sig);
844     redisLog(REDIS_WARNING,
845         "    Failed assertion: %s (%s:%d)", server.assert_failed,
846                         server.assert_file, server.assert_line);
847 
848     /* Log the stack trace */
849     redisLog(REDIS_WARNING, "--- STACK TRACE");
850     logStackTrace(uc);
851 
852     /* Log INFO and CLIENT LIST */
853     redisLog(REDIS_WARNING, "--- INFO OUTPUT");
854     infostring = genRedisInfoString("all");
855     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
856         dictGetHashFunctionSeed());
857     redisLogRaw(REDIS_WARNING, infostring);
858     redisLog(REDIS_WARNING, "--- CLIENT LIST OUTPUT");
859     clients = getAllClientsInfoString();
860     redisLogRaw(REDIS_WARNING, clients);
861     sdsfree(infostring);
862     sdsfree(clients);
863 
864     /* Log the current client */
865     logCurrentClient();
866 
867     /* Log dump of processor registers */
868     logRegisters(uc);
869 
870 #if defined(HAVE_PROC_MAPS)
871     /* Test memory */
872     redisLog(REDIS_WARNING, "--- FAST MEMORY TEST");
873     bioKillThreads();
874     if (memtest_test_linux_anonymous_maps()) {
875         redisLog(REDIS_WARNING,
876             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
877     } else {
878         redisLog(REDIS_WARNING,
879             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
880     }
881 #endif
882 
883     redisLog(REDIS_WARNING,
884 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
885 "       Please report the crash by opening an issue on github:\n\n"
886 "           http://github.com/antirez/redis/issues\n\n"
887 "  Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
888 );
889     /* free(messages); Don't call free() with possibly corrupted memory. */
890     if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
891 
892     /* Make sure we exit with the right signal at the end. So for instance
893      * the core will be dumped if enabled. */
894     sigemptyset (&act.sa_mask);
895     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
896     act.sa_handler = SIG_DFL;
897     sigaction (sig, &act, NULL);
898     kill(getpid(),sig);
899 }
900 #endif /* HAVE_BACKTRACE */
901 
902 /* ==================== Logging functions for debugging ===================== */
903 
904 void redisLogHexDump(int level, char *descr, void *value, size_t len) {
905     char buf[65], *b;
906     unsigned char *v = value;
907     char charset[] = "0123456789abcdef";
908 
909     redisLog(level,"%s (hexdump):", descr);
910     b = buf;
911     while(len) {
912         b[0] = charset[(*v)>>4];
913         b[1] = charset[(*v)&0xf];
914         b[2] = '\0';
915         b += 2;
916         len--;
917         v++;
918         if (b-buf == 64 || len == 0) {
919             redisLogRaw(level|REDIS_LOG_RAW,buf);
920             b = buf;
921         }
922     }
923     redisLogRaw(level|REDIS_LOG_RAW,"\n");
924 }
925 
926 /* =========================== Software Watchdog ============================ */
927 #include <sys/time.h>
928 
929 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
930 #ifdef HAVE_BACKTRACE
931     ucontext_t *uc = (ucontext_t*) secret;
932 #endif
933     REDIS_NOTUSED(info);
934     REDIS_NOTUSED(sig);
935 
936     redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
937 #ifdef HAVE_BACKTRACE
938     logStackTrace(uc);
939 #else
940     redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
941 #endif
942     redisLogFromHandler(REDIS_WARNING,"--------\n");
943 }
944 
945 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
946  * If a timer is already scheduled, this function will re-schedule it to the
947  * specified time. If period is 0 the current timer is disabled. */
948 void watchdogScheduleSignal(int period) {
949     struct itimerval it;
950 
951     /* Will stop the timer if period is 0. */
952     it.it_value.tv_sec = period/1000;
953     it.it_value.tv_usec = (period%1000)*1000;
954     /* Don't automatically restart. */
955     it.it_interval.tv_sec = 0;
956     it.it_interval.tv_usec = 0;
957     setitimer(ITIMER_REAL, &it, NULL);
958 }
959 
960 /* Enable the software watchdog with the specified period in milliseconds. */
961 void enableWatchdog(int period) {
962     int min_period;
963 
964     if (server.watchdog_period == 0) {
965         struct sigaction act;
966 
967         /* Watchdog was actually disabled, so we have to setup the signal
968          * handler. */
969         sigemptyset(&act.sa_mask);
970         act.sa_flags = SA_ONSTACK | SA_SIGINFO;
971         act.sa_sigaction = watchdogSignalHandler;
972         sigaction(SIGALRM, &act, NULL);
973     }
974     /* If the configured period is smaller than twice the timer period, it is
975      * too short for the software watchdog to work reliably. Fix it now
976      * if needed. */
977     min_period = (1000/server.hz)*2;
978     if (period < min_period) period = min_period;
979     watchdogScheduleSignal(period); /* Adjust the current timer. */
980     server.watchdog_period = period;
981 }
982 
983 /* Disable the software watchdog. */
984 void disableWatchdog(void) {
985     struct sigaction act;
986     if (server.watchdog_period == 0) return; /* Already disabled. */
987     watchdogScheduleSignal(0); /* Stop the current timer. */
988 
989     /* Set the signal handler to SIG_IGN, this will also remove pending
990      * signals from the queue. */
991     sigemptyset(&act.sa_mask);
992     act.sa_flags = 0;
993     act.sa_handler = SIG_IGN;
994     sigaction(SIGALRM, &act, NULL);
995     server.watchdog_period = 0;
996 }
997