xref: /redis-3.2.3/src/debug.c (revision fdc8e0bd)
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 "server.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 == OBJ_STRING) {
154                 mixObjectDigest(digest,o);
155             } else if (o->type == OBJ_LIST) {
156                 listTypeIterator *li = listTypeInitIterator(o,0,LIST_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 == OBJ_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 == OBJ_ZSET) {
173                 unsigned char eledigest[20];
174 
175                 if (o->encoding == OBJ_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                     serverAssert(eptr != NULL);
185                     sptr = ziplistNext(zl,eptr);
186                     serverAssert(sptr != NULL);
187 
188                     while (eptr != NULL) {
189                         serverAssert(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 == OBJ_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                     serverPanic("Unknown sorted set encoding");
223                 }
224             } else if (o->type == OBJ_HASH) {
225                 hashTypeIterator *hi;
226                 robj *obj;
227 
228                 hi = hashTypeInitIterator(o);
229                 while (hashTypeNext(hi) != C_ERR) {
230                     unsigned char eledigest[20];
231 
232                     memset(eledigest,0,20);
233                     obj = hashTypeCurrentObject(hi,OBJ_HASH_KEY);
234                     mixObjectDigest(eledigest,obj);
235                     decrRefCount(obj);
236                     obj = hashTypeCurrentObject(hi,OBJ_HASH_VALUE);
237                     mixObjectDigest(eledigest,obj);
238                     decrRefCount(obj);
239                     xorDigest(digest,eledigest,20);
240                 }
241                 hashTypeReleaseIterator(hi);
242             } else {
243                 serverPanic("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(client *c) {
262     if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
263         *((char*)-1) = 'x';
264     } else if (!strcasecmp(c->argv[1]->ptr,"restart") ||
265                !strcasecmp(c->argv[1]->ptr,"crash-and-recover"))
266     {
267         long long delay = 0;
268         if (c->argc >= 3) {
269             if (getLongLongFromObjectOrReply(c, c->argv[2], &delay, NULL)
270                 != C_OK) return;
271             if (delay < 0) delay = 0;
272         }
273         int flags = !strcasecmp(c->argv[1]->ptr,"restart") ?
274             (RESTART_SERVER_GRACEFULLY|RESTART_SERVER_CONFIG_REWRITE) :
275              RESTART_SERVER_NONE;
276         restartServer(flags,delay);
277         addReplyError(c,"failed to restart the server. Check server logs.");
278     } else if (!strcasecmp(c->argv[1]->ptr,"oom")) {
279         void *ptr = zmalloc(ULONG_MAX); /* Should trigger an out of memory. */
280         zfree(ptr);
281         addReply(c,shared.ok);
282     } else if (!strcasecmp(c->argv[1]->ptr,"assert")) {
283         if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
284         serverAssertWithInfo(c,c->argv[0],1 == 2);
285     } else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
286         if (rdbSave(server.rdb_filename) != C_OK) {
287             addReply(c,shared.err);
288             return;
289         }
290         emptyDb(NULL);
291         if (rdbLoad(server.rdb_filename) != C_OK) {
292             addReplyError(c,"Error trying to load the RDB dump");
293             return;
294         }
295         serverLog(LL_WARNING,"DB reloaded by DEBUG RELOAD");
296         addReply(c,shared.ok);
297     } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
298         emptyDb(NULL);
299         if (loadAppendOnlyFile(server.aof_filename) != C_OK) {
300             addReply(c,shared.err);
301             return;
302         }
303         server.dirty = 0; /* Prevent AOF / replication */
304         serverLog(LL_WARNING,"Append Only File loaded by DEBUG LOADAOF");
305         addReply(c,shared.ok);
306     } else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) {
307         dictEntry *de;
308         robj *val;
309         char *strenc;
310 
311         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
312             addReply(c,shared.nokeyerr);
313             return;
314         }
315         val = dictGetVal(de);
316         strenc = strEncoding(val->encoding);
317 
318         char extra[128] = {0};
319         if (val->encoding == OBJ_ENCODING_QUICKLIST) {
320             char *nextra = extra;
321             int remaining = sizeof(extra);
322             quicklist *ql = val->ptr;
323             /* Add number of quicklist nodes */
324             int used = snprintf(nextra, remaining, " ql_nodes:%u", ql->len);
325             nextra += used;
326             remaining -= used;
327             /* Add average quicklist fill factor */
328             double avg = (double)ql->count/ql->len;
329             used = snprintf(nextra, remaining, " ql_avg_node:%.2f", avg);
330             nextra += used;
331             remaining -= used;
332             /* Add quicklist fill level / max ziplist size */
333             used = snprintf(nextra, remaining, " ql_ziplist_max:%d", ql->fill);
334             nextra += used;
335             remaining -= used;
336             /* Add isCompressed? */
337             int compressed = ql->compress != 0;
338             used = snprintf(nextra, remaining, " ql_compressed:%d", compressed);
339             nextra += used;
340             remaining -= used;
341             /* Add total uncompressed size */
342             unsigned long sz = 0;
343             for (quicklistNode *node = ql->head; node; node = node->next) {
344                 sz += node->sz;
345             }
346             used = snprintf(nextra, remaining, " ql_uncompressed_size:%lu", sz);
347             nextra += used;
348             remaining -= used;
349         }
350 
351         addReplyStatusFormat(c,
352             "Value at:%p refcount:%d "
353             "encoding:%s serializedlength:%zu "
354             "lru:%d lru_seconds_idle:%llu%s",
355             (void*)val, val->refcount,
356             strenc, rdbSavedObjectLen(val),
357             val->lru, estimateObjectIdleTime(val)/1000, extra);
358     } else if (!strcasecmp(c->argv[1]->ptr,"sdslen") && c->argc == 3) {
359         dictEntry *de;
360         robj *val;
361         sds key;
362 
363         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
364             addReply(c,shared.nokeyerr);
365             return;
366         }
367         val = dictGetVal(de);
368         key = dictGetKey(de);
369 
370         if (val->type != OBJ_STRING || !sdsEncodedObject(val)) {
371             addReplyError(c,"Not an sds encoded string.");
372         } else {
373             addReplyStatusFormat(c,
374                 "key_sds_len:%lld, key_sds_avail:%lld, "
375                 "val_sds_len:%lld, val_sds_avail:%lld",
376                 (long long) sdslen(key),
377                 (long long) sdsavail(key),
378                 (long long) sdslen(val->ptr),
379                 (long long) sdsavail(val->ptr));
380         }
381     } else if (!strcasecmp(c->argv[1]->ptr,"populate") &&
382                (c->argc == 3 || c->argc == 4)) {
383         long keys, j;
384         robj *key, *val;
385         char buf[128];
386 
387         if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != C_OK)
388             return;
389         dictExpand(c->db->dict,keys);
390         for (j = 0; j < keys; j++) {
391             snprintf(buf,sizeof(buf),"%s:%lu",
392                 (c->argc == 3) ? "key" : (char*)c->argv[3]->ptr, j);
393             key = createStringObject(buf,strlen(buf));
394             if (lookupKeyWrite(c->db,key) != NULL) {
395                 decrRefCount(key);
396                 continue;
397             }
398             snprintf(buf,sizeof(buf),"value:%lu",j);
399             val = createStringObject(buf,strlen(buf));
400             dbAdd(c->db,key,val);
401             decrRefCount(key);
402         }
403         addReply(c,shared.ok);
404     } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
405         unsigned char digest[20];
406         sds d = sdsempty();
407         int j;
408 
409         computeDatasetDigest(digest);
410         for (j = 0; j < 20; j++)
411             d = sdscatprintf(d, "%02x",digest[j]);
412         addReplyStatus(c,d);
413         sdsfree(d);
414     } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
415         double dtime = strtod(c->argv[2]->ptr,NULL);
416         long long utime = dtime*1000000;
417         struct timespec tv;
418 
419         tv.tv_sec = utime / 1000000;
420         tv.tv_nsec = (utime % 1000000) * 1000;
421         nanosleep(&tv, NULL);
422         addReply(c,shared.ok);
423     } else if (!strcasecmp(c->argv[1]->ptr,"set-active-expire") &&
424                c->argc == 3)
425     {
426         server.active_expire_enabled = atoi(c->argv[2]->ptr);
427         addReply(c,shared.ok);
428     } else if (!strcasecmp(c->argv[1]->ptr,"lua-always-replicate-commands") &&
429                c->argc == 3)
430     {
431         server.lua_always_replicate_commands = atoi(c->argv[2]->ptr);
432         addReply(c,shared.ok);
433     } else if (!strcasecmp(c->argv[1]->ptr,"error") && c->argc == 3) {
434         sds errstr = sdsnewlen("-",1);
435 
436         errstr = sdscatsds(errstr,c->argv[2]->ptr);
437         errstr = sdsmapchars(errstr,"\n\r","  ",2); /* no newlines in errors. */
438         errstr = sdscatlen(errstr,"\r\n",2);
439         addReplySds(c,errstr);
440     } else if (!strcasecmp(c->argv[1]->ptr,"structsize") && c->argc == 2) {
441         sds sizes = sdsempty();
442         sizes = sdscatprintf(sizes,"bits:%d ",(sizeof(void*) == 8)?64:32);
443         sizes = sdscatprintf(sizes,"robj:%d ",(int)sizeof(robj));
444         sizes = sdscatprintf(sizes,"dictentry:%d ",(int)sizeof(dictEntry));
445         sizes = sdscatprintf(sizes,"sdshdr5:%d ",(int)sizeof(struct sdshdr5));
446         sizes = sdscatprintf(sizes,"sdshdr8:%d ",(int)sizeof(struct sdshdr8));
447         sizes = sdscatprintf(sizes,"sdshdr16:%d ",(int)sizeof(struct sdshdr16));
448         sizes = sdscatprintf(sizes,"sdshdr32:%d ",(int)sizeof(struct sdshdr32));
449         sizes = sdscatprintf(sizes,"sdshdr64:%d ",(int)sizeof(struct sdshdr64));
450         addReplyBulkSds(c,sizes);
451     } else if (!strcasecmp(c->argv[1]->ptr,"htstats") && c->argc == 3) {
452         long dbid;
453         sds stats = sdsempty();
454         char buf[4096];
455 
456         if (getLongFromObjectOrReply(c, c->argv[2], &dbid, NULL) != C_OK)
457             return;
458         if (dbid < 0 || dbid >= server.dbnum) {
459             addReplyError(c,"Out of range database");
460             return;
461         }
462 
463         stats = sdscatprintf(stats,"[Dictionary HT]\n");
464         dictGetStats(buf,sizeof(buf),server.db[dbid].dict);
465         stats = sdscat(stats,buf);
466 
467         stats = sdscatprintf(stats,"[Expires HT]\n");
468         dictGetStats(buf,sizeof(buf),server.db[dbid].expires);
469         stats = sdscat(stats,buf);
470 
471         addReplyBulkSds(c,stats);
472     } else if (!strcasecmp(c->argv[1]->ptr,"jemalloc") && c->argc == 3) {
473 #if defined(USE_JEMALLOC)
474         if (!strcasecmp(c->argv[2]->ptr, "info")) {
475             sds info = sdsempty();
476             je_malloc_stats_print(inputCatSds, &info, NULL);
477             addReplyBulkSds(c, info);
478         } else {
479             addReplyErrorFormat(c, "Valid jemalloc debug fields: info");
480         }
481 #else
482         addReplyErrorFormat(c, "jemalloc support not available");
483 #endif
484     } else {
485         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
486             (char*)c->argv[1]->ptr);
487     }
488 }
489 
490 /* =========================== Crash handling  ============================== */
491 
492 void _serverAssert(char *estr, char *file, int line) {
493     bugReportStart();
494     serverLog(LL_WARNING,"=== ASSERTION FAILED ===");
495     serverLog(LL_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
496 #ifdef HAVE_BACKTRACE
497     server.assert_failed = estr;
498     server.assert_file = file;
499     server.assert_line = line;
500     serverLog(LL_WARNING,"(forcing SIGSEGV to print the bug report.)");
501 #endif
502     *((char*)-1) = 'x';
503 }
504 
505 void _serverAssertPrintClientInfo(client *c) {
506     int j;
507 
508     bugReportStart();
509     serverLog(LL_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
510     serverLog(LL_WARNING,"client->flags = %d", c->flags);
511     serverLog(LL_WARNING,"client->fd = %d", c->fd);
512     serverLog(LL_WARNING,"client->argc = %d", c->argc);
513     for (j=0; j < c->argc; j++) {
514         char buf[128];
515         char *arg;
516 
517         if (c->argv[j]->type == OBJ_STRING && sdsEncodedObject(c->argv[j])) {
518             arg = (char*) c->argv[j]->ptr;
519         } else {
520             snprintf(buf,sizeof(buf),"Object type: %d, encoding: %d",
521                 c->argv[j]->type, c->argv[j]->encoding);
522             arg = buf;
523         }
524         serverLog(LL_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
525             j, arg, c->argv[j]->refcount);
526     }
527 }
528 
529 void serverLogObjectDebugInfo(robj *o) {
530     serverLog(LL_WARNING,"Object type: %d", o->type);
531     serverLog(LL_WARNING,"Object encoding: %d", o->encoding);
532     serverLog(LL_WARNING,"Object refcount: %d", o->refcount);
533     if (o->type == OBJ_STRING && sdsEncodedObject(o)) {
534         serverLog(LL_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
535         if (sdslen(o->ptr) < 4096) {
536             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
537             serverLog(LL_WARNING,"Object raw string content: %s", repr);
538             sdsfree(repr);
539         }
540     } else if (o->type == OBJ_LIST) {
541         serverLog(LL_WARNING,"List length: %d", (int) listTypeLength(o));
542     } else if (o->type == OBJ_SET) {
543         serverLog(LL_WARNING,"Set size: %d", (int) setTypeSize(o));
544     } else if (o->type == OBJ_HASH) {
545         serverLog(LL_WARNING,"Hash size: %d", (int) hashTypeLength(o));
546     } else if (o->type == OBJ_ZSET) {
547         serverLog(LL_WARNING,"Sorted set size: %d", (int) zsetLength(o));
548         if (o->encoding == OBJ_ENCODING_SKIPLIST)
549             serverLog(LL_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
550     }
551 }
552 
553 void _serverAssertPrintObject(robj *o) {
554     bugReportStart();
555     serverLog(LL_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
556     serverLogObjectDebugInfo(o);
557 }
558 
559 void _serverAssertWithInfo(client *c, robj *o, char *estr, char *file, int line) {
560     if (c) _serverAssertPrintClientInfo(c);
561     if (o) _serverAssertPrintObject(o);
562     _serverAssert(estr,file,line);
563 }
564 
565 void _serverPanic(char *msg, char *file, int line) {
566     bugReportStart();
567     serverLog(LL_WARNING,"------------------------------------------------");
568     serverLog(LL_WARNING,"!!! Software Failure. Press left mouse button to continue");
569     serverLog(LL_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
570 #ifdef HAVE_BACKTRACE
571     serverLog(LL_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
572 #endif
573     serverLog(LL_WARNING,"------------------------------------------------");
574     *((char*)-1) = 'x';
575 }
576 
577 void bugReportStart(void) {
578     if (server.bug_report_start == 0) {
579         serverLog(LL_WARNING,
580             "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===");
581         server.bug_report_start = 1;
582     }
583 }
584 
585 #ifdef HAVE_BACKTRACE
586 static void *getMcontextEip(ucontext_t *uc) {
587 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
588     /* OSX < 10.6 */
589     #if defined(__x86_64__)
590     return (void*) uc->uc_mcontext->__ss.__rip;
591     #elif defined(__i386__)
592     return (void*) uc->uc_mcontext->__ss.__eip;
593     #else
594     return (void*) uc->uc_mcontext->__ss.__srr0;
595     #endif
596 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
597     /* OSX >= 10.6 */
598     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
599     return (void*) uc->uc_mcontext->__ss.__rip;
600     #else
601     return (void*) uc->uc_mcontext->__ss.__eip;
602     #endif
603 #elif defined(__linux__)
604     /* Linux */
605     #if defined(__i386__)
606     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
607     #elif defined(__X86_64__) || defined(__x86_64__)
608     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
609     #elif defined(__ia64__) /* Linux IA64 */
610     return (void*) uc->uc_mcontext.sc_ip;
611     #endif
612 #else
613     return NULL;
614 #endif
615 }
616 
617 void logStackContent(void **sp) {
618     int i;
619     for (i = 15; i >= 0; i--) {
620         unsigned long addr = (unsigned long) sp+i;
621         unsigned long val = (unsigned long) sp[i];
622 
623         if (sizeof(long) == 4)
624             serverLog(LL_WARNING, "(%08lx) -> %08lx", addr, val);
625         else
626             serverLog(LL_WARNING, "(%016lx) -> %016lx", addr, val);
627     }
628 }
629 
630 void logRegisters(ucontext_t *uc) {
631     serverLog(LL_WARNING, "--- REGISTERS");
632 
633 /* OSX */
634 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
635   /* OSX AMD64 */
636     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
637     serverLog(LL_WARNING,
638     "\n"
639     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
640     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
641     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
642     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
643     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
644         (unsigned long) uc->uc_mcontext->__ss.__rax,
645         (unsigned long) uc->uc_mcontext->__ss.__rbx,
646         (unsigned long) uc->uc_mcontext->__ss.__rcx,
647         (unsigned long) uc->uc_mcontext->__ss.__rdx,
648         (unsigned long) uc->uc_mcontext->__ss.__rdi,
649         (unsigned long) uc->uc_mcontext->__ss.__rsi,
650         (unsigned long) uc->uc_mcontext->__ss.__rbp,
651         (unsigned long) uc->uc_mcontext->__ss.__rsp,
652         (unsigned long) uc->uc_mcontext->__ss.__r8,
653         (unsigned long) uc->uc_mcontext->__ss.__r9,
654         (unsigned long) uc->uc_mcontext->__ss.__r10,
655         (unsigned long) uc->uc_mcontext->__ss.__r11,
656         (unsigned long) uc->uc_mcontext->__ss.__r12,
657         (unsigned long) uc->uc_mcontext->__ss.__r13,
658         (unsigned long) uc->uc_mcontext->__ss.__r14,
659         (unsigned long) uc->uc_mcontext->__ss.__r15,
660         (unsigned long) uc->uc_mcontext->__ss.__rip,
661         (unsigned long) uc->uc_mcontext->__ss.__rflags,
662         (unsigned long) uc->uc_mcontext->__ss.__cs,
663         (unsigned long) uc->uc_mcontext->__ss.__fs,
664         (unsigned long) uc->uc_mcontext->__ss.__gs
665     );
666     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
667     #else
668     /* OSX x86 */
669     serverLog(LL_WARNING,
670     "\n"
671     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
672     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
673     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
674     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
675         (unsigned long) uc->uc_mcontext->__ss.__eax,
676         (unsigned long) uc->uc_mcontext->__ss.__ebx,
677         (unsigned long) uc->uc_mcontext->__ss.__ecx,
678         (unsigned long) uc->uc_mcontext->__ss.__edx,
679         (unsigned long) uc->uc_mcontext->__ss.__edi,
680         (unsigned long) uc->uc_mcontext->__ss.__esi,
681         (unsigned long) uc->uc_mcontext->__ss.__ebp,
682         (unsigned long) uc->uc_mcontext->__ss.__esp,
683         (unsigned long) uc->uc_mcontext->__ss.__ss,
684         (unsigned long) uc->uc_mcontext->__ss.__eflags,
685         (unsigned long) uc->uc_mcontext->__ss.__eip,
686         (unsigned long) uc->uc_mcontext->__ss.__cs,
687         (unsigned long) uc->uc_mcontext->__ss.__ds,
688         (unsigned long) uc->uc_mcontext->__ss.__es,
689         (unsigned long) uc->uc_mcontext->__ss.__fs,
690         (unsigned long) uc->uc_mcontext->__ss.__gs
691     );
692     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
693     #endif
694 /* Linux */
695 #elif defined(__linux__)
696     /* Linux x86 */
697     #if defined(__i386__)
698     serverLog(LL_WARNING,
699     "\n"
700     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
701     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
702     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
703     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
704         (unsigned long) uc->uc_mcontext.gregs[11],
705         (unsigned long) uc->uc_mcontext.gregs[8],
706         (unsigned long) uc->uc_mcontext.gregs[10],
707         (unsigned long) uc->uc_mcontext.gregs[9],
708         (unsigned long) uc->uc_mcontext.gregs[4],
709         (unsigned long) uc->uc_mcontext.gregs[5],
710         (unsigned long) uc->uc_mcontext.gregs[6],
711         (unsigned long) uc->uc_mcontext.gregs[7],
712         (unsigned long) uc->uc_mcontext.gregs[18],
713         (unsigned long) uc->uc_mcontext.gregs[17],
714         (unsigned long) uc->uc_mcontext.gregs[14],
715         (unsigned long) uc->uc_mcontext.gregs[15],
716         (unsigned long) uc->uc_mcontext.gregs[3],
717         (unsigned long) uc->uc_mcontext.gregs[2],
718         (unsigned long) uc->uc_mcontext.gregs[1],
719         (unsigned long) uc->uc_mcontext.gregs[0]
720     );
721     logStackContent((void**)uc->uc_mcontext.gregs[7]);
722     #elif defined(__X86_64__) || defined(__x86_64__)
723     /* Linux AMD64 */
724     serverLog(LL_WARNING,
725     "\n"
726     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
727     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
728     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
729     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
730     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
731         (unsigned long) uc->uc_mcontext.gregs[13],
732         (unsigned long) uc->uc_mcontext.gregs[11],
733         (unsigned long) uc->uc_mcontext.gregs[14],
734         (unsigned long) uc->uc_mcontext.gregs[12],
735         (unsigned long) uc->uc_mcontext.gregs[8],
736         (unsigned long) uc->uc_mcontext.gregs[9],
737         (unsigned long) uc->uc_mcontext.gregs[10],
738         (unsigned long) uc->uc_mcontext.gregs[15],
739         (unsigned long) uc->uc_mcontext.gregs[0],
740         (unsigned long) uc->uc_mcontext.gregs[1],
741         (unsigned long) uc->uc_mcontext.gregs[2],
742         (unsigned long) uc->uc_mcontext.gregs[3],
743         (unsigned long) uc->uc_mcontext.gregs[4],
744         (unsigned long) uc->uc_mcontext.gregs[5],
745         (unsigned long) uc->uc_mcontext.gregs[6],
746         (unsigned long) uc->uc_mcontext.gregs[7],
747         (unsigned long) uc->uc_mcontext.gregs[16],
748         (unsigned long) uc->uc_mcontext.gregs[17],
749         (unsigned long) uc->uc_mcontext.gregs[18]
750     );
751     logStackContent((void**)uc->uc_mcontext.gregs[15]);
752     #endif
753 #else
754     serverLog(LL_WARNING,
755         "  Dumping of registers not supported for this OS/arch");
756 #endif
757 }
758 
759 /* Logs the stack trace using the backtrace() call. This function is designed
760  * to be called from signal handlers safely. */
761 void logStackTrace(ucontext_t *uc) {
762     void *trace[100];
763     int trace_size = 0, fd;
764     int log_to_stdout = server.logfile[0] == '\0';
765 
766     /* Open the log file in append mode. */
767     fd = log_to_stdout ?
768         STDOUT_FILENO :
769         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
770     if (fd == -1) return;
771 
772     /* Generate the stack trace */
773     trace_size = backtrace(trace, 100);
774 
775     /* overwrite sigaction with caller's address */
776     if (getMcontextEip(uc) != NULL)
777         trace[1] = getMcontextEip(uc);
778 
779     /* Write symbols to log file */
780     backtrace_symbols_fd(trace, trace_size, fd);
781 
782     /* Cleanup */
783     if (!log_to_stdout) close(fd);
784 }
785 
786 /* Log information about the "current" client, that is, the client that is
787  * currently being served by Redis. May be NULL if Redis is not serving a
788  * client right now. */
789 void logCurrentClient(void) {
790     if (server.current_client == NULL) return;
791 
792     client *cc = server.current_client;
793     sds client;
794     int j;
795 
796     serverLog(LL_WARNING, "--- CURRENT CLIENT INFO");
797     client = catClientInfoString(sdsempty(),cc);
798     serverLog(LL_WARNING,"client: %s", client);
799     sdsfree(client);
800     for (j = 0; j < cc->argc; j++) {
801         robj *decoded;
802 
803         decoded = getDecodedObject(cc->argv[j]);
804         serverLog(LL_WARNING,"argv[%d]: '%s'", j, (char*)decoded->ptr);
805         decrRefCount(decoded);
806     }
807     /* Check if the first argument, usually a key, is found inside the
808      * selected DB, and if so print info about the associated object. */
809     if (cc->argc >= 1) {
810         robj *val, *key;
811         dictEntry *de;
812 
813         key = getDecodedObject(cc->argv[1]);
814         de = dictFind(cc->db->dict, key->ptr);
815         if (de) {
816             val = dictGetVal(de);
817             serverLog(LL_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
818             serverLogObjectDebugInfo(val);
819         }
820         decrRefCount(key);
821     }
822 }
823 
824 #if defined(HAVE_PROC_MAPS)
825 void memtest_non_destructive_invert(void *addr, size_t size);
826 void memtest_non_destructive_swap(void *addr, size_t size);
827 #define MEMTEST_MAX_REGIONS 128
828 
829 int memtest_test_linux_anonymous_maps(void) {
830     FILE *fp = fopen("/proc/self/maps","r");
831     char line[1024];
832     size_t start_addr, end_addr, size;
833     size_t start_vect[MEMTEST_MAX_REGIONS];
834     size_t size_vect[MEMTEST_MAX_REGIONS];
835     int regions = 0, j;
836     uint64_t crc1 = 0, crc2 = 0, crc3 = 0;
837 
838     while(fgets(line,sizeof(line),fp) != NULL) {
839         char *start, *end, *p = line;
840 
841         start = p;
842         p = strchr(p,'-');
843         if (!p) continue;
844         *p++ = '\0';
845         end = p;
846         p = strchr(p,' ');
847         if (!p) continue;
848         *p++ = '\0';
849         if (strstr(p,"stack") ||
850             strstr(p,"vdso") ||
851             strstr(p,"vsyscall")) continue;
852         if (!strstr(p,"00:00")) continue;
853         if (!strstr(p,"rw")) continue;
854 
855         start_addr = strtoul(start,NULL,16);
856         end_addr = strtoul(end,NULL,16);
857         size = end_addr-start_addr;
858 
859         start_vect[regions] = start_addr;
860         size_vect[regions] = size;
861         printf("Testing %lx %lu\n", (unsigned long) start_vect[regions],
862                                     (unsigned long) size_vect[regions]);
863         regions++;
864     }
865 
866     /* Test all the regions as an unique sequential region.
867      * 1) Take the CRC64 of the memory region. */
868     for (j = 0; j < regions; j++) {
869         crc1 = crc64(crc1,(void*)start_vect[j],size_vect[j]);
870     }
871 
872     /* 2) Invert bits, swap adjacent words, swap again, invert bits.
873      * This is the error amplification step. */
874     for (j = 0; j < regions; j++)
875         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
876     for (j = 0; j < regions; j++)
877         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
878     for (j = 0; j < regions; j++)
879         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
880     for (j = 0; j < regions; j++)
881         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
882 
883     /* 3) Take the CRC64 sum again. */
884     for (j = 0; j < regions; j++)
885         crc2 = crc64(crc2,(void*)start_vect[j],size_vect[j]);
886 
887     /* 4) Swap + Swap again */
888     for (j = 0; j < regions; j++)
889         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
890     for (j = 0; j < regions; j++)
891         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
892 
893     /* 5) Take the CRC64 sum again. */
894     for (j = 0; j < regions; j++)
895         crc3 = crc64(crc3,(void*)start_vect[j],size_vect[j]);
896 
897     /* NOTE: It is very important to close the file descriptor only now
898      * because closing it before may result into unmapping of some memory
899      * region that we are testing. */
900     fclose(fp);
901 
902     /* If the two CRC are not the same, we trapped a memory error. */
903     return crc1 != crc2 || crc2 != crc3;
904 }
905 #endif
906 
907 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
908     ucontext_t *uc = (ucontext_t*) secret;
909     sds infostring, clients;
910     struct sigaction act;
911     UNUSED(info);
912 
913     bugReportStart();
914     serverLog(LL_WARNING,
915         "    Redis %s crashed by signal: %d", REDIS_VERSION, sig);
916     serverLog(LL_WARNING,
917         "    Failed assertion: %s (%s:%d)", server.assert_failed,
918                         server.assert_file, server.assert_line);
919 
920     /* Log the stack trace */
921     serverLog(LL_WARNING, "--- STACK TRACE");
922     logStackTrace(uc);
923 
924     /* Log INFO and CLIENT LIST */
925     serverLog(LL_WARNING, "--- INFO OUTPUT");
926     infostring = genRedisInfoString("all");
927     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
928         dictGetHashFunctionSeed());
929     serverLogRaw(LL_WARNING, infostring);
930     serverLog(LL_WARNING, "--- CLIENT LIST OUTPUT");
931     clients = getAllClientsInfoString();
932     serverLogRaw(LL_WARNING, clients);
933     sdsfree(infostring);
934     sdsfree(clients);
935 
936     /* Log the current client */
937     logCurrentClient();
938 
939     /* Log dump of processor registers */
940     logRegisters(uc);
941 
942 #if defined(HAVE_PROC_MAPS)
943     /* Test memory */
944     serverLog(LL_WARNING, "--- FAST MEMORY TEST");
945     bioKillThreads();
946     if (memtest_test_linux_anonymous_maps()) {
947         serverLog(LL_WARNING,
948             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
949     } else {
950         serverLog(LL_WARNING,
951             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
952     }
953 #endif
954 
955     serverLog(LL_WARNING,
956 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
957 "       Please report the crash by opening an issue on github:\n\n"
958 "           http://github.com/antirez/redis/issues\n\n"
959 "  Suspect RAM error? Use redis-server --test-memory to verify it.\n\n"
960 );
961     /* free(messages); Don't call free() with possibly corrupted memory. */
962     if (server.daemonize && server.supervised == 0) unlink(server.pidfile);
963 
964     /* Make sure we exit with the right signal at the end. So for instance
965      * the core will be dumped if enabled. */
966     sigemptyset (&act.sa_mask);
967     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
968     act.sa_handler = SIG_DFL;
969     sigaction (sig, &act, NULL);
970     kill(getpid(),sig);
971 }
972 #endif /* HAVE_BACKTRACE */
973 
974 /* ==================== Logging functions for debugging ===================== */
975 
976 void serverLogHexDump(int level, char *descr, void *value, size_t len) {
977     char buf[65], *b;
978     unsigned char *v = value;
979     char charset[] = "0123456789abcdef";
980 
981     serverLog(level,"%s (hexdump):", descr);
982     b = buf;
983     while(len) {
984         b[0] = charset[(*v)>>4];
985         b[1] = charset[(*v)&0xf];
986         b[2] = '\0';
987         b += 2;
988         len--;
989         v++;
990         if (b-buf == 64 || len == 0) {
991             serverLogRaw(level|LL_RAW,buf);
992             b = buf;
993         }
994     }
995     serverLogRaw(level|LL_RAW,"\n");
996 }
997 
998 /* =========================== Software Watchdog ============================ */
999 #include <sys/time.h>
1000 
1001 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
1002 #ifdef HAVE_BACKTRACE
1003     ucontext_t *uc = (ucontext_t*) secret;
1004 #endif
1005     UNUSED(info);
1006     UNUSED(sig);
1007 
1008     serverLogFromHandler(LL_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
1009 #ifdef HAVE_BACKTRACE
1010     logStackTrace(uc);
1011 #else
1012     serverLogFromHandler(LL_WARNING,"Sorry: no support for backtrace().");
1013 #endif
1014     serverLogFromHandler(LL_WARNING,"--------\n");
1015 }
1016 
1017 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
1018  * If a timer is already scheduled, this function will re-schedule it to the
1019  * specified time. If period is 0 the current timer is disabled. */
1020 void watchdogScheduleSignal(int period) {
1021     struct itimerval it;
1022 
1023     /* Will stop the timer if period is 0. */
1024     it.it_value.tv_sec = period/1000;
1025     it.it_value.tv_usec = (period%1000)*1000;
1026     /* Don't automatically restart. */
1027     it.it_interval.tv_sec = 0;
1028     it.it_interval.tv_usec = 0;
1029     setitimer(ITIMER_REAL, &it, NULL);
1030 }
1031 
1032 /* Enable the software watchdog with the specified period in milliseconds. */
1033 void enableWatchdog(int period) {
1034     int min_period;
1035 
1036     if (server.watchdog_period == 0) {
1037         struct sigaction act;
1038 
1039         /* Watchdog was actually disabled, so we have to setup the signal
1040          * handler. */
1041         sigemptyset(&act.sa_mask);
1042         act.sa_flags = SA_ONSTACK | SA_SIGINFO;
1043         act.sa_sigaction = watchdogSignalHandler;
1044         sigaction(SIGALRM, &act, NULL);
1045     }
1046     /* If the configured period is smaller than twice the timer period, it is
1047      * too short for the software watchdog to work reliably. Fix it now
1048      * if needed. */
1049     min_period = (1000/server.hz)*2;
1050     if (period < min_period) period = min_period;
1051     watchdogScheduleSignal(period); /* Adjust the current timer. */
1052     server.watchdog_period = period;
1053 }
1054 
1055 /* Disable the software watchdog. */
1056 void disableWatchdog(void) {
1057     struct sigaction act;
1058     if (server.watchdog_period == 0) return; /* Already disabled. */
1059     watchdogScheduleSignal(0); /* Stop the current timer. */
1060 
1061     /* Set the signal handler to SIG_IGN, this will also remove pending
1062      * signals from the queue. */
1063     sigemptyset(&act.sa_mask);
1064     act.sa_flags = 0;
1065     act.sa_handler = SIG_IGN;
1066     sigaction(SIGALRM, &act, NULL);
1067     server.watchdog_period = 0;
1068 }
1069