xref: /redis-3.2.3/src/debug.c (revision 9bb91d19)
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 /* ================================= Debugging ============================== */
45 
46 /* Compute the sha1 of string at 's' with 'len' bytes long.
47  * The SHA1 is then xored against the string pointed by digest.
48  * Since xor is commutative, this operation is used in order to
49  * "add" digests relative to unordered elements.
50  *
51  * So digest(a,b,c,d) will be the same of digest(b,a,c,d) */
52 void xorDigest(unsigned char *digest, void *ptr, size_t len) {
53     SHA1_CTX ctx;
54     unsigned char hash[20], *s = ptr;
55     int j;
56 
57     SHA1Init(&ctx);
58     SHA1Update(&ctx,s,len);
59     SHA1Final(hash,&ctx);
60 
61     for (j = 0; j < 20; j++)
62         digest[j] ^= hash[j];
63 }
64 
65 void xorObjectDigest(unsigned char *digest, robj *o) {
66     o = getDecodedObject(o);
67     xorDigest(digest,o->ptr,sdslen(o->ptr));
68     decrRefCount(o);
69 }
70 
71 /* This function instead of just computing the SHA1 and xoring it
72  * against digest, also perform the digest of "digest" itself and
73  * replace the old value with the new one.
74  *
75  * So the final digest will be:
76  *
77  * digest = SHA1(digest xor SHA1(data))
78  *
79  * This function is used every time we want to preserve the order so
80  * that digest(a,b,c,d) will be different than digest(b,c,d,a)
81  *
82  * Also note that mixdigest("foo") followed by mixdigest("bar")
83  * will lead to a different digest compared to "fo", "obar".
84  */
85 void mixDigest(unsigned char *digest, void *ptr, size_t len) {
86     SHA1_CTX ctx;
87     char *s = ptr;
88 
89     xorDigest(digest,s,len);
90     SHA1Init(&ctx);
91     SHA1Update(&ctx,digest,20);
92     SHA1Final(digest,&ctx);
93 }
94 
95 void mixObjectDigest(unsigned char *digest, robj *o) {
96     o = getDecodedObject(o);
97     mixDigest(digest,o->ptr,sdslen(o->ptr));
98     decrRefCount(o);
99 }
100 
101 /* Compute the dataset digest. Since keys, sets elements, hashes elements
102  * are not ordered, we use a trick: every aggregate digest is the xor
103  * of the digests of their elements. This way the order will not change
104  * the result. For list instead we use a feedback entering the output digest
105  * as input in order to ensure that a different ordered list will result in
106  * a different digest. */
107 void computeDatasetDigest(unsigned char *final) {
108     unsigned char digest[20];
109     char buf[128];
110     dictIterator *di = NULL;
111     dictEntry *de;
112     int j;
113     uint32_t aux;
114 
115     memset(final,0,20); /* Start with a clean result */
116 
117     for (j = 0; j < server.dbnum; j++) {
118         redisDb *db = server.db+j;
119 
120         if (dictSize(db->dict) == 0) continue;
121         di = dictGetIterator(db->dict);
122 
123         /* hash the DB id, so the same dataset moved in a different
124          * DB will lead to a different digest */
125         aux = htonl(j);
126         mixDigest(final,&aux,sizeof(aux));
127 
128         /* Iterate this DB writing every entry */
129         while((de = dictNext(di)) != NULL) {
130             sds key;
131             robj *keyobj, *o;
132             long long expiretime;
133 
134             memset(digest,0,20); /* This key-val digest */
135             key = dictGetKey(de);
136             keyobj = createStringObject(key,sdslen(key));
137 
138             mixDigest(digest,key,sdslen(key));
139 
140             o = dictGetVal(de);
141 
142             aux = htonl(o->type);
143             mixDigest(digest,&aux,sizeof(aux));
144             expiretime = getExpire(db,keyobj);
145 
146             /* Save the key and associated value */
147             if (o->type == REDIS_STRING) {
148                 mixObjectDigest(digest,o);
149             } else if (o->type == REDIS_LIST) {
150                 listTypeIterator *li = listTypeInitIterator(o,0,REDIS_TAIL);
151                 listTypeEntry entry;
152                 while(listTypeNext(li,&entry)) {
153                     robj *eleobj = listTypeGet(&entry);
154                     mixObjectDigest(digest,eleobj);
155                     decrRefCount(eleobj);
156                 }
157                 listTypeReleaseIterator(li);
158             } else if (o->type == REDIS_SET) {
159                 setTypeIterator *si = setTypeInitIterator(o);
160                 robj *ele;
161                 while((ele = setTypeNextObject(si)) != NULL) {
162                     xorObjectDigest(digest,ele);
163                     decrRefCount(ele);
164                 }
165                 setTypeReleaseIterator(si);
166             } else if (o->type == REDIS_ZSET) {
167                 unsigned char eledigest[20];
168 
169                 if (o->encoding == REDIS_ENCODING_ZIPLIST) {
170                     unsigned char *zl = o->ptr;
171                     unsigned char *eptr, *sptr;
172                     unsigned char *vstr;
173                     unsigned int vlen;
174                     long long vll;
175                     double score;
176 
177                     eptr = ziplistIndex(zl,0);
178                     redisAssert(eptr != NULL);
179                     sptr = ziplistNext(zl,eptr);
180                     redisAssert(sptr != NULL);
181 
182                     while (eptr != NULL) {
183                         redisAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
184                         score = zzlGetScore(sptr);
185 
186                         memset(eledigest,0,20);
187                         if (vstr != NULL) {
188                             mixDigest(eledigest,vstr,vlen);
189                         } else {
190                             ll2string(buf,sizeof(buf),vll);
191                             mixDigest(eledigest,buf,strlen(buf));
192                         }
193 
194                         snprintf(buf,sizeof(buf),"%.17g",score);
195                         mixDigest(eledigest,buf,strlen(buf));
196                         xorDigest(digest,eledigest,20);
197                         zzlNext(zl,&eptr,&sptr);
198                     }
199                 } else if (o->encoding == REDIS_ENCODING_SKIPLIST) {
200                     zset *zs = o->ptr;
201                     dictIterator *di = dictGetIterator(zs->dict);
202                     dictEntry *de;
203 
204                     while((de = dictNext(di)) != NULL) {
205                         robj *eleobj = dictGetKey(de);
206                         double *score = dictGetVal(de);
207 
208                         snprintf(buf,sizeof(buf),"%.17g",*score);
209                         memset(eledigest,0,20);
210                         mixObjectDigest(eledigest,eleobj);
211                         mixDigest(eledigest,buf,strlen(buf));
212                         xorDigest(digest,eledigest,20);
213                     }
214                     dictReleaseIterator(di);
215                 } else {
216                     redisPanic("Unknown sorted set encoding");
217                 }
218             } else if (o->type == REDIS_HASH) {
219                 hashTypeIterator *hi;
220                 robj *obj;
221 
222                 hi = hashTypeInitIterator(o);
223                 while (hashTypeNext(hi) != REDIS_ERR) {
224                     unsigned char eledigest[20];
225 
226                     memset(eledigest,0,20);
227                     obj = hashTypeCurrentObject(hi,REDIS_HASH_KEY);
228                     mixObjectDigest(eledigest,obj);
229                     decrRefCount(obj);
230                     obj = hashTypeCurrentObject(hi,REDIS_HASH_VALUE);
231                     mixObjectDigest(eledigest,obj);
232                     decrRefCount(obj);
233                     xorDigest(digest,eledigest,20);
234                 }
235                 hashTypeReleaseIterator(hi);
236             } else {
237                 redisPanic("Unknown object type");
238             }
239             /* If the key has an expire, add it to the mix */
240             if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
241             /* We can finally xor the key-val digest to the final digest */
242             xorDigest(final,digest,20);
243             decrRefCount(keyobj);
244         }
245         dictReleaseIterator(di);
246     }
247 }
248 
249 void debugCommand(redisClient *c) {
250     if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
251         *((char*)-1) = 'x';
252     } else if (!strcasecmp(c->argv[1]->ptr,"oom")) {
253         void *ptr = zmalloc(ULONG_MAX); /* Should trigger an out of memory. */
254         zfree(ptr);
255         addReply(c,shared.ok);
256     } else if (!strcasecmp(c->argv[1]->ptr,"assert")) {
257         if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
258         redisAssertWithInfo(c,c->argv[0],1 == 2);
259     } else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
260         if (rdbSave(server.rdb_filename) != REDIS_OK) {
261             addReply(c,shared.err);
262             return;
263         }
264         emptyDb();
265         if (rdbLoad(server.rdb_filename) != REDIS_OK) {
266             addReplyError(c,"Error trying to load the RDB dump");
267             return;
268         }
269         redisLog(REDIS_WARNING,"DB reloaded by DEBUG RELOAD");
270         addReply(c,shared.ok);
271     } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
272         emptyDb();
273         if (loadAppendOnlyFile(server.aof_filename) != REDIS_OK) {
274             addReply(c,shared.err);
275             return;
276         }
277         server.dirty = 0; /* Prevent AOF / replication */
278         redisLog(REDIS_WARNING,"Append Only File loaded by DEBUG LOADAOF");
279         addReply(c,shared.ok);
280     } else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) {
281         dictEntry *de;
282         robj *val;
283         char *strenc;
284 
285         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
286             addReply(c,shared.nokeyerr);
287             return;
288         }
289         val = dictGetVal(de);
290         strenc = strEncoding(val->encoding);
291 
292         addReplyStatusFormat(c,
293             "Value at:%p refcount:%d "
294             "encoding:%s serializedlength:%lld "
295             "lru:%d lru_seconds_idle:%lu",
296             (void*)val, val->refcount,
297             strenc, (long long) rdbSavedObjectLen(val),
298             val->lru, estimateObjectIdleTime(val));
299     } else if (!strcasecmp(c->argv[1]->ptr,"sdslen") && c->argc == 3) {
300         dictEntry *de;
301         robj *val;
302         sds key;
303 
304         if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
305             addReply(c,shared.nokeyerr);
306             return;
307         }
308         val = dictGetVal(de);
309         key = dictGetKey(de);
310 
311         if (val->type != REDIS_STRING || !sdsEncodedObject(val)) {
312             addReplyError(c,"Not an sds encoded string.");
313         } else {
314             addReplyStatusFormat(c,
315                 "key_sds_len:%lld, key_sds_avail:%lld, "
316                 "val_sds_len:%lld, val_sds_avail:%lld",
317                 (long long) sdslen(key),
318                 (long long) sdsavail(key),
319                 (long long) sdslen(val->ptr),
320                 (long long) sdsavail(val->ptr));
321         }
322     } else if (!strcasecmp(c->argv[1]->ptr,"populate") && c->argc == 3) {
323         long keys, j;
324         robj *key, *val;
325         char buf[128];
326 
327         if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK)
328             return;
329         for (j = 0; j < keys; j++) {
330             snprintf(buf,sizeof(buf),"key:%lu",j);
331             key = createStringObject(buf,strlen(buf));
332             if (lookupKeyRead(c->db,key) != NULL) {
333                 decrRefCount(key);
334                 continue;
335             }
336             snprintf(buf,sizeof(buf),"value:%lu",j);
337             val = createStringObject(buf,strlen(buf));
338             dbAdd(c->db,key,val);
339             decrRefCount(key);
340         }
341         addReply(c,shared.ok);
342     } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
343         unsigned char digest[20];
344         sds d = sdsempty();
345         int j;
346 
347         computeDatasetDigest(digest);
348         for (j = 0; j < 20; j++)
349             d = sdscatprintf(d, "%02x",digest[j]);
350         addReplyStatus(c,d);
351         sdsfree(d);
352     } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
353         double dtime = strtod(c->argv[2]->ptr,NULL);
354         long long utime = dtime*1000000;
355         struct timespec tv;
356 
357         tv.tv_sec = utime / 1000000;
358         tv.tv_nsec = (utime % 1000000) * 1000;
359         nanosleep(&tv, NULL);
360         addReply(c,shared.ok);
361     } else if (!strcasecmp(c->argv[1]->ptr,"set-active-expire") &&
362                c->argc == 3)
363     {
364         server.active_expire_enabled = atoi(c->argv[2]->ptr);
365         addReply(c,shared.ok);
366     } else {
367         addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
368             (char*)c->argv[1]->ptr);
369     }
370 }
371 
372 /* =========================== Crash handling  ============================== */
373 
374 void _redisAssert(char *estr, char *file, int line) {
375     bugReportStart();
376     redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
377     redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
378 #ifdef HAVE_BACKTRACE
379     server.assert_failed = estr;
380     server.assert_file = file;
381     server.assert_line = line;
382     redisLog(REDIS_WARNING,"(forcing SIGSEGV to print the bug report.)");
383 #endif
384     *((char*)-1) = 'x';
385 }
386 
387 void _redisAssertPrintClientInfo(redisClient *c) {
388     int j;
389 
390     bugReportStart();
391     redisLog(REDIS_WARNING,"=== ASSERTION FAILED CLIENT CONTEXT ===");
392     redisLog(REDIS_WARNING,"client->flags = %d", c->flags);
393     redisLog(REDIS_WARNING,"client->fd = %d", c->fd);
394     redisLog(REDIS_WARNING,"client->argc = %d", c->argc);
395     for (j=0; j < c->argc; j++) {
396         char buf[128];
397         char *arg;
398 
399         if (c->argv[j]->type == REDIS_STRING && sdsEncodedObject(c->argv[j])) {
400             arg = (char*) c->argv[j]->ptr;
401         } else {
402             snprintf(buf,sizeof(buf),"Object type: %d, encoding: %d",
403                 c->argv[j]->type, c->argv[j]->encoding);
404             arg = buf;
405         }
406         redisLog(REDIS_WARNING,"client->argv[%d] = \"%s\" (refcount: %d)",
407             j, arg, c->argv[j]->refcount);
408     }
409 }
410 
411 void redisLogObjectDebugInfo(robj *o) {
412     redisLog(REDIS_WARNING,"Object type: %d", o->type);
413     redisLog(REDIS_WARNING,"Object encoding: %d", o->encoding);
414     redisLog(REDIS_WARNING,"Object refcount: %d", o->refcount);
415     if (o->type == REDIS_STRING && sdsEncodedObject(o)) {
416         redisLog(REDIS_WARNING,"Object raw string len: %zu", sdslen(o->ptr));
417         if (sdslen(o->ptr) < 4096) {
418             sds repr = sdscatrepr(sdsempty(),o->ptr,sdslen(o->ptr));
419             redisLog(REDIS_WARNING,"Object raw string content: %s", repr);
420             sdsfree(repr);
421         }
422     } else if (o->type == REDIS_LIST) {
423         redisLog(REDIS_WARNING,"List length: %d", (int) listTypeLength(o));
424     } else if (o->type == REDIS_SET) {
425         redisLog(REDIS_WARNING,"Set size: %d", (int) setTypeSize(o));
426     } else if (o->type == REDIS_HASH) {
427         redisLog(REDIS_WARNING,"Hash size: %d", (int) hashTypeLength(o));
428     } else if (o->type == REDIS_ZSET) {
429         redisLog(REDIS_WARNING,"Sorted set size: %d", (int) zsetLength(o));
430         if (o->encoding == REDIS_ENCODING_SKIPLIST)
431             redisLog(REDIS_WARNING,"Skiplist level: %d", (int) ((zset*)o->ptr)->zsl->level);
432     }
433 }
434 
435 void _redisAssertPrintObject(robj *o) {
436     bugReportStart();
437     redisLog(REDIS_WARNING,"=== ASSERTION FAILED OBJECT CONTEXT ===");
438     redisLogObjectDebugInfo(o);
439 }
440 
441 void _redisAssertWithInfo(redisClient *c, robj *o, char *estr, char *file, int line) {
442     if (c) _redisAssertPrintClientInfo(c);
443     if (o) _redisAssertPrintObject(o);
444     _redisAssert(estr,file,line);
445 }
446 
447 void _redisPanic(char *msg, char *file, int line) {
448     bugReportStart();
449     redisLog(REDIS_WARNING,"------------------------------------------------");
450     redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
451     redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
452 #ifdef HAVE_BACKTRACE
453     redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
454 #endif
455     redisLog(REDIS_WARNING,"------------------------------------------------");
456     *((char*)-1) = 'x';
457 }
458 
459 void bugReportStart(void) {
460     if (server.bug_report_start == 0) {
461         redisLog(REDIS_WARNING,
462             "\n\n=== REDIS BUG REPORT START: Cut & paste starting from here ===");
463         server.bug_report_start = 1;
464     }
465 }
466 
467 #ifdef HAVE_BACKTRACE
468 static void *getMcontextEip(ucontext_t *uc) {
469 #if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
470     /* OSX < 10.6 */
471     #if defined(__x86_64__)
472     return (void*) uc->uc_mcontext->__ss.__rip;
473     #elif defined(__i386__)
474     return (void*) uc->uc_mcontext->__ss.__eip;
475     #else
476     return (void*) uc->uc_mcontext->__ss.__srr0;
477     #endif
478 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
479     /* OSX >= 10.6 */
480     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
481     return (void*) uc->uc_mcontext->__ss.__rip;
482     #else
483     return (void*) uc->uc_mcontext->__ss.__eip;
484     #endif
485 #elif defined(__linux__)
486     /* Linux */
487     #if defined(__i386__)
488     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
489     #elif defined(__X86_64__) || defined(__x86_64__)
490     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
491     #elif defined(__ia64__) /* Linux IA64 */
492     return (void*) uc->uc_mcontext.sc_ip;
493     #endif
494 #else
495     return NULL;
496 #endif
497 }
498 
499 void logStackContent(void **sp) {
500     int i;
501     for (i = 15; i >= 0; i--) {
502         unsigned long addr = (unsigned long) sp+i;
503         unsigned long val = (unsigned long) sp[i];
504 
505         if (sizeof(long) == 4)
506             redisLog(REDIS_WARNING, "(%08lx) -> %08lx", addr, val);
507         else
508             redisLog(REDIS_WARNING, "(%016lx) -> %016lx", addr, val);
509     }
510 }
511 
512 void logRegisters(ucontext_t *uc) {
513     redisLog(REDIS_WARNING, "--- REGISTERS");
514 
515 /* OSX */
516 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
517   /* OSX AMD64 */
518     #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
519     redisLog(REDIS_WARNING,
520     "\n"
521     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
522     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
523     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
524     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
525     "RIP:%016lx EFL:%016lx\nCS :%016lx FS:%016lx  GS:%016lx",
526         (unsigned long) uc->uc_mcontext->__ss.__rax,
527         (unsigned long) uc->uc_mcontext->__ss.__rbx,
528         (unsigned long) uc->uc_mcontext->__ss.__rcx,
529         (unsigned long) uc->uc_mcontext->__ss.__rdx,
530         (unsigned long) uc->uc_mcontext->__ss.__rdi,
531         (unsigned long) uc->uc_mcontext->__ss.__rsi,
532         (unsigned long) uc->uc_mcontext->__ss.__rbp,
533         (unsigned long) uc->uc_mcontext->__ss.__rsp,
534         (unsigned long) uc->uc_mcontext->__ss.__r8,
535         (unsigned long) uc->uc_mcontext->__ss.__r9,
536         (unsigned long) uc->uc_mcontext->__ss.__r10,
537         (unsigned long) uc->uc_mcontext->__ss.__r11,
538         (unsigned long) uc->uc_mcontext->__ss.__r12,
539         (unsigned long) uc->uc_mcontext->__ss.__r13,
540         (unsigned long) uc->uc_mcontext->__ss.__r14,
541         (unsigned long) uc->uc_mcontext->__ss.__r15,
542         (unsigned long) uc->uc_mcontext->__ss.__rip,
543         (unsigned long) uc->uc_mcontext->__ss.__rflags,
544         (unsigned long) uc->uc_mcontext->__ss.__cs,
545         (unsigned long) uc->uc_mcontext->__ss.__fs,
546         (unsigned long) uc->uc_mcontext->__ss.__gs
547     );
548     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
549     #else
550     /* OSX x86 */
551     redisLog(REDIS_WARNING,
552     "\n"
553     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
554     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
555     "SS:%08lx  EFL:%08lx EIP:%08lx CS :%08lx\n"
556     "DS:%08lx  ES:%08lx  FS :%08lx GS :%08lx",
557         (unsigned long) uc->uc_mcontext->__ss.__eax,
558         (unsigned long) uc->uc_mcontext->__ss.__ebx,
559         (unsigned long) uc->uc_mcontext->__ss.__ecx,
560         (unsigned long) uc->uc_mcontext->__ss.__edx,
561         (unsigned long) uc->uc_mcontext->__ss.__edi,
562         (unsigned long) uc->uc_mcontext->__ss.__esi,
563         (unsigned long) uc->uc_mcontext->__ss.__ebp,
564         (unsigned long) uc->uc_mcontext->__ss.__esp,
565         (unsigned long) uc->uc_mcontext->__ss.__ss,
566         (unsigned long) uc->uc_mcontext->__ss.__eflags,
567         (unsigned long) uc->uc_mcontext->__ss.__eip,
568         (unsigned long) uc->uc_mcontext->__ss.__cs,
569         (unsigned long) uc->uc_mcontext->__ss.__ds,
570         (unsigned long) uc->uc_mcontext->__ss.__es,
571         (unsigned long) uc->uc_mcontext->__ss.__fs,
572         (unsigned long) uc->uc_mcontext->__ss.__gs
573     );
574     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
575     #endif
576 /* Linux */
577 #elif defined(__linux__)
578     /* Linux x86 */
579     #if defined(__i386__)
580     redisLog(REDIS_WARNING,
581     "\n"
582     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
583     "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
584     "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
585     "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
586         (unsigned long) uc->uc_mcontext.gregs[11],
587         (unsigned long) uc->uc_mcontext.gregs[8],
588         (unsigned long) uc->uc_mcontext.gregs[10],
589         (unsigned long) uc->uc_mcontext.gregs[9],
590         (unsigned long) uc->uc_mcontext.gregs[4],
591         (unsigned long) uc->uc_mcontext.gregs[5],
592         (unsigned long) uc->uc_mcontext.gregs[6],
593         (unsigned long) uc->uc_mcontext.gregs[7],
594         (unsigned long) uc->uc_mcontext.gregs[18],
595         (unsigned long) uc->uc_mcontext.gregs[17],
596         (unsigned long) uc->uc_mcontext.gregs[14],
597         (unsigned long) uc->uc_mcontext.gregs[15],
598         (unsigned long) uc->uc_mcontext.gregs[3],
599         (unsigned long) uc->uc_mcontext.gregs[2],
600         (unsigned long) uc->uc_mcontext.gregs[1],
601         (unsigned long) uc->uc_mcontext.gregs[0]
602     );
603     logStackContent((void**)uc->uc_mcontext.gregs[7]);
604     #elif defined(__X86_64__) || defined(__x86_64__)
605     /* Linux AMD64 */
606     redisLog(REDIS_WARNING,
607     "\n"
608     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
609     "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
610     "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
611     "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
612     "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
613         (unsigned long) uc->uc_mcontext.gregs[13],
614         (unsigned long) uc->uc_mcontext.gregs[11],
615         (unsigned long) uc->uc_mcontext.gregs[14],
616         (unsigned long) uc->uc_mcontext.gregs[12],
617         (unsigned long) uc->uc_mcontext.gregs[8],
618         (unsigned long) uc->uc_mcontext.gregs[9],
619         (unsigned long) uc->uc_mcontext.gregs[10],
620         (unsigned long) uc->uc_mcontext.gregs[15],
621         (unsigned long) uc->uc_mcontext.gregs[0],
622         (unsigned long) uc->uc_mcontext.gregs[1],
623         (unsigned long) uc->uc_mcontext.gregs[2],
624         (unsigned long) uc->uc_mcontext.gregs[3],
625         (unsigned long) uc->uc_mcontext.gregs[4],
626         (unsigned long) uc->uc_mcontext.gregs[5],
627         (unsigned long) uc->uc_mcontext.gregs[6],
628         (unsigned long) uc->uc_mcontext.gregs[7],
629         (unsigned long) uc->uc_mcontext.gregs[16],
630         (unsigned long) uc->uc_mcontext.gregs[17],
631         (unsigned long) uc->uc_mcontext.gregs[18]
632     );
633     logStackContent((void**)uc->uc_mcontext.gregs[15]);
634     #endif
635 #else
636     redisLog(REDIS_WARNING,
637         "  Dumping of registers not supported for this OS/arch");
638 #endif
639 }
640 
641 /* Logs the stack trace using the backtrace() call. This function is designed
642  * to be called from signal handlers safely. */
643 void logStackTrace(ucontext_t *uc) {
644     void *trace[100];
645     int trace_size = 0, fd;
646     int log_to_stdout = server.logfile[0] == '\0';
647 
648     /* Open the log file in append mode. */
649     fd = log_to_stdout ?
650         STDOUT_FILENO :
651         open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
652     if (fd == -1) return;
653 
654     /* Generate the stack trace */
655     trace_size = backtrace(trace, 100);
656 
657     /* overwrite sigaction with caller's address */
658     if (getMcontextEip(uc) != NULL)
659         trace[1] = getMcontextEip(uc);
660 
661     /* Write symbols to log file */
662     backtrace_symbols_fd(trace, trace_size, fd);
663 
664     /* Cleanup */
665     if (!log_to_stdout) close(fd);
666 }
667 
668 /* Log information about the "current" client, that is, the client that is
669  * currently being served by Redis. May be NULL if Redis is not serving a
670  * client right now. */
671 void logCurrentClient(void) {
672     if (server.current_client == NULL) return;
673 
674     redisClient *cc = server.current_client;
675     sds client;
676     int j;
677 
678     redisLog(REDIS_WARNING, "--- CURRENT CLIENT INFO");
679     client = getClientInfoString(cc);
680     redisLog(REDIS_WARNING,"client: %s", client);
681     sdsfree(client);
682     for (j = 0; j < cc->argc; j++) {
683         robj *decoded;
684 
685         decoded = getDecodedObject(cc->argv[j]);
686         redisLog(REDIS_WARNING,"argv[%d]: '%s'", j, (char*)decoded->ptr);
687         decrRefCount(decoded);
688     }
689     /* Check if the first argument, usually a key, is found inside the
690      * selected DB, and if so print info about the associated object. */
691     if (cc->argc >= 1) {
692         robj *val, *key;
693         dictEntry *de;
694 
695         key = getDecodedObject(cc->argv[1]);
696         de = dictFind(cc->db->dict, key->ptr);
697         if (de) {
698             val = dictGetVal(de);
699             redisLog(REDIS_WARNING,"key '%s' found in DB containing the following object:", (char*)key->ptr);
700             redisLogObjectDebugInfo(val);
701         }
702         decrRefCount(key);
703     }
704 }
705 
706 #if defined(HAVE_PROC_MAPS)
707 void memtest_non_destructive_invert(void *addr, size_t size);
708 void memtest_non_destructive_swap(void *addr, size_t size);
709 #define MEMTEST_MAX_REGIONS 128
710 
711 int memtest_test_linux_anonymous_maps(void) {
712     FILE *fp = fopen("/proc/self/maps","r");
713     char line[1024];
714     size_t start_addr, end_addr, size;
715     size_t start_vect[MEMTEST_MAX_REGIONS];
716     size_t size_vect[MEMTEST_MAX_REGIONS];
717     int regions = 0, j;
718     uint64_t crc1 = 0, crc2 = 0, crc3 = 0;
719 
720     while(fgets(line,sizeof(line),fp) != NULL) {
721         char *start, *end, *p = line;
722 
723         start = p;
724         p = strchr(p,'-');
725         if (!p) continue;
726         *p++ = '\0';
727         end = p;
728         p = strchr(p,' ');
729         if (!p) continue;
730         *p++ = '\0';
731         if (strstr(p,"stack") ||
732             strstr(p,"vdso") ||
733             strstr(p,"vsyscall")) continue;
734         if (!strstr(p,"00:00")) continue;
735         if (!strstr(p,"rw")) continue;
736 
737         start_addr = strtoul(start,NULL,16);
738         end_addr = strtoul(end,NULL,16);
739         size = end_addr-start_addr;
740 
741         start_vect[regions] = start_addr;
742         size_vect[regions] = size;
743         printf("Testing %lx %lu\n", (unsigned long) start_vect[regions],
744                                     (unsigned long) size_vect[regions]);
745         regions++;
746     }
747 
748     /* Test all the regions as an unique sequential region.
749      * 1) Take the CRC64 of the memory region. */
750     for (j = 0; j < regions; j++) {
751         crc1 = crc64(crc1,(void*)start_vect[j],size_vect[j]);
752     }
753 
754     /* 2) Invert bits, swap adjacent words, swap again, invert bits.
755      * This is the error amplification step. */
756     for (j = 0; j < regions; j++)
757         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
758     for (j = 0; j < regions; j++)
759         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
760     for (j = 0; j < regions; j++)
761         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
762     for (j = 0; j < regions; j++)
763         memtest_non_destructive_invert((void*)start_vect[j],size_vect[j]);
764 
765     /* 3) Take the CRC64 sum again. */
766     for (j = 0; j < regions; j++)
767         crc2 = crc64(crc2,(void*)start_vect[j],size_vect[j]);
768 
769     /* 4) Swap + Swap again */
770     for (j = 0; j < regions; j++)
771         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
772     for (j = 0; j < regions; j++)
773         memtest_non_destructive_swap((void*)start_vect[j],size_vect[j]);
774 
775     /* 5) Take the CRC64 sum again. */
776     for (j = 0; j < regions; j++)
777         crc3 = crc64(crc3,(void*)start_vect[j],size_vect[j]);
778 
779     /* NOTE: It is very important to close the file descriptor only now
780      * because closing it before may result into unmapping of some memory
781      * region that we are testing. */
782     fclose(fp);
783 
784     /* If the two CRC are not the same, we trapped a memory error. */
785     return crc1 != crc2 || crc2 != crc3;
786 }
787 #endif
788 
789 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
790     ucontext_t *uc = (ucontext_t*) secret;
791     sds infostring, clients;
792     struct sigaction act;
793     REDIS_NOTUSED(info);
794 
795     bugReportStart();
796     redisLog(REDIS_WARNING,
797         "    Redis %s crashed by signal: %d", REDIS_VERSION, sig);
798     redisLog(REDIS_WARNING,
799         "    Failed assertion: %s (%s:%d)", server.assert_failed,
800                         server.assert_file, server.assert_line);
801 
802     /* Log the stack trace */
803     redisLog(REDIS_WARNING, "--- STACK TRACE");
804     logStackTrace(uc);
805 
806     /* Log INFO and CLIENT LIST */
807     redisLog(REDIS_WARNING, "--- INFO OUTPUT");
808     infostring = genRedisInfoString("all");
809     infostring = sdscatprintf(infostring, "hash_init_value: %u\n",
810         dictGetHashFunctionSeed());
811     redisLogRaw(REDIS_WARNING, infostring);
812     redisLog(REDIS_WARNING, "--- CLIENT LIST OUTPUT");
813     clients = getAllClientsInfoString();
814     redisLogRaw(REDIS_WARNING, clients);
815     sdsfree(infostring);
816     sdsfree(clients);
817 
818     /* Log the current client */
819     logCurrentClient();
820 
821     /* Log dump of processor registers */
822     logRegisters(uc);
823 
824 #if defined(HAVE_PROC_MAPS)
825     /* Test memory */
826     redisLog(REDIS_WARNING, "--- FAST MEMORY TEST");
827     bioKillThreads();
828     if (memtest_test_linux_anonymous_maps()) {
829         redisLog(REDIS_WARNING,
830             "!!! MEMORY ERROR DETECTED! Check your memory ASAP !!!");
831     } else {
832         redisLog(REDIS_WARNING,
833             "Fast memory test PASSED, however your memory can still be broken. Please run a memory test for several hours if possible.");
834     }
835 #endif
836 
837     redisLog(REDIS_WARNING,
838 "\n=== REDIS BUG REPORT END. Make sure to include from START to END. ===\n\n"
839 "       Please report the crash opening an issue on github:\n\n"
840 "           http://github.com/antirez/redis/issues\n\n"
841 "  Suspect RAM error? Use redis-server --test-memory to veryfy it.\n\n"
842 );
843     /* free(messages); Don't call free() with possibly corrupted memory. */
844     if (server.daemonize) unlink(server.pidfile);
845 
846     /* Make sure we exit with the right signal at the end. So for instance
847      * the core will be dumped if enabled. */
848     sigemptyset (&act.sa_mask);
849     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
850     act.sa_handler = SIG_DFL;
851     sigaction (sig, &act, NULL);
852     kill(getpid(),sig);
853 }
854 #endif /* HAVE_BACKTRACE */
855 
856 /* ==================== Logging functions for debugging ===================== */
857 
858 void redisLogHexDump(int level, char *descr, void *value, size_t len) {
859     char buf[65], *b;
860     unsigned char *v = value;
861     char charset[] = "0123456789abcdef";
862 
863     redisLog(level,"%s (hexdump):", descr);
864     b = buf;
865     while(len) {
866         b[0] = charset[(*v)>>4];
867         b[1] = charset[(*v)&0xf];
868         b[2] = '\0';
869         b += 2;
870         len--;
871         v++;
872         if (b-buf == 64 || len == 0) {
873             redisLogRaw(level|REDIS_LOG_RAW,buf);
874             b = buf;
875         }
876     }
877     redisLogRaw(level|REDIS_LOG_RAW,"\n");
878 }
879 
880 /* =========================== Software Watchdog ============================ */
881 #include <sys/time.h>
882 
883 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
884 #ifdef HAVE_BACKTRACE
885     ucontext_t *uc = (ucontext_t*) secret;
886 #endif
887     REDIS_NOTUSED(info);
888     REDIS_NOTUSED(sig);
889 
890     redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
891 #ifdef HAVE_BACKTRACE
892     logStackTrace(uc);
893 #else
894     redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
895 #endif
896     redisLogFromHandler(REDIS_WARNING,"--------\n");
897 }
898 
899 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
900  * If a timer is already scheduled, this function will re-schedule it to the
901  * specified time. If period is 0 the current timer is disabled. */
902 void watchdogScheduleSignal(int period) {
903     struct itimerval it;
904 
905     /* Will stop the timer if period is 0. */
906     it.it_value.tv_sec = period/1000;
907     it.it_value.tv_usec = (period%1000)*1000;
908     /* Don't automatically restart. */
909     it.it_interval.tv_sec = 0;
910     it.it_interval.tv_usec = 0;
911     setitimer(ITIMER_REAL, &it, NULL);
912 }
913 
914 /* Enable the software watchdog with the specified period in milliseconds. */
915 void enableWatchdog(int period) {
916     int min_period;
917 
918     if (server.watchdog_period == 0) {
919         struct sigaction act;
920 
921         /* Watchdog was actually disabled, so we have to setup the signal
922          * handler. */
923         sigemptyset(&act.sa_mask);
924         act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_SIGINFO;
925         act.sa_sigaction = watchdogSignalHandler;
926         sigaction(SIGALRM, &act, NULL);
927     }
928     /* If the configured period is smaller than twice the timer period, it is
929      * too short for the software watchdog to work reliably. Fix it now
930      * if needed. */
931     min_period = (1000/server.hz)*2;
932     if (period < min_period) period = min_period;
933     watchdogScheduleSignal(period); /* Adjust the current timer. */
934     server.watchdog_period = period;
935 }
936 
937 /* Disable the software watchdog. */
938 void disableWatchdog(void) {
939     struct sigaction act;
940     if (server.watchdog_period == 0) return; /* Already disabled. */
941     watchdogScheduleSignal(0); /* Stop the current timer. */
942 
943     /* Set the signal handler to SIG_IGN, this will also remove pending
944      * signals from the queue. */
945     sigemptyset(&act.sa_mask);
946     act.sa_flags = 0;
947     act.sa_handler = SIG_IGN;
948     sigaction(SIGALRM, &act, NULL);
949     server.watchdog_period = 0;
950 }
951