X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/8918de9202669609442c40af7f7625b5685b8a7c..4b1f6ad3e7a5c7c28618e43e7539c9a937bf8521:/src/debug.c

diff --git a/src/debug.c b/src/debug.c
index 37e6a1f7..566b2b95 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -7,6 +7,7 @@
 #ifdef HAVE_BACKTRACE
 #include <execinfo.h>
 #include <ucontext.h>
+#include <fcntl.h>
 #endif /* HAVE_BACKTRACE */
 
 /* ================================= Debugging ============================== */
@@ -217,6 +218,10 @@ void computeDatasetDigest(unsigned char *final) {
 void debugCommand(redisClient *c) {
     if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
         *((char*)-1) = 'x';
+    } else if (!strcasecmp(c->argv[1]->ptr,"oom")) {
+        void *ptr = zmalloc(ULONG_MAX); /* Should trigger an out of memory. */
+        zfree(ptr);
+        addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"assert")) {
         if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
         redisAssertWithInfo(c,c->argv[0],1 == 2);
@@ -398,30 +403,31 @@ void bugReportStart(void) {
 
 #ifdef HAVE_BACKTRACE
 static void *getMcontextEip(ucontext_t *uc) {
-#if defined(__FreeBSD__)
-    return (void*) uc->uc_mcontext.mc_eip;
-#elif defined(__dietlibc__)
-    return (void*) uc->uc_mcontext.eip;
-#elif defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
-  #if __x86_64__
+#if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
+    /* OSX < 10.6 */
+    #if defined(__x86_64__)
     return (void*) uc->uc_mcontext->__ss.__rip;
-  #elif __i386__
+    #elif defined(__i386__)
     return (void*) uc->uc_mcontext->__ss.__eip;
-  #else
+    #else
     return (void*) uc->uc_mcontext->__ss.__srr0;
-  #endif
+    #endif
 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
-  #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
+    /* OSX >= 10.6 */
+    #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
     return (void*) uc->uc_mcontext->__ss.__rip;
-  #else
+    #else
     return (void*) uc->uc_mcontext->__ss.__eip;
-  #endif
-#elif defined(__i386__)
+    #endif
+#elif defined(__linux__)
+    /* Linux */
+    #if defined(__i386__)
     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
-#elif defined(__X86_64__) || defined(__x86_64__)
+    #elif defined(__X86_64__) || defined(__x86_64__)
     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
-#elif defined(__ia64__) /* Linux IA64 */
+    #elif defined(__ia64__) /* Linux IA64 */
     return (void*) uc->uc_mcontext.sc_ip;
+    #endif
 #else
     return NULL;
 #endif
@@ -439,8 +445,11 @@ void logStackContent(void **sp) {
 
 void logRegisters(ucontext_t *uc) {
     redisLog(REDIS_WARNING, "--- REGISTERS");
+
+/* OSX */
 #if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
-  #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
+  /* OSX AMD64 */
+    #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
     redisLog(REDIS_WARNING,
     "\n"
     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
@@ -471,7 +480,8 @@ void logRegisters(ucontext_t *uc) {
         uc->uc_mcontext->__ss.__gs
     );
     logStackContent((void**)uc->uc_mcontext->__ss.__rsp);
-  #else
+    #else
+    /* OSX x86 */
     redisLog(REDIS_WARNING,
     "\n"
     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
@@ -496,8 +506,11 @@ void logRegisters(ucontext_t *uc) {
         uc->uc_mcontext->__ss.__gs
     );
     logStackContent((void**)uc->uc_mcontext->__ss.__esp);
-  #endif
-#elif defined(__i386__)
+    #endif
+/* Linux */
+#elif defined(__linux__)
+    /* Linux x86 */
+    #if defined(__i386__)
     redisLog(REDIS_WARNING,
     "\n"
     "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
@@ -522,7 +535,8 @@ void logRegisters(ucontext_t *uc) {
         uc->uc_mcontext.gregs[0]
     );
     logStackContent((void**)uc->uc_mcontext.gregs[7]);
-#elif defined(__X86_64__) || defined(__x86_64__)
+    #elif defined(__X86_64__) || defined(__x86_64__)
+    /* Linux AMD64 */
     redisLog(REDIS_WARNING,
     "\n"
     "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
@@ -551,33 +565,37 @@ void logRegisters(ucontext_t *uc) {
         uc->uc_mcontext.gregs[18]
     );
     logStackContent((void**)uc->uc_mcontext.gregs[15]);
+    #endif
 #else
     redisLog(REDIS_WARNING,
         "  Dumping of registers not supported for this OS/arch");
 #endif
 }
 
-/* Logs the stack trace using the backtrace() call. */
-sds getStackTrace(ucontext_t *uc) {
+/* Logs the stack trace using the backtrace() call. This function is designed
+ * to be called from signal handlers safely. */
+void logStackTrace(ucontext_t *uc) {
     void *trace[100];
-    int i, trace_size = 0;
-    char **messages = NULL;
-    sds st = sdsempty();
+    int trace_size = 0, fd;
+
+    /* Open the log file in append mode. */
+    fd = server.logfile ?
+        open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644) :
+        STDOUT_FILENO;
+    if (fd == -1) return;
 
     /* Generate the stack trace */
     trace_size = backtrace(trace, 100);
 
     /* overwrite sigaction with caller's address */
-    if (getMcontextEip(uc) != NULL) {
+    if (getMcontextEip(uc) != NULL)
         trace[1] = getMcontextEip(uc);
-    }
-    messages = backtrace_symbols(trace, trace_size);
-    for (i=1; i<trace_size; ++i) {
-        st = sdscat(st,messages[i]);
-        st = sdscatlen(st,"\n",1);
-    }
-    zlibc_free(messages);
-    return st;
+
+    /* Write symbols to log file */
+    backtrace_symbols_fd(trace, trace_size, fd);
+
+    /* Cleanup */
+    if (server.logfile) close(fd);
 }
 
 /* Log information about the "current" client, that is, the client that is
@@ -620,7 +638,7 @@ void logCurrentClient(void) {
 
 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
     ucontext_t *uc = (ucontext_t*) secret;
-    sds infostring, clients, st;
+    sds infostring, clients;
     struct sigaction act;
     REDIS_NOTUSED(info);
 
@@ -632,9 +650,8 @@ void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
                         server.assert_file, server.assert_line);
 
     /* Log the stack trace */
-    st = getStackTrace(uc);
-    redisLog(REDIS_WARNING, "--- STACK TRACE\n%s", st);
-    sdsfree(st);
+    redisLog(REDIS_WARNING, "--- STACK TRACE");
+    logStackTrace(uc);
 
     /* Log INFO and CLIENT LIST */
     redisLog(REDIS_WARNING, "--- INFO OUTPUT");
@@ -673,26 +690,47 @@ void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
 }
 #endif /* HAVE_BACKTRACE */
 
+/* ==================== Logging functions for debugging ===================== */
+
+void redisLogHexDump(int level, char *descr, void *value, size_t len) {
+    char buf[65], *b;
+    unsigned char *v = value;
+    char charset[] = "0123456789abcdef";
+
+    redisLog(level,"%s (hexdump):", descr);
+    b = buf;
+    while(len) {
+        b[0] = charset[(*v)>>4];
+        b[1] = charset[(*v)&0xf];
+        b[2] = '\0';
+        b += 2;
+        len--;
+        v++;
+        if (b-buf == 64 || len == 0) {
+            redisLogRaw(level|REDIS_LOG_RAW,buf);
+            b = buf;
+        }
+    }
+    redisLogRaw(level|REDIS_LOG_RAW,"\n");
+}
+
 /* =========================== Software Watchdog ============================ */
 #include <sys/time.h>
 
 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
+#ifdef HAVE_BACKTRACE
     ucontext_t *uc = (ucontext_t*) secret;
+#endif
     REDIS_NOTUSED(info);
     REDIS_NOTUSED(sig);
-    sds st, log;
 
-    log = sdsnew("\n--- WATCHDOG TIMER EXPIRED ---\n");
+    redisLogFromHandler(REDIS_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
 #ifdef HAVE_BACKTRACE
-    st = getStackTrace(uc);
+    logStackTrace(uc);
 #else
-    st = sdsnew("Sorry: no support for backtrace().\n");
+    redisLogFromHandler(REDIS_WARNING,"Sorry: no support for backtrace().");
 #endif
-    log = sdscatsds(log,st);
-    log = sdscat(log,"------\n");
-    redisLogFromHandler(REDIS_WARNING,log);
-    sdsfree(st);
-    sdsfree(log);
+    redisLogFromHandler(REDIS_WARNING,"--------\n");
 }
 
 /* Schedule a SIGALRM delivery after the specified period in milliseconds.
@@ -712,6 +750,8 @@ void watchdogScheduleSignal(int period) {
 
 /* Enable the software watchdong with the specified period in milliseconds. */
 void enableWatchdog(int period) {
+    int min_period;
+
     if (server.watchdog_period == 0) {
         struct sigaction act;
 
@@ -722,7 +762,11 @@ void enableWatchdog(int period) {
         act.sa_sigaction = watchdogSignalHandler;
         sigaction(SIGALRM, &act, NULL);
     }
-    if (period < 200) period = 200; /* We don't accept periods < 200 ms. */
+    /* If the configured period is smaller than twice the timer period, it is
+     * too short for the software watchdog to work reliably. Fix it now
+     * if needed. */
+    min_period = (1000/REDIS_HZ)*2;
+    if (period < min_period) period = min_period;
     watchdogScheduleSignal(period); /* Adjust the current timer. */
     server.watchdog_period = period;
 }