diff --git a/liblog/include/private/android_logger.h b/liblog/include/private/android_logger.h
index 965de37..b927b46 100644
--- a/liblog/include/private/android_logger.h
+++ b/liblog/include/private/android_logger.h
@@ -173,7 +173,7 @@
 #if defined(_USING_LIBCXX)
   operator std::string() {
     if (ret) return std::string("");
-    const char* cp = NULL;
+    const char* cp = nullptr;
     ssize_t len = android_log_write_list_buffer(ctx, &cp);
     if (len < 0) ret = len;
     if (!cp || (len <= 0)) return std::string("");
diff --git a/logd/CommandListener.cpp b/logd/CommandListener.cpp
index 06c0ab5..7a843d8 100644
--- a/logd/CommandListener.cpp
+++ b/logd/CommandListener.cpp
@@ -288,9 +288,9 @@
         uid = AID_ROOT;
     }
 
-    const char* name = NULL;
-    const char* format = NULL;
-    const char* id = NULL;
+    const char* name = nullptr;
+    const char* format = nullptr;
+    const char* id = nullptr;
     for (int i = 1; i < argc; ++i) {
         static const char _name[] = "name=";
         if (!strncmp(argv[i], _name, strlen(_name))) {
diff --git a/logd/FlushCommand.cpp b/logd/FlushCommand.cpp
index 70ecbe0..658e079 100644
--- a/logd/FlushCommand.cpp
+++ b/logd/FlushCommand.cpp
@@ -36,7 +36,7 @@
 // reference counts are used to ensure that individual
 // LogTimeEntry lifetime is managed when not protected.
 void FlushCommand::runSocketCommand(SocketClient* client) {
-    LogTimeEntry* entry = NULL;
+    LogTimeEntry* entry = nullptr;
     LastLogTimes& times = mReader.logbuf().mTimes;
 
     LogTimeEntry::wrlock();
diff --git a/logd/LogAudit.cpp b/logd/LogAudit.cpp
index 27cd9a8..4ea7877 100644
--- a/logd/LogAudit.cpp
+++ b/logd/LogAudit.cpp
@@ -171,13 +171,13 @@
 }
 
 int LogAudit::logPrint(const char* fmt, ...) {
-    if (fmt == NULL) {
+    if (fmt == nullptr) {
         return -EINVAL;
     }
 
     va_list args;
 
-    char* str = NULL;
+    char* str = nullptr;
     va_start(args, fmt);
     int rc = vasprintf(&str, fmt, args);
     va_end(args);
@@ -228,7 +228,7 @@
         static char* last_str;
         static bool last_info;
 
-        if (last_str != NULL) {
+        if (last_str != nullptr) {
             static const char avc[] = "): avc: ";
             char* avcl = strstr(last_str, avc);
             bool skip = false;
@@ -265,10 +265,10 @@
 
                 writev(fdDmesg, iov, arraysize(iov));
                 free(last_str);
-                last_str = NULL;
+                last_str = nullptr;
             }
         }
-        if (last_str == NULL) {
+        if (last_str == nullptr) {
             count = 0;
             last_str = strdup(str);
             last_info = info;
@@ -357,7 +357,7 @@
     static const char comm_str[] = " comm=\"";
     const char* comm = strstr(str, comm_str);
     const char* estr = str + strlen(str);
-    const char* commfree = NULL;
+    const char* commfree = nullptr;
     if (comm) {
         estr = comm;
         comm += sizeof(comm_str) - 1;
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index f20ac45..2d627b9 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -91,7 +91,7 @@
 
 // caller must own and free character string
 char* android::tidToName(pid_t tid) {
-    char* retval = NULL;
+    char* retval = nullptr;
     char buffer[256];
     snprintf(buffer, sizeof(buffer), "/proc/%u/comm", tid);
     int fd = open(buffer, O_RDONLY);
@@ -114,7 +114,7 @@
     char* name = android::pidToName(tid);
     if (!retval) {
         retval = name;
-        name = NULL;
+        name = nullptr;
     }
 
     // check if comm is truncated, see if cmdline has full representation
@@ -162,15 +162,15 @@
         if (!strncmp(name + 1, commName + 1, len)) {
             if (commName[len + 1] == '\0') {
                 free(const_cast<char*>(commName));
-                commName = NULL;
+                commName = nullptr;
             } else {
                 free(const_cast<char*>(name));
-                name = NULL;
+                name = nullptr;
             }
         }
     }
     if (name) {
-        char* buf = NULL;
+        char* buf = nullptr;
         asprintf(&buf, "(%s)", name);
         if (buf) {
             free(const_cast<char*>(name));
@@ -178,7 +178,7 @@
         }
     }
     if (commName) {
-        char* buf = NULL;
+        char* buf = nullptr;
         asprintf(&buf, " %s", commName);
         if (buf) {
             free(const_cast<char*>(commName));
@@ -187,7 +187,7 @@
     }
     // identical to below to calculate the buffer size required
     const char* type = lastSame ? "identical" : "expire";
-    size_t len = snprintf(NULL, 0, format_uid, mUid, name ? name : "",
+    size_t len = snprintf(nullptr, 0, format_uid, mUid, name ? name : "",
                           commName ? commName : "", type, getDropped(),
                           (getDropped() > 1) ? "s" : "");
 
@@ -247,7 +247,7 @@
     iovec[0].iov_base = &entry;
     iovec[0].iov_len = entry.hdr_size;
 
-    char* buffer = NULL;
+    char* buffer = nullptr;
 
     if (mDropped) {
         entry.len = populateDroppedMessage(buffer, parent, lastSame);
diff --git a/logd/LogCommand.cpp b/logd/LogCommand.cpp
index 6d7c0a5..8bff9da 100644
--- a/logd/LogCommand.cpp
+++ b/logd/LogCommand.cpp
@@ -44,9 +44,9 @@
     char* ptr;
     static const char ws[] = " \n";
 
-    for (buf = strtok_r(buf, ws, &ptr); buf; buf = strtok_r(NULL, ws, &ptr)) {
+    for (buf = strtok_r(buf, ws, &ptr); buf; buf = strtok_r(nullptr, ws, &ptr)) {
         errno = 0;
-        gid_t Gid = strtol(buf, NULL, 10);
+        gid_t Gid = strtol(buf, nullptr, 10);
         if (errno != 0) {
             return false;
         }
@@ -98,7 +98,7 @@
             continue;
         }
 
-        char* line = NULL;
+        char* line = nullptr;
         size_t len = 0;
         while (getline(&line, &len, file) > 0) {
             static const char groups_string[] = "Groups:\t";
diff --git a/logd/LogListener.cpp b/logd/LogListener.cpp
index fc51dcf..e568ddc 100644
--- a/logd/LogListener.cpp
+++ b/logd/LogListener.cpp
@@ -50,7 +50,7 @@
 
     alignas(4) char control[CMSG_SPACE(sizeof(struct ucred))];
     struct msghdr hdr = {
-        NULL, 0, &iov, 1, control, sizeof(control), 0,
+        nullptr, 0, &iov, 1, control, sizeof(control), 0,
     };
 
     int socket = cli->getSocket();
@@ -66,10 +66,10 @@
 
     buffer[n] = 0;
 
-    struct ucred* cred = NULL;
+    struct ucred* cred = nullptr;
 
     struct cmsghdr* cmsg = CMSG_FIRSTHDR(&hdr);
-    while (cmsg != NULL) {
+    while (cmsg != nullptr) {
         if (cmsg->cmsg_level == SOL_SOCKET &&
             cmsg->cmsg_type == SCM_CREDENTIALS) {
             cred = (struct ucred*)CMSG_DATA(cmsg);
@@ -79,7 +79,7 @@
     }
 
     struct ucred fake_cred;
-    if (cred == NULL) {
+    if (cred == nullptr) {
         cred = &fake_cred;
         cred->pid = 0;
         cred->uid = DEFAULT_OVERFLOWUID;
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index af59ddc..cefacf7 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -56,7 +56,7 @@
 
 // caller must own and free character string
 char* pidToName(pid_t pid) {
-    char* retval = NULL;
+    char* retval = nullptr;
     if (pid == 0) {  // special case from auditd/klogd for kernel
         retval = strdup("logd");
     } else {
@@ -286,7 +286,7 @@
                     name = strdup(nameTmp);
                 } else if (fastcmp<strcmp>(name, nameTmp)) {
                     free(const_cast<char*>(name));
-                    name = NULL;
+                    name = nullptr;
                     break;
                 }
             }
@@ -872,7 +872,7 @@
     pidTable_t& writablePidTable = const_cast<pidTable_t&>(pidTable);
     const char* name = writablePidTable.add(pid)->second.getName();
     if (!name) {
-        return NULL;
+        return nullptr;
     }
     return strdup(name);
 }
diff --git a/logd/LogTags.cpp b/logd/LogTags.cpp
index ff7e762..1ab9dd1 100644
--- a/logd/LogTags.cpp
+++ b/logd/LogTags.cpp
@@ -91,7 +91,7 @@
         fd = TEMP_FAILURE_RETRY(open(
             filename, O_WRONLY | O_TRUNC | O_CLOEXEC | O_NOFOLLOW | O_BINARY));
         if (fd >= 0) {
-            time_t now = time(NULL);
+            time_t now = time(nullptr);
             struct tm tm;
             localtime_r(&now, &tm);
             char timebuf[20];
@@ -208,7 +208,7 @@
             } else if (lineStart) {
                 if (*cp == '#') {
                     /* comment; just scan to end */
-                    lineStart = NULL;
+                    lineStart = nullptr;
                 } else if (isdigit(*cp)) {
                     unsigned long Tag = strtoul(cp, &cp, 10);
                     if (warn && (Tag > emptyTag)) {
@@ -235,7 +235,7 @@
                     if (hasAlpha &&
                         ((cp >= endp) || (*cp == '#') || isspace(*cp))) {
                         if (Tag > emptyTag) {
-                            if (*cp != '\n') lineStart = NULL;
+                            if (*cp != '\n') lineStart = nullptr;
                             continue;
                         }
                         while ((cp < endp) && (*cp != '\n') && isspace(*cp))
@@ -245,14 +245,14 @@
                         while ((cp < endp) && (*cp != '\n')) {
                             if (*cp == '#') {
                                 uid = sniffUid(cp, endp);
-                                lineStart = NULL;
+                                lineStart = nullptr;
                                 break;
                             }
                             ++cp;
                         }
                         while ((cp > format) && isspace(cp[-1])) {
                             --cp;
-                            lineStart = NULL;
+                            lineStart = nullptr;
                         }
                         std::string Format(format, cp - format);
 
@@ -263,7 +263,7 @@
                             android::prdebug("tag name invalid %.*s",
                                              (int)(cp - name + 1), name);
                         }
-                        lineStart = NULL;
+                        lineStart = nullptr;
                     }
                 } else if (!isspace(*cp)) {
                     break;
@@ -364,7 +364,7 @@
     android::RWLock::AutoRLock readLock(const_cast<android::RWLock&>(rwlock));
 
     it = tag2name.find(tag);
-    if ((it == tag2name.end()) || (it->second.length() == 0)) return NULL;
+    if ((it == tag2name.end()) || (it->second.length() == 0)) return nullptr;
 
     return it->second.c_str();
 }
@@ -383,7 +383,7 @@
 const char* android::tagToName(uint32_t tag) {
     LogTags* me = logtags;
 
-    if (!me) return NULL;
+    if (!me) return nullptr;
     me->WritePmsgEventLogTags(tag);
     return me->tagToName(tag);
 }
@@ -412,7 +412,7 @@
     android::RWLock::AutoRLock readLock(const_cast<android::RWLock&>(rwlock));
 
     iform = tag2format.find(tag);
-    if (iform == tag2format.end()) return NULL;
+    if (iform == tag2format.end()) return nullptr;
 
     return iform->second.c_str();
 }
@@ -441,7 +441,7 @@
                                    bool& unique) {
     key2tag_const_iterator ik;
 
-    bool write = format != NULL;
+    bool write = format != nullptr;
     unique = write;
 
     if (!write) {
@@ -679,7 +679,7 @@
 // are in readonly mode.
 uint32_t LogTags::nameToTag(uid_t uid, const char* name, const char* format) {
     std::string Name = std::string(name);
-    bool write = format != NULL;
+    bool write = format != nullptr;
     bool updateUid = uid != AID_ROOT;
     bool updateFormat = format && *format;
     bool unique;
@@ -848,7 +848,7 @@
 
     if (!list) {
         // switch to read entry only if format == "*"
-        if (format && (format[0] == '*') && !format[1]) format = NULL;
+        if (format && (format[0] == '*') && !format[1]) format = nullptr;
 
         // WAI: for null format, only works for a single entry, we can have
         // multiple entries, one for each format, so we find first entry
diff --git a/logd/LogTags.h b/logd/LogTags.h
index 203318d..e4d165a 100644
--- a/logd/LogTags.h
+++ b/logd/LogTags.h
@@ -87,14 +87,14 @@
     bool RebuildFileEventLogTags(const char* filename, bool warn = true);
 
     void AddEventLogTags(uint32_t tag, uid_t uid, const std::string& Name,
-                         const std::string& Format, const char* source = NULL,
+                         const std::string& Format, const char* source = nullptr,
                          bool warn = false);
 
     void WriteDynamicEventLogTags(uint32_t tag, uid_t uid);
     void WriteDebugEventLogTags(uint32_t tag, uid_t uid);
     // push tag details to persistent storage
     void WritePersistEventLogTags(uint32_t tag, uid_t uid = AID_ROOT,
-                                  const char* source = NULL);
+                                  const char* source = nullptr);
 
     static const uint32_t emptyTag = uint32_t(-1);
 
diff --git a/logd/LogWhiteBlackList.cpp b/logd/LogWhiteBlackList.cpp
index 4b8b080..9d762dc 100644
--- a/logd/LogWhiteBlackList.cpp
+++ b/logd/LogWhiteBlackList.cpp
@@ -51,7 +51,7 @@
 }
 
 PruneList::PruneList() {
-    init(NULL);
+    init(nullptr);
 }
 
 PruneList::~PruneList() {
@@ -79,7 +79,7 @@
     // default here means take ro.logd.filter, persist.logd.filter then
     // internal default in that order.
     if (str && !strcmp(str, _default)) {
-        str = NULL;
+        str = nullptr;
     }
     static const char _disable[] = "disable";
     if (str && !strcmp(str, _disable)) {