diff --git a/adb/adb_trace.cpp b/adb/adb_trace.cpp
index 002d061..c369d60 100644
--- a/adb/adb_trace.cpp
+++ b/adb/adb_trace.cpp
@@ -109,8 +109,8 @@
     }
 
     std::unordered_map<std::string, int> trace_flags = {
-        {"1", 0},
-        {"all", 0},
+        {"1", -1},
+        {"all", -1},
         {"adb", ADB},
         {"sockets", SOCKETS},
         {"packets", PACKETS},
@@ -133,8 +133,8 @@
             continue;
         }
 
-        if (flag->second == 0) {
-            // 0 is used for the special values "1" and "all" that enable all
+        if (flag->second == -1) {
+            // -1 is used for the special values "1" and "all" that enable all
             // tracing.
             adb_trace_mask = ~0;
             return;
diff --git a/libcutils/fs_config.c b/libcutils/fs_config.c
index 032e361..6155d16 100644
--- a/libcutils/fs_config.c
+++ b/libcutils/fs_config.c
@@ -188,6 +188,9 @@
     { 00750, AID_ROOT,      AID_SHELL,     0, "init*" },
     { 00750, AID_ROOT,      AID_SHELL,     0, "sbin/fs_mgr" },
     { 00640, AID_ROOT,      AID_SHELL,     0, "fstab.*" },
+    { 00600, AID_ROOT,      AID_ROOT,      0, "system/build.prop" },
+    { 00600, AID_ROOT,      AID_ROOT,      0, "vendor/build.prop" },
+    { 00600, AID_ROOT,      AID_ROOT,      0, "default.prop" },
     { 00644, AID_ROOT,      AID_ROOT,      0, 0 },
 };
 
diff --git a/logd/LogAudit.cpp b/logd/LogAudit.cpp
index c3ccd84..aa05932 100644
--- a/logd/LogAudit.cpp
+++ b/logd/LogAudit.cpp
@@ -34,6 +34,7 @@
 #include "LogBuffer.h"
 #include "LogKlog.h"
 #include "LogReader.h"
+#include "LogUtils.h"
 
 #define KMSG_PRIORITY(PRI)                          \
     '<',                                            \
@@ -117,7 +118,8 @@
             if (avcl) {
                 char *avcr = strstr(str, avc);
 
-                skip = avcr && !strcmp(avcl + strlen(avc), avcr + strlen(avc));
+                skip = avcr && !fastcmp<strcmp>(avcl + strlen(avc),
+                                                avcr + strlen(avc));
                 if (skip) {
                     ++count;
                     free(last_str);
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index a009433..d476596 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -33,6 +33,7 @@
 #include "LogBuffer.h"
 #include "LogKlog.h"
 #include "LogReader.h"
+#include "LogUtils.h"
 
 #ifndef __predict_false
 #define __predict_false(exp) __builtin_expect((exp) != 0, 0)
@@ -110,9 +111,65 @@
         mTimes(*times) {
     pthread_mutex_init(&mLogElementsLock, NULL);
 
+    log_id_for_each(i) {
+        lastLoggedElements[i] = NULL;
+        droppedElements[i] = NULL;
+    }
+
     init();
 }
 
+LogBuffer::~LogBuffer() {
+    log_id_for_each(i) {
+        delete lastLoggedElements[i];
+        delete droppedElements[i];
+    }
+}
+
+static bool identical(LogBufferElement* elem, LogBufferElement* last) {
+    // is it mostly identical?
+//  if (!elem) return false;
+    unsigned short lenl = elem->getMsgLen();
+    if (!lenl) return false;
+//  if (!last) return false;
+    unsigned short lenr = last->getMsgLen();
+    if (!lenr) return false;
+//  if (elem->getLogId() != last->getLogId()) return false;
+    if (elem->getUid() != last->getUid()) return false;
+    if (elem->getPid() != last->getPid()) return false;
+    if (elem->getTid() != last->getTid()) return false;
+
+    // last is more than a minute old, stop squashing identical messages
+    if (elem->getRealTime().nsec() >
+        (last->getRealTime().nsec() + 60 * NS_PER_SEC)) return false;
+
+    // Identical message
+    const char* msgl = elem->getMsg();
+    const char* msgr = last->getMsg();
+    if ((lenl == lenr) && !fastcmp<memcmp>(msgl, msgr, lenl)) return true;
+
+    // audit message (except sequence number) identical?
+    static const char avc[] = "): avc: ";
+
+    if (last->isBinary()) {
+        if (fastcmp<memcmp>(msgl, msgr,
+                            sizeof(android_log_event_string_t) -
+                                sizeof(int32_t))) return false;
+        msgl += sizeof(android_log_event_string_t);
+        lenl -= sizeof(android_log_event_string_t);
+        msgr += sizeof(android_log_event_string_t);
+        lenr -= sizeof(android_log_event_string_t);
+    }
+    const char *avcl = android::strnstr(msgl, lenl, avc);
+    if (!avcl) return false;
+    lenl -= avcl - msgl;
+    const char *avcr = android::strnstr(msgr, lenr, avc);
+    if (!avcr) return false;
+    lenr -= avcr - msgr;
+    if (lenl != lenr) return false;
+    return !fastcmp<memcmp>(avcl + strlen(avc), avcr + strlen(avc), lenl);
+}
+
 int LogBuffer::log(log_id_t log_id, log_time realtime,
                    uid_t uid, pid_t pid, pid_t tid,
                    const char *msg, unsigned short len) {
@@ -145,14 +202,57 @@
     }
 
     pthread_mutex_lock(&mLogElementsLock);
+    LogBufferElement* currentLast = lastLoggedElements[log_id];
+    if (currentLast) {
+        LogBufferElement *dropped = droppedElements[log_id];
+        unsigned short count = dropped ? dropped->getDropped() : 0;
+        if (identical(elem, currentLast)) {
+            if (dropped) {
+                if (count == USHRT_MAX) {
+                    log(dropped);
+                    count = 1;
+                } else {
+                    delete dropped;
+                    ++count;
+                }
+            }
+            if (count) {
+                stats.add(currentLast);
+                stats.subtract(currentLast);
+                currentLast->setDropped(count);
+            }
+            droppedElements[log_id] = currentLast;
+            lastLoggedElements[log_id] = elem;
+            pthread_mutex_unlock(&mLogElementsLock);
+            return len;
+        }
+        if (dropped) {
+            log(dropped);
+            droppedElements[log_id] = NULL;
+        }
+        if (count) {
+            log(currentLast);
+        } else {
+            delete currentLast;
+        }
+    }
+    lastLoggedElements[log_id] = new LogBufferElement(*elem);
 
+    log(elem);
+    pthread_mutex_unlock(&mLogElementsLock);
+
+    return len;
+}
+
+// assumes mLogElementsLock held, owns elem, will look after garbage collection
+void LogBuffer::log(LogBufferElement* elem) {
     // Insert elements in time sorted order if possible
     //  NB: if end is region locked, place element at end of list
     LogBufferElementCollection::iterator it = mLogElements.end();
     LogBufferElementCollection::iterator last = it;
     while (last != mLogElements.begin()) {
         --it;
-        if ((*it)->getRealTime() <= realtime) {
+        if ((*it)->getRealTime() <= elem->getRealTime()) {
             break;
         }
         last = it;
@@ -169,7 +269,7 @@
 
         LastLogTimes::iterator times = mTimes.begin();
         while(times != mTimes.end()) {
-            LogTimeEntry *entry = (*times);
+            LogTimeEntry* entry = (*times);
             if (entry->owned_Locked()) {
                 if (!entry->mNonBlock) {
                     end_always = true;
@@ -187,17 +287,14 @@
                 || (end_set && (end >= (*last)->getSequence()))) {
             mLogElements.push_back(elem);
         } else {
-            mLogElements.insert(last,elem);
+            mLogElements.insert(last, elem);
         }
 
         LogTimeEntry::unlock();
     }
 
     stats.add(elem);
-    maybePrune(log_id);
-    pthread_mutex_unlock(&mLogElementsLock);
-
-    return len;
+    maybePrune(elem->getLogId());
 }
 
 // Prune at most 10% of the log entries or maxPrune, whichever is less.
diff --git a/logd/LogBuffer.h b/logd/LogBuffer.h
index ff9692e..932d55f 100644
--- a/logd/LogBuffer.h
+++ b/logd/LogBuffer.h
@@ -99,10 +99,15 @@
 
     bool monotonic;
 
+    LogBufferElement* lastLoggedElements[LOG_ID_MAX];
+    LogBufferElement* droppedElements[LOG_ID_MAX];
+    void log(LogBufferElement* elem);
+
 public:
     LastLogTimes &mTimes;
 
     explicit LogBuffer(LastLogTimes *times);
+    ~LogBuffer();
     void init();
     bool isMonotonic() { return monotonic; }
 
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index ec91f2a..5e37a30 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -50,6 +50,19 @@
         0;
 }
 
+LogBufferElement::LogBufferElement(const LogBufferElement &elem) :
+        mTag(elem.mTag),
+        mUid(elem.mUid),
+        mPid(elem.mPid),
+        mTid(elem.mTid),
+        mSequence(elem.mSequence),
+        mRealTime(elem.mRealTime),
+        mMsgLen(elem.mMsgLen),
+        mLogId(elem.mLogId) {
+    mMsg = new char[mMsgLen];
+    memcpy(mMsg, elem.mMsg, mMsgLen);
+}
+
 LogBufferElement::~LogBufferElement() {
     delete [] mMsg;
 }
@@ -157,8 +170,6 @@
                           mDropped, (mDropped > 1) ? "s" : "");
 
     size_t hdrLen;
-    // LOG_ID_SECURITY not strictly needed since spam filter not activated,
-    // but required for accuracy.
     if (isBinary()) {
         hdrLen = sizeof(android_log_event_string_t);
     } else {
diff --git a/logd/LogBufferElement.h b/logd/LogBufferElement.h
index fb7fbed..f8ffacd 100644
--- a/logd/LogBufferElement.h
+++ b/logd/LogBufferElement.h
@@ -59,6 +59,7 @@
     LogBufferElement(log_id_t log_id, log_time realtime,
                      uid_t uid, pid_t pid, pid_t tid,
                      const char *msg, unsigned short len);
+    LogBufferElement(const LogBufferElement &elem);
     virtual ~LogBufferElement();
 
     bool isBinary(void) const {
@@ -79,6 +80,7 @@
         return mDropped = value;
     }
     unsigned short getMsgLen() const { return mMsg ? mMsgLen : 0; }
+    const char* getMsg() const { return mMsg; }
     uint64_t getSequence(void) const { return mSequence; }
     static uint64_t getCurrentSequence(void) { return sequence.load(memory_order_relaxed); }
     log_time getRealTime(void) const { return mRealTime; }
diff --git a/logd/LogKlog.cpp b/logd/LogKlog.cpp
index 0b49fc1..f224079 100644
--- a/logd/LogKlog.cpp
+++ b/logd/LogKlog.cpp
@@ -306,19 +306,15 @@
 static const char resumeStr[] = "PM: suspend exit ";
 static const char suspendedStr[] = "Suspended for ";
 
-static const char *strnstr(const char *s, size_t len, const char *needle) {
+const char* android::strnstr(const char* s, size_t len, const char* needle) {
     char c;
 
-    if (!len) {
-        return NULL;
-    }
+    if (!len) return NULL;
     if ((c = *needle++) != 0) {
         size_t needleLen = strlen(needle);
         do {
             do {
-                if (len <= needleLen) {
-                    return NULL;
-                }
+                if (len <= needleLen) return NULL;
                 --len;
             } while (*s++ != c);
         } while (fastcmp<memcmp>(s, needle, needleLen));
@@ -349,25 +345,25 @@
             return;
         }
 
-        const char *b;
-        if (((b = strnstr(cp, len, suspendStr)))
+        const char* b;
+        if (((b = android::strnstr(cp, len, suspendStr)))
                 && ((size_t)((b += sizeof(suspendStr) - 1) - cp) < len)) {
             len -= b - cp;
             calculateCorrection(now, b, len);
-        } else if (((b = strnstr(cp, len, resumeStr)))
+        } else if (((b = android::strnstr(cp, len, resumeStr)))
                 && ((size_t)((b += sizeof(resumeStr) - 1) - cp) < len)) {
             len -= b - cp;
             calculateCorrection(now, b, len);
-        } else if (((b = strnstr(cp, len, healthd)))
+        } else if (((b = android::strnstr(cp, len, healthd)))
                 && ((size_t)((b += sizeof(healthd) - 1) - cp) < len)
-                && ((b = strnstr(b, len -= b - cp, battery)))
+                && ((b = android::strnstr(b, len -= b - cp, battery)))
                 && ((size_t)((b += sizeof(battery) - 1) - cp) < len)) {
             // NB: healthd is roughly 150us late, so we use it instead to
             //     trigger a check for ntp-induced or hardware clock drift.
             log_time real(CLOCK_REALTIME);
             log_time mono(CLOCK_MONOTONIC);
             correction = (real < mono) ? log_time::EPOCH : (real - mono);
-        } else if (((b = strnstr(cp, len, suspendedStr)))
+        } else if (((b = android::strnstr(cp, len, suspendedStr)))
                 && ((size_t)((b += sizeof(suspendStr) - 1) - cp) < len)) {
             len -= b - cp;
             log_time real;
@@ -466,18 +462,14 @@
 
 // Passed the entire SYSLOG_ACTION_READ_ALL buffer and interpret a
 // compensated start time.
-void LogKlog::synchronize(const char *buf, size_t len) {
-    const char *cp = strnstr(buf, len, suspendStr);
+void LogKlog::synchronize(const char* buf, size_t len) {
+    const char* cp = android::strnstr(buf, len, suspendStr);
     if (!cp) {
-        cp = strnstr(buf, len, resumeStr);
-        if (!cp) {
-            return;
-        }
+        cp = android::strnstr(buf, len, resumeStr);
+        if (!cp) return;
     } else {
-        const char *rp = strnstr(buf, len, resumeStr);
-        if (rp && (rp < cp)) {
-            cp = rp;
-        }
+        const char* rp = android::strnstr(buf, len, resumeStr);
+        if (rp && (rp < cp)) cp = rp;
     }
 
     do {
@@ -491,7 +483,7 @@
     log_time now;
     sniffTime(now, &cp, len - (cp - buf), true);
 
-    const char *suspended = strnstr(buf, len, suspendedStr);
+    const char* suspended = android::strnstr(buf, len, suspendedStr);
     if (!suspended || (suspended > cp)) {
         return;
     }
@@ -581,12 +573,12 @@
 //  logd.klogd:
 // return -1 if message logd.klogd: <signature>
 //
-int LogKlog::log(const char *buf, size_t len) {
-    if (auditd && strnstr(buf, len, " audit(")) {
+int LogKlog::log(const char* buf, size_t len) {
+    if (auditd && android::strnstr(buf, len, " audit(")) {
         return 0;
     }
 
-    const char *p = buf;
+    const char* p = buf;
     int pri = parseKernelPrio(&p, len);
 
     log_time now;
@@ -594,7 +586,7 @@
 
     // sniff for start marker
     const char klogd_message[] = "logd.klogd: ";
-    const char *start = strnstr(p, len - (p - buf), klogd_message);
+    const char* start = android::strnstr(p, len - (p - buf), klogd_message);
     if (start) {
         uint64_t sig = strtoll(start + sizeof(klogd_message) - 1, NULL, 10);
         if (sig == signature.nsec()) {
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index 3c8bd75..ddbb64f 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -71,8 +71,17 @@
     mSizes[log_id] += size;
     ++mElements[log_id];
 
-    mSizesTotal[log_id] += size;
-    ++mElementsTotal[log_id];
+    if (element->getDropped()) {
+        ++mDroppedElements[log_id];
+    } else {
+        // When caller adding a chatty entry, they will have already
+        // called add() and subtract() for each entry as they are
+        // evaluated and trimmed, thus recording size and number of
+        // elements, but we must recognize the manufactured dropped
+        // entry as not contributing to the lifetime totals.
+        mSizesTotal[log_id] += size;
+        ++mElementsTotal[log_id];
+    }
 
     if (log_id == LOG_ID_KERNEL) {
         return;
diff --git a/logd/LogStatistics.h b/logd/LogStatistics.h
index cb7ae2b..8bf655b 100644
--- a/logd/LogStatistics.h
+++ b/logd/LogStatistics.h
@@ -265,7 +265,7 @@
         if (pid != element->getPid()) {
             pid = -1;
         }
-        EntryBase::add(element);
+        EntryBaseDropped::add(element);
     }
 
     std::string formatHeader(const std::string &name, log_id_t id) const;
@@ -419,7 +419,7 @@
         if (pid != element->getPid()) {
             pid = -1;
         }
-        EntryBase::add(element);
+        EntryBaseDropped::add(element);
     }
 
     std::string formatHeader(const std::string &name, log_id_t id) const;
diff --git a/logd/LogUtils.h b/logd/LogUtils.h
index ec68062..d300a2a 100644
--- a/logd/LogUtils.h
+++ b/logd/LogUtils.h
@@ -40,6 +40,9 @@
 // Furnished in main.cpp. Thread safe.
 const char *tagToName(size_t *len, uint32_t tag);
 
+// Furnished by LogKlog.cpp.
+const char* strnstr(const char* s, size_t len, const char* needle);
+
 }
 
 // Furnished in LogCommand.cpp
diff --git a/logd/tests/logd_test.cpp b/logd/tests/logd_test.cpp
index 254a3f8..4e621e3 100644
--- a/logd/tests/logd_test.cpp
+++ b/logd/tests/logd_test.cpp
@@ -778,3 +778,102 @@
 
     close(fd);
 }
+
+static inline int32_t get4LE(const char* src)
+{
+    return src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
+}
+
+void __android_log_btwrite_multiple__helper(int count) {
+    log_time ts(CLOCK_MONOTONIC);
+
+    struct logger_list *logger_list;
+    ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
+        LOG_ID_EVENTS, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 1000, 0)));
+
+    log_time ts1(CLOCK_MONOTONIC);
+
+    pid_t pid = fork();
+
+    if (pid == 0) {
+        // child
+        for (int i = count; i; --i) {
+            ASSERT_LT(0, __android_log_btwrite(0, EVENT_TYPE_LONG, &ts, sizeof(ts)));
+            usleep(100);
+        }
+        ASSERT_LT(0, __android_log_btwrite(0, EVENT_TYPE_LONG, &ts1, sizeof(ts1)));
+        usleep(1000000);
+
+        _exit(0);
+    }
+
+    siginfo_t info{};
+    ASSERT_EQ(0, TEMP_FAILURE_RETRY(waitid(P_PID, pid, &info, WEXITED)));
+
+    int expected_count = (count < 2) ? count : 2;
+    int expected_chatty_count = (count <= 2) ? 0 : 1;
+    int expected_expire_count = (count < 2) ? 0 : (count - 2);
+
+    count = 0;
+    int second_count = 0;
+    int chatty_count = 0;
+    int expire_count = 0;
+
+    for (;;) {
+        log_msg log_msg;
+        if (android_logger_list_read(logger_list, &log_msg) <= 0) break;
+
+        if ((log_msg.entry.pid != pid) ||
+            (log_msg.entry.len < (4 + 1 + 8)) ||
+            (log_msg.id() != LOG_ID_EVENTS)) continue;
+
+        char *eventData = log_msg.msg();
+        if (!eventData) continue;
+
+        uint32_t tag = get4LE(eventData);
+
+        if ((eventData[4] == EVENT_TYPE_LONG) && (log_msg.entry.len == (4 + 1 + 8))) {
+            if (tag != 0) continue;
+
+            log_time tx(eventData + 4 + 1);
+            if (ts == tx) {
+                ++count;
+            } else if (ts1 == tx) {
+                ++second_count;
+            }
+        } else if (eventData[4] == EVENT_TYPE_STRING) {
+            // chatty
+            if (tag != 1004) continue;
+            ++chatty_count;
+            // int len = get4LE(eventData + 4 + 1);
+            const char *cp = strstr(eventData + 4 + 1 + 4, " expire ");
+            if (!cp) continue;
+            unsigned val = 0;
+            sscanf(cp, " expire %u lines", &val);
+            expire_count += val;
+        }
+    }
+
+    EXPECT_EQ(expected_count, count);
+    EXPECT_EQ(1, second_count);
+    EXPECT_EQ(expected_chatty_count, chatty_count);
+    EXPECT_EQ(expected_expire_count, expire_count);
+
+    android_logger_list_close(logger_list);
+}
+
+TEST(logd, multiple_test_1) {
+    __android_log_btwrite_multiple__helper(1);
+}
+
+TEST(logd, multiple_test_2) {
+    __android_log_btwrite_multiple__helper(2);
+}
+
+TEST(logd, multiple_test_3) {
+    __android_log_btwrite_multiple__helper(3);
+}
+
+TEST(logd, multiple_test_10) {
+    __android_log_btwrite_multiple__helper(10);
+}