diff --git a/logd/CommandListener.cpp b/logd/CommandListener.cpp
index 489bea6e5..031c74018 100644
--- a/logd/CommandListener.cpp
+++ b/logd/CommandListener.cpp
@@ -25,6 +25,9 @@
 #include <sys/socket.h>
 #include <sys/types.h>
 
+#include <string>
+
+#include <base/stringprintf.h>
 #include <cutils/sockets.h>
 #include <private/android_filesystem_config.h>
 #include <sysutils/SocketClient.h>
@@ -189,22 +192,13 @@ CommandListener::GetStatisticsCmd::GetStatisticsCmd(LogBuffer *buf) :
         mBuf(*buf) {
 }
 
-static void package_string(char **strp) {
-    const char *a = *strp;
-    if (!a) {
-        a = "";
-    }
-
+static std::string package_string(const std::string &str) {
     // Calculate total buffer size prefix, count is the string length w/o nul
     char fmt[32];
-    for(size_t l = strlen(a), y = 0, x = 6; y != x; y = x, x = strlen(fmt) - 2) {
+    for(size_t l = str.length(), y = 0, x = 6; y != x; y = x, x = strlen(fmt) - 2) {
         snprintf(fmt, sizeof(fmt), "%zu\n%%s\n\f", l + x);
     }
-
-    char *b = *strp;
-    *strp = NULL;
-    asprintf(strp, fmt, a);
-    free(b);
+    return android::base::StringPrintf(fmt, str.c_str());
 }
 
 int CommandListener::GetStatisticsCmd::runCommand(SocketClient *cli,
@@ -228,16 +222,7 @@ int CommandListener::GetStatisticsCmd::runCommand(SocketClient *cli,
         }
     }
 
-    char *buf = NULL;
-
-    mBuf.formatStatistics(&buf, uid, logMask);
-    if (!buf) {
-        cli->sendMsg("Failed");
-    } else {
-        package_string(&buf);
-        cli->sendMsg(buf);
-        free(buf);
-    }
+    cli->sendMsg(package_string(mBuf.formatStatistics(uid, logMask)).c_str());
     return 0;
 }
 
@@ -249,15 +234,7 @@ CommandListener::GetPruneListCmd::GetPruneListCmd(LogBuffer *buf) :
 int CommandListener::GetPruneListCmd::runCommand(SocketClient *cli,
                                          int /*argc*/, char ** /*argv*/) {
     setname();
-    char *buf = NULL;
-    mBuf.formatPrune(&buf);
-    if (!buf) {
-        cli->sendMsg("Failed");
-    } else {
-        package_string(&buf);
-        cli->sendMsg(buf);
-        free(buf);
-    }
+    cli->sendMsg(package_string(mBuf.formatPrune()).c_str());
     return 0;
 }
 
@@ -274,20 +251,15 @@ int CommandListener::SetPruneListCmd::runCommand(SocketClient *cli,
         return 0;
     }
 
-    char *cp = NULL;
+    std::string str;
     for (int i = 1; i < argc; ++i) {
-        char *p = cp;
-        if (p) {
-            cp = NULL;
-            asprintf(&cp, "%s %s", p, argv[i]);
-            free(p);
-        } else {
-            asprintf(&cp, "%s", argv[i]);
+        if (str.length()) {
+            str += " ";
         }
+        str += argv[i];
     }
 
-    int ret = mBuf.initPrune(cp);
-    free(cp);
+    int ret = mBuf.initPrune(str.c_str());
 
     if (ret) {
         cli->sendMsg("Invalid");
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index db3f26c72..6ea41097c 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -690,10 +690,12 @@ uint64_t LogBuffer::flushTo(
     return max;
 }
 
-void LogBuffer::formatStatistics(char **strp, uid_t uid, unsigned int logMask) {
+std::string LogBuffer::formatStatistics(uid_t uid, unsigned int logMask) {
     pthread_mutex_lock(&mLogElementsLock);
 
-    stats.format(strp, uid, logMask);
+    std::string ret = stats.format(uid, logMask);
 
     pthread_mutex_unlock(&mLogElementsLock);
+
+    return ret;
 }
diff --git a/logd/LogBuffer.h b/logd/LogBuffer.h
index e94598c82..fcb05f597 100644
--- a/logd/LogBuffer.h
+++ b/logd/LogBuffer.h
@@ -20,6 +20,7 @@
 #include <sys/types.h>
 
 #include <list>
+#include <string>
 
 #include <log/log.h>
 #include <sysutils/SocketClient.h>
@@ -67,15 +68,14 @@ public:
     int setSize(log_id_t id, unsigned long size);
     unsigned long getSizeUsed(log_id_t id);
     // *strp uses malloc, use free to release.
-    void formatStatistics(char **strp, uid_t uid, unsigned int logMask);
+    std::string formatStatistics(uid_t uid, unsigned int logMask);
 
     void enableStatistics() {
         stats.enableStatistics();
     }
 
-    int initPrune(char *cp) { return mPrune.init(cp); }
-    // *strp uses malloc, use free to release.
-    void formatPrune(char **strp) { mPrune.format(strp); }
+    int initPrune(const char *cp) { return mPrune.init(cp); }
+    std::string formatPrune() { return mPrune.format(); }
 
     // helper must be protected directly or implicitly by lock()/unlock()
     char *pidToName(pid_t pid) { return stats.pidToName(pid); }
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index 578dee59d..61fd5596a 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -20,8 +20,6 @@
 #include <string.h>
 #include <unistd.h>
 
-#include <string>
-
 #include <base/stringprintf.h>
 #include <log/logger.h>
 #include <private/android_filesystem_config.h>
@@ -206,14 +204,9 @@ static std::string format_line(
     }
 }
 
-void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) {
+std::string LogStatistics::format(uid_t uid, unsigned int logMask) {
     static const unsigned short spaces_total = 19;
 
-    if (*buf) {
-        free(*buf);
-        *buf = NULL;
-    }
-
     // Report on total logging, current and for all time
 
     std::string output = "size/num";
@@ -514,7 +507,7 @@ void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) {
         }
     }
 
-    *buf = strdup(output.c_str());
+    return output;
 }
 
 namespace android {
diff --git a/logd/LogStatistics.h b/logd/LogStatistics.h
index 760d6b20e..61000d284 100644
--- a/logd/LogStatistics.h
+++ b/logd/LogStatistics.h
@@ -331,8 +331,7 @@ public:
     size_t sizesTotal(log_id_t id) const { return mSizesTotal[id]; }
     size_t elementsTotal(log_id_t id) const { return mElementsTotal[id]; }
 
-    // *strp = malloc, balance with free
-    void format(char **strp, uid_t uid, unsigned int logMask);
+    std::string format(uid_t uid, unsigned int logMask);
 
     // helper (must be locked directly or implicitly by mLogElementsLock)
     char *pidToName(pid_t pid);
diff --git a/logd/LogWhiteBlackList.cpp b/logd/LogWhiteBlackList.cpp
index 0406bf3d0..ad005ec33 100644
--- a/logd/LogWhiteBlackList.cpp
+++ b/logd/LogWhiteBlackList.cpp
@@ -16,8 +16,6 @@
 
 #include <ctype.h>
 
-#include <string>
-
 #include <base/stringprintf.h>
 
 #include "LogWhiteBlackList.h"
@@ -37,18 +35,18 @@ int Prune::cmp(uid_t uid, pid_t pid) const {
     return uid - mUid;
 }
 
-void Prune::format(char **strp) {
+std::string Prune::format() {
     if (mUid != uid_all) {
         if (mPid != pid_all) {
-            asprintf(strp, "%u/%u", mUid, mPid);
-        } else {
-            asprintf(strp, "%u", mUid);
+            return android::base::StringPrintf("%u/%u", mUid, mPid);
         }
-    } else if (mPid != pid_all) {
-        asprintf(strp, "/%u", mPid);
-    } else { // NB: mPid == pid_all can not happen if mUid == uid_all
-        asprintf(strp, "/");
+        return android::base::StringPrintf("%u", mUid);
     }
+    if (mPid != pid_all) {
+        return android::base::StringPrintf("/%u", mPid);
+    }
+    // NB: mPid == pid_all can not happen if mUid == uid_all
+    return std::string("/");
 }
 
 PruneList::PruneList() : mWorstUidEnabled(true) {
@@ -64,7 +62,7 @@ PruneList::~PruneList() {
     }
 }
 
-int PruneList::init(char *str) {
+int PruneList::init(const char *str) {
     mWorstUidEnabled = true;
     PruneCollection::iterator it;
     for (it = mNice.begin(); it != mNice.end();) {
@@ -169,12 +167,7 @@ int PruneList::init(char *str) {
     return 0;
 }
 
-void PruneList::format(char **strp) {
-    if (*strp) {
-        free(*strp);
-        *strp = NULL;
-    }
-
+std::string PruneList::format() {
     static const char nice_format[] = " %s";
     const char *fmt = nice_format + 1;
 
@@ -188,28 +181,18 @@ void PruneList::format(char **strp) {
     PruneCollection::iterator it;
 
     for (it = mNice.begin(); it != mNice.end(); ++it) {
-        char *a = NULL;
-        (*it).format(&a);
-
-        string += android::base::StringPrintf(fmt, a);
+        string += android::base::StringPrintf(fmt, (*it).format().c_str());
         fmt = nice_format;
-
-        free(a);
     }
 
     static const char naughty_format[] = " ~%s";
     fmt = naughty_format + (*fmt != ' ');
     for (it = mNaughty.begin(); it != mNaughty.end(); ++it) {
-        char *a = NULL;
-        (*it).format(&a);
-
-        string += android::base::StringPrintf(fmt, a);
+        string += android::base::StringPrintf(fmt, (*it).format().c_str());
         fmt = naughty_format;
-
-        free(a);
     }
 
-    *strp = strdup(string.c_str());
+    return string;
 }
 
 // ToDo: Lists are in sorted order, Prune->cmp() returns + or -
diff --git a/logd/LogWhiteBlackList.h b/logd/LogWhiteBlackList.h
index 57cd03b98..00e1cad2d 100644
--- a/logd/LogWhiteBlackList.h
+++ b/logd/LogWhiteBlackList.h
@@ -20,6 +20,7 @@
 #include <sys/types.h>
 
 #include <list>
+#include <string.h>
 
 #include <LogBufferElement.h>
 
@@ -43,8 +44,7 @@ public:
 
     int cmp(LogBufferElement *e) const { return cmp(e->getUid(), e->getPid()); }
 
-    // *strp is malloc'd, use free to release
-    void format(char **strp);
+    std::string format();
 };
 
 typedef std::list<Prune> PruneCollection;
@@ -58,7 +58,7 @@ public:
     PruneList();
     ~PruneList();
 
-    int init(char *str);
+    int init(const char *str);
 
     bool naughty(LogBufferElement *element);
     bool naughty(void) { return !mNaughty.empty(); }
@@ -66,8 +66,7 @@ public:
     bool nice(void) { return !mNice.empty(); }
     bool worstUidEnabled() const { return mWorstUidEnabled; }
 
-    // *strp is malloc'd, use free to release
-    void format(char **strp);
+    std::string format();
 };
 
 #endif // _LOGD_LOG_WHITE_BLACK_LIST_H__