diff --git a/libc/bionic/assert.cpp b/libc/bionic/assert.cpp
index 7c0a860..e38c16d 100644
--- a/libc/bionic/assert.cpp
+++ b/libc/bionic/assert.cpp
@@ -32,6 +32,7 @@
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <private/debug_format.h>
 #include <private/logd.h>
 
 // We log to stderr for the benefit of "adb shell" users, and the log for the benefit
@@ -39,7 +40,7 @@
 
 void __assert(const char* file, int line, const char* failed_expression) {
   const char* fmt = "%s:%d: assertion \"%s\" failed\n";
-  __libc_android_log_print(ANDROID_LOG_FATAL, "libc", fmt, file, line, failed_expression);
+  __libc_format_log(ANDROID_LOG_FATAL, "libc", fmt, file, line, failed_expression);
   fprintf(stderr, fmt, file, line, failed_expression);
   abort();
   /* NOTREACHED */
@@ -47,7 +48,7 @@
 
 void __assert2(const char* file, int line, const char* function, const char* failed_expression) {
   const char* fmt = "%s:%d: %s: assertion \"%s\" failed\n";
-  __libc_android_log_print(ANDROID_LOG_FATAL, "libc", fmt, file, line, function, failed_expression);
+  __libc_format_log(ANDROID_LOG_FATAL, "libc", fmt, file, line, function, failed_expression);
   fprintf(stderr, fmt, file, line, function, failed_expression);
   abort();
   /* NOTREACHED */
diff --git a/libc/bionic/debug_format.cpp b/libc/bionic/debug_format.cpp
new file mode 100644
index 0000000..e8d6a45
--- /dev/null
+++ b/libc/bionic/debug_format.cpp
@@ -0,0 +1,634 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+// Temporarily disable _FORTIFY_SOURCE to get this code to
+// compile under GCC 4.7
+#undef _FORTIFY_SOURCE
+
+#include "debug_format.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+/* define UNIT_TESTS to build this file as a single executable that runs
+ * the formatter's unit tests
+ */
+#define xxUNIT_TESTS
+
+/*** Generic output sink
+ ***/
+
+struct Out {
+  void *opaque;
+  void (*send)(void *opaque, const char *data, int len);
+};
+
+static void out_send(Out *o, const char *data, size_t len) {
+    o->send(o->opaque, data, (int)len);
+}
+
+static void
+out_send_repeat(Out *o, char ch, int count)
+{
+    char pad[8];
+    const int padSize = (int)sizeof(pad);
+
+    memset(pad, ch, sizeof(pad));
+    while (count > 0) {
+        int avail = count;
+        if (avail > padSize) {
+            avail = padSize;
+        }
+        o->send(o->opaque, pad, avail);
+        count -= avail;
+    }
+}
+
+/* forward declaration */
+static void out_vformat(Out* o, const char* format, va_list args);
+
+/*** Bounded buffer output
+ ***/
+
+struct BufOut {
+  Out out[1];
+  char *buffer;
+  char *pos;
+  char *end;
+  int total;
+};
+
+static void buf_out_send(void *opaque, const char *data, int len) {
+    BufOut *bo = reinterpret_cast<BufOut*>(opaque);
+
+    if (len < 0) {
+        len = strlen(data);
+    }
+
+    bo->total += len;
+
+    while (len > 0) {
+        int avail = bo->end - bo->pos;
+        if (avail == 0)
+            break;
+        if (avail > len)
+            avail = len;
+        memcpy(bo->pos, data, avail);
+        bo->pos += avail;
+        bo->pos[0] = '\0';
+        len -= avail;
+    }
+}
+
+static Out*
+buf_out_init(BufOut *bo, char *buffer, size_t size)
+{
+    if (size == 0)
+        return NULL;
+
+    bo->out->opaque = bo;
+    bo->out->send   = buf_out_send;
+    bo->buffer      = buffer;
+    bo->end         = buffer + size - 1;
+    bo->pos         = bo->buffer;
+    bo->pos[0]      = '\0';
+    bo->total       = 0;
+
+    return bo->out;
+}
+
+static int
+buf_out_length(BufOut *bo)
+{
+    return bo->total;
+}
+
+static int
+vformat_buffer(char *buff, size_t buffsize, const char *format, va_list args)
+{
+    BufOut bo;
+    Out *out;
+
+    out = buf_out_init(&bo, buff, buffsize);
+    if (out == NULL)
+        return 0;
+
+    out_vformat(out, format, args);
+
+    return buf_out_length(&bo);
+}
+
+int __libc_format_buffer(char* buffer, size_t buffer_size, const char* format, ...) {
+  va_list args;
+  va_start(args, format);
+  int result = vformat_buffer(buffer, buffer_size, format, args);
+  va_end(args);
+  return result;
+}
+
+
+/*** File descriptor output
+ ***/
+
+struct FdOut {
+  Out out[1];
+  int fd;
+  int total;
+};
+
+static void
+fd_out_send(void *opaque, const char *data, int len)
+{
+    FdOut *fdo = reinterpret_cast<FdOut*>(opaque);
+
+    if (len < 0)
+        len = strlen(data);
+
+    while (len > 0) {
+        int ret = write(fdo->fd, data, len);
+        if (ret < 0) {
+            if (errno == EINTR)
+                continue;
+            break;
+        }
+        data += ret;
+        len -= ret;
+        fdo->total += ret;
+    }
+}
+
+static Out*
+fd_out_init(FdOut *fdo, int  fd)
+{
+    fdo->out->opaque = fdo;
+    fdo->out->send = fd_out_send;
+    fdo->fd = fd;
+    fdo->total = 0;
+
+    return fdo->out;
+}
+
+static int
+fd_out_length(FdOut *fdo)
+{
+    return fdo->total;
+}
+
+
+int __libc_format_fd(int fd, const char* format, ...) {
+  FdOut fdo;
+  Out* out = fd_out_init(&fdo, fd);
+  if (out == NULL) {
+    return 0;
+  }
+
+  va_list args;
+  va_start(args, format);
+  out_vformat(out, format, args);
+  va_end(args);
+
+  return fd_out_length(&fdo);
+}
+
+/*** Log output
+ ***/
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/uio.h>
+
+int __libc_format_log_va_list(int priority, const char* tag, const char* fmt, va_list args) {
+  char buf[1024];
+  int result = vformat_buffer(buf, sizeof buf, fmt, args);
+
+  static int log_fd = -1;
+  if (log_fd == -1) {
+    log_fd = open("/dev/log/main", O_WRONLY);
+    if (log_fd == -1) {
+      return result;
+    }
+  }
+
+  struct iovec vec[3];
+  vec[0].iov_base = (unsigned char *) &priority;
+  vec[0].iov_len = 1;
+  vec[1].iov_base = (void *) tag;
+  vec[1].iov_len = strlen(tag) + 1;
+  vec[2].iov_base = (void *) buf;
+  vec[2].iov_len = strlen(buf) + 1;
+
+  TEMP_FAILURE_RETRY(writev(log_fd, vec, 3));
+
+  return result;
+}
+
+int __libc_format_log(int priority, const char* tag, const char* format, ...) {
+  va_list args;
+  va_start(args, format);
+  int result = __libc_format_log_va_list(priority, tag, format, args);
+  va_end(args);
+  return result;
+}
+
+/*** formatted output implementation
+ ***/
+
+/* Parse a decimal string from 'format + *ppos',
+ * return the value, and writes the new position past
+ * the decimal string in '*ppos' on exit.
+ *
+ * NOTE: Does *not* handle a sign prefix.
+ */
+static unsigned
+parse_decimal(const char *format, int *ppos)
+{
+    const char* p = format + *ppos;
+    unsigned result = 0;
+
+    for (;;) {
+        int ch = *p;
+        unsigned d = (unsigned)(ch - '0');
+
+        if (d >= 10U)
+            break;
+
+        result = result*10 + d;
+        p++;
+    }
+    *ppos = p - format;
+    return result;
+}
+
+// Writes number 'value' in base 'base' into buffer 'buf' of size 'buf_size' bytes.
+// Assumes that buf_size > 0.
+static void format_number(char* buf, size_t buf_size, uint64_t value, int base, bool caps) {
+  char* p = buf;
+  char* end = buf + buf_size - 1;
+
+  // Generate digit string in reverse order.
+  while (value) {
+    unsigned d = value % base;
+    value /= base;
+    if (p != end) {
+      char ch;
+      if (d < 10) {
+        ch = '0' + d;
+      } else {
+        ch = (caps ? 'A' : 'a') + (d - 10);
+      }
+      *p++ = ch;
+    }
+  }
+
+  // Special case for 0.
+  if (p == buf) {
+    if (p != end) {
+      *p++ = '0';
+    }
+  }
+  *p = '\0';
+
+  // Reverse digit string in-place.
+  size_t length = p - buf;
+  for (size_t i = 0, j = length - 1; i < j; ++i, --j) {
+    char ch = buf[i];
+    buf[i] = buf[j];
+    buf[j] = ch;
+  }
+}
+
+/* Write an integer (octal or decimal) into a buffer, assumes buffsize > 2 */
+static void
+format_integer(char *buffer, size_t buffsize, uint64_t value, int base, int isSigned)
+{
+    // TODO: this is incorrect for MIN_INT.
+    if (isSigned && (int64_t)value < 0) {
+        buffer[0] = '-';
+        buffer += 1;
+        buffsize -= 1;
+        value = (uint64_t)(-(int64_t)value);
+    }
+
+    format_number(buffer, buffsize, value, base, false);
+}
+
+// Assumes buf_size > 2.
+static void format_hex(char* buf, size_t buf_size, uint64_t value, bool caps) {
+  format_number(buf, buf_size, value, 16, caps);
+}
+
+
+/* Perform formatted output to an output target 'o' */
+static void
+out_vformat(Out *o, const char *format, va_list args)
+{
+    int nn = 0;
+
+    for (;;) {
+        int mm;
+        int padZero = 0;
+        int padLeft = 0;
+        char sign = '\0';
+        int width = -1;
+        int prec  = -1;
+        size_t bytelen = sizeof(int);
+        const char*  str;
+        int slen;
+        char buffer[32];  /* temporary buffer used to format numbers */
+
+        char  c;
+
+        /* first, find all characters that are not 0 or '%' */
+        /* then send them to the output directly */
+        mm = nn;
+        do {
+            c = format[mm];
+            if (c == '\0' || c == '%')
+                break;
+            mm++;
+        } while (1);
+
+        if (mm > nn) {
+            out_send(o, format+nn, mm-nn);
+            nn = mm;
+        }
+
+        /* is this it ? then exit */
+        if (c == '\0')
+            break;
+
+        /* nope, we are at a '%' modifier */
+        nn++;  // skip it
+
+        /* parse flags */
+        for (;;) {
+            c = format[nn++];
+            if (c == '\0') {  /* single trailing '%' ? */
+                c = '%';
+                out_send(o, &c, 1);
+                return;
+            }
+            else if (c == '0') {
+                padZero = 1;
+                continue;
+            }
+            else if (c == '-') {
+                padLeft = 1;
+                continue;
+            }
+            else if (c == ' ' || c == '+') {
+                sign = c;
+                continue;
+            }
+            break;
+        }
+
+        /* parse field width */
+        if ((c >= '0' && c <= '9')) {
+            nn --;
+            width = (int)parse_decimal(format, &nn);
+            c = format[nn++];
+        }
+
+        /* parse precision */
+        if (c == '.') {
+            prec = (int)parse_decimal(format, &nn);
+            c = format[nn++];
+        }
+
+        /* length modifier */
+        switch (c) {
+        case 'h':
+            bytelen = sizeof(short);
+            if (format[nn] == 'h') {
+                bytelen = sizeof(char);
+                nn += 1;
+            }
+            c = format[nn++];
+            break;
+        case 'l':
+            bytelen = sizeof(long);
+            if (format[nn] == 'l') {
+                bytelen = sizeof(long long);
+                nn += 1;
+            }
+            c = format[nn++];
+            break;
+        case 'z':
+            bytelen = sizeof(size_t);
+            c = format[nn++];
+            break;
+        case 't':
+            bytelen = sizeof(ptrdiff_t);
+            c = format[nn++];
+            break;
+        default:
+            ;
+        }
+
+        /* conversion specifier */
+        if (c == 's') {
+            /* string */
+            str = va_arg(args, const char*);
+        } else if (c == 'c') {
+            /* character */
+            /* NOTE: char is promoted to int when passed through the stack */
+            buffer[0] = (char) va_arg(args, int);
+            buffer[1] = '\0';
+            str = buffer;
+        } else if (c == 'p') {
+            uint64_t  value = (uintptr_t) va_arg(args, void*);
+            buffer[0] = '0';
+            buffer[1] = 'x';
+            format_hex(buffer + 2, sizeof buffer-2, value, false);
+            str = buffer;
+        } else {
+            /* integers - first read value from stack */
+            uint64_t value;
+            int isSigned = (c == 'd' || c == 'i' || c == 'o');
+
+            /* NOTE: int8_t and int16_t are promoted to int when passed
+             *       through the stack
+             */
+            switch (bytelen) {
+            case 1: value = (uint8_t)  va_arg(args, int); break;
+            case 2: value = (uint16_t) va_arg(args, int); break;
+            case 4: value = va_arg(args, uint32_t); break;
+            case 8: value = va_arg(args, uint64_t); break;
+            default: return;  /* should not happen */
+            }
+
+            /* sign extension, if needed */
+            if (isSigned) {
+                int shift = 64 - 8*bytelen;
+                value = (uint64_t)(((int64_t)(value << shift)) >> shift);
+            }
+
+            /* format the number properly into our buffer */
+            switch (c) {
+            case 'i': case 'd':
+                format_integer(buffer, sizeof buffer, value, 10, isSigned);
+                break;
+            case 'o':
+                format_integer(buffer, sizeof buffer, value, 8, isSigned);
+                break;
+            case 'x': case 'X':
+                format_hex(buffer, sizeof buffer, value, (c == 'X'));
+                break;
+            default:
+                buffer[0] = '\0';
+            }
+            /* then point to it */
+            str = buffer;
+        }
+
+        /* if we are here, 'str' points to the content that must be
+         * outputted. handle padding and alignment now */
+
+        slen = strlen(str);
+
+        if (sign != '\0' || prec != -1) {
+            __assert(__FILE__, __LINE__, "sign/precision unsupported");
+        }
+
+        if (slen < width && !padLeft) {
+            char padChar = padZero ? '0' : ' ';
+            out_send_repeat(o, padChar, width - slen);
+        }
+
+        out_send(o, str, slen);
+
+        if (slen < width && padLeft) {
+            char padChar = padZero ? '0' : ' ';
+            out_send_repeat(o, padChar, width - slen);
+        }
+    }
+}
+
+
+#ifdef UNIT_TESTS
+
+#include <stdio.h>
+
+static int   gFails = 0;
+
+#define  MARGIN  40
+
+#define  UTEST_CHECK(condition,message) \
+    printf("Checking %-*s: ", MARGIN, message); fflush(stdout); \
+    if (!(condition)) { \
+        printf("KO\n"); \
+        gFails += 1; \
+    } else { \
+        printf("ok\n"); \
+    }
+
+static void
+utest_BufOut(void)
+{
+    char buffer[16];
+    BufOut bo[1];
+    Out* out;
+    int ret;
+
+    buffer[0] = '1';
+    out = buf_out_init(bo, buffer, sizeof buffer);
+    UTEST_CHECK(buffer[0] == '\0', "buf_out_init clears initial byte");
+    out_send(out, "abc", 3);
+    UTEST_CHECK(!memcmp(buffer, "abc", 4), "out_send() works with BufOut");
+    out_send_repeat(out, 'X', 4);
+    UTEST_CHECK(!memcmp(buffer, "abcXXXX", 8), "out_send_repeat() works with BufOut");
+    buffer[sizeof buffer-1] = 'x';
+    out_send_repeat(out, 'Y', 2*sizeof(buffer));
+    UTEST_CHECK(buffer[sizeof buffer-1] == '\0', "overflows always zero-terminates");
+
+    out = buf_out_init(bo, buffer, sizeof buffer);
+    out_send_repeat(out, 'X', 2*sizeof(buffer));
+    ret = buf_out_length(bo);
+    UTEST_CHECK(ret == 2*sizeof(buffer), "correct size returned on overflow");
+}
+
+static void
+utest_expect(const char*  result, const char*  format, ...)
+{
+    va_list args;
+    BufOut bo[1];
+    char buffer[256];
+    Out* out = buf_out_init(bo, buffer, sizeof buffer);
+
+    printf("Checking %-*s: ", MARGIN, format); fflush(stdout);
+    va_start(args, format);
+    out_vformat(out, format, args);
+    va_end(args);
+
+    if (strcmp(result, buffer)) {
+        printf("KO. got '%s' expecting '%s'\n", buffer, result);
+        gFails += 1;
+    } else {
+        printf("ok. got '%s'\n", result);
+    }
+}
+
+int  main(void)
+{
+    utest_BufOut();
+    utest_expect("", "");
+    utest_expect("a", "a");
+    utest_expect("01234", "01234", "");
+    utest_expect("01234", "%s", "01234");
+    utest_expect("aabbcc", "aa%scc", "bb");
+    utest_expect("a", "%c", 'a');
+    utest_expect("1234", "%d", 1234);
+    utest_expect("-8123", "%d", -8123);
+    utest_expect("16", "%hd", 0x7fff0010);
+    utest_expect("16", "%hhd", 0x7fffff10);
+    utest_expect("68719476736", "%lld", 0x1000000000LL);
+    utest_expect("70000", "%ld", 70000);
+    utest_expect("0xb0001234", "%p", (void*)0xb0001234);
+    utest_expect("12ab", "%x", 0x12ab);
+    utest_expect("12AB", "%X", 0x12ab);
+    utest_expect("00123456", "%08x", 0x123456);
+    utest_expect("01234", "0%d", 1234);
+    utest_expect(" 1234", "%5d", 1234);
+    utest_expect("01234", "%05d", 1234);
+    utest_expect("    1234", "%8d", 1234);
+    utest_expect("1234    ", "%-8d", 1234);
+    utest_expect("abcdef     ", "%-11s", "abcdef");
+    utest_expect("something:1234", "%s:%d", "something", 1234);
+    utest_expect("005:5:05", "%03d:%d:%02d", 5, 5, 5);
+    utest_expect("5,0x0", "%d,%p", 5, NULL);
+    utest_expect("68719476736,6,7,8", "%lld,%d,%d,%d", 0x1000000000LL, 6, 7, 8);
+    return gFails != 0;
+}
+
+#endif /* UNIT_TESTS */
diff --git a/libc/bionic/debug_mapinfo.cpp b/libc/bionic/debug_mapinfo.cpp
new file mode 100644
index 0000000..174cc28
--- /dev/null
+++ b/libc/bionic/debug_mapinfo.cpp
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "dlmalloc.h"
+#include "debug_mapinfo.h"
+
+// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419   /system/lib/libcomposer.so
+// 012345678901234567890123456789012345678901234567890123456789
+// 0         1         2         3         4         5
+
+static mapinfo_t* parse_maps_line(char* line) {
+  int len = strlen(line);
+
+  if (len < 1) return 0;
+  line[--len] = 0;
+
+  if (len < 50) return 0;
+  if (line[20] != 'x') return 0;
+
+  mapinfo_t* mi = static_cast<mapinfo_t*>(dlmalloc(sizeof(mapinfo_t) + (len - 47)));
+  if (mi == 0) return 0;
+
+  mi->start = strtoul(line, 0, 16);
+  mi->end = strtoul(line + 9, 0, 16);
+  mi->next = 0;
+  strcpy(mi->name, line + 49);
+
+  return mi;
+}
+
+__LIBC_HIDDEN__ mapinfo_t* mapinfo_create(int pid) {
+  struct mapinfo_t* milist = NULL;
+  char data[1024]; // Used to read lines as well as to construct the filename.
+  snprintf(data, sizeof(data), "/proc/%d/maps", pid);
+  FILE* fp = fopen(data, "r");
+  if (fp != NULL) {
+    while (fgets(data, sizeof(data), fp) != NULL) {
+      mapinfo_t* mi = parse_maps_line(data);
+      if (mi) {
+        mi->next = milist;
+        milist = mi;
+      }
+    }
+    fclose(fp);
+  }
+  return milist;
+}
+
+__LIBC_HIDDEN__ void mapinfo_destroy(mapinfo_t* mi) {
+  while (mi) {
+    mapinfo_t* del = mi;
+    mi = mi->next;
+    dlfree(del);
+  }
+}
+
+// Find the containing map info for the PC.
+__LIBC_HIDDEN__ const mapinfo_t* mapinfo_find(mapinfo_t* mi, unsigned pc, unsigned* rel_pc) {
+  *rel_pc = pc;
+  for (; mi != NULL; mi = mi->next) {
+    if ((pc >= mi->start) && (pc < mi->end)) {
+      *rel_pc -= mi->start;
+      return mi;
+    }
+  }
+  return NULL;
+}
diff --git a/libc/bionic/malloc_debug_check_mapinfo.h b/libc/bionic/debug_mapinfo.h
similarity index 77%
rename from libc/bionic/malloc_debug_check_mapinfo.h
rename to libc/bionic/debug_mapinfo.h
index e19f71e..6df55c5 100644
--- a/libc/bionic/malloc_debug_check_mapinfo.h
+++ b/libc/bionic/debug_mapinfo.h
@@ -26,21 +26,20 @@
  * SUCH DAMAGE.
  */
 
-#ifndef MALLOC_DEBUG_CHECK_MAPINFO_H
-#define MALLOC_DEBUG_CHECK_MAPINFO_H
+#ifndef DEBUG_MAPINFO_H
+#define DEBUG_MAPINFO_H
 
 #include <sys/cdefs.h>
 
-struct mapinfo {
-  struct mapinfo* next;
+struct mapinfo_t {
+  struct mapinfo_t* next;
   unsigned start;
   unsigned end;
   char name[];
 };
 
-__LIBC_HIDDEN__ mapinfo *init_mapinfo(int pid);
-__LIBC_HIDDEN__ void deinit_mapinfo(mapinfo *mi);
-__LIBC_HIDDEN__ const char *map_to_name(mapinfo *mi, unsigned pc, const char* def);
-__LIBC_HIDDEN__ const mapinfo *pc_to_mapinfo(mapinfo *mi, unsigned pc, unsigned *rel_pc);
+__LIBC_HIDDEN__ mapinfo_t* mapinfo_create(int pid);
+__LIBC_HIDDEN__ void mapinfo_destroy(mapinfo_t* mi);
+__LIBC_HIDDEN__ const mapinfo_t* mapinfo_find(mapinfo_t* mi, unsigned pc, unsigned* rel_pc);
 
-#endif /*MALLOC_DEBUG_CHECK_MAPINFO_H*/
+#endif /* DEBUG_MAPINFO_H */
diff --git a/libc/bionic/debug_stacktrace.cpp b/libc/bionic/debug_stacktrace.cpp
new file mode 100644
index 0000000..4b080a4
--- /dev/null
+++ b/libc/bionic/debug_stacktrace.cpp
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "debug_stacktrace.h"
+
+#include <dlfcn.h>
+#include <unistd.h>
+#include <unwind.h>
+#include <sys/types.h>
+
+#include "debug_format.h"
+#include "debug_mapinfo.h"
+#include "logd.h"
+
+/* depends how the system includes define this */
+#ifdef HAVE_UNWIND_CONTEXT_STRUCT
+typedef struct _Unwind_Context __unwind_context;
+#else
+typedef _Unwind_Context __unwind_context;
+#endif
+
+static _Unwind_Reason_Code trace_function(__unwind_context* context, void* arg) {
+  stack_crawl_state_t* state = static_cast<stack_crawl_state_t*>(arg);
+  if (state->count) {
+    intptr_t ip = (intptr_t)_Unwind_GetIP(context);
+    if (ip) {
+      state->addrs[0] = ip;
+      state->addrs++;
+      state->count--;
+      return _URC_NO_REASON;
+    }
+  }
+  // If we run out of space to record the address or 0 has been seen, stop
+  // unwinding the stack.
+  return _URC_END_OF_STACK;
+}
+
+__LIBC_HIDDEN__ int get_backtrace(intptr_t* addrs, size_t max_entries) {
+  stack_crawl_state_t state;
+  state.count = max_entries;
+  state.addrs = addrs;
+  _Unwind_Backtrace(trace_function, &state);
+  return max_entries - state.count;
+}
+
+__LIBC_HIDDEN__ void log_backtrace(mapinfo_t* map_info, intptr_t* addrs, size_t c) {
+  intptr_t self_bt[16];
+  if (addrs == NULL) {
+    c = get_backtrace(self_bt, 16);
+    addrs = self_bt;
+  }
+
+  __libc_format_log(ANDROID_LOG_ERROR, "libc",
+                    "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
+
+  int index = 0;
+  for (size_t i = 0 ; i < c; ++i) {
+    void* offset = 0;
+    const char* symbol = NULL;
+
+    Dl_info info;
+    if (dladdr((void*) addrs[i], &info) != 0) {
+      offset = info.dli_saddr;
+      symbol = info.dli_sname;
+    }
+
+    // This test is a bit sketchy, but it allows us to skip the
+    // stack trace entries due to this debugging code. it works
+    // because those don't have a symbol (they're not exported).
+    if (symbol != NULL || index > 0) {
+      unsigned int rel_pc;
+      const mapinfo_t* mi = mapinfo_find(map_info, addrs[i], &rel_pc);
+      const char* soname = mi ? mi->name : info.dli_fname;
+      if (soname == NULL) {
+        soname = "unknown";
+      }
+      if (symbol) {
+        __libc_format_log(ANDROID_LOG_ERROR, "libc", "          #%02d  pc %08x  %s (%s+0x%x)",
+                          index, rel_pc, soname, symbol, addrs[i] - (intptr_t)offset);
+      } else {
+        __libc_format_log(ANDROID_LOG_ERROR, "libc", "          #%02d  pc %08x  %s",
+                          index, rel_pc, soname);
+      }
+      ++index;
+    }
+  }
+}
diff --git a/libc/bionic/malloc_debug_check_mapinfo.h b/libc/bionic/debug_stacktrace.h
similarity index 71%
copy from libc/bionic/malloc_debug_check_mapinfo.h
copy to libc/bionic/debug_stacktrace.h
index e19f71e..3c66ea6 100644
--- a/libc/bionic/malloc_debug_check_mapinfo.h
+++ b/libc/bionic/debug_stacktrace.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 The Android Open Source Project
+ * Copyright (C) 2013 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -26,21 +26,20 @@
  * SUCH DAMAGE.
  */
 
-#ifndef MALLOC_DEBUG_CHECK_MAPINFO_H
-#define MALLOC_DEBUG_CHECK_MAPINFO_H
+#ifndef DEBUG_STACKTRACE_H
+#define DEBUG_STACKTRACE_H
 
+#include <stdint.h>
 #include <sys/cdefs.h>
 
-struct mapinfo {
-  struct mapinfo* next;
-  unsigned start;
-  unsigned end;
-  char name[];
+struct stack_crawl_state_t {
+  size_t count;
+  intptr_t* addrs;
 };
 
-__LIBC_HIDDEN__ mapinfo *init_mapinfo(int pid);
-__LIBC_HIDDEN__ void deinit_mapinfo(mapinfo *mi);
-__LIBC_HIDDEN__ const char *map_to_name(mapinfo *mi, unsigned pc, const char* def);
-__LIBC_HIDDEN__ const mapinfo *pc_to_mapinfo(mapinfo *mi, unsigned pc, unsigned *rel_pc);
+struct mapinfo_t;
 
-#endif /*MALLOC_DEBUG_CHECK_MAPINFO_H*/
+__LIBC_HIDDEN__ int get_backtrace(intptr_t* stack_frames, size_t max_entries);
+__LIBC_HIDDEN__ void log_backtrace(mapinfo_t* map_info, intptr_t* stack_frames, size_t frame_count);
+
+#endif /* DEBUG_STACKTRACE_H */
diff --git a/libc/bionic/logd_write.c b/libc/bionic/logd_write.c
index 71a6f8e..11c0e68 100644
--- a/libc/bionic/logd_write.c
+++ b/libc/bionic/logd_write.c
@@ -250,9 +250,7 @@
 
 __LIBC_HIDDEN__
 void __fortify_chk_fail(const char *msg, uint32_t tag) {
-    __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
-                             "FORTIFY_SOURCE: %s. Calling abort().\n",
-                             msg);
+    __libc_format_log(ANDROID_LOG_FATAL, "libc", "FORTIFY_SOURCE: %s. Calling abort().\n", msg);
     if (tag != 0) {
         __libc_android_log_event_uid(tag);
     }
diff --git a/libc/bionic/malloc_debug_check.cpp b/libc/bionic/malloc_debug_check.cpp
index 5ad3486..60ee0cc 100644
--- a/libc/bionic/malloc_debug_check.cpp
+++ b/libc/bionic/malloc_debug_check.cpp
@@ -45,18 +45,19 @@
 #include <unistd.h>
 #include <unwind.h>
 
+#include "debug_mapinfo.h"
+#include "debug_stacktrace.h"
 #include "dlmalloc.h"
 #include "logd.h"
-#include "malloc_debug_check_mapinfo.h"
 #include "malloc_debug_common.h"
 #include "ScopedPthreadMutexLocker.h"
 
-static mapinfo *milist;
+static mapinfo_t* gMapInfo;
 
 /* libc.debug.malloc.backlog */
 extern unsigned int malloc_double_free_backlog;
 
-#define MAX_BACKTRACE_DEPTH 15
+#define MAX_BACKTRACE_DEPTH 16
 #define ALLOCATION_TAG      0x1ee7d00d
 #define BACKLOG_TAG         0xbabecafe
 #define FREE_POISON         0xa5
@@ -67,20 +68,10 @@
 #define REAR_GUARD_LEN      (1<<5)
 
 static void log_message(const char* format, ...) {
-    extern const MallocDebug __libc_malloc_default_dispatch;
-    extern const MallocDebug* __libc_malloc_dispatch;
-    extern pthread_mutex_t gAllocationsMutex;
-
-    va_list args;
-    {
-        ScopedPthreadMutexLocker locker(&gAllocationsMutex);
-        const MallocDebug* current_dispatch = __libc_malloc_dispatch;
-        __libc_malloc_dispatch = &__libc_malloc_default_dispatch;
-        va_start(args, format);
-        __libc_android_log_vprint(ANDROID_LOG_ERROR, "libc", format, args);
-        va_end(args);
-        __libc_malloc_dispatch = current_dispatch;
-    }
+  va_list args;
+  va_start(args, format);
+  __libc_format_log_va_list(ANDROID_LOG_ERROR, "libc", format, args);
+  va_end(args);
 }
 
 struct hdr_t {
@@ -121,28 +112,6 @@
 static hdr_t *backlog_head;
 static pthread_mutex_t backlog_lock = PTHREAD_MUTEX_INITIALIZER;
 
-extern __LIBC_HIDDEN__ int get_backtrace(intptr_t* addrs, size_t max_entries);
-
-static void print_backtrace(const intptr_t *bt, unsigned int depth) {
-    const mapinfo *mi;
-    unsigned int cnt;
-    unsigned int rel_pc;
-    intptr_t self_bt[MAX_BACKTRACE_DEPTH];
-
-    if (!bt) {
-        depth = get_backtrace(self_bt, MAX_BACKTRACE_DEPTH);
-        bt = self_bt;
-    }
-
-    log_message("*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
-    for (cnt = 0; cnt < depth && cnt < MAX_BACKTRACE_DEPTH; cnt++) {
-        mi = pc_to_mapinfo(milist, bt[cnt], &rel_pc);
-        log_message("\t#%02d  pc %08x  %s\n", cnt,
-                   mi ? (intptr_t)rel_pc : bt[cnt],
-                   mi ? mi->name : "(unknown)");
-    }
-}
-
 static inline void init_front_guard(hdr_t *hdr) {
     memset(hdr->front_guard, FRONT_GUARD, FRONT_GUARD_LEN);
 }
@@ -292,11 +261,11 @@
     if (!valid && *safe) {
         log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
                         user(hdr), hdr->size);
-        print_backtrace(hdr->bt, hdr->bt_depth);
+        log_backtrace(gMapInfo, hdr->bt, hdr->bt_depth);
         if (hdr->tag == BACKLOG_TAG) {
             log_message("+++ ALLOCATION %p SIZE %d FREED HERE:\n",
                        user(hdr), hdr->size);
-            print_backtrace(hdr->freed_bt, hdr->freed_bt_depth);
+            log_backtrace(gMapInfo, hdr->freed_bt, hdr->freed_bt_depth);
         }
     }
 
@@ -381,18 +350,18 @@
                        user(hdr), hdr->size);
             log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
                        user(hdr), hdr->size);
-            print_backtrace(hdr->bt, hdr->bt_depth);
+            log_backtrace(gMapInfo, hdr->bt, hdr->bt_depth);
             /* hdr->freed_bt_depth should be nonzero here */
             log_message("+++ ALLOCATION %p SIZE %d FIRST FREED HERE:\n",
                        user(hdr), hdr->size);
-            print_backtrace(hdr->freed_bt, hdr->freed_bt_depth);
+            log_backtrace(gMapInfo, hdr->freed_bt, hdr->freed_bt_depth);
             log_message("+++ ALLOCATION %p SIZE %d NOW BEING FREED HERE:\n",
                        user(hdr), hdr->size);
-            print_backtrace(bt, depth);
+            log_backtrace(gMapInfo, bt, depth);
         } else {
             log_message("+++ ALLOCATION %p IS CORRUPTED OR NOT ALLOCATED VIA TRACKER!\n",
                        user(hdr));
-            print_backtrace(bt, depth);
+            log_backtrace(gMapInfo, bt, depth);
             /* Leak here so that we do not crash */
             //dlfree(user(hdr));
         }
@@ -428,14 +397,14 @@
                        user(hdr), size, hdr->size);
             log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
                        user(hdr), hdr->size);
-            print_backtrace(hdr->bt, hdr->bt_depth);
+            log_backtrace(gMapInfo, hdr->bt, hdr->bt_depth);
             /* hdr->freed_bt_depth should be nonzero here */
             log_message("+++ ALLOCATION %p SIZE %d FIRST FREED HERE:\n",
                        user(hdr), hdr->size);
-            print_backtrace(hdr->freed_bt, hdr->freed_bt_depth);
+            log_backtrace(gMapInfo, hdr->freed_bt, hdr->freed_bt_depth);
             log_message("+++ ALLOCATION %p SIZE %d NOW BEING REALLOCATED HERE:\n",
                        user(hdr), hdr->size);
-            print_backtrace(bt, depth);
+            log_backtrace(gMapInfo, bt, depth);
 
              /* We take the memory out of the backlog and fall through so the
              * reallocation below succeeds.  Since we didn't really free it, we
@@ -445,7 +414,7 @@
         } else {
             log_message("+++ REALLOCATION %p SIZE %d IS CORRUPTED OR NOT ALLOCATED VIA TRACKER!\n",
                        user(hdr), size);
-            print_backtrace(bt, depth);
+            log_backtrace(gMapInfo, bt, depth);
             // just get a whole new allocation and leak the old one
             return dlrealloc(0, size);
             // return dlrealloc(user(hdr), size); // assuming it was allocated externally
@@ -467,8 +436,7 @@
     size_t total_size = nmemb * size;
     hdr_t* hdr = static_cast<hdr_t*>(dlcalloc(1, sizeof(hdr_t) + total_size + sizeof(ftr_t)));
     if (hdr) {
-        hdr->bt_depth = get_backtrace(
-                            hdr->bt, MAX_BACKTRACE_DEPTH);
+        hdr->bt_depth = get_backtrace(hdr->bt, MAX_BACKTRACE_DEPTH);
         add(hdr, total_size);
         return user(hdr);
     }
@@ -476,21 +444,20 @@
 }
 
 static void heaptracker_free_leaked_memory() {
+    size_t total = num;
     if (num) {
-        log_message("+++ THERE ARE %d LEAKED ALLOCATIONS\n", num);
+        log_message("+++ Leaked allocations: %d\n", num);
     }
 
     hdr_t *del = NULL;
     while (head) {
         int safe;
         del = head;
-        log_message("+++ DELETING %d BYTES OF LEAKED MEMORY AT %p (%d REMAINING)\n",
-                del->size, user(del), num);
+        log_message("+++ Leaked block of size %d at %p (leak %d of %d)\n",
+                del->size, user(del), 1 + total - num, total);
         if (del_leak(del, &safe)) {
             /* safe == 1, because the allocation is valid */
-            log_message("+++ ALLOCATION %p SIZE %d ALLOCATED HERE:\n",
-                        user(del), del->size);
-            print_backtrace(del->bt, del->bt_depth);
+            log_backtrace(gMapInfo, del->bt, del->bt_depth);
         }
         dlfree(del);
     }
@@ -507,13 +474,14 @@
  * See comments on MallocDebugInit in malloc_debug_common.h
  */
 extern "C" int malloc_debug_initialize() {
-    if (!malloc_double_free_backlog)
-        malloc_double_free_backlog = BACKLOG_DEFAULT_LEN;
-    milist = init_mapinfo(getpid());
-    return 0;
+  if (!malloc_double_free_backlog) {
+    malloc_double_free_backlog = BACKLOG_DEFAULT_LEN;
+  }
+  gMapInfo = mapinfo_create(getpid());
+  return 0;
 }
 
 extern "C" void malloc_debug_finalize() {
-    heaptracker_free_leaked_memory();
-    deinit_mapinfo(milist);
+  heaptracker_free_leaked_memory();
+  mapinfo_destroy(gMapInfo);
 }
diff --git a/libc/bionic/malloc_debug_check_mapinfo.cpp b/libc/bionic/malloc_debug_check_mapinfo.cpp
deleted file mode 100644
index 8cc2c99..0000000
--- a/libc/bionic/malloc_debug_check_mapinfo.cpp
+++ /dev/null
@@ -1,120 +0,0 @@
-/*
- * Copyright (C) 2012 The Android Open Source Project
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-
-#include "dlmalloc.h"
-#include "malloc_debug_check_mapinfo.h"
-
-// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419   /system/lib/libcomposer.so
-// 012345678901234567890123456789012345678901234567890123456789
-// 0         1         2         3         4         5
-
-static mapinfo* parse_maps_line(char* line) {
-    int len = strlen(line);
-
-    if (len < 1) return 0;
-    line[--len] = 0;
-
-    if (len < 50) return 0;
-    if (line[20] != 'x') return 0;
-
-    mapinfo* mi = static_cast<mapinfo*>(dlmalloc(sizeof(mapinfo) + (len - 47)));
-    if (mi == 0) return 0;
-
-    mi->start = strtoul(line, 0, 16);
-    mi->end = strtoul(line + 9, 0, 16);
-    /* To be filled in parse_elf_info if the mapped section starts with
-     * elf_header
-     */
-    mi->next = 0;
-    strcpy(mi->name, line + 49);
-
-    return mi;
-}
-
-__LIBC_HIDDEN__
-mapinfo *init_mapinfo(int pid) {
-    struct mapinfo *milist = NULL;
-    char data[1024]; // Used to read lines as well as to construct the filename.
-    snprintf(data, sizeof(data), "/proc/%d/maps", pid);
-    FILE *fp = fopen(data, "r");
-    if (fp) {
-        while (fgets(data, sizeof(data), fp)) {
-            mapinfo *mi = parse_maps_line(data);
-            if (mi) {
-                mi->next = milist;
-                milist = mi;
-            }
-        }
-        fclose(fp);
-    }
-
-    return milist;
-}
-
-__LIBC_HIDDEN__
-void deinit_mapinfo(mapinfo *mi) {
-    mapinfo *del;
-    while (mi) {
-        del = mi;
-        mi = mi->next;
-        dlfree(del);
-    }
-}
-
-/* Map a pc address to the name of the containing ELF file */
-__LIBC_HIDDEN__
-const char *map_to_name(mapinfo *mi, unsigned pc, const char* def) {
-    while (mi) {
-        if ((pc >= mi->start) && (pc < mi->end)) {
-            return mi->name;
-        }
-        mi = mi->next;
-    }
-    return def;
-}
-
-/* Find the containing map info for the pc */
-__LIBC_HIDDEN__
-const mapinfo *pc_to_mapinfo(mapinfo *mi, unsigned pc, unsigned *rel_pc) {
-    *rel_pc = pc;
-    while (mi) {
-        if ((pc >= mi->start) && (pc < mi->end)) {
-            // Only calculate the relative offset for shared libraries
-            if (strstr(mi->name, ".so")) {
-                *rel_pc -= mi->start;
-            }
-            return mi;
-        }
-        mi = mi->next;
-    }
-    return NULL;
-}
diff --git a/libc/bionic/malloc_debug_common.cpp b/libc/bionic/malloc_debug_common.cpp
index 624a40e..bba0472 100644
--- a/libc/bionic/malloc_debug_common.cpp
+++ b/libc/bionic/malloc_debug_common.cpp
@@ -294,8 +294,8 @@
 unsigned int malloc_double_free_backlog;
 
 static void InitMalloc(MallocDebug* table, int debug_level, const char* prefix) {
-  __libc_android_log_print(ANDROID_LOG_INFO, "libc", "%s: using libc.debug.malloc %d (%s)\n",
-                           __progname, debug_level, prefix);
+  __libc_format_log(ANDROID_LOG_INFO, "libc", "%s: using libc.debug.malloc %d (%s)\n",
+                    __progname, debug_level, prefix);
 
   char symbol[128];
 
@@ -429,7 +429,7 @@
         dlclose(libc_malloc_impl_handle);
         return;
     }
-    if (malloc_debug_initialize()) {
+    if (malloc_debug_initialize() == -1) {
         dlclose(libc_malloc_impl_handle);
         return;
     }
@@ -487,11 +487,19 @@
 }
 
 static void malloc_fini_impl() {
-    if (libc_malloc_impl_handle) {
+    // Our BSD stdio implementation doesn't close the standard streams, it only flushes them.
+    // And it doesn't do that until its atexit handler (_cleanup) is run, and we run first!
+    // It's great that other unclosed FILE*s show up as malloc leaks, but we need to manually
+    // clean up the standard streams ourselves.
+    fclose(stdin);
+    fclose(stdout);
+    fclose(stderr);
+
+    if (libc_malloc_impl_handle != NULL) {
         MallocDebugFini malloc_debug_finalize =
             reinterpret_cast<MallocDebugFini>(dlsym(libc_malloc_impl_handle,
                                                     "malloc_debug_finalize"));
-        if (malloc_debug_finalize) {
+        if (malloc_debug_finalize != NULL) {
             malloc_debug_finalize();
         }
     }
diff --git a/libc/bionic/malloc_debug_common.h b/libc/bionic/malloc_debug_common.h
index 78ad5e5..3d12f87 100644
--- a/libc/bionic/malloc_debug_common.h
+++ b/libc/bionic/malloc_debug_common.h
@@ -35,6 +35,8 @@
 
 #include <stdlib.h>
 
+#include <private/debug_format.h>
+
 #define HASHTABLE_SIZE      1543
 #define BACKTRACE_SIZE      32
 /* flag definitions, currently sharing storage with "size" */
@@ -97,10 +99,10 @@
 // =============================================================================
 
 #define debug_log(format, ...)  \
-    __libc_android_log_print(ANDROID_LOG_DEBUG, "malloc_leak_check", (format), ##__VA_ARGS__ )
+    __libc_format_log(ANDROID_LOG_DEBUG, "malloc_leak_check", (format), ##__VA_ARGS__ )
 #define error_log(format, ...)  \
-    __libc_android_log_print(ANDROID_LOG_ERROR, "malloc_leak_check", (format), ##__VA_ARGS__ )
+    __libc_format_log(ANDROID_LOG_ERROR, "malloc_leak_check", (format), ##__VA_ARGS__ )
 #define info_log(format, ...)  \
-    __libc_android_log_print(ANDROID_LOG_INFO, "malloc_leak_check", (format), ##__VA_ARGS__ )
+    __libc_format_log(ANDROID_LOG_INFO, "malloc_leak_check", (format), ##__VA_ARGS__ )
 
 #endif  // MALLOC_DEBUG_COMMON_H
diff --git a/libc/bionic/malloc_debug_leak.cpp b/libc/bionic/malloc_debug_leak.cpp
index 090a981..68b6ae2 100644
--- a/libc/bionic/malloc_debug_leak.cpp
+++ b/libc/bionic/malloc_debug_leak.cpp
@@ -45,6 +45,7 @@
 #include <unistd.h>
 #include <unwind.h>
 
+#include "debug_stacktrace.h"
 #include "dlmalloc.h"
 #include "logd.h"
 #include "malloc_debug_common.h"
@@ -255,8 +256,6 @@
 
 static void* MEMALIGN_GUARD = reinterpret_cast<void*>(0xA1A41520);
 
-extern __LIBC_HIDDEN__ int get_backtrace(intptr_t* addrs, size_t max_entries);
-
 extern "C" void* leak_malloc(size_t bytes) {
     // allocate enough space infront of the allocation to store the pointer for
     // the alloc structure. This will making free'ing the structer really fast!
diff --git a/libc/bionic/malloc_debug_qemu.cpp b/libc/bionic/malloc_debug_qemu.cpp
index e586b1b..812a451 100644
--- a/libc/bionic/malloc_debug_qemu.cpp
+++ b/libc/bionic/malloc_debug_qemu.cpp
@@ -257,8 +257,8 @@
                              INFO_TRACING_ENABLED)
 
 /* Prints a string to the emulator's stdout.
- * In early stages of system loading, logging mesages via
- * __libc_android_log_print API is not available, because ADB API has not been
+ * In early stages of system loading, logging messages to logcat
+ * is not available, because ADB API has not been
  * hooked up yet. So, in order to see such messages we need to print them to
  * the emulator's stdout.
  * Parameters passed to this macro are the same as parameters for printf
@@ -289,8 +289,7 @@
  */
 #define qemu_debug_log(format, ...)                                         \
     do {                                                                    \
-        __libc_android_log_print(ANDROID_LOG_DEBUG, "memcheck",             \
-                                 (format), ##__VA_ARGS__);                  \
+        __libc_format_log(ANDROID_LOG_DEBUG, "memcheck", (format), ##__VA_ARGS__); \
         if (tracing_flags & DEBUG_TRACING_ENABLED) {                        \
             qemu_log(ANDROID_LOG_DEBUG, (format), ##__VA_ARGS__);           \
         }                                                                   \
@@ -298,8 +297,7 @@
 
 #define qemu_error_log(format, ...)                                         \
     do {                                                                    \
-        __libc_android_log_print(ANDROID_LOG_ERROR, "memcheck",             \
-                                 (format), ##__VA_ARGS__);                  \
+        __libc_format_log(ANDROID_LOG_ERROR, "memcheck", (format), ##__VA_ARGS__); \
         if (tracing_flags & ERROR_TRACING_ENABLED) {                        \
             qemu_log(ANDROID_LOG_ERROR, (format), ##__VA_ARGS__);           \
         }                                                                   \
@@ -307,8 +305,7 @@
 
 #define qemu_info_log(format, ...)                                          \
     do {                                                                    \
-        __libc_android_log_print(ANDROID_LOG_INFO, "memcheck",              \
-                                 (format), ##__VA_ARGS__);                  \
+        __libc_format_log(ANDROID_LOG_INFO, "memcheck", (format), ##__VA_ARGS__); \
         if (tracing_flags & INFO_TRACING_ENABLED) {                         \
             qemu_log(ANDROID_LOG_INFO, (format), ##__VA_ARGS__);            \
         }                                                                   \
@@ -318,20 +315,19 @@
  * Param:
  *  type - Message type: debug, error, or info
  *  desc - MallocDesc instance to dump.
- *  frmt + rest - Formats message preceding dumped descriptor.
+ *  fmt + rest - Formats message preceding dumped descriptor.
 */
-#define log_mdesc(type, desc, frmt, ...)                                    \
+#define log_mdesc(type, desc, fmt, ...)                                    \
     do {                                                                    \
         if (tracing_enabled(type)) {                                        \
             char log_str[4096];                                             \
-            size_t str_len;                                                 \
-            snprintf(log_str, sizeof(log_str), frmt, ##__VA_ARGS__);        \
+            __libc_format_buffer(log_str, sizeof(log_str), fmt, ##__VA_ARGS__); \
             log_str[sizeof(log_str) - 1] = '\0';                            \
-            str_len = strlen(log_str);                                      \
+            size_t str_len = strlen(log_str);                               \
             dump_malloc_descriptor(log_str + str_len,                       \
                                    sizeof(log_str) - str_len,               \
                                    (desc));                                 \
-            type##_log(log_str);                                            \
+            type##_log("%s", log_str);                                      \
         }                                                                   \
     } while (0)
 
diff --git a/libc/bionic/malloc_debug_stacktrace.cpp b/libc/bionic/malloc_debug_stacktrace.cpp
deleted file mode 100644
index 32b8ac0..0000000
--- a/libc/bionic/malloc_debug_stacktrace.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright (C) 2012 The Android Open Source Project
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-#include <unwind.h>
-#include <sys/types.h>
-
-// =============================================================================
-// stack trace functions
-// =============================================================================
-
-struct stack_crawl_state_t {
-    size_t count;
-    intptr_t* addrs;
-};
-
-
-/* depends how the system includes define this */
-#ifdef HAVE_UNWIND_CONTEXT_STRUCT
-typedef struct _Unwind_Context __unwind_context;
-#else
-typedef _Unwind_Context __unwind_context;
-#endif
-
-static _Unwind_Reason_Code trace_function(__unwind_context* context, void* arg) {
-    stack_crawl_state_t* state = static_cast<stack_crawl_state_t*>(arg);
-    if (state->count) {
-        intptr_t ip = (intptr_t)_Unwind_GetIP(context);
-        if (ip) {
-            state->addrs[0] = ip;
-            state->addrs++;
-            state->count--;
-            return _URC_NO_REASON;
-        }
-    }
-    /*
-     * If we run out of space to record the address or 0 has been seen, stop
-     * unwinding the stack.
-     */
-    return _URC_END_OF_STACK;
-}
-
-__LIBC_HIDDEN__ int get_backtrace(intptr_t* addrs, size_t max_entries) {
-    stack_crawl_state_t state;
-    state.count = max_entries;
-    state.addrs = addrs;
-    _Unwind_Backtrace(trace_function, &state);
-    return max_entries - state.count;
-}
diff --git a/libc/bionic/pthread.c b/libc/bionic/pthread.c
index f294723..f2a7ebe 100644
--- a/libc/bionic/pthread.c
+++ b/libc/bionic/pthread.c
@@ -50,6 +50,7 @@
 #include "bionic_pthread.h"
 #include "bionic_ssp.h"
 #include "bionic_tls.h"
+#include "debug_format.h"
 #include "pthread_internal.h"
 #include "thread_private.h"
 
@@ -229,7 +230,7 @@
             // For backwards compatibility reasons, we just warn about failures here.
             // error = errno;
             const char* msg = "pthread_create sched_setscheduler call failed: %s\n";
-            __libc_android_log_print(ANDROID_LOG_WARN, "libc", msg, strerror(errno));
+            __libc_format_log(ANDROID_LOG_WARN, "libc", msg, strerror(errno));
         }
     }
 
diff --git a/libc/bionic/pthread_debug.c b/libc/bionic/pthread_debug.cpp
similarity index 76%
rename from libc/bionic/pthread_debug.c
rename to libc/bionic/pthread_debug.cpp
index 7ee208c..c557211 100644
--- a/libc/bionic/pthread_debug.c
+++ b/libc/bionic/pthread_debug.cpp
@@ -31,9 +31,7 @@
 #include <sys/system_properties.h>
 #include <sys/mman.h>
 
-#if HAVE_DLADDR
-#include <dlfcn.h>
-#endif
+//#include <dlfcn.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -42,8 +40,12 @@
 #include <unwind.h>
 #include <unistd.h>
 
-#include "logd.h"
 #include "bionic_tls.h"
+#include "debug_mapinfo.h"
+#include "debug_stacktrace.h"
+#include "logd.h"
+
+#include <private/debug_format.h>
 
 /*
  * ===========================================================================
@@ -97,20 +99,16 @@
 // =============================================================================
 
 #define LOGD(format, ...)  \
-    __libc_android_log_print(ANDROID_LOG_DEBUG, \
-            "pthread_debug", (format), ##__VA_ARGS__ )
+    __libc_format_log(ANDROID_LOG_DEBUG, "pthread_debug", (format), ##__VA_ARGS__ )
 
 #define LOGW(format, ...)  \
-    __libc_android_log_print(ANDROID_LOG_WARN, \
-            "pthread_debug", (format), ##__VA_ARGS__ )
+    __libc_format_log(ANDROID_LOG_WARN, "pthread_debug", (format), ##__VA_ARGS__ )
 
 #define LOGE(format, ...)  \
-    __libc_android_log_print(ANDROID_LOG_ERROR, \
-            "pthread_debug", (format), ##__VA_ARGS__ )
+    __libc_format_log(ANDROID_LOG_ERROR, "pthread_debug", (format), ##__VA_ARGS__ )
 
 #define LOGI(format, ...)  \
-    __libc_android_log_print(ANDROID_LOG_INFO, \
-            "pthread_debug", (format), ##__VA_ARGS__ )
+    __libc_format_log(ANDROID_LOG_INFO, "pthread_debug", (format), ##__VA_ARGS__ )
 
 static const char* const kStartBanner =
         "===============================================================";
@@ -120,185 +118,9 @@
 
 extern char* __progname;
 
-// =============================================================================
-// map info functions
-// =============================================================================
-
-typedef struct mapinfo {
-    struct mapinfo *next;
-    unsigned start;
-    unsigned end;
-    char name[];
-} mapinfo;
-
-static mapinfo* sMapInfo = NULL;
-
-static mapinfo *parse_maps_line(char *line)
-{
-    mapinfo *mi;
-    int len = strlen(line);
-
-    if(len < 1) return 0;
-    line[--len] = 0;
-
-    if(len < 50) return 0;
-    if(line[20] != 'x') return 0;
-
-    mi = malloc(sizeof(mapinfo) + (len - 47));
-    if(mi == 0) return 0;
-
-    mi->start = strtoul(line, 0, 16);
-    mi->end = strtoul(line + 9, 0, 16);
-    /* To be filled in parse_elf_info if the mapped section starts with
-     * elf_header
-     */
-    mi->next = 0;
-    strcpy(mi->name, line + 49);
-
-    return mi;
-}
-
-static mapinfo *init_mapinfo(int pid)
-{
-    struct mapinfo *milist = NULL;
-    char data[1024];
-    sprintf(data, "/proc/%d/maps", pid);
-    FILE *fp = fopen(data, "r");
-    if(fp) {
-        while(fgets(data, sizeof(data), fp)) {
-            mapinfo *mi = parse_maps_line(data);
-            if(mi) {
-                mi->next = milist;
-                milist = mi;
-            }
-        }
-        fclose(fp);
-    }
-
-    return milist;
-}
-
-static void deinit_mapinfo(mapinfo *mi)
-{
-   mapinfo *del;
-   while(mi) {
-       del = mi;
-       mi = mi->next;
-       free(del);
-   }
-}
-
-/* Find the containing map info for the pc */
-static const mapinfo *pc_to_mapinfo(mapinfo *mi, unsigned pc, unsigned *rel_pc)
-{
-    *rel_pc = pc;
-    while(mi) {
-        if((pc >= mi->start) && (pc < mi->end)){
-            // Only calculate the relative offset for shared libraries
-            if (strstr(mi->name, ".so")) {
-                *rel_pc -= mi->start;
-            }
-            return mi;
-        }
-        mi = mi->next;
-    }
-    return NULL;
-}
-
-// =============================================================================
-// stack trace functions
-// =============================================================================
-
 #define STACK_TRACE_DEPTH 16
 
-typedef struct
-{
-    size_t count;
-    intptr_t* addrs;
-} stack_crawl_state_t;
-
-/* depends how the system includes define this */
-#ifdef HAVE_UNWIND_CONTEXT_STRUCT
-typedef struct _Unwind_Context __unwind_context;
-#else
-typedef _Unwind_Context __unwind_context;
-#endif
-
-static _Unwind_Reason_Code trace_function(__unwind_context *context, void *arg)
-{
-    stack_crawl_state_t* state = (stack_crawl_state_t*)arg;
-    if (state->count) {
-        intptr_t ip = (intptr_t)_Unwind_GetIP(context);
-        if (ip) {
-            state->addrs[0] = ip;
-            state->addrs++;
-            state->count--;
-            return _URC_NO_REASON;
-        }
-    }
-    /*
-     * If we run out of space to record the address or 0 has been seen, stop
-     * unwinding the stack.
-     */
-    return _URC_END_OF_STACK;
-}
-
-static inline
-int get_backtrace(intptr_t* addrs, size_t max_entries)
-{
-    stack_crawl_state_t state;
-    state.count = max_entries;
-    state.addrs = (intptr_t*)addrs;
-    _Unwind_Backtrace(trace_function, (void*)&state);
-    return max_entries - state.count;
-}
-
-static void log_backtrace(intptr_t* addrs, size_t c)
-{
-    int index = 0;
-    size_t i;
-    for (i=0 ; i<c; i++) {
-        unsigned int relpc;
-        void* offset = 0;
-        const char* symbol = NULL;
-
-#if HAVE_DLADDR
-        Dl_info info;
-        if (dladdr((void*)addrs[i], &info)) {
-            offset = info.dli_saddr;
-            symbol = info.dli_sname;
-        }
-#endif
-
-        if (symbol || index>0 || !HAVE_DLADDR) {
-            /*
-             * this test is a bit sketchy, but it allows us to skip the
-             * stack trace entries due to this debugging code. it works
-             * because those don't have a symbol (they're not exported)
-             */
-            mapinfo const* mi = pc_to_mapinfo(sMapInfo, addrs[i], &relpc);
-            char const* soname = mi ? mi->name : NULL;
-#if HAVE_DLADDR
-            if (!soname)
-                soname = info.dli_fname;
-#endif
-            if (!soname)
-                soname = "unknown";
-
-            if (symbol) {
-                LOGW("          "
-                     "#%02d  pc %08lx  %s (%s+0x%x)",
-                     index, relpc, soname, symbol,
-                     addrs[i] - (intptr_t)offset);
-            } else {
-                LOGW("          "
-                     "#%02d  pc %08lx  %s",
-                     index, relpc, soname);
-            }
-            index++;
-        }
-    }
-}
+static mapinfo_t* gMapInfo;
 
 /****************************************************************************/
 
@@ -322,18 +144,21 @@
 static size_t sDbgAllocOffset = DBG_ALLOC_BLOCK_SIZE;
 static char* sDbgAllocPtr = NULL;
 
-static void* DbgAllocLocked(size_t size) {
+template <typename T>
+static T* DbgAllocLocked(size_t count = 1) {
+    size_t size = sizeof(T) * count;
     if ((sDbgAllocOffset + size) > DBG_ALLOC_BLOCK_SIZE) {
         sDbgAllocOffset = 0;
-        sDbgAllocPtr = mmap(NULL, DBG_ALLOC_BLOCK_SIZE, PROT_READ|PROT_WRITE,
-                MAP_ANON | MAP_PRIVATE, 0, 0);
+        sDbgAllocPtr = reinterpret_cast<char*>(mmap(NULL, DBG_ALLOC_BLOCK_SIZE,
+                                                    PROT_READ|PROT_WRITE,
+                                                    MAP_ANON | MAP_PRIVATE, 0, 0));
         if (sDbgAllocPtr == MAP_FAILED) {
             return NULL;
         }
     }
     void* addr = sDbgAllocPtr + sDbgAllocOffset;
     sDbgAllocOffset += size;
-    return addr;
+    return reinterpret_cast<T*>(addr);
 }
 
 static void* debug_realloc(void *ptr, size_t size, size_t old_size) {
@@ -460,9 +285,9 @@
 
 /****************************************************************************/
 
-static void dup_backtrace(CallStack* stack, int count, intptr_t const* addrs) {
+static void dup_backtrace(CallStack* stack, size_t count, intptr_t const* addrs) {
     stack->depth = count;
-    stack->addrs = DbgAllocLocked(count * sizeof(intptr_t));
+    stack->addrs = DbgAllocLocked<intptr_t>(count);
     memcpy(stack->addrs, addrs, count * sizeof(intptr_t));
 }
 
@@ -545,9 +370,9 @@
         /* Turn off prediction temporarily in this thread while logging */
         sPthreadDebugDisabledThread = gettid();
 
-        if (sMapInfo == NULL) {
-            // note: we're protected by sDbgLock
-            sMapInfo = init_mapinfo(getpid());
+        if (gMapInfo == NULL) {
+            // note: we're protected by sDbgLock.
+            gMapInfo = mapinfo_create(getpid());
         }
 
         LOGW("%s\n", kStartBanner);
@@ -555,7 +380,7 @@
         LOGW("Illegal lock attempt:\n");
         LOGW("--- pthread_mutex_t at %p\n", obj->mutex);
         stackDepth = get_backtrace(addrs, STACK_TRACE_DEPTH);
-        log_backtrace(addrs, stackDepth);
+        log_backtrace(gMapInfo, addrs, stackDepth);
 
         LOGW("+++ Currently held locks in this thread (in reverse order):");
         MutexInfo* cur = obj;
@@ -566,7 +391,7 @@
             if (parent->owner == ourtid) {
                 LOGW("--- pthread_mutex_t at %p\n", parent->mutex);
                 if (sPthreadDebugLevel >= CAPTURE_CALLSTACK) {
-                    log_backtrace(parent->stackTrace, parent->stackDepth);
+                    log_backtrace(gMapInfo, parent->stackTrace, parent->stackDepth);
                 }
                 cur = parent;
                 break;
@@ -589,13 +414,13 @@
             if (sPthreadDebugLevel >= CAPTURE_CALLSTACK) {
                 int index = historyListHas(&obj->parents, objParent);
                 if ((size_t)index < (size_t)obj->stacks.count) {
-                    log_backtrace(
-                            obj->stacks.stack[index].addrs,
-                            obj->stacks.stack[index].depth);
+                    log_backtrace(gMapInfo,
+                                  obj->stacks.stack[index].addrs,
+                                  obj->stacks.stack[index].depth);
                 } else {
-                    log_backtrace(
-                            obj->stackTrace,
-                            obj->stackDepth);
+                    log_backtrace(gMapInfo,
+                                  obj->stackTrace,
+                                  obj->stackDepth);
                 }
             }
             result = 0;
@@ -640,8 +465,8 @@
 
     linkParentToChild(mrl, object);
     if (!traverseTree(object, mrl)) {
-        deinit_mapinfo(sMapInfo);
-        sMapInfo = NULL;
+        mapinfo_destroy(gMapInfo);
+        gMapInfo = NULL;
         LOGW("%s\n", kEndBanner);
         unlinkParentFromChild(mrl, object);
         // reenable pthread debugging for this thread
@@ -758,7 +583,7 @@
 
     if (entry == NULL) {
         // create a new entry
-        entry = (HashEntry*)DbgAllocLocked(sizeof(HashEntry));
+        entry = DbgAllocLocked<HashEntry>();
         entry->data = NULL;
         entry->slot = slot;
         entry->prev = NULL;
@@ -785,8 +610,9 @@
             &mutex, sizeof(mutex),
             &MutexInfo_equals);
     if (entry->data == NULL) {
-        entry->data = (MutexInfo*)DbgAllocLocked(sizeof(MutexInfo));
-        initMutexInfo(entry->data, mutex);
+        MutexInfo* mutex_info = DbgAllocLocked<MutexInfo>();
+        entry->data = mutex_info;
+        initMutexInfo(mutex_info, mutex);
     }
 
     pthread_mutex_unlock_unchecked(&sDbgLock);
@@ -808,8 +634,9 @@
             &pid, sizeof(pid),
             &ThreadInfo_equals);
     if (entry->data == NULL) {
-        entry->data = (ThreadInfo*)DbgAllocLocked(sizeof(ThreadInfo));
-        initThreadInfo(entry->data, pid);
+        ThreadInfo* thread_info = DbgAllocLocked<ThreadInfo>();
+        entry->data = thread_info;
+        initThreadInfo(thread_info, pid);
     }
 
     pthread_mutex_unlock_unchecked(&sDbgLock);
@@ -848,8 +675,7 @@
  * after system properties have been initialized
  */
 
-__LIBC_HIDDEN__
-void pthread_debug_init(void) {
+extern "C" __LIBC_HIDDEN__ void pthread_debug_init() {
     char env[PROP_VALUE_MAX];
     if (__system_property_get("debug.libc.pthread", env)) {
         int level = atoi(env);
@@ -872,8 +698,7 @@
  * the checks before the lock is held.)
  */
 
-__LIBC_HIDDEN__
-void pthread_debug_mutex_lock_check(pthread_mutex_t *mutex)
+extern "C" __LIBC_HIDDEN__ void pthread_debug_mutex_lock_check(pthread_mutex_t *mutex)
 {
     if (sPthreadDebugLevel == 0) return;
     // prediction disabled for this thread
@@ -890,8 +715,7 @@
  * still held (ie: before calling the real unlock)
  */
 
-__LIBC_HIDDEN__
-void pthread_debug_mutex_unlock_check(pthread_mutex_t *mutex)
+extern "C" __LIBC_HIDDEN__ void pthread_debug_mutex_unlock_check(pthread_mutex_t *mutex)
 {
     if (sPthreadDebugLevel == 0) return;
     // prediction disabled for this thread
diff --git a/libc/bionic/ssp.cpp b/libc/bionic/ssp.cpp
index fdf8832..08c36c5 100644
--- a/libc/bionic/ssp.cpp
+++ b/libc/bionic/ssp.cpp
@@ -63,8 +63,8 @@
     path[count] = '\0';
   }
 
-  // Do a best effort at logging. This ends up calling writev(2).
-  __libc_android_log_print(ANDROID_LOG_FATAL, path, "stack corruption detected: aborted");
+  // Do a best effort at logging.
+  __libc_android_log_write(ANDROID_LOG_FATAL, path, "stack corruption detected: aborted");
 
   // Make sure there is no default action for SIGABRT.
   struct sigaction sa;
diff --git a/libc/bionic/stubs.cpp b/libc/bionic/stubs.cpp
index 48281b4..3f24d1b 100644
--- a/libc/bionic/stubs.cpp
+++ b/libc/bionic/stubs.cpp
@@ -32,6 +32,7 @@
 #include <mntent.h>
 #include <netdb.h>
 #include <private/android_filesystem_config.h>
+#include <private/debug_format.h>
 #include <private/logd.h>
 #include <pthread.h>
 #include <pwd.h>
@@ -435,7 +436,7 @@
 
 static void unimplemented_stub(const char* function) {
   const char* fmt = "%s(3) is not implemented on Android\n";
-  __libc_android_log_print(ANDROID_LOG_WARN, "libc", fmt, function);
+  __libc_format_log(ANDROID_LOG_WARN, "libc", fmt, function);
   fprintf(stderr, fmt, function);
 }