Fix the duplication in the debugging code.

We had two copies of the backtrace code, and two copies of the
libcorkscrew /proc/pid/maps code. This patch gets us down to one.

We also had hacks so we could log in the malloc debugging code.
This patch pulls the non-allocating "printf" code out of the
dynamic linker so everyone can share.

This patch also makes the leak diagnostics easier to read, and
makes it possible to paste them directly into the 'stack' tool (by
using relative PCs).

This patch also fixes the stdio standard stream leak that was
causing a leak warning every time tf_daemon ran.

Bug: 7291287
Change-Id: I66e4083ac2c5606c8d2737cb45c8ac8a32c7cfe8

25 files changed, 430 insertions, 632 deletions

diff --git a/libc/Android.mk b/libc/Android.mk
index c98d2ff..05373dc 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -272,6 +272,7 @@ libc_common_src_files := \
 
 libc_bionic_src_files := \
     bionic/assert.cpp \
+    bionic/debug_format.cpp \
     bionic/dirent.cpp \
     bionic/eventfd.cpp \
     bionic/__fgets_chk.cpp \
@@ -881,7 +882,7 @@ LOCAL_SRC_FILES := \
 	$(libc_static_common_src_files) \
 	bionic/dlmalloc.c \
 	bionic/malloc_debug_common.cpp \
-	bionic/pthread_debug.c \
+	bionic/pthread_debug.cpp \
 	bionic/libc_init_dynamic.c
 
 ifeq ($(TARGET_ARCH),arm)
@@ -934,10 +935,10 @@ LOCAL_CFLAGS := \
 LOCAL_C_INCLUDES := $(libc_common_c_includes)
 
 LOCAL_SRC_FILES := \
+	bionic/debug_mapinfo.cpp \
+	bionic/debug_stacktrace.cpp \
 	bionic/malloc_debug_leak.cpp \
 	bionic/malloc_debug_check.cpp \
-	bionic/malloc_debug_check_mapinfo.cpp \
-	bionic/malloc_debug_stacktrace.cpp
 
 LOCAL_MODULE:= libc_malloc_debug_leak
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
diff --git a/libc/arch-arm/bionic/atexit_legacy.c b/libc/arch-arm/bionic/atexit_legacy.c
index 4abe839..6e299ac 100644
--- a/libc/arch-arm/bionic/atexit_legacy.c
+++ b/libc/arch-arm/bionic/atexit_legacy.c
@@ -50,10 +50,9 @@ atexit(void (*func)(void))
      * calling library may have been dlclose()'d, causing the program to
      * crash.
      */
-    static char const warning[] =
-        "WARNING: generic atexit() called from legacy shared library\n";
+    static char const warning[] = "WARNING: generic atexit() called from legacy shared library\n";
 
-    __libc_android_log_print(ANDROID_LOG_WARN, "libc", warning);
+    __libc_android_log_write(ANDROID_LOG_WARN, "libc", warning);
     fprintf(stderr, warning);
 
     return (__cxa_atexit((void (*)(void *))func, NULL, NULL));
diff --git a/libc/arch-mips/bionic/cacheflush.c b/libc/arch-mips/bionic/cacheflush.c
index 05085b6..1911687 100644
--- a/libc/arch-mips/bionic/cacheflush.c
+++ b/libc/arch-mips/bionic/cacheflush.c
@@ -29,9 +29,9 @@
 #include <sys/cachectl.h>
 
 #ifdef DEBUG
-#include <logd.h>
-#define  XLOG(...)   \
-	__libc_android_log_print(ANDROID_LOG_DEBUG,"libc-cacheflush",__VA_ARGS__)
+#include <private/logd.h>
+#include <private/debug_format.h>
+#define  XLOG(...) __libc_format_log(ANDROID_LOG_DEBUG,"libc-cacheflush",__VA_ARGS__)
 #endif
 
 /*
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 __assert(const char* file, int line, const char* failed_expression) {
 
 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/linker/linker_format.cpp b/libc/bionic/debug_format.cpp
index e631ca1..e8d6a45 100644
--- a/linker/linker_format.cpp
+++ b/libc/bionic/debug_format.cpp
@@ -30,7 +30,7 @@
 // compile under GCC 4.7
 #undef _FORTIFY_SOURCE
 
-#include "linker_format.h"
+#include "debug_format.h"
 
 #include <assert.h>
 #include <errno.h>
@@ -40,8 +40,6 @@
 #include <string.h>
 #include <unistd.h>
 
-#include "linker_debug.h"
-
 /* define UNIT_TESTS to build this file as a single executable that runs
  * the formatter's unit tests
  */
@@ -150,47 +148,14 @@ vformat_buffer(char *buff, size_t buffsize, const char *format, va_list args)
     return buf_out_length(&bo);
 }
 
-int
-format_buffer(char *buff, size_t buffsize, const char *format, ...)
-{
-    va_list args;
-    int ret;
-
-    va_start(args, format);
-    ret = vformat_buffer(buff, buffsize, format, args);
-    va_end(args);
-
-    return ret;
-}
-
-/* The __stack_chk_fail() function calls __libc_android_log_print()
- * which calls vsnprintf().
- *
- * We define our version of the function here to avoid dragging
- * about 25 KB of C library routines related to formatting.
- */
-int
-vsnprintf(char *buff, size_t bufsize, const char *format, va_list args)
-{
-    return format_buffer(buff, bufsize, format, args);
-}
-
-/* The pthread implementation uses snprintf(). If we define it here, we
- * avoid pulling the stdio vfprintf() implementation into the linker
- * saving about 19KB of machine code.
- */
-int
-snprintf(char* buff, size_t bufsize, const char* format, ...)
-{
-    va_list args;
-    int ret;
-    va_start(args, format);
-    ret = vsnprintf(buff, bufsize, format, args);
-    va_end(args);
-    return ret;
+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;
 }
 
-#if !LINKER_DEBUG_TO_LOG
 
 /*** File descriptor output
  ***/
@@ -204,7 +169,7 @@ struct FdOut {
 static void
 fd_out_send(void *opaque, const char *data, int len)
 {
-    FdOut *fdo = opaque;
+    FdOut *fdo = reinterpret_cast<FdOut*>(opaque);
 
     if (len < 0)
         len = strlen(data);
@@ -240,96 +205,61 @@ fd_out_length(FdOut *fdo)
 }
 
 
-int
-format_fd(int fd, const char *format, ...)
-{
-    FdOut fdo;
-    Out* out;
-    va_list args;
-
-    out = fd_out_init(&fdo, fd);
-    if (out == NULL)
-        return 0;
+int __libc_format_fd(int fd, const char* format, ...) {
+  FdOut fdo;
+  Out* out = fd_out_init(&fdo, fd);
+  if (out == NULL) {
+    return 0;
+  }
 
-    va_start(args, format);
-    out_vformat(out, format, args);
-    va_end(args);
+  va_list args;
+  va_start(args, format);
+  out_vformat(out, format, args);
+  va_end(args);
 
-    return fd_out_length(&fdo);
+  return fd_out_length(&fdo);
 }
 
-#else /* LINKER_DEBUG_TO_LOG */
-
 /*** Log output
  ***/
 
-/* We need our own version of __libc_android_log_vprint, otherwise
- * the log output is completely broken. Probably due to the fact
- * that the C library is not initialized yet.
- *
- * You can test that by setting CUSTOM_LOG_VPRINT to 0
- */
-#define  CUSTOM_LOG_VPRINT  1
-
-#if CUSTOM_LOG_VPRINT
-
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/uio.h>
 
-static int log_vprint(int prio, const char *tag, const char *fmt, va_list  args)
-{
-    char buf[1024];
-    int result;
-    static int log_fd = -1;
-
-    result = vformat_buffer(buf, sizeof buf, fmt, args);
+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);
 
-    if (log_fd < 0) {
-        log_fd = open("/dev/log/main", O_WRONLY);
-        if (log_fd < 0)
-            return result;
+  static int log_fd = -1;
+  if (log_fd == -1) {
+    log_fd = open("/dev/log/main", O_WRONLY);
+    if (log_fd == -1) {
+      return result;
     }
+  }
 
-    {
-        ssize_t ret;
-        struct iovec vec[3];
+  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;
 
-        vec[0].iov_base = (unsigned char *) &prio;
-        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));
 
-        do {
-            ret = writev(log_fd, vec, 3);
-        } while ((ret < 0) && (errno == EINTR));
-    }
-    return result;
+  return result;
 }
 
-#define  __libc_android_log_vprint  log_vprint
-
-#else /* !CUSTOM_LOG_VPRINT */
-
-extern "C" int __libc_android_log_vprint(int  prio, const char* tag, const char*  format, va_list ap);
-
-#endif /* !CUSTOM_LOG_VPRINT */
-
-int
-format_log(int prio, const char *tag, const char *format, ...)
-{
-    int ret;
-    va_list  args;
-    va_start(args, format);
-    ret = __libc_android_log_vprint(prio, tag, format, args);
-    va_end(args);
-    return ret;
+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;
 }
 
-#endif /* LINKER_DEBUG_TO_LOG */
-
 /*** formatted output implementation
  ***/
 
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
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/linker/linker_format.h b/libc/bionic/debug_stacktrace.h
index 862e439..3c66ea6 100644
--- a/linker/linker_format.h
+++ b/libc/bionic/debug_stacktrace.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010 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
@@ -26,17 +26,20 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _LINKER_FORMAT_H
-#define _LINKER_FORMAT_H
+#ifndef DEBUG_STACKTRACE_H
+#define DEBUG_STACKTRACE_H
 
-#include <stdarg.h>
-#include <stddef.h>
+#include <stdint.h>
+#include <sys/cdefs.h>
 
-// Formatting routines for the dynamic linker's debug traces
-// We want to avoid dragging the whole C library fprintf()
-// implementation into the dynamic linker since this creates
-// issues (it uses malloc()/free()) and increases code size.
-int format_buffer(char* buffer, size_t buffer_size, const char* format, ...)
-    __attribute__((__format__(printf, 3, 4)));
+struct stack_crawl_state_t {
+  size_t count;
+  intptr_t* addrs;
+};
 
-#endif /* _LINKER_FORMAT_H */
+struct mapinfo_t;
+
+__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 @@ void __libc_android_log_event_uid(int32_t tag)
 
 __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 @@ extern unsigned int malloc_double_free_backlog;
 #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_tail;
 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 @@ static inline int check_allocation_locked(hdr_t *hdr, int *safe) {
     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 @@ extern "C" void chk_free(void *ptr) {
                        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 @@ extern "C" void *chk_realloc(void *ptr, size_t size) {
                        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 @@ extern "C" void *chk_realloc(void *ptr, size_t size) {
         } 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 @@ extern "C" void *chk_calloc(int nmemb, size_t size) {
     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 @@ extern "C" void *chk_calloc(int nmemb, size_t size) {
 }
 
 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 @@ static void heaptracker_free_leaked_memory() {
  * 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 @@ static void* libc_malloc_impl_handle = NULL;
 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 @@ static void malloc_init_impl() {
         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_init_impl() {
 }
 
 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 @@ typedef void (*MallocDebugFini)();
 // =============================================================================
 
 #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 @@ extern "C" void* fill_memalign(size_t alignment, size_t bytes) {
 
 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 @@ static void dump_malloc_descriptor(char* str,
                              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 @@ static void dump_malloc_descriptor(char* str,
  */
 #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 @@ static void dump_malloc_descriptor(char* str,
 
 #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 @@ static void dump_malloc_descriptor(char* str,
 
 #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 @@ static void dump_malloc_descriptor(char* str,
  * 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/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 @@ int _init_thread(pthread_internal_t* thread, pid_t kernel_id, const pthread_attr
             // 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
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 @@ the lock has been acquired.
 // =============================================================================
 
 #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 @@ static const char* const kEndBanner =
 
 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 pthread_mutex_t sDbgLock = PTHREAD_MUTEX_INITIALIZER;
 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 int pthread_mutex_unlock_unchecked(pthread_mutex_t *mutex) {
 
 /****************************************************************************/
 
-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 @@ static int traverseTree(MutexInfo* obj, MutexInfo const* objParent)
         /* 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 @@ static int traverseTree(MutexInfo* obj, MutexInfo const* objParent)
         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 @@ static int traverseTree(MutexInfo* obj, MutexInfo const* objParent)
             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 @@ static int traverseTree(MutexInfo* obj, MutexInfo const* objParent)
             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 @@ static void mutex_lock_checked(MutexInfo* mrl, MutexInfo* object)
 
     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 @@ static HashEntry* hashmap_lookup(HashTable* table,
 
     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 @@ static MutexInfo* get_mutex_info(pthread_mutex_t *mutex)
             &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 @@ static ThreadInfo* get_thread_info(pid_t pid)
             &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 @@ static MutexInfo* get_most_recently_locked() {
  * 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 @@ void pthread_debug_init(void) {
  * 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 @@ void pthread_debug_mutex_lock_check(pthread_mutex_t *mutex)
  * 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 @@ void __stack_chk_fail() {
     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 @@ protoent* getprotobynumber(int /*proto*/) {
 
 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);
 }
 
diff --git a/libc/bionic/malloc_debug_stacktrace.cpp b/libc/private/debug_format.h
index 32b8ac0..0bc1148 100644
--- a/libc/bionic/malloc_debug_stacktrace.cpp
+++ b/libc/private/debug_format.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 The Android Open Source Project
+ * Copyright (C) 2010 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,48 +25,31 @@
  * 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
-// =============================================================================
+#ifndef _DEBUG_FORMAT_H
+#define _DEBUG_FORMAT_H
 
-struct stack_crawl_state_t {
-    size_t count;
-    intptr_t* addrs;
-};
+#include <sys/cdefs.h>
+#include <stdarg.h>
+#include <stddef.h>
 
+__BEGIN_DECLS
 
-/* 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
+// Formatting routines for the C library's internal debugging.
+// Unlike the usual alternatives, these don't allocate.
 
-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 __libc_format_buffer(char* buffer, size_t buffer_size, const char* format, ...)
+    __attribute__((__format__(printf, 3, 4)));
 
-__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__ int __libc_format_fd(int fd, const char* format, ...)
+    __attribute__((__format__(printf, 2, 3)));
+
+__LIBC_HIDDEN__ int __libc_format_log(int priority, const char* tag, const char* format, ...)
+    __attribute__((__format__(printf, 3, 4)));
+
+__LIBC_HIDDEN__ int __libc_format_log_va_list(int priority, const char* tag, const char* format,
+                                              va_list ap);
+
+__END_DECLS
+
+#endif /* _DEBUG_FORMAT_H */
diff --git a/linker/Android.mk b/linker/Android.mk
index c85b09e..9718d90 100644
--- a/linker/Android.mk
+++ b/linker/Android.mk
@@ -13,7 +13,6 @@ LOCAL_SRC_FILES:= \
     dlfcn.cpp \
     linker.cpp \
     linker_environ.cpp \
-    linker_format.cpp \
     linker_phdr.cpp \
     rt.cpp
 
diff --git a/linker/debugger.cpp b/linker/debugger.cpp
index 5fd5cb7..a14e30a 100644
--- a/linker/debugger.cpp
+++ b/linker/debugger.cpp
@@ -27,7 +27,6 @@
  */
 
 #include "linker.h"
-#include "linker_format.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -38,6 +37,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 
+#include <private/debug_format.h>
 #include <private/logd.h>
 
 extern "C" int tgkill(int tgid, int tid, int sig);
@@ -135,12 +135,12 @@ static void logSignalSummary(int signum, const siginfo_t* info) {
     char buffer[128];
     // "info" will be NULL if the siginfo_t information was not available.
     if (info != NULL) {
-        format_buffer(buffer, sizeof(buffer),
+        __libc_format_buffer(buffer, sizeof(buffer),
                       "Fatal signal %d (%s) at 0x%08x (code=%d), thread %d (%s)",
                       signum, signame, reinterpret_cast<uintptr_t>(info->si_addr),
                       info->si_code, gettid(), threadname);
     } else {
-        format_buffer(buffer, sizeof(buffer),
+        __libc_format_buffer(buffer, sizeof(buffer),
             "Fatal signal %d (%s), thread %d (%s)",
             signum, signame, gettid(), threadname);
     }
@@ -215,7 +215,7 @@ void debugger_signal_handler(int n, siginfo_t* info, void*) {
 
         if (ret < 0) {
             /* read or write failed -- broken connection? */
-            format_buffer(msgbuf, sizeof(msgbuf),
+            __libc_format_buffer(msgbuf, sizeof(msgbuf),
                 "Failed while talking to debuggerd: %s", strerror(errno));
             __libc_android_log_write(ANDROID_LOG_FATAL, "libc", msgbuf);
         }
@@ -223,7 +223,7 @@ void debugger_signal_handler(int n, siginfo_t* info, void*) {
         close(s);
     } else {
         /* socket failed; maybe process ran out of fds */
-        format_buffer(msgbuf, sizeof(msgbuf),
+        __libc_format_buffer(msgbuf, sizeof(msgbuf),
             "Unable to open connection to debuggerd: %s", strerror(errno));
         __libc_android_log_write(ANDROID_LOG_FATAL, "libc", msgbuf);
     }
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 0a89b72..c8a2a84 100755
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -41,13 +41,13 @@
 
 // Private C library headers.
 #include <private/bionic_tls.h>
+#include <private/debug_format.h>
 #include <private/logd.h>
 #include <private/ScopedPthreadMutexLocker.h>
 
 #include "linker.h"
 #include "linker_debug.h"
 #include "linker_environ.h"
-#include "linker_format.h"
 #include "linker_phdr.h"
 
 /* Assume average path length of 64 and max 8 paths */
@@ -159,7 +159,7 @@ static char tmp_err_buf[768];
 static char __linker_dl_err_buf[768];
 #define DL_ERR(fmt, x...) \
     do { \
-        format_buffer(__linker_dl_err_buf, sizeof(__linker_dl_err_buf), fmt, ##x); \
+        __libc_format_buffer(__linker_dl_err_buf, sizeof(__linker_dl_err_buf), fmt, ##x); \
         /* If LD_DEBUG is set high enough, send every dlerror(3) message to the log. */ \
         DEBUG(fmt "\n", ##x); \
     } while(0)
@@ -674,7 +674,7 @@ static void dump(soinfo *si)
 static int open_library_on_path(const char* name, const char* const paths[]) {
   char buf[512];
   for (size_t i = 0; paths[i] != NULL; ++i) {
-    int n = format_buffer(buf, sizeof(buf), "%s/%s", paths[i], name);
+    int n = __libc_format_buffer(buf, sizeof(buf), "%s/%s", paths[i], name);
     if (n < 0 || n >= static_cast<int>(sizeof(buf))) {
       PRINT("Warning: ignoring very long library path: %s/%s\n", paths[i], name);
       continue;
diff --git a/linker/linker_debug.h b/linker/linker_debug.h
index 0a3710b..b326d00 100644
--- a/linker/linker_debug.h
+++ b/linker/linker_debug.h
@@ -52,19 +52,17 @@
 
 /*********************************************************************/
 
-#include "linker_format.h"
+#include <private/debug_format.h>
 
 #if LINKER_DEBUG_TO_LOG
-extern int format_log(int, const char*, const char*, ...) __attribute__((__format__(printf, 3, 4)));
 #define _PRINTVF(v,x...)                                        \
     do {                                                          \
-        if (debug_verbosity > (v)) format_log(5-(v),"linker",x);  \
+        if (debug_verbosity > (v)) __libc_format_log(5-(v),"linker",x);  \
     } while (0)
 #else /* !LINKER_DEBUG_TO_LOG */
-extern int format_fd(int, const char *, ...) __attribute__((__format__(printf, 2, 3)));
 #define _PRINTVF(v,x...)                           \
     do {                                             \
-        if (debug_verbosity > (v)) format_fd(1, x);  \
+        if (debug_verbosity > (v)) __libc_format_fd(1, x);  \
     } while (0)
 #endif /* !LINKER_DEBUG_TO_LOG */