diff --git a/HACKING.txt b/HACKING.txt
index fb93b5a..27e1368 100644
--- a/HACKING.txt
+++ b/HACKING.txt
@@ -81,13 +81,6 @@
   private/
     # These are private header files meant for use within bionic itself.
 
-  stdio/
-  stdlib/
-  unistd/
-    # These are legacy files of unknown provenance. In the past, bionic was a
-    # mess of random versions of random files from all three of FreeBSD, NetBSD,
-    # and OpenBSD! We've been working to clean that up, but these directories
-    # are basically where all the stuff we haven't got to yet lives.
   dns/
     # Contains the DNS resolver (originates from NetBSD code).
 
@@ -114,6 +107,10 @@
     # current upstream source in one of the upstream directories or by
     # switching the file to C++ and cleaning it up.
 
+  stdio/
+    # These are legacy files of dubious provenance. We're working to clean
+    # this mess up, and this directory should disappear.
+
   tools/
     # Various tools used to maintain bionic.
 
diff --git a/libc/Android.mk b/libc/Android.mk
index 0adaff7..fd3da96 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -67,7 +67,6 @@
     bionic/unlockpt.c \
     stdio/snprintf.c\
     stdio/sprintf.c \
-    unistd/syslog.c \
 
 # Fortify implementations of libc functions.
 libc_common_src_files += \
@@ -218,6 +217,7 @@
     bionic/stubs.cpp \
     bionic/symlink.cpp \
     bionic/sysconf.cpp \
+    bionic/syslog.cpp \
     bionic/sys_siglist.c \
     bionic/sys_signame.c \
     bionic/system_properties.cpp \
diff --git a/libc/bionic/libc_logging.cpp b/libc/bionic/libc_logging.cpp
index e656a12..88d9790 100644
--- a/libc/bionic/libc_logging.cpp
+++ b/libc/bionic/libc_logging.cpp
@@ -378,6 +378,9 @@
         } else if (c == '%') {
             buffer[0] = '%';
             buffer[1] = '\0';
+        } else if (c == 'm') {
+            // syslog-like %m for strerror(errno).
+            str = strerror(errno);
         } else {
             __assert(__FILE__, __LINE__, "conversion specifier unsupported");
         }
diff --git a/libc/bionic/syslog.cpp b/libc/bionic/syslog.cpp
new file mode 100644
index 0000000..7e153eb
--- /dev/null
+++ b/libc/bionic/syslog.cpp
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <syslog.h>
+
+#include <stdlib.h>
+
+#include "private/libc_logging.h"
+
+static const char* syslog_log_tag = NULL;
+static int syslog_priority_mask = 0xff;
+
+void closelog() {
+}
+
+void openlog(const char* log_tag, int /*options*/, int /*facility*/) {
+  syslog_log_tag = log_tag;
+}
+
+int setlogmask(int new_mask) {
+  int old_mask = syslog_priority_mask;
+  // 0 is used to query the current mask.
+  if (new_mask != 0) {
+    syslog_priority_mask = new_mask;
+  }
+  return old_mask;
+}
+
+void syslog(int priority, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  vsyslog(priority, fmt, args);
+  va_end(args);
+}
+
+void vsyslog(int priority, const char* fmt, va_list args) {
+  // Check whether we're supposed to be logging messages of this priority.
+  if ((syslog_priority_mask & LOG_MASK(LOG_PRI(priority))) == 0) {
+    return;
+  }
+
+  // What's our log tag?
+  const char* log_tag = syslog_log_tag;
+  if (log_tag == NULL) {
+    log_tag = getprogname();
+  }
+
+  // What's our Android log priority?
+  priority &= LOG_PRIMASK;
+  int android_log_priority;
+  if (priority < LOG_ERR) {
+    android_log_priority = ANDROID_LOG_ERROR;
+  } else if (priority == LOG_WARNING) {
+    android_log_priority = ANDROID_LOG_WARN;
+  } else if (priority <= LOG_INFO) {
+    android_log_priority = ANDROID_LOG_INFO;
+  } else {
+    android_log_priority = ANDROID_LOG_DEBUG;
+  }
+
+  __libc_format_log_va_list(android_log_priority, log_tag, fmt, args);
+}
diff --git a/libc/include/syslog.h b/libc/include/syslog.h
index a52e811..f396fec 100644
--- a/libc/include/syslog.h
+++ b/libc/include/syslog.h
@@ -74,20 +74,18 @@
 #define LOG_MASK(pri) (1 << (pri))
 #define LOG_UPTO(pri) ((1 << ((pri)+1)) - 1)
 
-#define LOG_PID    0x01    /* include pid with message */
-#define LOG_CONS   0x02    /* write to console on logger error */
-#define LOG_ODELAY 0x04    /* delay connection until syslog() */
-#define LOG_NDELAY 0x08    /* open connection immediately */
-#define LOG_NOWAIT 0x10    /* wait for child processes (unused on linux) */
-#define LOG_PERROR 0x20    /* additional logging to stderr */
+#define LOG_PID    0x01
+#define LOG_CONS   0x02
+#define LOG_ODELAY 0x04
+#define LOG_NDELAY 0x08
+#define LOG_NOWAIT 0x10
+#define LOG_PERROR 0x20
 
-#define _PATH_LOG  "/dev/syslog"
-
-extern void	closelog(void);
-extern void	openlog(const char *, int, int);
-extern int	setlogmask(int);
-extern void	syslog(int, const char *, ...) __printflike(2, 3);
-extern void	vsyslog(int, const char *, va_list) __printflike(2, 0);
+extern void closelog(void);
+extern void openlog(const char*, int, int);
+extern int setlogmask(int);
+extern void syslog(int, const char*, ...) __printflike(2, 3);
+extern void vsyslog(int, const char*, va_list) __printflike(2, 0);
 
 __END_DECLS
 
diff --git a/libc/unistd/syslog.c b/libc/unistd/syslog.c
deleted file mode 100644
index 339df68..0000000
--- a/libc/unistd/syslog.c
+++ /dev/null
@@ -1,392 +0,0 @@
-/*	$OpenBSD: syslog.c,v 1.28 2005/08/08 08:05:34 espie Exp $ */
-/*
- * Copyright (c) 1983, 1988, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. 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.
- * 3. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/types.h>
-#include <sys/socket.h>
-#include <sys/uio.h>
-#include <syslog.h>
-#include <sys/un.h>
-#include <netdb.h>
-
-#include <errno.h>
-#include <fcntl.h>
-#include <paths.h>
-#include <stdio.h>
-#include <string.h>
-#include <time.h>
-#include <unistd.h>
-#include <stdarg.h>
-
-struct syslog_data {
-  int log_file;
-  int connected;
-  int opened;
-  int log_stat;
-  const char* log_tag;
-  int log_fac;
-  int log_mask;
-};
-
-#define SYSLOG_DATA_INIT {-1, 0, 0, 0, (const char *)0, LOG_USER, 0xff}
-
-static struct syslog_data sdata = SYSLOG_DATA_INIT;
-
-extern const char	*__progname;		/* Program name, from crt0. */
-
-static void	disconnectlog_r(struct syslog_data *);	/* disconnect from syslogd */
-static void	connectlog_r(struct syslog_data *);	/* (re)connect to syslogd */
-
-#if defined(__LP64__)
-#define SYSLOG_R_VISIBILITY static
-#else
-#define SYSLOG_R_VISIBILITY extern
-#endif
-
-SYSLOG_R_VISIBILITY void closelog_r(struct syslog_data*);
-SYSLOG_R_VISIBILITY void openlog_r(const char*, int, int, struct syslog_data*);
-SYSLOG_R_VISIBILITY int setlogmask_r(int, struct syslog_data*);
-SYSLOG_R_VISIBILITY void syslog_r(int, struct syslog_data*, const char*, ...) __printflike(3, 4);
-SYSLOG_R_VISIBILITY void vsyslog_r(int, struct syslog_data*, const char*, va_list) __printflike(3, 0);
-
-/*
- * syslog, vsyslog --
- *	print message on log file; output is intended for syslogd(8).
- */
-void
-syslog(int pri, const char *fmt, ...)
-{
-	va_list ap;
-
-	va_start(ap, fmt);
-	vsyslog(pri, fmt, ap);
-	va_end(ap);
-}
-
-void
-vsyslog(int pri, const char *fmt, va_list ap)
-{
-	vsyslog_r(pri, &sdata, fmt, ap);
-}
-
-void
-openlog(const char *ident, int logstat, int logfac)
-{
-	openlog_r(ident, logstat, logfac, &sdata);
-}
-
-void
-closelog(void)
-{
-	closelog_r(&sdata);
-}
-
-/* setlogmask -- set the log mask level */
-int
-setlogmask(int pmask)
-{
-	return setlogmask_r(pmask, &sdata);
-}
-
-/* Reentrant version of syslog, i.e. syslog_r() */
-
-void
-syslog_r(int pri, struct syslog_data *data, const char *fmt, ...)
-{
-	va_list ap;
-
-	va_start(ap, fmt);
-	vsyslog_r(pri, data, fmt, ap);
-	va_end(ap);
-}
-
-void
-vsyslog_r(int pri, struct syslog_data *data, const char *fmt, va_list ap)
-{
-	int cnt;
-	char ch, *p, *t;
-	time_t now;
-	int fd, saved_errno, error;
-#define	TBUF_LEN	2048
-#define	FMT_LEN		1024
-	char *stdp = NULL, tbuf[TBUF_LEN], fmt_cpy[FMT_LEN];
-	int tbuf_left, fmt_left, prlen;
-
-#define	INTERNALLOG	LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
-	/* Check for invalid bits. */
-	if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
-		if (data == &sdata) {
-			syslog(INTERNALLOG,
-			    "syslog: unknown facility/priority: %x", pri);
-		} else {
-			syslog_r(INTERNALLOG, data,
-			    "syslog_r: unknown facility/priority: %x", pri);
-		}
-		pri &= LOG_PRIMASK|LOG_FACMASK;
-	}
-
-	/* Check priority against setlogmask values. */
-	if (!(LOG_MASK(LOG_PRI(pri)) & data->log_mask))
-		return;
-
-	saved_errno = errno;
-
-	/* Set default facility if none specified. */
-	if ((pri & LOG_FACMASK) == 0)
-		pri |= data->log_fac;
-
-	/* If we have been called through syslog(), no need for reentrancy. */
-	if (data == &sdata)
-		(void)time(&now);
-
-	p = tbuf;
-	tbuf_left = TBUF_LEN;
-
-#define	DEC()	\
-	do {					\
-		if (prlen < 0)			\
-			prlen = 0;		\
-		if (prlen >= tbuf_left)		\
-			prlen = tbuf_left - 1;	\
-		p += prlen;			\
-		tbuf_left -= prlen;		\
-	} while (0)
-
-	prlen = snprintf(p, tbuf_left, "<%d>", pri);
-	DEC();
-
-	/*
-	 * syslogd will expand time automagically for reentrant case, and
-	 * for normal case, just do like before
-	 */
-	if (data == &sdata) {
-		prlen = strftime(p, tbuf_left, "%h %e %T ", localtime(&now));
-		DEC();
-	}
-
-	if (data->log_stat & LOG_PERROR)
-		stdp = p;
-	if (data->log_tag == NULL)
-		data->log_tag = __progname;
-	if (data->log_tag != NULL) {
-		prlen = snprintf(p, tbuf_left, "%s", data->log_tag);
-		DEC();
-	}
-	if (data->log_stat & LOG_PID) {
-		prlen = snprintf(p, tbuf_left, "[%ld]", (long)getpid());
-		DEC();
-	}
-	if (data->log_tag != NULL) {
-		if (tbuf_left > 1) {
-			*p++ = ':';
-			tbuf_left--;
-		}
-		if (tbuf_left > 1) {
-			*p++ = ' ';
-			tbuf_left--;
-		}
-	}
-
-	/* strerror() is not reentrant */
-
-	for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) {
-		if (ch == '%' && fmt[1] == 'm') {
-			++fmt;
-			if (data == &sdata) {
-				prlen = snprintf(t, fmt_left, "%s",
-				    strerror(saved_errno));
-			} else {
-				prlen = snprintf(t, fmt_left, "Error %d",
-				    saved_errno);
-			}
-			if (prlen < 0)
-				prlen = 0;
-			if (prlen >= fmt_left)
-				prlen = fmt_left - 1;
-			t += prlen;
-			fmt_left -= prlen;
-		} else if (ch == '%' && fmt[1] == '%' && fmt_left > 2) {
-			*t++ = '%';
-			*t++ = '%';
-			fmt++;
-			fmt_left -= 2;
-		} else {
-			if (fmt_left > 1) {
-				*t++ = ch;
-				fmt_left--;
-			}
-		}
-	}
-	*t = '\0';
-
-	prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap);
-	DEC();
-	cnt = p - tbuf;
-
-	/* Output to stderr if requested. */
-	if (data->log_stat & LOG_PERROR) {
-		struct iovec iov[2];
-
-		iov[0].iov_base = stdp;
-		iov[0].iov_len = cnt - (stdp - tbuf);
-		iov[1].iov_base = "\n";
-		iov[1].iov_len = 1;
-		(void)writev(STDERR_FILENO, iov, 2);
-	}
-
-	/* Get connected, output the message to the local logger. */
-	if (!data->opened)
-		openlog_r(data->log_tag, data->log_stat, 0, data);
-	connectlog_r(data);
-
-	/*
-	 * If the send() failed, there are two likely scenarios:
-	 *  1) syslogd was restarted
-	 *  2) /dev/log is out of socket buffer space
-	 * We attempt to reconnect to /dev/log to take care of
-	 * case #1 and keep send()ing data to cover case #2
-	 * to give syslogd a chance to empty its socket buffer.
-	 */
-	if ((error = send(data->log_file, tbuf, cnt, 0)) < 0) {
-		if (errno != ENOBUFS) {
-			disconnectlog_r(data);
-			connectlog_r(data);
-		}
-		do {
-			usleep(1);
-			if ((error = send(data->log_file, tbuf, cnt, 0)) >= 0)
-				break;
-		} while (errno == ENOBUFS);
-	}
-
-	/*
-	 * Output the message to the console; try not to block
-	 * as a blocking console should not stop other processes.
-	 * Make sure the error reported is the one from the syslogd failure.
-	 */
-	if (error == -1 && (data->log_stat & LOG_CONS) &&
-	    (fd = open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) {
-		struct iovec iov[2];
-
-		p = strchr(tbuf, '>') + 1;
-		iov[0].iov_base = p;
-		iov[0].iov_len = cnt - (p - tbuf);
-		iov[1].iov_base = "\r\n";
-		iov[1].iov_len = 2;
-		(void)writev(fd, iov, 2);
-		(void)close(fd);
-	}
-
-	if (data != &sdata)
-		closelog_r(data);
-}
-
-static void
-disconnectlog_r(struct syslog_data *data)
-{
-	/*
-	 * If the user closed the FD and opened another in the same slot,
-	 * that's their problem.  They should close it before calling on
-	 * system services.
-	 */
-	if (data->log_file != -1) {
-		close(data->log_file);
-		data->log_file = -1;
-	}
-	data->connected = 0;		/* retry connect */
-}
-
-static void
-connectlog_r(struct syslog_data *data)
-{
-    union {
-        struct sockaddr     syslogAddr;
-        struct sockaddr_un  syslogAddrUn;
-    } u;
-
-#define SyslogAddr   u.syslogAddrUn
-
-	if (data->log_file == -1) {
-		if ((data->log_file = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
-			return;
-		(void)fcntl(data->log_file, F_SETFD, 1);
-	}
-	if (data->log_file != -1 && !data->connected) {
-		memset(&SyslogAddr, '\0', sizeof(SyslogAddr));
-#if 0
-                /* BIONIC: no sun_len field to fill on Linux */
-		SyslogAddr.sun_len = sizeof(SyslogAddr);
-#endif
-		SyslogAddr.sun_family = AF_UNIX;
-		strlcpy(SyslogAddr.sun_path, _PATH_LOG,
-		    sizeof(SyslogAddr.sun_path));
-		if (connect(data->log_file, &u.syslogAddr,
-		    sizeof(SyslogAddr)) == -1) {
-			(void)close(data->log_file);
-			data->log_file = -1;
-		} else
-			data->connected = 1;
-	}
-}
-
-void
-openlog_r(const char *ident, int logstat, int logfac, struct syslog_data *data)
-{
-	if (ident != NULL)
-		data->log_tag = ident;
-	data->log_stat = logstat;
-	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
-		data->log_fac = logfac;
-
-	if (data->log_stat & LOG_NDELAY)	/* open immediately */
-		connectlog_r(data);
-
-	data->opened = 1;	/* ident and facility has been set */
-}
-
-void
-closelog_r(struct syslog_data *data)
-{
-	(void)close(data->log_file);
-	data->log_file = -1;
-	data->connected = 0;
-	data->log_tag = NULL;
-}
-
-/* setlogmask -- set the log mask level */
-int
-setlogmask_r(int pmask, struct syslog_data *data)
-{
-	int omask;
-
-	omask = data->log_mask;
-	if (pmask != 0)
-		data->log_mask = pmask;
-	return (omask);
-}
diff --git a/tests/libc_logging_test.cpp b/tests/libc_logging_test.cpp
index 950161e..ef39d1c 100644
--- a/tests/libc_logging_test.cpp
+++ b/tests/libc_logging_test.cpp
@@ -176,3 +176,14 @@
   GTEST_LOG_(INFO) << "This test does nothing.\n";
 #endif // __BIONIC__
 }
+
+TEST(libc_logging, m) {
+#if defined(__BIONIC__)
+  char buf[BUFSIZ];
+  errno = EBADF;
+  __libc_format_buffer(buf, sizeof(buf), "<%m>");
+  EXPECT_STREQ("<Bad file number>", buf);
+#else // __BIONIC__
+  GTEST_LOG_(INFO) << "This test does nothing.\n";
+#endif // __BIONIC__
+}