auto import from //depot/cupcake/@135843
diff --git a/libc/bionic/system_properties.c b/libc/bionic/system_properties.c
new file mode 100644
index 0000000..5e3b9e7
--- /dev/null
+++ b/libc/bionic/system_properties.c
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2008 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 <stdlib.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <errno.h>
+
+#include <sys/mman.h>
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/select.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+
+#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
+#include <sys/_system_properties.h>
+
+#include <sys/atomics.h>
+
+static const char property_service_name[] = PROP_SERVICE_NAME;
+
+static unsigned dummy_props = 0;
+
+prop_area *__system_property_area__ = (void*) &dummy_props;
+
+int __system_properties_init(void)
+{
+ prop_area *pa;
+ int s, fd;
+ unsigned sz;
+ char *env;
+
+ if(__system_property_area__ != ((void*) &dummy_props)) {
+ return 0;
+ }
+
+ env = getenv("ANDROID_PROPERTY_WORKSPACE");
+ if (!env) {
+ return -1;
+ }
+ fd = atoi(env);
+ env = strchr(env, ',');
+ if (!env) {
+ return -1;
+ }
+ sz = atoi(env + 1);
+
+ pa = mmap(0, sz, PROT_READ, MAP_SHARED, fd, 0);
+
+ if(pa == MAP_FAILED) {
+ return -1;
+ }
+
+ if((pa->magic != PROP_AREA_MAGIC) || (pa->version != PROP_AREA_VERSION)) {
+ munmap(pa, sz);
+ return -1;
+ }
+
+ __system_property_area__ = pa;
+ return 0;
+}
+
+const prop_info *__system_property_find_nth(unsigned n)
+{
+ prop_area *pa = __system_property_area__;
+
+ if(n >= pa->count) {
+ return 0;
+ } else {
+ return TOC_TO_INFO(pa, pa->toc[n]);
+ }
+}
+
+const prop_info *__system_property_find(const char *name)
+{
+ prop_area *pa = __system_property_area__;
+ unsigned count = pa->count;
+ unsigned *toc = pa->toc;
+ unsigned len = strlen(name);
+ prop_info *pi;
+
+ while(count--) {
+ unsigned entry = *toc++;
+ if(TOC_NAME_LEN(entry) != len) continue;
+
+ pi = TOC_TO_INFO(pa, entry);
+ if(memcmp(name, pi->name, len)) continue;
+
+ return pi;
+ }
+
+ return 0;
+}
+
+int __system_property_read(const prop_info *pi, char *name, char *value)
+{
+ unsigned serial, len;
+
+ for(;;) {
+ serial = pi->serial;
+ while(SERIAL_DIRTY(serial)) {
+ __futex_wait(&pi->serial, serial, 0);
+ serial = pi->serial;
+ }
+ len = SERIAL_VALUE_LEN(serial);
+ memcpy(value, pi->value, len + 1);
+ if(serial == pi->serial) {
+ if(name != 0) {
+ strcpy(name, pi->name);
+ }
+ return len;
+ }
+ }
+}
+
+int __system_property_get(const char *name, char *value)
+{
+ const prop_info *pi = __system_property_find(name);
+
+ if(pi != 0) {
+ return __system_property_read(pi, 0, value);
+ } else {
+ value[0] = 0;
+ return 0;
+ }
+}
+
+int __system_property_wait(const prop_info *pi)
+{
+ unsigned n;
+ if(pi == 0) {
+ prop_area *pa = __system_property_area__;
+ n = pa->serial;
+ do {
+ __futex_wait(&pa->serial, n, 0);
+ } while(n == pa->serial);
+ } else {
+ n = pi->serial;
+ do {
+ __futex_wait(&pi->serial, n, 0);
+ } while(n == pi->serial);
+ }
+ return 0;
+}