diff --git a/libc/Android.bp b/libc/Android.bp
index a02139a..52e53e2 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1402,6 +1402,7 @@
         "bionic/wmempcpy.cpp",
         "system_properties/context_node.cpp",
         "system_properties/contexts_split.cpp",
+        "system_properties/contexts_serialized.cpp",
         "system_properties/prop_area.cpp",
         "system_properties/prop_info.cpp",
         "system_properties/system_properties.cpp",
@@ -1423,6 +1424,7 @@
             cflags: ["-D__ANDROID_TREBLE__"],
         },
     },
+    whole_static_libs: ["libpropertyinfoparser"],
     cppflags: ["-Wold-style-cast"],
     local_include_dirs: ["stdio"],
     include_dirs: ["bionic/libstdc++/include"],
diff --git a/libc/stdio/vfscanf.c b/libc/stdio/vfscanf.c
index 887b435..c9e4385 100644
--- a/libc/stdio/vfscanf.c
+++ b/libc/stdio/vfscanf.c
@@ -324,10 +324,7 @@
         /* scan arbitrary characters (sets NOSKIP) */
         if (width == 0) width = 1;
         if (flags & LONG) {
-          if ((flags & SUPPRESS) == 0)
-            wcp = va_arg(ap, wchar_t*);
-          else
-            wcp = NULL;
+          wcp = ((flags & SUPPRESS) == 0) ? va_arg(ap, wchar_t*) : NULL;
           n = 0;
           while (width != 0) {
             if (n == (int)MB_CUR_MAX) {
@@ -388,20 +385,17 @@
         break;
 
       case CT_CCL:
-        /* scan a (nonempty) character class (sets NOSKIP) */
-        if (width == 0) width = (size_t)~0; /* `infinity' */
-        /* take only those things in the class */
+      case CT_STRING:
+        // CT_CCL: scan a (nonempty) character class (sets NOSKIP).
+        // CT_STRING: like CCL, but zero-length string OK, & no NOSKIP.
+        if (width == 0) width = (size_t)~0; // 'infinity'.
         if (flags & LONG) {
           wchar_t twc;
-          int nchars;
+          int nchars = 0;
 
-          if ((flags & SUPPRESS) == 0)
-            wcp = va_arg(ap, wchar_t*);
-          else
-            wcp = &twc;
+          wcp = (flags & SUPPRESS) == 0 ? va_arg(ap, wchar_t*) : &twc;
           n = 0;
-          nchars = 0;
-          while (width != 0) {
+          while ((c == CT_CCL || !isspace(*fp->_p)) && width != 0) {
             if (n == (int)MB_CUR_MAX) {
               fp->_flags |= __SERR;
               goto input_failure;
@@ -417,7 +411,7 @@
             }
             if (nconv == 0) *wcp = L'\0';
             if (nconv != (size_t)-2) {
-              if (wctob(*wcp) != EOF && !ccltab[wctob(*wcp)]) {
+              if ((c == CT_CCL && wctob(*wcp) != EOF && !ccltab[wctob(*wcp)]) || (c == CT_STRING && iswspace(*wcp))) {
                 while (n != 0) {
                   n--;
                   ungetc(buf[n], fp);
@@ -438,121 +432,46 @@
               break;
             }
           }
-          if (n != 0) {
+          if (c == CT_CCL && n != 0) {
             fp->_flags |= __SERR;
             goto input_failure;
           }
           n = nchars;
-          if (n == 0) goto match_failure;
-          if (!(flags & SUPPRESS)) {
-            *wcp = L'\0';
-            nassigned++;
-          }
-        } else
-            /* take only those things in the class */
-            if (flags & SUPPRESS) {
+        } else if (flags & SUPPRESS) {
           n = 0;
-          while (ccltab[*fp->_p]) {
+          while ((c == CT_CCL && ccltab[*fp->_p]) || (c == CT_STRING && !isspace(*fp->_p))) {
             n++, fp->_r--, fp->_p++;
             if (--width == 0) break;
             if (fp->_r <= 0 && __srefill(fp)) {
-              if (n == 0) goto input_failure;
+              if (c == CT_CCL && n == 0) goto input_failure;
               break;
             }
           }
-          if (n == 0) goto match_failure;
         } else {
           p0 = p = va_arg(ap, char*);
-          while (ccltab[*fp->_p]) {
+          while ((c == CT_CCL && ccltab[*fp->_p]) || (c == CT_STRING && !isspace(*fp->_p))) {
             fp->_r--;
             *p++ = *fp->_p++;
             if (--width == 0) break;
             if (fp->_r <= 0 && __srefill(fp)) {
-              if (p == p0) goto input_failure;
+              if (c == CT_CCL && p == p0) goto input_failure;
               break;
             }
           }
           n = p - p0;
-          if (n == 0) goto match_failure;
-          *p = '\0';
-          nassigned++;
+        }
+        if (c == CT_CCL && n == 0) goto match_failure;
+        if (!(flags & SUPPRESS)) {
+          if (flags & LONG) {
+            *wcp = L'\0';
+          } else {
+            *p = '\0';
+          }
+          ++nassigned;
         }
         nread += n;
         break;
 
-      case CT_STRING:
-        /* like CCL, but zero-length string OK, & no NOSKIP */
-        if (width == 0) width = (size_t)~0;
-        if (flags & LONG) {
-          wchar_t twc;
-
-          if ((flags & SUPPRESS) == 0)
-            wcp = va_arg(ap, wchar_t*);
-          else
-            wcp = &twc;
-          n = 0;
-          while (!isspace(*fp->_p) && width != 0) {
-            if (n == (int)MB_CUR_MAX) {
-              fp->_flags |= __SERR;
-              goto input_failure;
-            }
-            buf[n++] = *fp->_p;
-            fp->_p++;
-            fp->_r--;
-            memset(&mbs, 0, sizeof(mbs));
-            nconv = mbrtowc(wcp, buf, n, &mbs);
-            if (nconv == (size_t)-1) {
-              fp->_flags |= __SERR;
-              goto input_failure;
-            }
-            if (nconv == 0) *wcp = L'\0';
-            if (nconv != (size_t)-2) {
-              if (iswspace(*wcp)) {
-                while (n != 0) {
-                  n--;
-                  ungetc(buf[n], fp);
-                }
-                break;
-              }
-              nread += n;
-              width--;
-              if (!(flags & SUPPRESS)) wcp++;
-              n = 0;
-            }
-            if (fp->_r <= 0 && __srefill(fp)) {
-              if (n != 0) {
-                fp->_flags |= __SERR;
-                goto input_failure;
-              }
-              break;
-            }
-          }
-          if (!(flags & SUPPRESS)) {
-            *wcp = L'\0';
-            nassigned++;
-          }
-        } else if (flags & SUPPRESS) {
-          n = 0;
-          while (!isspace(*fp->_p)) {
-            n++, fp->_r--, fp->_p++;
-            if (--width == 0) break;
-            if (fp->_r <= 0 && __srefill(fp)) break;
-          }
-          nread += n;
-        } else {
-          p0 = p = va_arg(ap, char*);
-          while (!isspace(*fp->_p)) {
-            fp->_r--;
-            *p++ = *fp->_p++;
-            if (--width == 0) break;
-            if (fp->_r <= 0 && __srefill(fp)) break;
-          }
-          *p = '\0';
-          nread += p - p0;
-          nassigned++;
-        }
-        continue;
-
       case CT_INT:
         /* scan an integer as if by strtoimax/strtoumax */
 #ifdef hardway
diff --git a/libc/stdio/vfwscanf.c b/libc/stdio/vfwscanf.c
index 1030a62..71cd49b 100644
--- a/libc/stdio/vfwscanf.c
+++ b/libc/stdio/vfwscanf.c
@@ -182,7 +182,7 @@
         if ((wi = __fgetwc_unlock(fp)) == WEOF) goto input_failure;
         if (wi != c) {
           __ungetwc(wi, fp);
-          goto input_failure;
+          goto match_failure;
         }
         nread++;
         continue;
@@ -402,28 +402,26 @@
         break;
 
       case CT_CCL:
-        /* scan a (nonempty) character class (sets NOSKIP) */
-        if (width == 0) width = (size_t)~0; /* `infinity' */
-        /* take only those things in the class */
+      case CT_STRING:
+        // CT_CCL: scan a (nonempty) character class (sets NOSKIP).
+        // CT_STRING: like CCL, but zero-length string OK, & no NOSKIP.
+        if (width == 0) width = (size_t)~0; // 'infinity'.
         if ((flags & SUPPRESS) && (flags & LONG)) {
           n = 0;
-          while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && in_ccl(wi, ccl)) n++;
+          while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && ((c == CT_CCL && in_ccl(wi, ccl)) || (c == CT_STRING && !iswspace(wi)))) n++;
           if (wi != WEOF) __ungetwc(wi, fp);
-          if (n == 0) goto match_failure;
         } else if (flags & LONG) {
           p0 = p = va_arg(ap, wchar_t*);
-          while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && in_ccl(wi, ccl))
+          while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && ((c == CT_CCL && in_ccl(wi, ccl)) || (c == CT_STRING && !iswspace(wi)))) {
             *p++ = (wchar_t)wi;
+          }
           if (wi != WEOF) __ungetwc(wi, fp);
           n = p - p0;
-          if (n == 0) goto match_failure;
-          *p = 0;
-          nassigned++;
         } else {
           if (!(flags & SUPPRESS)) mbp = va_arg(ap, char*);
           n = 0;
           memset(&mbs, 0, sizeof(mbs));
-          while ((wi = __fgetwc_unlock(fp)) != WEOF && width != 0 && in_ccl(wi, ccl)) {
+          while ((wi = __fgetwc_unlock(fp)) != WEOF && width != 0 && ((c == CT_CCL && in_ccl(wi, ccl)) || (c == CT_STRING && !iswspace(wi)))) {
             if (width >= MB_CUR_MAX && !(flags & SUPPRESS)) {
               nconv = wcrtomb(mbp, wi, &mbs);
               if (nconv == (size_t)-1) goto input_failure;
@@ -438,57 +436,20 @@
             n++;
           }
           if (wi != WEOF) __ungetwc(wi, fp);
-          if (n == 0) goto match_failure;
-          if (!(flags & SUPPRESS)) {
-            *mbp = 0;
-            nassigned++;
+        }
+        if (c == CT_CCL && n == 0) goto match_failure;
+        if (!(flags & SUPPRESS)) {
+          if (flags & LONG) {
+            *p = L'\0';
+          } else {
+            *mbp = '\0';
           }
+          ++nassigned;
         }
         nread += n;
         nconversions++;
         break;
 
-      case CT_STRING:
-        /* like CCL, but zero-length string OK, & no NOSKIP */
-        if (width == 0) width = (size_t)~0;
-        if ((flags & SUPPRESS) && (flags & LONG)) {
-          while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && !iswspace(wi)) nread++;
-          if (wi != WEOF) __ungetwc(wi, fp);
-        } else if (flags & LONG) {
-          p0 = p = va_arg(ap, wchar_t*);
-          while ((wi = __fgetwc_unlock(fp)) != WEOF && width-- != 0 && !iswspace(wi)) {
-            *p++ = (wchar_t)wi;
-            nread++;
-          }
-          if (wi != WEOF) __ungetwc(wi, fp);
-          *p = 0;
-          nassigned++;
-        } else {
-          if (!(flags & SUPPRESS)) mbp = va_arg(ap, char*);
-          memset(&mbs, 0, sizeof(mbs));
-          while ((wi = __fgetwc_unlock(fp)) != WEOF && width != 0 && !iswspace(wi)) {
-            if (width >= MB_CUR_MAX && !(flags & SUPPRESS)) {
-              nconv = wcrtomb(mbp, wi, &mbs);
-              if (nconv == (size_t)-1) goto input_failure;
-            } else {
-              nconv = wcrtomb(mbbuf, wi, &mbs);
-              if (nconv == (size_t)-1) goto input_failure;
-              if (nconv > width) break;
-              if (!(flags & SUPPRESS)) memcpy(mbp, mbbuf, nconv);
-            }
-            if (!(flags & SUPPRESS)) mbp += nconv;
-            width -= nconv;
-            nread++;
-          }
-          if (wi != WEOF) __ungetwc(wi, fp);
-          if (!(flags & SUPPRESS)) {
-            *mbp = 0;
-            nassigned++;
-          }
-        }
-        nconversions++;
-        continue;
-
       case CT_INT:
         /* scan an integer as if by strtoimax/strtoumax */
         if (width == 0 || width > sizeof(buf) / sizeof(*buf) - 1)
diff --git a/libc/system_properties/context_node.h b/libc/system_properties/context_node.h
index 1c6cbbb..769b853 100644
--- a/libc/system_properties/context_node.h
+++ b/libc/system_properties/context_node.h
@@ -41,9 +41,16 @@
   ~ContextNode() {
     Unmap();
   }
+
+  ContextNode(const ContextNode&) = delete;
+  ContextNode(ContextNode&&) = delete;
+  void operator=(const ContextNode&) = delete;
+  void operator=(const ContextNode&&) = delete;
+
   bool Open(bool access_rw, bool* fsetxattr_failed);
   bool CheckAccessAndOpen();
   void ResetAccess();
+  void Unmap();
 
   const char* context() const {
     return context_;
@@ -54,7 +61,6 @@
 
  private:
   bool CheckAccess();
-  void Unmap();
 
   Lock lock_;
   const char* context_;
diff --git a/libc/system_properties/contexts_serialized.cpp b/libc/system_properties/contexts_serialized.cpp
new file mode 100644
index 0000000..117b5cf
--- /dev/null
+++ b/libc/system_properties/contexts_serialized.cpp
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2017 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 "contexts_serialized.h"
+
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <new>
+
+#include <async_safe/log.h>
+
+#include "private/bionic_prctl.h"
+#include "property_filename.h"
+
+bool ContextsSerialized::InitializeContextNodes() {
+  auto num_context_nodes = property_info_area_file_->num_contexts();
+  auto context_nodes_mmap_size = sizeof(ContextNode) * num_context_nodes;
+  // We want to avoid malloc in system properties, so we take an anonymous map instead (b/31659220).
+  void* const map_result = mmap(nullptr, context_nodes_mmap_size, PROT_READ | PROT_WRITE,
+                                MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (map_result == MAP_FAILED) {
+    return false;
+  }
+
+  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map_result, context_nodes_mmap_size,
+        "System property context nodes");
+
+  context_nodes_ = reinterpret_cast<ContextNode*>(map_result);
+  num_context_nodes_ = num_context_nodes;
+  context_nodes_mmap_size_ = context_nodes_mmap_size;
+
+  for (size_t i = 0; i < num_context_nodes; ++i) {
+    new (&context_nodes_[i]) ContextNode(property_info_area_file_->context(i));
+  }
+
+  return true;
+}
+
+bool ContextsSerialized::MapSerialPropertyArea(bool access_rw, bool* fsetxattr_failed) {
+  char filename[PROP_FILENAME_MAX];
+  int len = async_safe_format_buffer(filename, sizeof(filename), "%s/properties_serial",
+                                     property_filename);
+  if (len < 0 || len > PROP_FILENAME_MAX) {
+    serial_prop_area_ = nullptr;
+    return false;
+  }
+
+  if (access_rw) {
+    serial_prop_area_ =
+        prop_area::map_prop_area_rw(filename, "u:object_r:properties_serial:s0", fsetxattr_failed);
+  } else {
+    serial_prop_area_ = prop_area::map_prop_area(filename);
+  }
+  return serial_prop_area_;
+}
+
+bool ContextsSerialized::InitializeProperties() {
+  if (!property_info_area_file_.LoadDefaultPath()) {
+    return false;
+  }
+
+  if (!InitializeContextNodes()) {
+    FreeAndUnmap();
+    return false;
+  }
+
+  return true;
+}
+
+bool ContextsSerialized::Initialize(bool writable) {
+  if (!InitializeProperties()) {
+    return false;
+  }
+
+  if (writable) {
+    mkdir(property_filename, S_IRWXU | S_IXGRP | S_IXOTH);
+    bool open_failed = false;
+    bool fsetxattr_failed = false;
+
+    for (size_t i = 0; i < num_context_nodes_; ++i) {
+      if (!context_nodes_[i].Open(true, &fsetxattr_failed)) {
+        open_failed = true;
+      }
+    }
+    if (open_failed || !MapSerialPropertyArea(true, &fsetxattr_failed)) {
+      FreeAndUnmap();
+      return false;
+    }
+
+    return !fsetxattr_failed;
+  } else {
+    if (!MapSerialPropertyArea(false, nullptr)) {
+      FreeAndUnmap();
+      return false;
+    }
+  }
+  return true;
+}
+
+prop_area* ContextsSerialized::GetPropAreaForName(const char* name) {
+  uint32_t index;
+  property_info_area_file_->GetPropertyInfoIndexes(name, &index, nullptr);
+  if (index == ~0u || index >= num_context_nodes_) {
+    async_safe_format_log(ANDROID_LOG_ERROR, "libc", "Could not find context for property \"%s\"",
+                          name);
+    return nullptr;
+  }
+  auto* context_node = &context_nodes_[index];
+  if (!context_node->pa()) {
+    // We explicitly do not check no_access_ in this case because unlike the
+    // case of foreach(), we want to generate an selinux audit for each
+    // non-permitted property access in this function.
+    context_node->Open(false, nullptr);
+  }
+  return context_node->pa();
+}
+
+void ContextsSerialized::ForEach(void (*propfn)(const prop_info* pi, void* cookie), void* cookie) {
+  for (size_t i = 0; i < num_context_nodes_; ++i) {
+    if (context_nodes_[i].CheckAccessAndOpen()) {
+      context_nodes_[i].pa()->foreach (propfn, cookie);
+    }
+  }
+}
+
+void ContextsSerialized::ResetAccess() {
+  for (size_t i = 0; i < num_context_nodes_; ++i) {
+    context_nodes_[i].ResetAccess();
+  }
+}
+
+void ContextsSerialized::FreeAndUnmap() {
+  property_info_area_file_.Reset();
+  if (context_nodes_ != nullptr) {
+    for (size_t i = 0; i < num_context_nodes_; ++i) {
+      context_nodes_[i].Unmap();
+    }
+    munmap(context_nodes_, context_nodes_mmap_size_);
+    context_nodes_ = nullptr;
+  }
+  prop_area::unmap_prop_area(&serial_prop_area_);
+  serial_prop_area_ = nullptr;
+}
diff --git a/libc/system_properties/contexts_serialized.h b/libc/system_properties/contexts_serialized.h
new file mode 100644
index 0000000..52474c3
--- /dev/null
+++ b/libc/system_properties/contexts_serialized.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#ifndef SYSTEM_PROPERTIES_CONTEXTS_SERIALIZED_H
+#define SYSTEM_PROPERTIES_CONTEXTS_SERIALIZED_H
+
+#include <property_info_parser/property_info_parser.h>
+
+#include "context_node.h"
+#include "contexts.h"
+
+class ContextsSerialized : public Contexts {
+ public:
+  virtual ~ContextsSerialized() override {
+  }
+
+  virtual bool Initialize(bool writable) override;
+  virtual prop_area* GetPropAreaForName(const char* name) override;
+  virtual prop_area* GetSerialPropArea() override {
+    return serial_prop_area_;
+  }
+  virtual void ForEach(void (*propfn)(const prop_info* pi, void* cookie), void* cookie) override;
+  virtual void ResetAccess() override;
+  virtual void FreeAndUnmap() override;
+
+ private:
+  bool InitializeContextNodes();
+  bool InitializeProperties();
+  bool MapSerialPropertyArea(bool access_rw, bool* fsetxattr_failed);
+
+  android::properties::PropertyInfoAreaFile property_info_area_file_;
+  ContextNode* context_nodes_ = nullptr;
+  size_t num_context_nodes_ = 0;
+  size_t context_nodes_mmap_size_ = 0;
+  prop_area* serial_prop_area_ = nullptr;
+};
+
+#endif
diff --git a/libc/system_properties/prop_area.cpp b/libc/system_properties/prop_area.cpp
index e11f292..032fa4e 100644
--- a/libc/system_properties/prop_area.cpp
+++ b/libc/system_properties/prop_area.cpp
@@ -26,6 +26,7 @@
  * SUCH DAMAGE.
  */
 
+#include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <sys/cdefs.h>
diff --git a/libc/system_properties/system_properties.cpp b/libc/system_properties/system_properties.cpp
index 89a6fe7..93184a3 100644
--- a/libc/system_properties/system_properties.cpp
+++ b/libc/system_properties/system_properties.cpp
@@ -59,6 +59,7 @@
 #include "context_node.h"
 #include "contexts.h"
 #include "contexts_pre_split.h"
+#include "contexts_serialized.h"
 #include "contexts_split.h"
 #include "prop_area.h"
 #include "prop_info.h"
@@ -71,6 +72,7 @@
 static union ContextsUnion {
   ContextsUnion() {}
   ~ContextsUnion() {}
+  ContextsSerialized contexts_serialized;
   ContextsSplit contexts_split;
   ContextsPreSplit contexts_pre_split;
 } contexts_union;
diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index f0e0ab6..e060cd9 100644
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -1016,6 +1016,95 @@
   CheckScanf(swscanf, L"+,-/.", L"%[+--/]", 1, "+,-/");
 }
 
+// https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=202240
+TEST(STDIO_TEST, scanf_wscanf_EOF) {
+  EXPECT_EQ(0, sscanf("b", "ab"));
+  EXPECT_EQ(EOF, sscanf("", "a"));
+  EXPECT_EQ(0, swscanf(L"b", L"ab"));
+  EXPECT_EQ(EOF, swscanf(L"", L"a"));
+}
+
+TEST(STDIO_TEST, scanf_invalid_UTF8) {
+#if 0 // TODO: more tests invented during code review; no regressions, so fix later.
+  char buf[BUFSIZ];
+  wchar_t wbuf[BUFSIZ];
+
+  memset(buf, 0, sizeof(buf));
+  memset(wbuf, 0, sizeof(wbuf));
+  EXPECT_EQ(0, sscanf("\xc0" " foo", "%ls %s", wbuf, buf));
+#endif
+}
+
+TEST(STDIO_TEST, scanf_no_match_no_termination) {
+  char buf[4] = "x";
+  EXPECT_EQ(0, sscanf("d", "%[abc]", buf));
+  EXPECT_EQ('x', buf[0]);
+  EXPECT_EQ(0, swscanf(L"d", L"%[abc]", buf));
+  EXPECT_EQ('x', buf[0]);
+
+  wchar_t wbuf[4] = L"x";
+  EXPECT_EQ(0, swscanf(L"d", L"%l[abc]", wbuf));
+  EXPECT_EQ(L'x', wbuf[0]);
+
+  EXPECT_EQ(EOF, sscanf("", "%s", buf));
+  EXPECT_EQ('x', buf[0]);
+
+  EXPECT_EQ(EOF, swscanf(L"", L"%ls", wbuf));
+  EXPECT_EQ(L'x', wbuf[0]);
+}
+
+TEST(STDIO_TEST, scanf_wscanf_wide_character_class) {
+#if 0 // TODO: more tests invented during code review; no regressions, so fix later.
+  wchar_t buf[BUFSIZ];
+
+  // A wide character shouldn't match an ASCII-only class for scanf or wscanf.
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, sscanf("xĀyz", "%l[xy]", buf));
+  EXPECT_EQ(L"x"s, std::wstring(buf));
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, swscanf(L"xĀyz", L"%l[xy]", buf));
+  EXPECT_EQ(L"x"s, std::wstring(buf));
+
+  // Even if scanf has wide characters in a class, they won't match...
+  // TODO: is that a bug?
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, sscanf("xĀyz", "%l[xĀy]", buf));
+  EXPECT_EQ(L"x"s, std::wstring(buf));
+  // ...unless you use wscanf.
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, swscanf(L"xĀyz", L"%l[xĀy]", buf));
+  EXPECT_EQ(L"xĀy"s, std::wstring(buf));
+
+  // Negation only covers ASCII for scanf...
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, sscanf("xĀyz", "%l[^ab]", buf));
+  EXPECT_EQ(L"x"s, std::wstring(buf));
+  // ...but covers wide characters for wscanf.
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, swscanf(L"xĀyz", L"%l[^ab]", buf));
+  EXPECT_EQ(L"xĀyz"s, std::wstring(buf));
+
+  // We already determined that non-ASCII characters are ignored in scanf classes.
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, sscanf("x"
+                      "\xc4\x80" // Matches a byte from each wide char in the class.
+                      "\xc6\x82" // Neither byte is in the class.
+                      "yz",
+                      "%l[xy" "\xc5\x80" "\xc4\x81" "]", buf));
+  EXPECT_EQ(L"x", std::wstring(buf));
+  // bionic and glibc both behave badly for wscanf, so let's call it right for now...
+  memset(buf, 0, sizeof(buf));
+  EXPECT_EQ(1, swscanf(L"x"
+                       L"\xc4\x80"
+                       L"\xc6\x82"
+                       L"yz",
+                       L"%l[xy" L"\xc5\x80" L"\xc4\x81" L"]", buf));
+  // Note that this isn't L"xĀ" --- although the *bytes* matched, they're
+  // not put back together as a wide character.
+  EXPECT_EQ(L"x" L"\xc4" L"\x80", std::wstring(buf));
+#endif
+}
+
 TEST(STDIO_TEST, cantwrite_EBADF) {
   // If we open a file read-only...
   FILE* fp = fopen("/proc/version", "r");
diff --git a/tools/versioner/platforms b/tools/versioner/platforms
deleted file mode 120000
index bcb7da8..0000000
--- a/tools/versioner/platforms
+++ /dev/null
@@ -1 +0,0 @@
-../../../development/ndk/platforms
\ No newline at end of file
diff --git a/tools/versioner/src/SymbolDatabase.cpp b/tools/versioner/src/SymbolDatabase.cpp
index 8521f4d..5b8ed5a 100644
--- a/tools/versioner/src/SymbolDatabase.cpp
+++ b/tools/versioner/src/SymbolDatabase.cpp
@@ -61,91 +61,3 @@
 
   return result;
 }
-
-// The NDK platforms are built by copying the platform directories on top of
-// each other to build each successive API version. Thus, we need to walk
-// backwards to find each desired file.
-static std::string readPlatformFile(const CompilationType& type, llvm::StringRef platform_dir,
-                                    const std::string& filename, bool required) {
-  int api_level = type.api_level;
-  std::ifstream stream;
-  while (api_level >= arch_min_api[type.arch]) {
-    std::string path = std::string(platform_dir) + "/android-" + std::to_string(api_level) +
-                       "/arch-" + to_string(type.arch) + "/symbols/" + filename;
-
-    stream = std::ifstream(path);
-    if (stream) {
-      return std::string(std::istreambuf_iterator<char>(stream), std::istreambuf_iterator<char>());
-    }
-
-    --api_level;
-  }
-
-  if (required) {
-    errx(1, "failed to find platform file '%s' for %s", filename.c_str(), to_string(type).c_str());
-  }
-
-  return std::string();
-}
-
-static std::map<std::string, NdkSymbolType> parsePlatform(const CompilationType& type,
-                                                          const std::string& platform_dir) {
-  std::map<std::string, NdkSymbolType> result;
-  std::map<std::string, bool /*required*/> wanted_files = {
-    { "libc.so.functions.txt", true },
-    { "libc.so.variables.txt", false },
-    { "libdl.so.functions.txt", false },
-    { "libm.so.functions.txt", false },
-    { "libm.so.variables.txt", false },
-  };
-
-  for (const auto& pair : wanted_files) {
-    llvm::StringRef file = pair.first;
-    bool required = pair.second;
-    NdkSymbolType symbol_type;
-    if (file.endswith(".functions.txt")) {
-      symbol_type = NdkSymbolType::function;
-    } else if (file.endswith(".variables.txt")) {
-      symbol_type = NdkSymbolType::variable;
-    } else {
-      errx(1, "internal error: unexpected platform filename '%s'\n", file.str().c_str());
-    }
-
-    std::string platform_file = readPlatformFile(type, platform_dir, file, required);
-    if (platform_file.empty()) {
-      continue;
-    }
-
-    llvm::SmallVector<llvm::StringRef, 0> symbols;
-    llvm::StringRef(platform_file).split(symbols, "\n");
-
-    for (llvm::StringRef symbol_name : symbols) {
-      if (symbol_name.empty()) {
-        continue;
-      }
-
-      if (result.count(symbol_name) != 0) {
-        if (strict) {
-          printf("duplicated symbol '%s' in '%s'\n", symbol_name.str().c_str(), file.str().c_str());
-        }
-      }
-
-      result[symbol_name] = symbol_type;
-    }
-  }
-
-  return result;
-}
-
-NdkSymbolDatabase parsePlatforms(const std::set<CompilationType>& types,
-                                 const std::string& platform_dir) {
-  std::map<std::string, std::map<CompilationType, NdkSymbolType>> result;
-  for (const CompilationType& type : types) {
-    std::map<std::string, NdkSymbolType> symbols = parsePlatform(type, platform_dir);
-    for (const auto& it : symbols) {
-      result[it.first][type] = it.second;
-    }
-  }
-
-  return result;
-}
diff --git a/tools/versioner/src/SymbolDatabase.h b/tools/versioner/src/SymbolDatabase.h
index 09948f5..c5b89d7 100644
--- a/tools/versioner/src/SymbolDatabase.h
+++ b/tools/versioner/src/SymbolDatabase.h
@@ -32,5 +32,3 @@
 };
 
 using NdkSymbolDatabase = std::map<std::string, std::map<CompilationType, NdkSymbolType>>;
-NdkSymbolDatabase parsePlatforms(const std::set<CompilationType>& types,
-                                 const std::string& platform_dir);
diff --git a/tools/versioner/src/versioner.cpp b/tools/versioner/src/versioner.cpp
index a082f07..efb39bd 100644
--- a/tools/versioner/src/versioner.cpp
+++ b/tools/versioner/src/versioner.cpp
@@ -33,6 +33,7 @@
 #include <iostream>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <sstream>
 #include <string>
@@ -614,9 +615,6 @@
     std::string versioner_dir = to_string(top) + "/bionic/tools/versioner";
     location.header_path = versioner_dir + "/current";
     location.dependency_dir = versioner_dir + "/dependencies";
-    if (platform_dir.empty()) {
-      platform_dir = versioner_dir + "/platforms";
-    }
   } else {
     if (!android::base::Realpath(argv[optind], &location.header_path)) {
       err(1, "failed to get realpath for path '%s'", argv[optind]);
@@ -653,16 +651,10 @@
   }
 
   std::set<CompilationType> compilation_types;
-  NdkSymbolDatabase symbol_database;
+  std::optional<NdkSymbolDatabase> symbol_database;
 
   compilation_types = generateCompilationTypes(selected_architectures, selected_levels);
 
-  // Do this before compiling so that we can early exit if the platforms don't match what we
-  // expect.
-  if (!platform_dir.empty()) {
-    symbol_database = parsePlatforms(compilation_types, platform_dir);
-  }
-
   auto start = std::chrono::high_resolution_clock::now();
   std::unique_ptr<HeaderDatabase> declaration_database =
       compileHeaders(compilation_types, location);
@@ -682,8 +674,8 @@
       failed = true;
     }
 
-    if (!platform_dir.empty()) {
-      if (!checkVersions(compilation_types, declaration_database.get(), symbol_database)) {
+    if (symbol_database) {
+      if (!checkVersions(compilation_types, declaration_database.get(), *symbol_database)) {
         printf("versioner: version check failed\n");
         failed = true;
       }