Fork of the Android NDK crazy linker.

third_party/android_crazy_linker/src/src/crazy_linker_ashmem.h

Index: third_party/android_crazy_linker/src/src/crazy_linker_ashmem.h
diff --git a/third_party/android_crazy_linker/src/src/crazy_linker_ashmem.h b/third_party/android_crazy_linker/src/src/crazy_linker_ashmem.h
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index 0000000000000000000000000000000000000000..9159caa74da1edb319b511649c697a63528a25ad
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+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CRAZY_LINKER_ASHMEM_H
+#define CRAZY_LINKER_ASHMEM_H
+
+#include <unistd.h>
+
+namespace crazy {
+
+// Helper class to hold a scoped ashmem region file descriptor.
+class AshmemRegion {
+ public:
+  AshmemRegion() : fd_(-1) {}
+
+  ~AshmemRegion() { Reset(-1); }
+
+  int fd() const { return fd_; }
+
+  int Release() {
+    int ret = fd_;
+    fd_ = -1;
+    return ret;
+  }
+
+  void Reset(int fd) {
+    if (fd_ != -1) {
+      ::close(fd_);
+    }
+    fd_ = fd;
+  }
+
+  // Try to allocate a new ashmem region of |region_size|
+  // (page-aligned) bytes. |region_name| is optional, if not NULL
+  // it will be the name of the region (only used for debugging).
+  // Returns true on success, false otherwise.
+  bool Allocate(size_t region_size, const char* region_name);
+
+  // Change the protection flags of the region. Returns true on success.
+  // On failure, check errno for an error code.
+  bool SetProtectionFlags(int prot_flags);
+
+  // Check that the region tied to file descriptor |fd| is properly read-only:
+  // I.e. that it cannot be mapped writable, or that a read-only mapping cannot
+  // be mprotect()-ed into MAP_WRITE. On failure, return false and sets errno.
+  //
+  // See:
+  //   http://www.cvedetails.com/cve/CVE-2011-1149/
+  // And kernel patch at:
+  //   https://android.googlesource.com/kernel/common.git/+/
+  //     56f76fc68492af718fff88927bc296635d634b78%5E%21/
+  static bool CheckFileDescriptorIsReadOnly(int fd);
+
+ private:
+  AshmemRegion(const AshmemRegion& other);
+  AshmemRegion& operator=(const AshmemRegion& other);
+
+  int fd_;
+};
+
+}  // namespace crazy
+
+#endif  // CRAZY_LINKER_ASHMEM_H