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Diffstat (limited to 'fake-android-guest/android/dlext.h')
| -rw-r--r-- | fake-android-guest/android/dlext.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/fake-android-guest/android/dlext.h b/fake-android-guest/android/dlext.h new file mode 100644 index 00000000..37459d4e --- /dev/null +++ b/fake-android-guest/android/dlext.h @@ -0,0 +1,196 @@ +/* + * 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. + */ + +#ifndef __ANDROID_DLEXT_H__ +#define __ANDROID_DLEXT_H__ + +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <sys/cdefs.h> +#include <sys/types.h> /* for off64_t */ + +/** + * @addtogroup libdl Dynamic Linker + * @{ + */ + +/** + * \file + * Advanced dynamic library opening support. Most users will want to use + * the standard [dlopen(3)](http://man7.org/linux/man-pages/man3/dlopen.3.html) + * functionality in `<dlfcn.h>` instead. + */ + +__BEGIN_DECLS + +/** Bitfield definitions for `android_dlextinfo::flags`. */ +enum { + /** + * When set, the `reserved_addr` and `reserved_size` fields must point to an + * already-reserved region of address space which will be used to load the + * library if it fits. + * + * If the reserved region is not large enough, loading will fail. + */ + ANDROID_DLEXT_RESERVED_ADDRESS = 0x1, + + /** + * Like `ANDROID_DLEXT_RESERVED_ADDRESS`, but if the reserved region is not large enough, + * the linker will choose an available address instead. + */ + ANDROID_DLEXT_RESERVED_ADDRESS_HINT = 0x2, + + /** + * When set, write the GNU RELRO section of the mapped library to `relro_fd` + * after relocation has been performed, to allow it to be reused by another + * process loading the same library at the same address. This implies + * `ANDROID_DLEXT_USE_RELRO`. + * + * This is mainly useful for the system WebView implementation. + */ + ANDROID_DLEXT_WRITE_RELRO = 0x4, + + /** + * When set, compare the GNU RELRO section of the mapped library to `relro_fd` + * after relocation has been performed, and replace any relocated pages that + * are identical with a version mapped from the file. + * + * This is mainly useful for the system WebView implementation. + */ + ANDROID_DLEXT_USE_RELRO = 0x8, + + /** + * Use `library_fd` instead of opening the file by name. + * The filename parameter is still used to identify the library. + */ + ANDROID_DLEXT_USE_LIBRARY_FD = 0x10, + + /** + * If opening a library using `library_fd` read it starting at `library_fd_offset`. + * This is mainly useful for loading a library stored within another file (such as uncompressed + * inside a ZIP archive). + * This flag is only valid when `ANDROID_DLEXT_USE_LIBRARY_FD` is set. + */ + ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET = 0x20, + + /** + * When set, do not use `stat(2)` to check if the library has already been loaded. + * + * This flag allows forced loading of the library in the case when for some + * reason multiple ELF files share the same filename (because the already-loaded + * library has been removed and overwritten, for example). + * + * Note that if the library has the same `DT_SONAME` as an old one and some other + * library has the soname in its `DT_NEEDED` list, the first one will be used to resolve any + * dependencies. + */ + ANDROID_DLEXT_FORCE_LOAD = 0x40, + + /** + * When set, if the minimum `p_vaddr` of the ELF file's `PT_LOAD` segments is non-zero, + * the dynamic linker will load it at that address. + * + * This flag is for ART internal use only. + */ + ANDROID_DLEXT_FORCE_FIXED_VADDR = 0x80, + + /** + * Instructs dlopen to load the library at the address specified by reserved_addr. + * + * The difference between `ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS` and + * `ANDROID_DLEXT_RESERVED_ADDRESS` is that for `ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS` the linker + * reserves memory at `reserved_addr` whereas for `ANDROID_DLEXT_RESERVED_ADDRESS` the linker + * relies on the caller to reserve the memory. + * + * This flag can be used with `ANDROID_DLEXT_FORCE_FIXED_VADDR`. When + * `ANDROID_DLEXT_FORCE_FIXED_VADDR` is set and `load_bias` is not 0 (`load_bias` is the + * minimum `p_vaddr` of all `PT_LOAD` segments) this flag is ignored because the linker has to + * pick one address over the other and this way is more convenient for ART. + * Note that `ANDROID_DLEXT_FORCE_FIXED_VADDR` does not generate an error when the minimum + * `p_vaddr` is 0. + * + * Cannot be used with `ANDROID_DLEXT_RESERVED_ADDRESS` or `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`. + * + * This flag is for ART internal use only. + */ + ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS = 0x100, + + /** + * This flag used to load library in a different namespace. The namespace is + * specified in `library_namespace`. + * + * This flag is for internal use only (since there is no NDK API for namespaces). + */ + ANDROID_DLEXT_USE_NAMESPACE = 0x200, + + /** Mask of valid bits. */ + ANDROID_DLEXT_VALID_FLAG_BITS = ANDROID_DLEXT_RESERVED_ADDRESS | + ANDROID_DLEXT_RESERVED_ADDRESS_HINT | + ANDROID_DLEXT_WRITE_RELRO | + ANDROID_DLEXT_USE_RELRO | + ANDROID_DLEXT_USE_LIBRARY_FD | + ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET | + ANDROID_DLEXT_FORCE_LOAD | + ANDROID_DLEXT_FORCE_FIXED_VADDR | + ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS | + ANDROID_DLEXT_USE_NAMESPACE, +}; + +struct android_namespace_t; + +typedef int64_t off64_t; + +/** Used to pass Android-specific arguments to `android_dlopen_ext`. */ +typedef struct { + /** A bitmask of `ANDROID_DLEXT_` enum values. */ + uint64_t flags; + + /** Used by `ANDROID_DLEXT_RESERVED_ADDRESS` and `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`. */ + void* reserved_addr; + /** Used by `ANDROID_DLEXT_RESERVED_ADDRESS` and `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`. */ + size_t reserved_size; + + /** Used by `ANDROID_DLEXT_WRITE_RELRO` and `ANDROID_DLEXT_USE_RELRO`. */ + int relro_fd; + + /** Used by `ANDROID_DLEXT_USE_LIBRARY_FD`. */ + int library_fd; + /** Used by `ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET` */ + off64_t library_fd_offset; + + /** Used by `ANDROID_DLEXT_USE_NAMESPACE`. */ + struct android_namespace_t* library_namespace; +} android_dlextinfo; + +/** + * Opens the given library. The `__filename` and `__flags` arguments are + * the same as for [dlopen(3)](http://man7.org/linux/man-pages/man3/dlopen.3.html), + * with the Android-specific flags supplied via the `flags` member of `__info`. + * + * Available since API level 21. + */ +static inline void* android_dlopen_ext(const char* __filename, + int __flags, + const android_dlextinfo* __info) { + return dlopen(__filename, __flags); +} + +__END_DECLS + +/** @} */ + +#endif |