1ffec1cc4d
The anonymous namespace is introduced to handle cases when linker can not find the caller. This usually happens when caller code was not loaded by dynamic linker; for example mono-generated code. Bug: http://b/25844435 Bug: http://b/22548808 Change-Id: I9e5b1d23c1c75bc78548d68e79216a6a943a33cf
169 lines
7.1 KiB
C
169 lines
7.1 KiB
C
/*
|
|
* 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 <stddef.h>
|
|
#include <stdint.h>
|
|
#include <sys/cdefs.h>
|
|
#include <sys/types.h> /* for off64_t */
|
|
|
|
__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, the load
|
|
* will fail.
|
|
*/
|
|
ANDROID_DLEXT_RESERVED_ADDRESS = 0x1,
|
|
|
|
/* As 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.
|
|
*/
|
|
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.
|
|
*/
|
|
ANDROID_DLEXT_USE_RELRO = 0x8,
|
|
|
|
/* Instruct dlopen to use library_fd instead of opening 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 flag is only valid when ANDROID_DLEXT_USE_LIBRARY_FD is set.
|
|
*/
|
|
ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET = 0x20,
|
|
|
|
/* When set, do not check if the library has already been loaded by file stat(2)s.
|
|
*
|
|
* 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 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 min(p_vaddr) of PT_LOAD segments) this flag is ignored.
|
|
* This is implemented this way 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 min(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.
|
|
*/
|
|
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 struct {
|
|
uint64_t flags;
|
|
void* reserved_addr;
|
|
size_t reserved_size;
|
|
int relro_fd;
|
|
int library_fd;
|
|
off64_t library_fd_offset;
|
|
struct android_namespace_t* library_namespace;
|
|
} android_dlextinfo;
|
|
|
|
extern void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo);
|
|
|
|
/*
|
|
* Initializes public and anonymous namespaces. The public_ns_sonames is the list of sonames
|
|
* to be included into public namespace separated by colon. Example: "libc.so:libm.so:libdl.so".
|
|
* The libraries in this list should be loaded prior to this call.
|
|
*
|
|
* The anon_ns_library_path is the search path for anonymous namespace. The anonymous namespace
|
|
* is used in the case when linker cannot identify the caller of dlopen/dlsym. This happens
|
|
* for the code not loaded by dynamic linker; for example calls from the mono-compiled code.
|
|
*/
|
|
extern bool android_init_namespaces(const char* public_ns_sonames,
|
|
const char* anon_ns_library_path);
|
|
|
|
/*
|
|
* Creates new linker namespace.
|
|
* ld_library_path and default_library_path represent the search path
|
|
* for the libraries in the namespace.
|
|
*
|
|
* The libraries in the namespace are searched by folowing order:
|
|
* 1. ld_library_path (Think of this as namespace-local LD_LIBRARY_PATH)
|
|
* 2. In directories specified by DT_RUNPATH of the "needed by" binary.
|
|
* 3. deault_library_path (This of this as namespace-local default library path)
|
|
*
|
|
* When is_isolated is true the resulted namespace requires all of the libraries
|
|
* to be on the search path; the search_path is ld_library_path:default_library_path.
|
|
*
|
|
* If a library or any of its dependencies are outside of the search path and not
|
|
* part of the public namespace dlopen will fail.
|
|
*/
|
|
extern struct android_namespace_t* android_create_namespace(const char* name,
|
|
const char* ld_library_path,
|
|
const char* default_library_path,
|
|
bool is_isolated);
|
|
|
|
__END_DECLS
|
|
|
|
#endif /* __ANDROID_DLEXT_H__ */
|