• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #pragma once
30 
31 #include <dlfcn.h>
32 #include <android/dlext.h>
33 #include <elf.h>
34 #include <inttypes.h>
35 #include <link.h>
36 #include <sys/stat.h>
37 #include <unistd.h>
38 
39 #include "platform/bionic/page.h"
40 #include "linked_list.h"
41 #include "linker_common_types.h"
42 #include "linker_logger.h"
43 #include "linker_soinfo.h"
44 
45 #include <string>
46 #include <vector>
47 
48 #if defined(__LP64__)
49 #define ELFW(what) ELF64_ ## what
50 #else
51 #define ELFW(what) ELF32_ ## what
52 #endif
53 
54 #define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE | DF_1_PIE | DF_1_ORIGIN)
55 
56 // Class used construct version dependency graph.
57 class VersionTracker {
58  public:
59   VersionTracker() = default;
60   bool init(const soinfo* si_from);
61 
62   const version_info* get_version_info(ElfW(Versym) source_symver) const;
63  private:
64   bool init_verneed(const soinfo* si_from);
65   bool init_verdef(const soinfo* si_from);
66   void add_version_info(size_t source_index, ElfW(Word) elf_hash,
67       const char* ver_name, const soinfo* target_si);
68 
69   std::vector<version_info> version_infos;
70 
71   DISALLOW_COPY_AND_ASSIGN(VersionTracker);
72 };
73 
74 soinfo* get_libdl_info(const soinfo& linker_si);
75 
76 soinfo* find_containing_library(const void* p);
77 
78 int open_executable(const char* path, off64_t* file_offset, std::string* realpath);
79 
80 void do_android_get_LD_LIBRARY_PATH(char*, size_t);
81 void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path);
82 void* do_dlopen(const char* name,
83                 int flags,
84                 const android_dlextinfo* extinfo,
85                 const void* caller_addr);
86 
87 int do_dlclose(void* handle);
88 
89 int do_dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data), void* data);
90 
91 #if defined(__arm__)
92 _Unwind_Ptr do_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount);
93 #endif
94 
95 bool do_dlsym(void* handle, const char* sym_name,
96               const char* sym_ver,
97               const void* caller_addr,
98               void** symbol);
99 
100 int do_dladdr(const void* addr, Dl_info* info);
101 
102 void set_application_target_sdk_version(int target);
103 int get_application_target_sdk_version();
104 
105 bool get_transparent_hugepages_supported();
106 
107 void set_16kb_appcompat_mode(bool enable_app_compat);
108 bool get_16kb_appcompat_mode();
109 
110 enum {
111   /* A regular namespace is the namespace with a custom search path that does
112    * not impose any restrictions on the location of native libraries.
113    */
114   ANDROID_NAMESPACE_TYPE_REGULAR = 0,
115 
116   /* An isolated namespace requires all the libraries to be on the search path
117    * or under permitted_when_isolated_path. The search path is the union of
118    * ld_library_path and default_library_path.
119    */
120   ANDROID_NAMESPACE_TYPE_ISOLATED = 1,
121 
122   /* The shared namespace clones the list of libraries of the caller namespace upon creation
123    * which means that they are shared between namespaces - the caller namespace and the new one
124    * will use the same copy of a library if it was loaded prior to android_create_namespace call.
125    *
126    * Note that libraries loaded after the namespace is created will not be shared.
127    *
128    * Shared namespaces can be isolated or regular. Note that they do not inherit the search path nor
129    * permitted_path from the caller's namespace.
130    */
131   ANDROID_NAMESPACE_TYPE_SHARED = 2,
132 
133   /* This flag instructs linker to enable exempt-list workaround for the namespace.
134    * See http://b/26394120 for details.
135    */
136   ANDROID_NAMESPACE_TYPE_EXEMPT_LIST_ENABLED = 0x08000000,
137 
138   /* This flag instructs linker to use this namespace as the anonymous
139    * namespace. There can be only one anonymous namespace in a process. If there
140    * already an anonymous namespace in the process, using this flag when
141    * creating a new namespace causes an error
142    */
143   ANDROID_NAMESPACE_TYPE_ALSO_USED_AS_ANONYMOUS = 0x10000000,
144 
145   ANDROID_NAMESPACE_TYPE_SHARED_ISOLATED = ANDROID_NAMESPACE_TYPE_SHARED |
146                                            ANDROID_NAMESPACE_TYPE_ISOLATED,
147 };
148 
149 bool init_anonymous_namespace(const char* shared_lib_sonames, const char* library_search_path);
150 android_namespace_t* create_namespace(const void* caller_addr,
151                                       const char* name,
152                                       const char* ld_library_path,
153                                       const char* default_library_path,
154                                       uint64_t type,
155                                       const char* permitted_when_isolated_path,
156                                       android_namespace_t* parent_namespace);
157 
158 bool link_namespaces(android_namespace_t* namespace_from,
159                      android_namespace_t* namespace_to,
160                      const char* shared_lib_sonames);
161 
162 bool link_namespaces_all_libs(android_namespace_t* namespace_from,
163                               android_namespace_t* namespace_to);
164 
165 android_namespace_t* get_exported_namespace(const char* name);
166 
167 void increment_dso_handle_reference_counter(void* dso_handle);
168 void decrement_dso_handle_reference_counter(void* dso_handle);
169 
170 void purge_unused_memory();
171 
172 struct address_space_params {
173   void* start_addr = nullptr;
174   size_t reserved_size = 0;
175   bool must_use_address = false;
176 };
177 
178 int get_application_target_sdk_version();
179 ElfW(Versym) find_verdef_version_index(const soinfo* si, const version_info* vi);
180 bool validate_verdef_section(const soinfo* si);
181 bool relocate_relr(const ElfW(Relr) * begin, const ElfW(Relr) * end, ElfW(Addr) load_bias,
182                    bool has_memtag_globals);
183 
184 struct platform_properties {
185 #if defined(__aarch64__)
186   bool bti_supported = false;
187 #endif
188 };
189