• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2015 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 #ifndef _PRIVATE_BIONIC_GLOBALS_H
30 #define _PRIVATE_BIONIC_GLOBALS_H
31 
32 #include <inttypes.h>
33 #include <link.h>
34 #include <platform/bionic/malloc.h>
35 #include <pthread.h>
36 #include <stdatomic.h>
37 #include <sys/cdefs.h>
38 
39 #include "private/WriteProtected.h"
40 #include "private/bionic_allocator.h"
41 #include "private/bionic_elf_tls.h"
42 #include "private/bionic_fdsan.h"
43 #include "private/bionic_malloc_dispatch.h"
44 #include "private/bionic_vdso.h"
45 
46 struct libc_globals {
47   vdso_entry vdso[VDSO_END];
48   long setjmp_cookie;
49   uintptr_t heap_pointer_tag;
50   _Atomic(bool) memtag_stack;
51 
52   // In order to allow a complete switch between dispatch tables without
53   // the need for copying each function by function in the structure,
54   // use a single atomic pointer to switch.
55   // The current_dispatch_table pointer can only ever be set to a complete
56   // table. Any dispatch table that is pointed to by current_dispatch_table
57   // cannot be modified after that. If the pointer changes in the future,
58   // the old pointer must always stay valid.
59   // The malloc_dispatch_table is modified by malloc debug, malloc hooks,
60   // and heaprofd. Only one of these modes can be active at any given time.
61   _Atomic(const MallocDispatch*) current_dispatch_table;
62   // This pointer is only used by the allocation limit code when both a
63   // limit is enabled and some other hook is enabled at the same time.
64   _Atomic(const MallocDispatch*) default_dispatch_table;
65   MallocDispatch malloc_dispatch_table;
66 };
67 
68 __LIBC_HIDDEN__ extern WriteProtected<libc_globals> __libc_globals;
69 
70 struct abort_msg_t;
71 namespace gwp_asan {
72 struct AllocatorState;
73 struct AllocationMetadata;
74 };  // namespace gwp_asan
75 
76 // Globals shared between the dynamic linker and libc.so.
77 struct libc_shared_globals {
78   // Construct the shared globals using a constexpr constructor to ensure that
79   // the object doesn't need dynamic initialization. The object is accessed
80   // before the dynamic linker has relocated itself.
libc_shared_globalslibc_shared_globals81   constexpr libc_shared_globals() {}
82 
83   FdTable fd_table;
84 
85   // When the linker is invoked on a binary (e.g. `linker64 /system/bin/date`),
86   // record the number of arguments passed to the linker itself rather than to
87   // the program it's loading. Typically 0, sometimes 1.
88   int initial_linker_arg_count = 0;
89 
90   ElfW(auxv_t)* auxv = nullptr;
91 
92   pthread_mutex_t abort_msg_lock = PTHREAD_MUTEX_INITIALIZER;
93   abort_msg_t* abort_msg = nullptr;
94 
95   StaticTlsLayout static_tls_layout;
96   TlsModules tls_modules;
97   BionicAllocator tls_allocator;
98 
99   // Values passed from libc.so to the loader.
100   void (*load_hook)(ElfW(Addr) base, const ElfW(Phdr)* phdr, ElfW(Half) phnum) = nullptr;
101   void (*unload_hook)(ElfW(Addr) base, const ElfW(Phdr)* phdr, ElfW(Half) phnum) = nullptr;
102   void (*set_target_sdk_version_hook)(int target) = nullptr;
103 
104   // Values passed from the linker to libc.so.
105   const char* init_progname = nullptr;
106   char** init_environ = nullptr;
107 
108   const gwp_asan::AllocatorState* gwp_asan_state = nullptr;
109   const gwp_asan::AllocationMetadata* gwp_asan_metadata = nullptr;
110   bool (*debuggerd_needs_gwp_asan_recovery)(void* fault_addr) = nullptr;
111   void (*debuggerd_gwp_asan_pre_crash_report)(void* fault_addr) = nullptr;
112   void (*debuggerd_gwp_asan_post_crash_report)(void* fault_addr) = nullptr;
113 
114   const char* scudo_stack_depot = nullptr;
115   const char* scudo_region_info = nullptr;
116   const char* scudo_ring_buffer = nullptr;
117   size_t scudo_ring_buffer_size = 0;
118 
119   HeapTaggingLevel initial_heap_tagging_level = M_HEAP_TAGGING_LEVEL_NONE;
120   bool initial_memtag_stack = false;
121   int64_t heap_tagging_upgrade_timer_sec = 0;
122 };
123 
124 __LIBC_HIDDEN__ libc_shared_globals* __libc_shared_globals();
125 __LIBC_HIDDEN__ void __libc_init_fdsan();
126 __LIBC_HIDDEN__ void __libc_init_fdtrack();
127 __LIBC_HIDDEN__ void __libc_init_profiling_handlers();
128 
129 __LIBC_HIDDEN__ void __libc_init_malloc(libc_globals* globals);
130 __LIBC_HIDDEN__ void __libc_init_setjmp_cookie(libc_globals* globals);
131 __LIBC_HIDDEN__ void __libc_init_vdso(libc_globals* globals);
132 
133 #if defined(__i386__)
134 __LIBC_HIDDEN__ extern void* __libc_sysinfo;
135 extern "C" __LIBC_HIDDEN__ void __libc_int0x80();
136 __LIBC_HIDDEN__ void __libc_init_sysinfo();
137 #endif
138 
139 #endif
140