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) decay_time_enabled; 51 _Atomic(bool) memtag; 52 53 // In order to allow a complete switch between dispatch tables without 54 // the need for copying each function by function in the structure, 55 // use a single atomic pointer to switch. 56 // The current_dispatch_table pointer can only ever be set to a complete 57 // table. Any dispatch table that is pointed to by current_dispatch_table 58 // cannot be modified after that. If the pointer changes in the future, 59 // the old pointer must always stay valid. 60 // The malloc_dispatch_table is modified by malloc debug, malloc hooks, 61 // and heaprofd. Only one of these modes can be active at any given time. 62 _Atomic(const MallocDispatch*) current_dispatch_table; 63 // This pointer is only used by the allocation limit code when both a 64 // limit is enabled and some other hook is enabled at the same time. 65 _Atomic(const MallocDispatch*) default_dispatch_table; 66 MallocDispatch malloc_dispatch_table; 67 }; 68 69 struct memtag_dynamic_entries_t { 70 void* memtag_globals; 71 size_t memtag_globalssz; 72 bool has_memtag_mode; 73 unsigned memtag_mode; 74 bool memtag_heap; 75 bool memtag_stack; 76 }; 77 78 __LIBC_HIDDEN__ extern WriteProtected<libc_globals> __libc_globals; 79 // These cannot be in __libc_globals, because we cannot access the 80 // WriteProtected in a thread-safe way. 81 // See b/328256432. 82 // 83 // __libc_memtag_stack says whether stack MTE is enabled on the process, i.e. 84 // whether the stack pages are mapped with PROT_MTE. This is always false if 85 // MTE is disabled for the process (i.e. libc_globals.memtag is false). 86 __LIBC_HIDDEN__ extern _Atomic(bool) __libc_memtag_stack; 87 // __libc_memtag_stack_abi says whether the process contains any code that was 88 // compiled with memtag-stack. This is true even if the process does not have 89 // MTE enabled (e.g. because it was overridden using MEMTAG_OPTIONS, or because 90 // MTE is disabled for the device). 91 // Code compiled with memtag-stack needs a stack history buffer in 92 // TLS_SLOT_STACK_MTE, because the codegen will emit an unconditional 93 // (to keep the code branchless) write to it. 94 // Protected by g_heap_creation_lock. 95 __LIBC_HIDDEN__ extern bool __libc_memtag_stack_abi; 96 97 struct abort_msg_t; 98 struct crash_detail_page_t; 99 namespace gwp_asan { 100 struct AllocatorState; 101 struct AllocationMetadata; 102 }; // namespace gwp_asan 103 104 // Globals shared between the dynamic linker and libc.so. 105 struct libc_shared_globals { 106 // Construct the shared globals using a constexpr constructor to ensure that 107 // the object doesn't need dynamic initialization. The object is accessed 108 // before the dynamic linker has relocated itself. libc_shared_globalslibc_shared_globals109 constexpr libc_shared_globals() {} 110 111 FdTable fd_table; 112 113 // When the linker is invoked on a binary (e.g. `linker64 /system/bin/date`), 114 // record the number of arguments passed to the linker itself rather than to 115 // the program it's loading. Typically 0, sometimes 1. 116 int initial_linker_arg_count = 0; 117 118 ElfW(auxv_t)* auxv = nullptr; 119 120 pthread_mutex_t abort_msg_lock = PTHREAD_MUTEX_INITIALIZER; 121 abort_msg_t* abort_msg = nullptr; 122 123 StaticTlsLayout static_tls_layout; 124 TlsModules tls_modules; 125 BionicAllocator tls_allocator; 126 127 // Values passed from libc.so to the loader. 128 void (*load_hook)(ElfW(Addr) base, const ElfW(Phdr)* phdr, ElfW(Half) phnum) = nullptr; 129 void (*unload_hook)(ElfW(Addr) base, const ElfW(Phdr)* phdr, ElfW(Half) phnum) = nullptr; 130 void (*set_target_sdk_version_hook)(int target) = nullptr; 131 132 // Values passed from the linker to libc.so. 133 const char* init_progname = nullptr; 134 char** init_environ = nullptr; 135 136 const gwp_asan::AllocatorState* gwp_asan_state = nullptr; 137 const gwp_asan::AllocationMetadata* gwp_asan_metadata = nullptr; 138 bool (*debuggerd_needs_gwp_asan_recovery)(void* fault_addr) = nullptr; 139 void (*debuggerd_gwp_asan_pre_crash_report)(void* fault_addr) = nullptr; 140 void (*debuggerd_gwp_asan_post_crash_report)(void* fault_addr) = nullptr; 141 142 const char* scudo_stack_depot = nullptr; 143 const char* scudo_region_info = nullptr; 144 const char* scudo_ring_buffer = nullptr; 145 size_t scudo_ring_buffer_size = 0; 146 size_t scudo_stack_depot_size = 0; 147 148 HeapTaggingLevel initial_heap_tagging_level = M_HEAP_TAGGING_LEVEL_NONE; 149 // See comments for __libc_memtag_stack / __libc_memtag_stack_abi above. 150 bool initial_memtag_stack = false; 151 bool initial_memtag_stack_abi = false; 152 int64_t heap_tagging_upgrade_timer_sec = 0; 153 154 void (*memtag_stack_dlopen_callback)() = nullptr; 155 pthread_mutex_t crash_detail_page_lock = PTHREAD_MUTEX_INITIALIZER; 156 crash_detail_page_t* crash_detail_page = nullptr; 157 }; 158 159 __LIBC_HIDDEN__ libc_shared_globals* __libc_shared_globals(); 160 __LIBC_HIDDEN__ bool __libc_mte_enabled(); 161 __LIBC_HIDDEN__ void __libc_init_mte(const memtag_dynamic_entries_t*, const void*, size_t, 162 uintptr_t); 163 __LIBC_HIDDEN__ void __libc_init_mte_stack(void*); 164 __LIBC_HIDDEN__ void __libc_init_fdsan(); 165 __LIBC_HIDDEN__ void __libc_init_fdtrack(); 166 __LIBC_HIDDEN__ void __libc_init_profiling_handlers(); 167 168 __LIBC_HIDDEN__ void __libc_init_malloc(libc_globals* globals); 169 __LIBC_HIDDEN__ void __libc_init_setjmp_cookie(libc_globals* globals); 170 __LIBC_HIDDEN__ void __libc_init_vdso(libc_globals* globals); 171 172 #if defined(__i386__) 173 __LIBC_HIDDEN__ extern void* __libc_sysinfo; 174 extern "C" __LIBC_HIDDEN__ void __libc_int0x80(); 175 __LIBC_HIDDEN__ void __libc_init_sysinfo(); 176 #endif 177 178 #endif 179