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 <stdatomic.h> 33 #include <sys/cdefs.h> 34 #include <link.h> 35 #include <pthread.h> 36 37 #include "private/bionic_allocator.h" 38 #include "private/bionic_elf_tls.h" 39 #include "private/bionic_fdsan.h" 40 #include "private/bionic_malloc_dispatch.h" 41 #include "private/bionic_vdso.h" 42 #include "private/WriteProtected.h" 43 44 struct libc_globals { 45 vdso_entry vdso[VDSO_END]; 46 long setjmp_cookie; 47 uintptr_t heap_pointer_tag; 48 49 // In order to allow a complete switch between dispatch tables without 50 // the need for copying each function by function in the structure, 51 // use a single atomic pointer to switch. 52 // The current_dispatch_table pointer can only ever be set to a complete 53 // table. Any dispatch table that is pointed to by current_dispatch_table 54 // cannot be modified after that. If the pointer changes in the future, 55 // the old pointer must always stay valid. 56 // The malloc_dispatch_table is modified by malloc debug, malloc hooks, 57 // and heaprofd. Only one of these modes can be active at any given time. 58 _Atomic(const MallocDispatch*) current_dispatch_table; 59 // This pointer is only used by the allocation limit code when both a 60 // limit is enabled and some other hook is enabled at the same time. 61 _Atomic(const MallocDispatch*) default_dispatch_table; 62 MallocDispatch malloc_dispatch_table; 63 }; 64 65 __LIBC_HIDDEN__ extern WriteProtected<libc_globals> __libc_globals; 66 67 struct abort_msg_t; 68 namespace gwp_asan { 69 struct AllocatorState; 70 struct AllocationMetadata; 71 }; // namespace gwp_asan 72 73 // Globals shared between the dynamic linker and libc.so. 74 struct libc_shared_globals { 75 // Construct the shared globals using a constexpr constructor to ensure that 76 // the object doesn't need dynamic initialization. The object is accessed 77 // before the dynamic linker has relocated itself. libc_shared_globalslibc_shared_globals78 constexpr libc_shared_globals() {} 79 80 FdTable fd_table; 81 82 // When the linker is invoked on a binary (e.g. `linker64 /system/bin/date`), 83 // record the number of arguments passed to the linker itself rather than to 84 // the program it's loading. Typically 0, sometimes 1. 85 int initial_linker_arg_count = 0; 86 87 ElfW(auxv_t)* auxv = nullptr; 88 89 pthread_mutex_t abort_msg_lock = PTHREAD_MUTEX_INITIALIZER; 90 abort_msg_t* abort_msg = nullptr; 91 92 StaticTlsLayout static_tls_layout; 93 TlsModules tls_modules; 94 BionicAllocator tls_allocator; 95 96 // Values passed from the HWASan runtime (via libc.so) to the loader. 97 void (*load_hook)(ElfW(Addr) base, const ElfW(Phdr)* phdr, ElfW(Half) phnum) = nullptr; 98 void (*unload_hook)(ElfW(Addr) base, const ElfW(Phdr)* phdr, ElfW(Half) phnum) = nullptr; 99 100 // Values passed from the linker to libc.so. 101 const char* init_progname = nullptr; 102 char** init_environ = nullptr; 103 104 const gwp_asan::AllocatorState *gwp_asan_state = nullptr; 105 const gwp_asan::AllocationMetadata *gwp_asan_metadata = nullptr; 106 }; 107 108 __LIBC_HIDDEN__ libc_shared_globals* __libc_shared_globals(); 109 __LIBC_HIDDEN__ void __libc_init_fdsan(); 110 __LIBC_HIDDEN__ void __libc_init_fdtrack(); 111 __LIBC_HIDDEN__ void __libc_init_profiling_handlers(); 112 113 __LIBC_HIDDEN__ void __libc_init_malloc(libc_globals* globals); 114 __LIBC_HIDDEN__ void __libc_init_setjmp_cookie(libc_globals* globals); 115 __LIBC_HIDDEN__ void __libc_init_vdso(libc_globals* globals); 116 117 #if defined(__i386__) 118 __LIBC_HIDDEN__ extern void* __libc_sysinfo; 119 __LIBC_HIDDEN__ void __libc_int0x80(); 120 __LIBC_HIDDEN__ void __libc_init_sysinfo(); 121 #endif 122 123 #endif 124