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 48 // In order to allow a complete switch between dispatch tables without 49 // the need for copying each function by function in the structure, 50 // use a single atomic pointer to switch. 51 // The current_dispatch_table pointer can only ever be set to a complete 52 // table. Any dispatch table that is pointed to by current_dispatch_table 53 // cannot be modified after that. If the pointer changes in the future, 54 // the old pointer must always stay valid. 55 // The malloc_dispatch_table is modified by malloc debug, malloc hooks, 56 // and heaprofd. Only one of these modes can be active at any given time. 57 _Atomic(const MallocDispatch*) current_dispatch_table; 58 // This pointer is only used by the allocation limit code when both a 59 // limit is enabled and some other hook is enabled at the same time. 60 _Atomic(const MallocDispatch*) default_dispatch_table; 61 MallocDispatch malloc_dispatch_table; 62 }; 63 64 __LIBC_HIDDEN__ extern WriteProtected<libc_globals> __libc_globals; 65 66 struct abort_msg_t; 67 68 // Globals shared between the dynamic linker and libc.so. 69 struct libc_shared_globals { 70 // Construct the shared globals using a constexpr constructor to ensure that 71 // the object doesn't need dynamic initialization. The object is accessed 72 // before the dynamic linker has relocated itself. libc_shared_globalslibc_shared_globals73 constexpr libc_shared_globals() {} 74 75 FdTable fd_table; 76 77 // When the linker is invoked on a binary (e.g. `linker64 /system/bin/date`), 78 // record the number of arguments passed to the linker itself rather than to 79 // the program it's loading. Typically 0, sometimes 1. 80 int initial_linker_arg_count = 0; 81 82 ElfW(auxv_t)* auxv = nullptr; 83 84 pthread_mutex_t abort_msg_lock = PTHREAD_MUTEX_INITIALIZER; 85 abort_msg_t* abort_msg = nullptr; 86 87 StaticTlsLayout static_tls_layout; 88 TlsModules tls_modules; 89 BionicAllocator tls_allocator; 90 91 // Values passed from the linker to libc.so. 92 const char* init_progname = nullptr; 93 char** init_environ = nullptr; 94 }; 95 96 __LIBC_HIDDEN__ libc_shared_globals* __libc_shared_globals(); 97 __LIBC_HIDDEN__ void __libc_init_fdsan(); 98 99 __LIBC_HIDDEN__ void __libc_init_malloc(libc_globals* globals); 100 __LIBC_HIDDEN__ void __libc_init_setjmp_cookie(libc_globals* globals); 101 __LIBC_HIDDEN__ void __libc_init_vdso(libc_globals* globals); 102 103 #if defined(__i386__) 104 __LIBC_HIDDEN__ extern void* __libc_sysinfo; 105 __LIBC_HIDDEN__ void __libc_int0x80(); 106 __LIBC_HIDDEN__ void __libc_init_sysinfo(); 107 #endif 108 109 #endif 110