1 //===-- sanitizer_asm.h -----------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // Various support for assembler. 10 // 11 //===----------------------------------------------------------------------===// 12 13 // Some toolchains do not support .cfi asm directives, so we have to hide 14 // them inside macros. 15 #if defined(__clang__) || \ 16 (defined(__GNUC__) && defined(__GCC_HAVE_DWARF2_CFI_ASM)) 17 // GCC defined __GCC_HAVE_DWARF2_CFI_ASM if it supports CFI. 18 // Clang seems to support CFI by default (or not?). 19 // We need two versions of macros: for inline asm and standalone asm files. 20 # define CFI_INL_ADJUST_CFA_OFFSET(n) ".cfi_adjust_cfa_offset " #n ";" 21 22 # define CFI_STARTPROC .cfi_startproc 23 # define CFI_ENDPROC .cfi_endproc 24 # define CFI_ADJUST_CFA_OFFSET(n) .cfi_adjust_cfa_offset n 25 # define CFI_DEF_CFA_OFFSET(n) .cfi_def_cfa_offset n 26 # define CFI_REL_OFFSET(reg, n) .cfi_rel_offset reg, n 27 # define CFI_OFFSET(reg, n) .cfi_offset reg, n 28 # define CFI_DEF_CFA_REGISTER(reg) .cfi_def_cfa_register reg 29 # define CFI_DEF_CFA(reg, n) .cfi_def_cfa reg, n 30 # define CFI_RESTORE(reg) .cfi_restore reg 31 32 #else // No CFI 33 # define CFI_INL_ADJUST_CFA_OFFSET(n) 34 # define CFI_STARTPROC 35 # define CFI_ENDPROC 36 # define CFI_ADJUST_CFA_OFFSET(n) 37 # define CFI_DEF_CFA_OFFSET(n) 38 # define CFI_REL_OFFSET(reg, n) 39 # define CFI_OFFSET(reg, n) 40 # define CFI_DEF_CFA_REGISTER(reg) 41 # define CFI_DEF_CFA(reg, n) 42 # define CFI_RESTORE(reg) 43 #endif 44 45 #if defined(__aarch64__) && defined(__ARM_FEATURE_BTI_DEFAULT) 46 # define ASM_STARTPROC CFI_STARTPROC; hint #34 47 # define C_ASM_STARTPROC SANITIZER_STRINGIFY(CFI_STARTPROC) "\nhint #34" 48 #else 49 # define ASM_STARTPROC CFI_STARTPROC 50 # define C_ASM_STARTPROC SANITIZER_STRINGIFY(CFI_STARTPROC) 51 #endif 52 #define ASM_ENDPROC CFI_ENDPROC 53 #define C_ASM_ENDPROC SANITIZER_STRINGIFY(CFI_ENDPROC) 54 55 #if defined(__x86_64__) || defined(__i386__) || defined(__sparc__) 56 # define ASM_TAIL_CALL jmp 57 #elif defined(__arm__) || defined(__aarch64__) || defined(__mips__) || \ 58 defined(__powerpc__) || defined(__loongarch_lp64) 59 # define ASM_TAIL_CALL b 60 #elif defined(__s390__) 61 # define ASM_TAIL_CALL jg 62 #elif defined(__riscv) 63 # define ASM_TAIL_CALL tail 64 #endif 65 66 // Currently, almost all of the shared libraries rely on the value of 67 // $t9 to get the address of current function, instead of PCREL, even 68 // on MIPSr6. To be compatiable with them, we have to set $t9 properly. 69 // MIPS uses GOT to get the address of preemptible functions. 70 #if defined(__mips64) 71 # define C_ASM_TAIL_CALL(t_func, i_func) \ 72 "lui $t8, %hi(%neg(%gp_rel(" t_func ")))\n" \ 73 "daddu $t8, $t8, $t9\n" \ 74 "daddiu $t8, $t8, %lo(%neg(%gp_rel(" t_func ")))\n" \ 75 "ld $t9, %got_disp(" i_func ")($t8)\n" \ 76 "jr $t9\n" 77 #elif defined(__mips__) 78 # define C_ASM_TAIL_CALL(t_func, i_func) \ 79 ".set noreorder\n" \ 80 ".cpload $t9\n" \ 81 ".set reorder\n" \ 82 "lw $t9, %got(" i_func ")($gp)\n" \ 83 "jr $t9\n" 84 #elif defined(ASM_TAIL_CALL) 85 # define C_ASM_TAIL_CALL(t_func, i_func) \ 86 SANITIZER_STRINGIFY(ASM_TAIL_CALL) " " i_func 87 #endif 88 89 #if defined(__ELF__) && defined(__x86_64__) || defined(__i386__) || \ 90 defined(__riscv) 91 # define ASM_PREEMPTIBLE_SYM(sym) sym@plt 92 #else 93 # define ASM_PREEMPTIBLE_SYM(sym) sym 94 #endif 95 96 #if !defined(__APPLE__) 97 # define ASM_HIDDEN(symbol) .hidden symbol 98 # if defined(__arm__) || defined(__aarch64__) 99 # define ASM_TYPE_FUNCTION(symbol) .type symbol, %function 100 # else 101 # define ASM_TYPE_FUNCTION(symbol) .type symbol, @function 102 # endif 103 # define ASM_SIZE(symbol) .size symbol, .-symbol 104 # define ASM_SYMBOL(symbol) symbol 105 # define ASM_SYMBOL_INTERCEPTOR(symbol) symbol 106 # if defined(__i386__) || defined(__powerpc__) || defined(__s390__) || \ 107 defined(__sparc__) 108 // For details, see interception.h 109 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol 110 # define ASM_TRAMPOLINE_ALIAS(symbol, name) \ 111 .weak symbol; \ 112 .set symbol, ASM_WRAPPER_NAME(name) 113 # define ASM_INTERCEPTOR_TRAMPOLINE(name) 114 # define ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT 0 115 # else // Architecture supports interceptor trampoline 116 // Keep trampoline implementation in sync with interception/interception.h 117 # define ASM_WRAPPER_NAME(symbol) ___interceptor_##symbol 118 # define ASM_TRAMPOLINE_ALIAS(symbol, name) \ 119 .weak symbol; \ 120 .set symbol, __interceptor_trampoline_##name 121 # define ASM_INTERCEPTOR_TRAMPOLINE(name) \ 122 .weak __interceptor_##name; \ 123 .set __interceptor_##name, ASM_WRAPPER_NAME(name); \ 124 .globl __interceptor_trampoline_##name; \ 125 ASM_TYPE_FUNCTION(__interceptor_trampoline_##name); \ 126 __interceptor_trampoline_##name: \ 127 ASM_STARTPROC; \ 128 ASM_TAIL_CALL ASM_PREEMPTIBLE_SYM(__interceptor_##name); \ 129 ASM_ENDPROC; \ 130 ASM_SIZE(__interceptor_trampoline_##name) 131 # define ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT 1 132 # endif // Architecture supports interceptor trampoline 133 #else 134 # define ASM_HIDDEN(symbol) 135 # define ASM_TYPE_FUNCTION(symbol) 136 # define ASM_SIZE(symbol) 137 # define ASM_SYMBOL(symbol) _##symbol 138 # define ASM_SYMBOL_INTERCEPTOR(symbol) _wrap_##symbol 139 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol 140 #endif 141 142 #if defined(__ELF__) && (defined(__GNU__) || defined(__FreeBSD__) || \ 143 defined(__Fuchsia__) || defined(__linux__)) 144 // clang-format off 145 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits 146 // clang-format on 147 #else 148 #define NO_EXEC_STACK_DIRECTIVE 149 #endif 150 151 #if (defined(__x86_64__) || defined(__i386__)) && defined(__has_include) && __has_include(<cet.h>) 152 #include <cet.h> 153 #endif 154 #ifndef _CET_ENDBR 155 #define _CET_ENDBR 156 #endif 157