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(__x86_64__) || defined(__i386__) || defined(__sparc__) 46 # define ASM_TAIL_CALL jmp 47 #elif defined(__arm__) || defined(__aarch64__) || defined(__mips__) || \ 48 defined(__powerpc__) || defined(__loongarch_lp64) 49 # define ASM_TAIL_CALL b 50 #elif defined(__s390__) 51 # define ASM_TAIL_CALL jg 52 #elif defined(__riscv) 53 # define ASM_TAIL_CALL tail 54 #endif 55 56 // Currently, almost all of the shared libraries rely on the value of 57 // $t9 to get the address of current function, instead of PCREL, even 58 // on MIPSr6. To be compatiable with them, we have to set $t9 properly. 59 // MIPS uses GOT to get the address of preemptible functions. 60 #if defined(__mips64) 61 # define C_ASM_TAIL_CALL(t_func, i_func) \ 62 "lui $t8, %hi(%neg(%gp_rel(" t_func ")))\n" \ 63 "daddu $t8, $t8, $t9\n" \ 64 "daddiu $t8, $t8, %lo(%neg(%gp_rel(" t_func ")))\n" \ 65 "ld $t9, %got_disp(" i_func ")($t8)\n" \ 66 "jr $t9\n" 67 #elif defined(__mips__) 68 # define C_ASM_TAIL_CALL(t_func, i_func) \ 69 ".set noreorder\n" \ 70 ".cpload $t9\n" \ 71 ".set reorder\n" \ 72 "lw $t9, %got(" i_func ")($gp)\n" \ 73 "jr $t9\n" 74 #elif defined(ASM_TAIL_CALL) 75 # define C_ASM_TAIL_CALL(t_func, i_func) \ 76 SANITIZER_STRINGIFY(ASM_TAIL_CALL) " " i_func 77 #endif 78 79 #if defined(__ELF__) && defined(__x86_64__) || defined(__i386__) || \ 80 defined(__riscv) 81 # define ASM_PREEMPTIBLE_SYM(sym) sym@plt 82 #else 83 # define ASM_PREEMPTIBLE_SYM(sym) sym 84 #endif 85 86 #if !defined(__APPLE__) 87 # define ASM_HIDDEN(symbol) .hidden symbol 88 # if defined(__arm__) || defined(__aarch64__) 89 # define ASM_TYPE_FUNCTION(symbol) .type symbol, %function 90 # else 91 # define ASM_TYPE_FUNCTION(symbol) .type symbol, @function 92 # endif 93 # define ASM_SIZE(symbol) .size symbol, .-symbol 94 # define ASM_SYMBOL(symbol) symbol 95 # define ASM_SYMBOL_INTERCEPTOR(symbol) symbol 96 # if defined(__i386__) || defined(__powerpc__) || defined(__s390__) || \ 97 defined(__sparc__) 98 // For details, see interception.h 99 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol 100 # define ASM_TRAMPOLINE_ALIAS(symbol, name) \ 101 .weak symbol; \ 102 .set symbol, ASM_WRAPPER_NAME(name) 103 # define ASM_INTERCEPTOR_TRAMPOLINE(name) 104 # define ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT 0 105 # else // Architecture supports interceptor trampoline 106 // Keep trampoline implementation in sync with interception/interception.h 107 # define ASM_WRAPPER_NAME(symbol) ___interceptor_##symbol 108 # define ASM_TRAMPOLINE_ALIAS(symbol, name) \ 109 .weak symbol; \ 110 .set symbol, __interceptor_trampoline_##name 111 # define ASM_INTERCEPTOR_TRAMPOLINE(name) \ 112 .weak __interceptor_##name; \ 113 .set __interceptor_##name, ASM_WRAPPER_NAME(name); \ 114 .globl __interceptor_trampoline_##name; \ 115 ASM_TYPE_FUNCTION(__interceptor_trampoline_##name); \ 116 __interceptor_trampoline_##name: \ 117 CFI_STARTPROC; \ 118 ASM_TAIL_CALL ASM_PREEMPTIBLE_SYM(__interceptor_##name); \ 119 CFI_ENDPROC; \ 120 ASM_SIZE(__interceptor_trampoline_##name) 121 # define ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT 1 122 # endif // Architecture supports interceptor trampoline 123 #else 124 # define ASM_HIDDEN(symbol) 125 # define ASM_TYPE_FUNCTION(symbol) 126 # define ASM_SIZE(symbol) 127 # define ASM_SYMBOL(symbol) _##symbol 128 # define ASM_SYMBOL_INTERCEPTOR(symbol) _wrap_##symbol 129 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol 130 #endif 131 132 #if defined(__ELF__) && (defined(__GNU__) || defined(__FreeBSD__) || \ 133 defined(__Fuchsia__) || defined(__linux__)) 134 // clang-format off 135 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits 136 // clang-format on 137 #else 138 #define NO_EXEC_STACK_DIRECTIVE 139 #endif 140 141 #if (defined(__x86_64__) || defined(__i386__)) && defined(__has_include) && __has_include(<cet.h>) 142 #include <cet.h> 143 #endif 144 #ifndef _CET_ENDBR 145 #define _CET_ENDBR 146 #endif 147