libsanitizer/builtins/assembly.h

   1 //===-- assembly.h - compiler-rt assembler support macros -----------------===//
   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 // This file defines macros for use in compiler-rt assembler source.
  10 // This file is not part of the interface of this library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef COMPILERRT_ASSEMBLY_H
  15 #define COMPILERRT_ASSEMBLY_H
  16
  17 #if defined(__linux__) && defined(__CET__)
  18 #if __has_include(<cet.h>)
  19 #include <cet.h>
  20 #endif
  21 #endif
  22
  23 #if defined(__APPLE__) && defined(__aarch64__)
  24 #define SEPARATOR %%
  25 #else
  26 #define SEPARATOR ;
  27 #endif
  28
  29 #if defined(__APPLE__)
  30 #define HIDDEN(name) .private_extern name
  31 #define LOCAL_LABEL(name) L_##name
  32 // tell linker it can break up file at label boundaries
  33 #define FILE_LEVEL_DIRECTIVE .subsections_via_symbols
  34 #define SYMBOL_IS_FUNC(name)
  35 #define CONST_SECTION .const
  36
  37 #define NO_EXEC_STACK_DIRECTIVE
  38
  39 #elif defined(__ELF__)
  40
  41 #define HIDDEN(name) .hidden name
  42 #define LOCAL_LABEL(name) .L_##name
  43 #define FILE_LEVEL_DIRECTIVE
  44 #if defined(__arm__) || defined(__aarch64__)
  45 #define SYMBOL_IS_FUNC(name) .type name,%function
  46 #else
  47 #define SYMBOL_IS_FUNC(name) .type name,@function
  48 #endif
  49 #define CONST_SECTION .section .rodata
  50
  51 #if defined(__GNU__) || defined(__FreeBSD__) || defined(__Fuchsia__) ||        \
  52     defined(__linux__)
  53 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
  54 #else
  55 #define NO_EXEC_STACK_DIRECTIVE
  56 #endif
  57
  58 #else // !__APPLE__ && !__ELF__
  59
  60 #define HIDDEN(name)
  61 #define LOCAL_LABEL(name) .L ## name
  62 #define FILE_LEVEL_DIRECTIVE
  63 #define SYMBOL_IS_FUNC(name)                                                   \
  64   .def name SEPARATOR                                                          \
  65     .scl 2 SEPARATOR                                                           \
  66     .type 32 SEPARATOR                                                         \
  67   .endef
  68 #define CONST_SECTION .section .rdata,"rd"
  69
  70 #define NO_EXEC_STACK_DIRECTIVE
  71
  72 #endif
  73
  74 #if defined(__arm__) || defined(__aarch64__)
  75 #define FUNC_ALIGN                                                             \
  76   .text SEPARATOR                                                              \
  77   .balign 16 SEPARATOR
  78 #else
  79 #define FUNC_ALIGN
  80 #endif
  81
  82 // BTI and PAC gnu property note
  83 #define NT_GNU_PROPERTY_TYPE_0 5
  84 #define GNU_PROPERTY_AARCH64_FEATURE_1_AND 0xc0000000
  85 #define GNU_PROPERTY_AARCH64_FEATURE_1_BTI 1
  86 #define GNU_PROPERTY_AARCH64_FEATURE_1_PAC 2
  87
  88 #if defined(__ARM_FEATURE_BTI_DEFAULT)
  89 #define BTI_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  90 #else
  91 #define BTI_FLAG 0
  92 #endif
  93
  94 #if __ARM_FEATURE_PAC_DEFAULT & 3
  95 #define PAC_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_PAC
  96 #else
  97 #define PAC_FLAG 0
  98 #endif
  99
 100 #define GNU_PROPERTY(type, value)                                              \
 101   .pushsection .note.gnu.property, "a" SEPARATOR                               \
 102   .p2align 3 SEPARATOR                                                         \
 103   .word 4 SEPARATOR                                                            \
 104   .word 16 SEPARATOR                                                           \
 105   .word NT_GNU_PROPERTY_TYPE_0 SEPARATOR                                       \
 106   .asciz "GNU" SEPARATOR                                                       \
 107   .word type SEPARATOR                                                         \
 108   .word 4 SEPARATOR                                                            \
 109   .word value SEPARATOR                                                        \
 110   .word 0 SEPARATOR                                                            \
 111   .popsection
 112
 113 #if BTI_FLAG != 0
 114 #define BTI_C hint #34
 115 #define BTI_J hint #36
 116 #else
 117 #define BTI_C
 118 #define BTI_J
 119 #endif
 120
 121 #if (BTI_FLAG | PAC_FLAG) != 0
 122 #define GNU_PROPERTY_BTI_PAC                                                   \
 123   GNU_PROPERTY(GNU_PROPERTY_AARCH64_FEATURE_1_AND, BTI_FLAG | PAC_FLAG)
 124 #else
 125 #define GNU_PROPERTY_BTI_PAC
 126 #endif
 127
 128 #if defined(__clang__) || defined(__GCC_HAVE_DWARF2_CFI_ASM)
 129 #define CFI_START .cfi_startproc
 130 #define CFI_END .cfi_endproc
 131 #else
 132 #define CFI_START
 133 #define CFI_END
 134 #endif
 135
 136 #if defined(__arm__)
 137
 138 // Determine actual [ARM][THUMB[1][2]] ISA using compiler predefined macros:
 139 // - for '-mthumb -march=armv6' compiler defines '__thumb__'
 140 // - for '-mthumb -march=armv7' compiler defines '__thumb__' and '__thumb2__'
 141 #if defined(__thumb2__) || defined(__thumb__)
 142 #define DEFINE_CODE_STATE .thumb SEPARATOR
 143 #define DECLARE_FUNC_ENCODING    .thumb_func SEPARATOR
 144 #if defined(__thumb2__)
 145 #define USE_THUMB_2
 146 #define IT(cond)  it cond
 147 #define ITT(cond) itt cond
 148 #define ITE(cond) ite cond
 149 #else
 150 #define USE_THUMB_1
 151 #define IT(cond)
 152 #define ITT(cond)
 153 #define ITE(cond)
 154 #endif // defined(__thumb__2)
 155 #else // !defined(__thumb2__) && !defined(__thumb__)
 156 #define DEFINE_CODE_STATE .arm SEPARATOR
 157 #define DECLARE_FUNC_ENCODING
 158 #define IT(cond)
 159 #define ITT(cond)
 160 #define ITE(cond)
 161 #endif
 162
 163 #if defined(USE_THUMB_1) && defined(USE_THUMB_2)
 164 #error "USE_THUMB_1 and USE_THUMB_2 can't be defined together."
 165 #endif
 166
 167 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
 168 #define ARM_HAS_BX
 169 #endif
 170 #if !defined(__ARM_FEATURE_CLZ) && !defined(USE_THUMB_1) &&  \
 171     (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
 172 #define __ARM_FEATURE_CLZ
 173 #endif
 174
 175 #ifdef ARM_HAS_BX
 176 #define JMP(r) bx r
 177 #define JMPc(r, c) bx##c r
 178 #else
 179 #define JMP(r) mov pc, r
 180 #define JMPc(r, c) mov##c pc, r
 181 #endif
 182
 183 // pop {pc} can't switch Thumb mode on ARMv4T
 184 #if __ARM_ARCH >= 5
 185 #define POP_PC() pop {pc}
 186 #else
 187 #define POP_PC()                                                               \
 188   pop {ip};                                                                    \
 189   JMP(ip)
 190 #endif
 191
 192 #if defined(USE_THUMB_2)
 193 #define WIDE(op) op.w
 194 #else
 195 #define WIDE(op) op
 196 #endif
 197 #else // !defined(__arm)
 198 #define DECLARE_FUNC_ENCODING
 199 #define DEFINE_CODE_STATE
 200 #endif
 201
 202 #define GLUE2_(a, b) a##b
 203 #define GLUE(a, b) GLUE2_(a, b)
 204 #define GLUE2(a, b) GLUE2_(a, b)
 205 #define GLUE3_(a, b, c) a##b##c
 206 #define GLUE3(a, b, c) GLUE3_(a, b, c)
 207 #define GLUE4_(a, b, c, d) a##b##c##d
 208 #define GLUE4(a, b, c, d) GLUE4_(a, b, c, d)
 209
 210 #define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
 211
 212 #ifdef VISIBILITY_HIDDEN
 213 #define DECLARE_SYMBOL_VISIBILITY(name)                                        \
 214   HIDDEN(SYMBOL_NAME(name)) SEPARATOR
 215 #define DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name) \
 216   HIDDEN(name) SEPARATOR
 217 #else
 218 #define DECLARE_SYMBOL_VISIBILITY(name)
 219 #define DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name)
 220 #endif
 221
 222 #define DEFINE_COMPILERRT_FUNCTION(name)                                       \
 223   DEFINE_CODE_STATE                                                            \
 224   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
 225   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 226   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 227   DECLARE_SYMBOL_VISIBILITY(name)                                              \
 228   DECLARE_FUNC_ENCODING                                                        \
 229   SYMBOL_NAME(name):
 230
 231 #define DEFINE_COMPILERRT_THUMB_FUNCTION(name)                                 \
 232   DEFINE_CODE_STATE                                                            \
 233   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
 234   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 235   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 236   DECLARE_SYMBOL_VISIBILITY(name) SEPARATOR                                    \
 237   .thumb_func SEPARATOR                                                        \
 238   SYMBOL_NAME(name):
 239
 240 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
 241   DEFINE_CODE_STATE                                                            \
 242   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
 243   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 244   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 245   HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
 246   DECLARE_FUNC_ENCODING                                                        \
 247   SYMBOL_NAME(name):
 248
 249 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
 250   DEFINE_CODE_STATE                                                            \
 251   .globl name SEPARATOR                                                        \
 252   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
 253   HIDDEN(name) SEPARATOR                                                       \
 254   DECLARE_FUNC_ENCODING                                                        \
 255   name:
 256
 257 #define DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(name)                     \
 258   DEFINE_CODE_STATE                                                            \
 259   FUNC_ALIGN                                                                   \
 260   .globl name SEPARATOR                                                        \
 261   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
 262   DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name) SEPARATOR                          \
 263   CFI_START SEPARATOR                                                          \
 264   DECLARE_FUNC_ENCODING                                                        \
 265   name: SEPARATOR BTI_C
 266
 267 #define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
 268   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 269   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 270   DECLARE_SYMBOL_VISIBILITY(name) SEPARATOR                                    \
 271   .set SYMBOL_NAME(name), SYMBOL_NAME(target) SEPARATOR
 272
 273 #if defined(__ARM_EABI__)
 274 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)                          \
 275   DEFINE_COMPILERRT_FUNCTION_ALIAS(aeabi_name, name)
 276 #else
 277 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)
 278 #endif
 279
 280 #ifdef __ELF__
 281 #define END_COMPILERRT_FUNCTION(name)                                          \
 282   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
 283 #define END_COMPILERRT_OUTLINE_FUNCTION(name)                                  \
 284   CFI_END SEPARATOR                                                            \
 285   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
 286 #else
 287 #define END_COMPILERRT_FUNCTION(name)
 288 #define END_COMPILERRT_OUTLINE_FUNCTION(name)                                  \
 289   CFI_END
 290 #endif
 291
 292 #endif // COMPILERRT_ASSEMBLY_H