compiler-rt/lib/sanitizer_common/sanitizer_asm.h

   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