1 //===-- sanitizer_asm.h -----------------------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // Various support for assembler.
11 //===----------------------------------------------------------------------===//
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 ";"
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
33 # define CFI_INL_ADJUST_CFA_OFFSET(n)
34 # define CFI_STARTPROC
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)
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
56 #if defined(__ELF__) && defined(__x86_64__) || defined(__i386__) || \
58 # define ASM_PREEMPTIBLE_SYM(sym) sym@plt
60 # define ASM_PREEMPTIBLE_SYM(sym) sym
63 #if !defined(__APPLE__)
64 # define ASM_HIDDEN(symbol) .hidden symbol
65 # define ASM_TYPE_FUNCTION(symbol) .type symbol, %function
66 # define ASM_SIZE(symbol) .size symbol, .-symbol
67 # define ASM_SYMBOL(symbol) symbol
68 # define ASM_SYMBOL_INTERCEPTOR(symbol) symbol
69 # if defined(__i386__) || defined(__powerpc__) || defined(__s390__) || \
71 // For details, see interception.h
72 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol
73 # define ASM_TRAMPOLINE_ALIAS(symbol, name) \
75 .set symbol, ASM_WRAPPER_NAME(name)
76 # define ASM_INTERCEPTOR_TRAMPOLINE(name)
77 # define ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT 0
78 # else // Architecture supports interceptor trampoline
79 // Keep trampoline implementation in sync with interception/interception.h
80 # define ASM_WRAPPER_NAME(symbol) ___interceptor_##symbol
81 # define ASM_TRAMPOLINE_ALIAS(symbol, name) \
83 .set symbol, __interceptor_trampoline_##name
84 # define ASM_INTERCEPTOR_TRAMPOLINE(name) \
85 .weak __interceptor_##name; \
86 .set __interceptor_##name, ASM_WRAPPER_NAME(name); \
87 .globl __interceptor_trampoline_##name; \
88 ASM_TYPE_FUNCTION(__interceptor_trampoline_##name); \
89 __interceptor_trampoline_##name: \
91 ASM_TAIL_CALL ASM_PREEMPTIBLE_SYM(__interceptor_##name); \
93 ASM_SIZE(__interceptor_trampoline_##name)
94 # define ASM_INTERCEPTOR_TRAMPOLINE_SUPPORT 1
95 # endif // Architecture supports interceptor trampoline
97 # define ASM_HIDDEN(symbol)
98 # define ASM_TYPE_FUNCTION(symbol)
99 # define ASM_SIZE(symbol)
100 # define ASM_SYMBOL(symbol) _##symbol
101 # define ASM_SYMBOL_INTERCEPTOR(symbol) _wrap_##symbol
102 # define ASM_WRAPPER_NAME(symbol) __interceptor_##symbol
105 #if defined(__ELF__) && (defined(__GNU__) || defined(__FreeBSD__) || \
106 defined(__Fuchsia__) || defined(__linux__))
108 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
111 #define NO_EXEC_STACK_DIRECTIVE
114 #if (defined(__x86_64__) || defined(__i386__)) && defined(__has_include) && __has_include(<cet.h>)