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 | |