1//===-- hwasan_setjmp_aarch64.S -------------------------------------------===//
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 is a part of HWAddressSanitizer.
10//
11// HWAddressSanitizer runtime.
12//===----------------------------------------------------------------------===//
13
14#include "sanitizer_common/sanitizer_asm.h"
15#include "builtins/assembly.h"
16
17#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__)
18#include "sanitizer_common/sanitizer_platform.h"
19
20// We want to save the context of the calling function.
21// That requires
22// 1) No modification of the link register by this function.
23// 2) No modification of the stack pointer by this function.
24// 3) (no modification of any other saved register, but that's not really going
25// to occur, and hence isn't as much of a worry).
26//
27// There's essentially no way to ensure that the compiler will not modify the
28// stack pointer when compiling a C function.
29// Hence we have to write this function in assembly.
30
31.section .text
32.file "hwasan_setjmp_aarch64.S"
33
34.global ASM_WRAPPER_NAME(setjmp)
35ASM_TYPE_FUNCTION(ASM_WRAPPER_NAME(setjmp))
36ASM_WRAPPER_NAME(setjmp):
37  CFI_STARTPROC
38  BTI_C
39  mov	x1, #0
40  b	ASM_WRAPPER_NAME(sigsetjmp)
41  CFI_ENDPROC
42ASM_SIZE(ASM_WRAPPER_NAME(setjmp))
43
44ASM_INTERCEPTOR_TRAMPOLINE(setjmp)
45
46#if SANITIZER_ANDROID
47// Bionic also defines a function `setjmp` that calls `sigsetjmp` saving the
48// current signal.
49.global ASM_WRAPPER_NAME(setjmp_bionic)
50ASM_TYPE_FUNCTION(ASM_WRAPPER_NAME(setjmp_bionic))
51ASM_WRAPPER_NAME(setjmp_bionic):
52  CFI_STARTPROC
53  BTI_C
54  mov	x1, #1
55  b	ASM_WRAPPER_NAME(sigsetjmp)
56  CFI_ENDPROC
57ASM_SIZE(ASM_WRAPPER_NAME(setjmp_bionic))
58
59ASM_INTERCEPTOR_TRAMPOLINE(setjmp_bionic)
60#endif
61
62.global ASM_WRAPPER_NAME(sigsetjmp)
63ASM_TYPE_FUNCTION(ASM_WRAPPER_NAME(sigsetjmp))
64ASM_WRAPPER_NAME(sigsetjmp):
65  CFI_STARTPROC
66  BTI_C
67  stp	x19, x20, [x0, #0<<3]
68  stp	x21, x22, [x0, #2<<3]
69  stp	x23, x24, [x0, #4<<3]
70  stp	x25, x26, [x0, #6<<3]
71  stp	x27, x28, [x0, #8<<3]
72  stp	x29, x30, [x0, #10<<3]
73  stp	 d8,  d9, [x0, #14<<3]
74  stp	d10, d11, [x0, #16<<3]
75  stp	d12, d13, [x0, #18<<3]
76  stp	d14, d15, [x0, #20<<3]
77  mov	x2,  sp
78  str	x2,  [x0, #13<<3]
79  // We always have the second argument to __sigjmp_save (savemask) set, since
80  // the _setjmp function above has set it for us as `false`.
81  // This function is defined in hwasan_interceptors.cc
82  b	__sigjmp_save
83  CFI_ENDPROC
84ASM_SIZE(ASM_WRAPPER_NAME(sigsetjmp))
85
86ASM_INTERCEPTOR_TRAMPOLINE(sigsetjmp)
87
88
89#if SANITIZER_ANDROID
90ASM_TRAMPOLINE_ALIAS(sigsetjmp, sigsetjmp)
91ASM_TRAMPOLINE_ALIAS(setjmp, setjmp_bionic)
92#else
93ASM_TRAMPOLINE_ALIAS(__sigsetjmp, sigsetjmp)
94#endif
95
96ASM_TRAMPOLINE_ALIAS(_setjmp, setjmp)
97#endif
98
99// We do not need executable stack.
100NO_EXEC_STACK_DIRECTIVE
101
102GNU_PROPERTY_BTI_PAC
103