1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <bits/stdint.h>
#include <signal.h>
#include <stdbool.h>
#include <sys/cdefs.h>
#include <sys/types.h>
__BEGIN_DECLS
//
// /!\ This structure is accessed inside setjmp.S, keep both files in sync!
//
struct __jmp_buf {
#if defined(__x86_64__)
uint64_t rbx;
uint64_t r12;
uint64_t r13;
uint64_t r14;
uint64_t r15;
uint64_t rbp;
uint64_t rsp;
uint64_t rip;
#elif defined(__aarch64__)
// FIXME: This is likely incorrect.
uint64_t regs[22];
#else
# error
#endif
int did_save_signal_mask;
sigset_t saved_signal_mask;
};
typedef struct __jmp_buf jmp_buf[1];
typedef struct __jmp_buf sigjmp_buf[1];
/**
* Since setjmp.h may be included by ports written in C, we need to guard this.
*/
#ifdef __cplusplus
# if defined(__x86_64__)
static_assert(sizeof(struct __jmp_buf) == 72, "struct __jmp_buf unsynchronized with x86_64/setjmp.S");
# elif defined(__aarch64__)
static_assert(sizeof(struct __jmp_buf) == 184, "struct __jmp_buf unsynchronized with aarch64/setjmp.S");
# else
# error
# endif
#endif
/**
* Calling conventions mandates that sigsetjmp() cannot call setjmp(),
* otherwise the restored calling environment will not be the original caller's
* but sigsetjmp()'s and we'll return to the wrong call site on siglongjmp().
*
* The setjmp(), sigsetjmp() and longjmp() functions have to be implemented in
* assembly because they touch the call stack and registers in non-portable
* ways. However, we *can* implement siglongjmp() as a standard C function.
*/
int setjmp(jmp_buf);
__attribute__((noreturn)) void longjmp(jmp_buf, int val);
int sigsetjmp(sigjmp_buf, int savesigs);
__attribute__((noreturn)) void siglongjmp(sigjmp_buf, int val);
/**
* _setjmp() and _longjmp() are specified as behaving the exactly the same as
* setjmp() and longjmp(), except they are not supposed to modify the signal mask.
*
* Our implementations already follow this restriction, so we just map them directly
* to the same functions.
*
* https://pubs.opengroup.org/onlinepubs/9699969599/functions/_setjmp.html
*/
int _setjmp(jmp_buf);
__attribute__((noreturn)) void _longjmp(jmp_buf, int val);
__END_DECLS
|
