syscalls 0.8.1

A list of Linux system calls.
Documentation 
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
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194

// On x86-64, the following registers are used for args 1-6:
// arg1: %rdi
// arg2: %rsi
// arg3: %rdx
// arg4: %r10
// arg5: %r8
// arg6: %r9
//
// rax is used for both the syscall number and the syscall return value.
//
// rcx and r11 are always clobbered. syscalls can also modify memory. With the
// `asm!()` macro, it is assumed that memory is clobbered unless the nomem
// option is specified.
use core::arch::asm;

/// Issues a raw system call with 0 arguments.
///
/// # Safety
///
/// Running a system call is inherently unsafe. It is the caller's
/// responsibility to ensure safety.
#[inline]
pub unsafe fn syscall0(n: usize) -> usize {
    let mut ret: usize;
    asm!(
        "syscall",
        inlateout("rax") n => ret,
        out("rcx") _, // rcx is used to store old rip
        out("r11") _, // r11 is used to store old rflags
        options(nostack, preserves_flags)
    );
    ret
}

/// Issues a raw system call with 1 argument.
///
/// # Safety
///
/// Running a system call is inherently unsafe. It is the caller's
/// responsibility to ensure safety.
#[inline]
pub unsafe fn syscall1(n: usize, arg1: usize) -> usize {
    let mut ret: usize;
    asm!(
        "syscall",
        inlateout("rax") n => ret,
        in("rdi") arg1,
        out("rcx") _, // rcx is used to store old rip
        out("r11") _, // r11 is used to store old rflags
        options(nostack, preserves_flags)
    );
    ret
}

/// Issues a raw system call with 2 arguments.
///
/// # Safety
///
/// Running a system call is inherently unsafe. It is the caller's
/// responsibility to ensure safety.
#[inline]
pub unsafe fn syscall2(n: usize, arg1: usize, arg2: usize) -> usize {
    let mut ret: usize;
    asm!(
        "syscall",
        inlateout("rax") n => ret,
        in("rdi") arg1,
        in("rsi") arg2,
        out("rcx") _, // rcx is used to store old rip
        out("r11") _, // r11 is used to store old rflags
        options(nostack, preserves_flags)
    );
    ret
}

/// Issues a raw system call with 3 arguments.
///
/// # Safety
///
/// Running a system call is inherently unsafe. It is the caller's
/// responsibility to ensure safety.
#[inline]
pub unsafe fn syscall3(
    n: usize,
    arg1: usize,
    arg2: usize,
    arg3: usize,
) -> usize {
    let mut ret: usize;
    asm!(
        "syscall",
        inlateout("rax") n => ret,
        in("rdi") arg1,
        in("rsi") arg2,
        in("rdx") arg3,
        out("rcx") _, // rcx is used to store old rip
        out("r11") _, // r11 is used to store old rflags
        options(nostack, preserves_flags)
    );
    ret
}

/// Issues a raw system call with 4 arguments.
///
/// # Safety
///
/// Running a system call is inherently unsafe. It is the caller's
/// responsibility to ensure safety.
#[inline]
pub unsafe fn syscall4(
    n: usize,
    arg1: usize,
    arg2: usize,
    arg3: usize,
    arg4: usize,
) -> usize {
    let mut ret: usize;
    asm!(
        "syscall",
        inlateout("rax") n => ret,
        in("rdi") arg1,
        in("rsi") arg2,
        in("rdx") arg3,
        in("r10") arg4,
        out("rcx") _, // rcx is used to store old rip
        out("r11") _, // r11 is used to store old rflags
        options(nostack, preserves_flags)
    );
    ret
}

/// Issues a raw system call with 5 arguments.
///
/// # Safety
///
/// Running a system call is inherently unsafe. It is the caller's
/// responsibility to ensure safety.
#[inline]
pub unsafe fn syscall5(
    n: usize,
    arg1: usize,
    arg2: usize,
    arg3: usize,
    arg4: usize,
    arg5: usize,
) -> usize {
    let mut ret: usize;
    asm!(
        "syscall",
        inlateout("rax") n => ret,
        in("rdi") arg1,
        in("rsi") arg2,
        in("rdx") arg3,
        in("r10") arg4,
        in("r8")  arg5,
        out("rcx") _, // rcx is used to store old rip
        out("r11") _, // r11 is used to store old rflags
        options(nostack, preserves_flags)
    );
    ret
}

/// Issues a raw system call with 6 arguments.
///
/// # Safety
///
/// Running a system call is inherently unsafe. It is the caller's
/// responsibility to ensure safety.
#[inline]
pub unsafe fn syscall6(
    n: usize,
    arg1: usize,
    arg2: usize,
    arg3: usize,
    arg4: usize,
    arg5: usize,
    arg6: usize,
) -> usize {
    let mut ret: usize;
    asm!(
        "syscall",
        inlateout("rax") n => ret,
        in("rdi") arg1,
        in("rsi") arg2,
        in("rdx") arg3,
        in("r10") arg4,
        in("r8")  arg5,
        in("r9")  arg6,
        out("rcx") _, // rcx is used to store old rip
        out("r11") _, // r11 is used to store old rflags
        options(nostack, preserves_flags)
    );
    ret
}