aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/clang16-rt/lib/sanitizer_common/sanitizer_syscall_linux_riscv64.inc
blob: 89c12602057c7336d3c18503b566229d8169ed43 (plain) (blame)
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
//===-- sanitizer_syscall_linux_riscv64.inc ---------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Implementations of internal_syscall and internal_iserror for Linux/riscv64.
//
//===----------------------------------------------------------------------===//

// About local register variables:
// https://gcc.gnu.org/onlinedocs/gcc/Local-Register-Variables.html#Local-Register-Variables
//
// Kernel ABI...
// To my surprise I haven't found much information regarding it.
// Kernel source and internet browsing shows that:
//  syscall number is passed in a7
//  (http://man7.org/linux/man-pages/man2/syscall.2.html) results are return in
//  a0 and a1 (http://man7.org/linux/man-pages/man2/syscall.2.html) arguments
//  are passed in: a0-a7 (see below)
//
//  Regarding the arguments. The only "documentation" I could find is
//  this comment (!!!) by Bruce Hold on google forums (!!!):
//    https://groups.google.com/a/groups.riscv.org/forum/#!topic/sw-dev/exbrzM3GZDQ
//    Confirmed by inspecting glibc sources.
//  Great way to document things.
#define SYSCALL(name) __NR_##name

#define INTERNAL_SYSCALL_CLOBBERS "memory"

static uptr __internal_syscall(u64 nr) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0");
  __asm__ volatile("ecall\n\t"
                   : "=r"(a0)
                   : "r"(a7)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall0(n) (__internal_syscall)(n)

static uptr __internal_syscall(u64 nr, u64 arg1) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0") = arg1;
  __asm__ volatile("ecall\n\t"
                   : "+r"(a0)
                   : "r"(a7)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall1(n, a1) (__internal_syscall)(n, (u64)(a1))

static uptr __internal_syscall(u64 nr, u64 arg1, long arg2) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0") = arg1;
  register u64 a1 asm("a1") = arg2;
  __asm__ volatile("ecall\n\t"
                   : "+r"(a0)
                   : "r"(a7), "r"(a1)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall2(n, a1, a2) \
  (__internal_syscall)(n, (u64)(a1), (long)(a2))

static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0") = arg1;
  register u64 a1 asm("a1") = arg2;
  register u64 a2 asm("a2") = arg3;
  __asm__ volatile("ecall\n\t"
                   : "+r"(a0)
                   : "r"(a7), "r"(a1), "r"(a2)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall3(n, a1, a2, a3) \
  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3))

static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3,
                               u64 arg4) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0") = arg1;
  register u64 a1 asm("a1") = arg2;
  register u64 a2 asm("a2") = arg3;
  register u64 a3 asm("a3") = arg4;
  __asm__ volatile("ecall\n\t"
                   : "+r"(a0)
                   : "r"(a7), "r"(a1), "r"(a2), "r"(a3)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall4(n, a1, a2, a3, a4) \
  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4))

static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3, u64 arg4,
                               long arg5) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0") = arg1;
  register u64 a1 asm("a1") = arg2;
  register u64 a2 asm("a2") = arg3;
  register u64 a3 asm("a3") = arg4;
  register u64 a4 asm("a4") = arg5;
  __asm__ volatile("ecall\n\t"
                   : "+r"(a0)
                   : "r"(a7), "r"(a1), "r"(a2), "r"(a3), "r"(a4)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall5(n, a1, a2, a3, a4, a5)                       \
  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4), \
                       (u64)(a5))

static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3, u64 arg4,
                               long arg5, long arg6) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0") = arg1;
  register u64 a1 asm("a1") = arg2;
  register u64 a2 asm("a2") = arg3;
  register u64 a3 asm("a3") = arg4;
  register u64 a4 asm("a4") = arg5;
  register u64 a5 asm("a5") = arg6;
  __asm__ volatile("ecall\n\t"
                   : "+r"(a0)
                   : "r"(a7), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall6(n, a1, a2, a3, a4, a5, a6)                   \
  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4), \
                       (u64)(a5), (long)(a6))

static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3, u64 arg4,
                               long arg5, long arg6, long arg7) {
  register u64 a7 asm("a7") = nr;
  register u64 a0 asm("a0") = arg1;
  register u64 a1 asm("a1") = arg2;
  register u64 a2 asm("a2") = arg3;
  register u64 a3 asm("a3") = arg4;
  register u64 a4 asm("a4") = arg5;
  register u64 a5 asm("a5") = arg6;
  register u64 a6 asm("a6") = arg7;
  __asm__ volatile("ecall\n\t"
                   : "+r"(a0)
                   : "r"(a7), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5),
                     "r"(a6)
                   : INTERNAL_SYSCALL_CLOBBERS);
  return a0;
}
#define __internal_syscall7(n, a1, a2, a3, a4, a5, a6, a7)               \
  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4), \
                       (u64)(a5), (long)(a6), (long)(a7))

#define __SYSCALL_NARGS_X(a1, a2, a3, a4, a5, a6, a7, a8, n, ...) n
#define __SYSCALL_NARGS(...) \
  __SYSCALL_NARGS_X(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0, )
#define __SYSCALL_CONCAT_X(a, b) a##b
#define __SYSCALL_CONCAT(a, b) __SYSCALL_CONCAT_X(a, b)
#define __SYSCALL_DISP(b, ...) \
  __SYSCALL_CONCAT(b, __SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)

#define internal_syscall(...) __SYSCALL_DISP(__internal_syscall, __VA_ARGS__)

// Helper function used to avoid clobbering of errno.
bool internal_iserror(uptr retval, int *rverrno) {
  if (retval >= (uptr)-4095) {
    if (rverrno)
      *rverrno = -retval;
    return true;
  }
  return false;
}