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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
|
/* Copyright (C) 1992, 93, 1995-2000, 2002, 2003, 2005, 2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995.
ARM changes by Philip Blundell, <pjb27@cam.ac.uk>, May 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _LINUX_ARM_SYSDEP_H
#define _LINUX_ARM_SYSDEP_H 1
/* There is some commonality. */
#include <sysdeps/unix/arm/sysdep.h>
/* Defines RTLD_PRIVATE_ERRNO and USE_DL_SYSINFO. */
#include <dl-sysdep.h>
/* For Linux we can use the system call table in the header file
/usr/include/asm/unistd.h
of the kernel. But these symbols do not follow the SYS_* syntax
so we have to redefine the `SYS_ify' macro here. */
#undef SYS_ify
#define SWI_BASE (0x900000)
#define SYS_ify(syscall_name) (__NR_##syscall_name)
/* The following must match the kernel's <asm/procinfo.h>. */
#define HWCAP_ARM_SWP 1
#define HWCAP_ARM_HALF 2
#define HWCAP_ARM_THUMB 4
#define HWCAP_ARM_26BIT 8
#define HWCAP_ARM_FAST_MULT 16
#define HWCAP_ARM_FPA 32
#define HWCAP_ARM_VFP 64
#define HWCAP_ARM_EDSP 128
#define HWCAP_ARM_JAVA 256
#define HWCAP_ARM_IWMMXT 512
#ifdef __ASSEMBLER__
/* Linux uses a negative return value to indicate syscall errors,
unlike most Unices, which use the condition codes' carry flag.
Since version 2.1 the return value of a system call might be
negative even if the call succeeded. E.g., the `lseek' system call
might return a large offset. Therefore we must not anymore test
for < 0, but test for a real error by making sure the value in R0
is a real error number. Linus said he will make sure the no syscall
returns a value in -1 .. -4095 as a valid result so we can safely
test with -4095. */
#undef PSEUDO
#define PSEUDO(name, syscall_name, args) \
.text; \
ENTRY (name); \
DO_CALL (syscall_name, args); \
cmn r0, $4096;
#define PSEUDO_RET \
RETINSTR(cc, lr); \
b PLTJMP(SYSCALL_ERROR)
#undef ret
#define ret PSEUDO_RET
#undef PSEUDO_END
#define PSEUDO_END(name) \
SYSCALL_ERROR_HANDLER \
END (name)
#undef PSEUDO_NOERRNO
#define PSEUDO_NOERRNO(name, syscall_name, args) \
.text; \
ENTRY (name); \
DO_CALL (syscall_name, args);
#define PSEUDO_RET_NOERRNO \
DO_RET (lr);
#undef ret_NOERRNO
#define ret_NOERRNO PSEUDO_RET_NOERRNO
#undef PSEUDO_END_NOERRNO
#define PSEUDO_END_NOERRNO(name) \
END (name)
/* The function has to return the error code. */
#undef PSEUDO_ERRVAL
#define PSEUDO_ERRVAL(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (syscall_name, args); \
rsb r0, r0, #0
#undef PSEUDO_END_ERRVAL
#define PSEUDO_END_ERRVAL(name) \
END (name)
#define ret_ERRVAL PSEUDO_RET_NOERRNO
#if NOT_IN_libc
# define SYSCALL_ERROR __local_syscall_error
# if RTLD_PRIVATE_ERRNO
# define SYSCALL_ERROR_HANDLER \
__local_syscall_error: \
ldr r1, 1f; \
rsb r0, r0, #0; \
0: str r0, [pc, r1]; \
mvn r0, #0; \
DO_RET(lr); \
1: .word C_SYMBOL_NAME(rtld_errno) - 0b - 8;
# else
# define SYSCALL_ERROR_HANDLER \
__local_syscall_error: \
str lr, [sp, #-4]!; \
str r0, [sp, #-4]!; \
bl PLTJMP(C_SYMBOL_NAME(__errno_location)); \
ldr r1, [sp], #4; \
rsb r1, r1, #0; \
str r1, [r0]; \
mvn r0, #0; \
ldr pc, [sp], #4;
# endif
#else
# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
# define SYSCALL_ERROR __syscall_error
#endif
/* Linux takes system call args in registers:
syscall number in the SWI instruction
arg 1 r0
arg 2 r1
arg 3 r2
arg 4 r3
arg 5 r4 (this is different from the APCS convention)
arg 6 r5
arg 7 r6
The compiler is going to form a call by coming here, through PSEUDO, with
arguments
syscall number in the DO_CALL macro
arg 1 r0
arg 2 r1
arg 3 r2
arg 4 r3
arg 5 [sp]
arg 6 [sp+4]
arg 7 [sp+8]
We need to shuffle values between R4..R6 and the stack so that the
caller's v1..v3 and stack frame are not corrupted, and the kernel
sees the right arguments.
*/
#undef DO_CALL
#define DO_CALL(syscall_name, args) \
DOARGS_##args \
swi SYS_ify (syscall_name); \
UNDOARGS_##args
#define DOARGS_0 /* nothing */
#define DOARGS_1 /* nothing */
#define DOARGS_2 /* nothing */
#define DOARGS_3 /* nothing */
#define DOARGS_4 /* nothing */
#define DOARGS_5 str r4, [sp, $-4]!; ldr r4, [sp, $4];
#define DOARGS_6 mov ip, sp; stmfd sp!, {r4, r5}; ldmia ip, {r4, r5};
#define DOARGS_7 mov ip, sp; stmfd sp!, {r4, r5, r6}; ldmia ip, {r4, r5, r6};
#define UNDOARGS_0 /* nothing */
#define UNDOARGS_1 /* nothing */
#define UNDOARGS_2 /* nothing */
#define UNDOARGS_3 /* nothing */
#define UNDOARGS_4 /* nothing */
#define UNDOARGS_5 ldr r4, [sp], $4;
#define UNDOARGS_6 ldmfd sp!, {r4, r5};
#define UNDOARGS_7 ldmfd sp!, {r4, r5, r6};
#else /* not __ASSEMBLER__ */
/* Define a macro which expands into the inline wrapper code for a system
call. */
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ unsigned int _sys_result = INTERNAL_SYSCALL (name, , nr, args); \
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_sys_result, ), 0)) \
{ \
__set_errno (INTERNAL_SYSCALL_ERRNO (_sys_result, )); \
_sys_result = (unsigned int) -1; \
} \
(int) _sys_result; })
#undef INTERNAL_SYSCALL_DECL
#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
#undef INTERNAL_SYSCALL_RAW
#define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
({ unsigned int _sys_result; \
{ \
register int _a1 asm ("a1"); \
LOAD_ARGS_##nr (args) \
asm volatile ("swi %1 @ syscall " #name \
: "=r" (_a1) \
: "i" (name) ASM_ARGS_##nr \
: "memory"); \
_sys_result = _a1; \
} \
(int) _sys_result; })
#undef INTERNAL_SYSCALL
#define INTERNAL_SYSCALL(name, err, nr, args...) \
INTERNAL_SYSCALL_RAW(SYS_ify(name), err, nr, args)
#undef INTERNAL_SYSCALL_ARM
#define INTERNAL_SYSCALL_ARM(name, err, nr, args...) \
INTERNAL_SYSCALL_RAW(__ARM_NR_##name, err, nr, args)
#undef INTERNAL_SYSCALL_ERROR_P
#define INTERNAL_SYSCALL_ERROR_P(val, err) \
((unsigned int) (val) >= 0xfffff001u)
#undef INTERNAL_SYSCALL_ERRNO
#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
#define LOAD_ARGS_0()
#define ASM_ARGS_0
#define LOAD_ARGS_1(a1) \
_a1 = (int) (a1); \
LOAD_ARGS_0 ()
#define ASM_ARGS_1 ASM_ARGS_0, "r" (_a1)
#define LOAD_ARGS_2(a1, a2) \
register int _a2 asm ("a2") = (int) (a2); \
LOAD_ARGS_1 (a1)
#define ASM_ARGS_2 ASM_ARGS_1, "r" (_a2)
#define LOAD_ARGS_3(a1, a2, a3) \
register int _a3 asm ("a3") = (int) (a3); \
LOAD_ARGS_2 (a1, a2)
#define ASM_ARGS_3 ASM_ARGS_2, "r" (_a3)
#define LOAD_ARGS_4(a1, a2, a3, a4) \
register int _a4 asm ("a4") = (int) (a4); \
LOAD_ARGS_3 (a1, a2, a3)
#define ASM_ARGS_4 ASM_ARGS_3, "r" (_a4)
#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \
register int _v1 asm ("v1") = (int) (a5); \
LOAD_ARGS_4 (a1, a2, a3, a4)
#define ASM_ARGS_5 ASM_ARGS_4, "r" (_v1)
#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \
register int _v2 asm ("v2") = (int) (a6); \
LOAD_ARGS_5 (a1, a2, a3, a4, a5)
#define ASM_ARGS_6 ASM_ARGS_5, "r" (_v2)
#define LOAD_ARGS_7(a1, a2, a3, a4, a5, a6, a7) \
register int _v3 asm ("v3") = (int) (a7); \
LOAD_ARGS_6 (a1, a2, a3, a4, a5, a6)
#define ASM_ARGS_7 ASM_ARGS_6, "r" (_v3)
/* We can't implement non-constant syscalls directly since the syscall
number is normally encoded in the instruction. So use SYS_syscall. */
#define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \
INTERNAL_SYSCALL_NCS_##nr (number, err, args)
#define INTERNAL_SYSCALL_NCS_0(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 1, number, args)
#define INTERNAL_SYSCALL_NCS_1(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 2, number, args)
#define INTERNAL_SYSCALL_NCS_2(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 3, number, args)
#define INTERNAL_SYSCALL_NCS_3(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 4, number, args)
#define INTERNAL_SYSCALL_NCS_4(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 5, number, args)
#define INTERNAL_SYSCALL_NCS_5(number, err, args...) \
INTERNAL_SYSCALL (syscall, err, 6, number, args)
#endif /* __ASSEMBLER__ */
#endif /* linux/arm/sysdep.h */
|
