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688903eb | 1 | /* Copyright (C) 1996-2018 Free Software Foundation, Inc. |
36e28152 UD |
2 | This file is part of the GNU C Library. |
3 | Written by Andreas Schwab, <schwab@issan.informatik.uni-dortmund.de>, | |
4 | December 1995. | |
9298f9e1 | 5 | |
36e28152 | 6 | The GNU C Library is free software; you can redistribute it and/or |
3214b89b AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
9298f9e1 | 10 | |
36e28152 UD |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
3214b89b | 14 | Lesser General Public License for more details. |
9298f9e1 | 15 | |
3214b89b | 16 | You should have received a copy of the GNU Lesser General Public |
ab84e3ff PE |
17 | License along with the GNU C Library. If not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
9298f9e1 | 19 | |
fb1cf108 | 20 | #include <sysdeps/unix/sysv/linux/sysdep.h> |
40111cb9 | 21 | #include <tls.h> |
9298f9e1 | 22 | |
9d3831f3 AS |
23 | /* Defines RTLD_PRIVATE_ERRNO. */ |
24 | #include <dl-sysdep.h> | |
25 | ||
b2801dda RM |
26 | /* For Linux we can use the system call table in the header file |
27 | /usr/include/asm/unistd.h | |
28 | of the kernel. But these symbols do not follow the SYS_* syntax | |
29 | so we have to redefine the `SYS_ify' macro here. */ | |
30 | #undef SYS_ify | |
53bce1b5 | 31 | #define SYS_ify(syscall_name) __NR_##syscall_name |
b2801dda | 32 | |
e0ebc3b2 | 33 | #ifdef __ASSEMBLER__ |
9298f9e1 | 34 | |
9298f9e1 | 35 | /* Linux uses a negative return value to indicate syscall errors, unlike |
5415516c UD |
36 | most Unices, which use the condition codes' carry flag. |
37 | ||
38 | Since version 2.1 the return value of a system call might be negative | |
39 | even if the call succeeded. E.g., the `lseek' system call might return | |
40 | a large offset. Therefore we must not anymore test for < 0, but test | |
41 | for a real error by making sure the value in %d0 is a real error | |
dd4b8913 | 42 | number. Linus said he will make sure the no syscall returns a value |
6acf09f4 | 43 | in -1 .. -4095 as a valid result so we can savely test with -4095. */ |
2cd49338 AS |
44 | |
45 | /* We don't want the label for the error handler to be visible in the symbol | |
46 | table when we define it here. */ | |
47 | #ifdef PIC | |
48 | #define SYSCALL_ERROR_LABEL .Lsyscall_error | |
49 | #else | |
50 | #define SYSCALL_ERROR_LABEL __syscall_error | |
51 | #endif | |
52 | ||
56d7f029 | 53 | #undef PSEUDO |
9298f9e1 RM |
54 | #define PSEUDO(name, syscall_name, args) \ |
55 | .text; \ | |
9298f9e1 | 56 | ENTRY (name) \ |
56d7f029 | 57 | DO_CALL (syscall_name, args); \ |
6acf09f4 | 58 | cmp.l &-4095, %d0; \ |
2cd49338 | 59 | jcc SYSCALL_ERROR_LABEL |
5415516c UD |
60 | |
61 | #undef PSEUDO_END | |
b8bd7edd UD |
62 | #define PSEUDO_END(name) \ |
63 | SYSCALL_ERROR_HANDLER; \ | |
64 | END (name) | |
9298f9e1 | 65 | |
98f7320f UD |
66 | #undef PSEUDO_NOERRNO |
67 | #define PSEUDO_NOERRNO(name, syscall_name, args) \ | |
68 | .text; \ | |
69 | ENTRY (name) \ | |
70 | DO_CALL (syscall_name, args) | |
71 | ||
72 | #undef PSEUDO_END_NOERRNO | |
73 | #define PSEUDO_END_NOERRNO(name) \ | |
74 | END (name) | |
75 | ||
fd1f2c4a AS |
76 | #define ret_NOERRNO rts |
77 | ||
78 | /* The function has to return the error code. */ | |
79 | #undef PSEUDO_ERRVAL | |
80 | #define PSEUDO_ERRVAL(name, syscall_name, args) \ | |
81 | .text; \ | |
82 | ENTRY (name) \ | |
83 | DO_CALL (syscall_name, args); \ | |
84 | negl %d0 | |
85 | ||
86 | #undef PSEUDO_END_ERRVAL | |
87 | #define PSEUDO_END_ERRVAL(name) \ | |
88 | END (name) | |
89 | ||
90 | #define ret_ERRVAL rts | |
64928a88 | 91 | |
9298f9e1 | 92 | #ifdef PIC |
4b5b9a07 | 93 | # if RTLD_PRIVATE_ERRNO |
9d3831f3 AS |
94 | # define SYSCALL_ERROR_HANDLER \ |
95 | SYSCALL_ERROR_LABEL: \ | |
9c986f87 | 96 | PCREL_OP (lea, rtld_errno, %a0, %a0); \ |
9d3831f3 AS |
97 | neg.l %d0; \ |
98 | move.l %d0, (%a0); \ | |
99 | move.l &-1, %d0; \ | |
100 | /* Copy return value to %a0 for syscalls that are declared to return \ | |
101 | a pointer (e.g., mmap). */ \ | |
102 | move.l %d0, %a0; \ | |
103 | rts; | |
df62b0cd | 104 | # elif defined _LIBC_REENTRANT |
4f41c682 | 105 | # if IS_IN (libc) |
dbd0094b AS |
106 | # define SYSCALL_ERROR_ERRNO __libc_errno |
107 | # else | |
108 | # define SYSCALL_ERROR_ERRNO errno | |
109 | # endif | |
110 | # define SYSCALL_ERROR_HANDLER \ | |
111 | SYSCALL_ERROR_LABEL: \ | |
112 | neg.l %d0; \ | |
113 | move.l %d0, -(%sp); \ | |
50e73d13 | 114 | cfi_adjust_cfa_offset (4); \ |
dbd0094b | 115 | jbsr __m68k_read_tp@PLTPC; \ |
690d264a | 116 | SYSCALL_ERROR_LOAD_GOT (%a1); \ |
dbd0094b AS |
117 | add.l (SYSCALL_ERROR_ERRNO@TLSIE, %a1), %a0; \ |
118 | move.l (%sp)+, (%a0); \ | |
50e73d13 | 119 | cfi_adjust_cfa_offset (-4); \ |
dbd0094b AS |
120 | move.l &-1, %d0; \ |
121 | /* Copy return value to %a0 for syscalls that are declared to return \ | |
122 | a pointer (e.g., mmap). */ \ | |
123 | move.l %d0, %a0; \ | |
124 | rts; | |
dbd0094b AS |
125 | # else /* !_LIBC_REENTRANT */ |
126 | /* Store (- %d0) into errno through the GOT. */ | |
127 | # define SYSCALL_ERROR_HANDLER \ | |
2cd49338 | 128 | SYSCALL_ERROR_LABEL: \ |
bf4b3107 UD |
129 | move.l (errno@GOTPC, %pc), %a0; \ |
130 | neg.l %d0; \ | |
131 | move.l %d0, (%a0); \ | |
5415516c | 132 | move.l &-1, %d0; \ |
bf4b3107 UD |
133 | /* Copy return value to %a0 for syscalls that are declared to return \ |
134 | a pointer (e.g., mmap). */ \ | |
135 | move.l %d0, %a0; \ | |
136 | rts; | |
dbd0094b | 137 | # endif /* _LIBC_REENTRANT */ |
bf4b3107 | 138 | #else |
9d3831f3 | 139 | # define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ |
bf4b3107 | 140 | #endif /* PIC */ |
9298f9e1 RM |
141 | |
142 | /* Linux takes system call arguments in registers: | |
143 | ||
144 | syscall number %d0 call-clobbered | |
145 | arg 1 %d1 call-clobbered | |
146 | arg 2 %d2 call-saved | |
147 | arg 3 %d3 call-saved | |
148 | arg 4 %d4 call-saved | |
149 | arg 5 %d5 call-saved | |
40111cb9 | 150 | arg 6 %a0 call-clobbered |
9298f9e1 RM |
151 | |
152 | The stack layout upon entering the function is: | |
153 | ||
40111cb9 | 154 | 24(%sp) Arg# 6 |
9298f9e1 RM |
155 | 20(%sp) Arg# 5 |
156 | 16(%sp) Arg# 4 | |
157 | 12(%sp) Arg# 3 | |
158 | 8(%sp) Arg# 2 | |
159 | 4(%sp) Arg# 1 | |
160 | (%sp) Return address | |
161 | ||
162 | (Of course a function with say 3 arguments does not have entries for | |
163 | arguments 4 and 5.) | |
164 | ||
165 | Separate move's are faster than movem, but need more space. Since | |
166 | speed is more important, we don't use movem. Since %a0 and %a1 are | |
167 | scratch registers, we can use them for saving as well. */ | |
168 | ||
56d7f029 AS |
169 | #define DO_CALL(syscall_name, args) \ |
170 | move.l &SYS_ify(syscall_name), %d0; \ | |
9298f9e1 | 171 | DOARGS_##args \ |
5415516c | 172 | trap &0; \ |
9298f9e1 RM |
173 | UNDOARGS_##args |
174 | ||
175 | #define DOARGS_0 /* No arguments to frob. */ | |
176 | #define UNDOARGS_0 /* No arguments to unfrob. */ | |
177 | #define _DOARGS_0(n) /* No arguments to frob. */ | |
178 | ||
179 | #define DOARGS_1 _DOARGS_1 (4) | |
180 | #define _DOARGS_1(n) move.l n(%sp), %d1; _DOARGS_0 (n) | |
181 | #define UNDOARGS_1 UNDOARGS_0 | |
182 | ||
183 | #define DOARGS_2 _DOARGS_2 (8) | |
50e73d13 AS |
184 | #define _DOARGS_2(n) move.l %d2, %a0; cfi_register (%d2, %a0); \ |
185 | move.l n(%sp), %d2; _DOARGS_1 (n-4) | |
186 | #define UNDOARGS_2 UNDOARGS_1; move.l %a0, %d2; cfi_restore (%d2) | |
9298f9e1 RM |
187 | |
188 | #define DOARGS_3 _DOARGS_3 (12) | |
50e73d13 AS |
189 | #define _DOARGS_3(n) move.l %d3, %a1; cfi_register (%d3, %a1); \ |
190 | move.l n(%sp), %d3; _DOARGS_2 (n-4) | |
191 | #define UNDOARGS_3 UNDOARGS_2; move.l %a1, %d3; cfi_restore (%d3) | |
9298f9e1 RM |
192 | |
193 | #define DOARGS_4 _DOARGS_4 (16) | |
50e73d13 AS |
194 | #define _DOARGS_4(n) move.l %d4, -(%sp); \ |
195 | cfi_adjust_cfa_offset (4); cfi_rel_offset (%d4, 0); \ | |
196 | move.l n+4(%sp), %d4; _DOARGS_3 (n) | |
197 | #define UNDOARGS_4 UNDOARGS_3; move.l (%sp)+, %d4; \ | |
198 | cfi_adjust_cfa_offset (-4); cfi_restore (%d4) | |
9298f9e1 RM |
199 | |
200 | #define DOARGS_5 _DOARGS_5 (20) | |
50e73d13 AS |
201 | #define _DOARGS_5(n) move.l %d5, -(%sp); \ |
202 | cfi_adjust_cfa_offset (4); cfi_rel_offset (%d5, 0); \ | |
203 | move.l n+4(%sp), %d5; _DOARGS_4 (n) | |
204 | #define UNDOARGS_5 UNDOARGS_4; move.l (%sp)+, %d5; \ | |
205 | cfi_adjust_cfa_offset (-4); cfi_restore (%d5) | |
9298f9e1 | 206 | |
5dde0182 | 207 | #define DOARGS_6 _DOARGS_6 (24) |
50e73d13 AS |
208 | #define _DOARGS_6(n) _DOARGS_5 (n-4); move.l %a0, -(%sp); \ |
209 | cfi_adjust_cfa_offset (4); \ | |
210 | move.l n+12(%sp), %a0; | |
211 | #define UNDOARGS_6 move.l (%sp)+, %a0; cfi_adjust_cfa_offset (-4); \ | |
212 | UNDOARGS_5 | |
5dde0182 | 213 | |
9298f9e1 RM |
214 | |
215 | #define ret rts | |
216 | #if 0 /* Not used by Linux */ | |
217 | #define r0 %d0 | |
218 | #define r1 %d1 | |
219 | #define MOVE(x,y) movel x , y | |
220 | #endif | |
221 | ||
dca17080 AS |
222 | #else /* not __ASSEMBLER__ */ |
223 | ||
224 | /* Define a macro which expands into the inline wrapper code for a system | |
225 | call. */ | |
226 | #undef INLINE_SYSCALL | |
5d384858 | 227 | #define INLINE_SYSCALL(name, nr, args...) \ |
aeeec7fb UD |
228 | ({ unsigned int _sys_result = INTERNAL_SYSCALL (name, , nr, args); \ |
229 | if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_sys_result, ), 0))\ | |
5d384858 | 230 | { \ |
aeeec7fb | 231 | __set_errno (INTERNAL_SYSCALL_ERRNO (_sys_result, )); \ |
5d384858 AS |
232 | _sys_result = (unsigned int) -1; \ |
233 | } \ | |
234 | (int) _sys_result; }) | |
235 | ||
aeeec7fb UD |
236 | #undef INTERNAL_SYSCALL_DECL |
237 | #define INTERNAL_SYSCALL_DECL(err) do { } while (0) | |
238 | ||
5d384858 AS |
239 | /* Define a macro which expands inline into the wrapper code for a system |
240 | call. This use is for internal calls that do not need to handle errors | |
241 | normally. It will never touch errno. This returns just what the kernel | |
242 | gave back. */ | |
243 | #undef INTERNAL_SYSCALL | |
40111cb9 | 244 | #define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ |
dca17080 AS |
245 | ({ unsigned int _sys_result; \ |
246 | { \ | |
693687e6 AS |
247 | /* Load argument values in temporary variables |
248 | to perform side effects like function calls | |
249 | before the call used registers are set. */ \ | |
dca17080 | 250 | LOAD_ARGS_##nr (args) \ |
693687e6 | 251 | LOAD_REGS_##nr \ |
40111cb9 | 252 | register int _d0 asm ("%d0") = name; \ |
dca17080 AS |
253 | asm volatile ("trap #0" \ |
254 | : "=d" (_d0) \ | |
ec2a735f | 255 | : "0" (_d0) ASM_ARGS_##nr \ |
48bfe445 | 256 | : "memory"); \ |
dca17080 AS |
257 | _sys_result = _d0; \ |
258 | } \ | |
dca17080 | 259 | (int) _sys_result; }) |
40111cb9 MK |
260 | #define INTERNAL_SYSCALL(name, err, nr, args...) \ |
261 | INTERNAL_SYSCALL_NCS (__NR_##name, err, nr, ##args) | |
dca17080 | 262 | |
5d384858 | 263 | #undef INTERNAL_SYSCALL_ERROR_P |
aeeec7fb UD |
264 | #define INTERNAL_SYSCALL_ERROR_P(val, err) \ |
265 | ((unsigned int) (val) >= -4095U) | |
5d384858 AS |
266 | |
267 | #undef INTERNAL_SYSCALL_ERRNO | |
aeeec7fb | 268 | #define INTERNAL_SYSCALL_ERRNO(val, err) (-(val)) |
5d384858 | 269 | |
dca17080 | 270 | #define LOAD_ARGS_0() |
693687e6 | 271 | #define LOAD_REGS_0 |
dca17080 AS |
272 | #define ASM_ARGS_0 |
273 | #define LOAD_ARGS_1(a1) \ | |
693687e6 AS |
274 | LOAD_ARGS_0 () \ |
275 | int __arg1 = (int) (a1); | |
276 | #define LOAD_REGS_1 \ | |
277 | register int _d1 asm ("d1") = __arg1; \ | |
278 | LOAD_REGS_0 | |
dca17080 AS |
279 | #define ASM_ARGS_1 ASM_ARGS_0, "d" (_d1) |
280 | #define LOAD_ARGS_2(a1, a2) \ | |
693687e6 AS |
281 | LOAD_ARGS_1 (a1) \ |
282 | int __arg2 = (int) (a2); | |
283 | #define LOAD_REGS_2 \ | |
284 | register int _d2 asm ("d2") = __arg2; \ | |
285 | LOAD_REGS_1 | |
dca17080 AS |
286 | #define ASM_ARGS_2 ASM_ARGS_1, "d" (_d2) |
287 | #define LOAD_ARGS_3(a1, a2, a3) \ | |
693687e6 AS |
288 | LOAD_ARGS_2 (a1, a2) \ |
289 | int __arg3 = (int) (a3); | |
290 | #define LOAD_REGS_3 \ | |
291 | register int _d3 asm ("d3") = __arg3; \ | |
292 | LOAD_REGS_2 | |
dca17080 AS |
293 | #define ASM_ARGS_3 ASM_ARGS_2, "d" (_d3) |
294 | #define LOAD_ARGS_4(a1, a2, a3, a4) \ | |
693687e6 AS |
295 | LOAD_ARGS_3 (a1, a2, a3) \ |
296 | int __arg4 = (int) (a4); | |
297 | #define LOAD_REGS_4 \ | |
298 | register int _d4 asm ("d4") = __arg4; \ | |
299 | LOAD_REGS_3 | |
dca17080 AS |
300 | #define ASM_ARGS_4 ASM_ARGS_3, "d" (_d4) |
301 | #define LOAD_ARGS_5(a1, a2, a3, a4, a5) \ | |
693687e6 AS |
302 | LOAD_ARGS_4 (a1, a2, a3, a4) \ |
303 | int __arg5 = (int) (a5); | |
304 | #define LOAD_REGS_5 \ | |
305 | register int _d5 asm ("d5") = __arg5; \ | |
306 | LOAD_REGS_4 | |
dca17080 | 307 | #define ASM_ARGS_5 ASM_ARGS_4, "d" (_d5) |
0798f1ad | 308 | #define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \ |
693687e6 AS |
309 | LOAD_ARGS_5 (a1, a2, a3, a4, a5) \ |
310 | int __arg6 = (int) (a6); | |
311 | #define LOAD_REGS_6 \ | |
312 | register int _a0 asm ("a0") = __arg6; \ | |
313 | LOAD_REGS_5 | |
0798f1ad | 314 | #define ASM_ARGS_6 ASM_ARGS_5, "a" (_a0) |
dca17080 AS |
315 | |
316 | #endif /* not __ASSEMBLER__ */ | |
40111cb9 MK |
317 | |
318 | /* Pointer mangling is not yet supported for M68K. */ | |
319 | #define PTR_MANGLE(var) (void) (var) | |
320 | #define PTR_DEMANGLE(var) (void) (var) | |
321 | ||
322 | #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO | |
323 | /* M68K needs system-supplied DSO to access TLS helpers | |
324 | even when statically linked. */ | |
325 | # define NEED_STATIC_SYSINFO_DSO 1 | |
326 | #endif |