summaryrefslogtreecommitdiff
path: root/src/pkg/runtime/sys_linux_386.s
blob: fcda739db4ae963a7fbcbd0ce4520c0b2198ed3a (plain)
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
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//
// System calls and other sys.stuff for 386, Linux
//

#include "zasm_GOOS_GOARCH.h"
#include "../../cmd/ld/textflag.h"

TEXT runtime·exit(SB),NOSPLIT,$0
	MOVL	$252, AX	// syscall number
	MOVL	4(SP), BX
	CALL	*runtime·_vdso(SB)
	INT $3	// not reached
	RET

TEXT runtime·exit1(SB),NOSPLIT,$0
	MOVL	$1, AX	// exit - exit the current os thread
	MOVL	4(SP), BX
	CALL	*runtime·_vdso(SB)
	INT $3	// not reached
	RET

TEXT runtime·open(SB),NOSPLIT,$0
	MOVL	$5, AX		// syscall - open
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·close(SB),NOSPLIT,$0
	MOVL	$6, AX		// syscall - close
	MOVL	4(SP), BX
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·write(SB),NOSPLIT,$0
	MOVL	$4, AX		// syscall - write
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·read(SB),NOSPLIT,$0
	MOVL	$3, AX		// syscall - read
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·getrlimit(SB),NOSPLIT,$0
	MOVL	$191, AX		// syscall - ugetrlimit
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·usleep(SB),NOSPLIT,$8
	MOVL	$0, DX
	MOVL	usec+0(FP), AX
	MOVL	$1000000, CX
	DIVL	CX
	MOVL	AX, 0(SP)
	MOVL	DX, 4(SP)

	// select(0, 0, 0, 0, &tv)
	MOVL	$142, AX
	MOVL	$0, BX
	MOVL	$0, CX
	MOVL	$0, DX
	MOVL	$0, SI
	LEAL	0(SP), DI
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·raise(SB),NOSPLIT,$12
	MOVL	$224, AX	// syscall - gettid
	CALL	*runtime·_vdso(SB)
	MOVL	AX, BX	// arg 1 tid
	MOVL	sig+0(FP), CX	// arg 2 signal
	MOVL	$238, AX	// syscall - tkill
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·setitimer(SB),NOSPLIT,$0-24
	MOVL	$104, AX			// syscall - setitimer
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·mincore(SB),NOSPLIT,$0-24
	MOVL	$218, AX			// syscall - mincore
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	CALL	*runtime·_vdso(SB)
	RET

// func now() (sec int64, nsec int32)
TEXT time·now(SB), NOSPLIT, $32
	MOVL	$265, AX			// syscall - clock_gettime
	MOVL	$0, BX
	LEAL	8(SP), CX
	MOVL	$0, DX
	CALL	*runtime·_vdso(SB)
	MOVL	8(SP), AX	// sec
	MOVL	12(SP), BX	// nsec

	// sec is in AX, nsec in BX
	MOVL	AX, sec+0(FP)
	MOVL	$0, sec+4(FP)
	MOVL	BX, nsec+8(FP)
	RET

// int64 nanotime(void) so really
// void nanotime(int64 *nsec)
TEXT runtime·nanotime(SB), NOSPLIT, $32
	MOVL	$265, AX			// syscall - clock_gettime
	MOVL	$0, BX
	LEAL	8(SP), CX
	MOVL	$0, DX
	CALL	*runtime·_vdso(SB)
	MOVL	8(SP), AX	// sec
	MOVL	12(SP), BX	// nsec

	// sec is in AX, nsec in BX
	// convert to DX:AX nsec
	MOVL	$1000000000, CX
	MULL	CX
	ADDL	BX, AX
	ADCL	$0, DX

	MOVL	ret+0(FP), DI
	MOVL	AX, 0(DI)
	MOVL	DX, 4(DI)
	RET

TEXT runtime·rtsigprocmask(SB),NOSPLIT,$0
	MOVL	$175, AX		// syscall entry
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	MOVL	16(SP), SI
	CALL	*runtime·_vdso(SB)
	CMPL	AX, $0xfffff001
	JLS	2(PC)
	INT $3
	RET

TEXT runtime·rt_sigaction(SB),NOSPLIT,$0
	MOVL	$174, AX		// syscall - rt_sigaction
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	MOVL	16(SP), SI
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·sigtramp(SB),NOSPLIT,$44
	get_tls(CX)

	// check that m exists
	MOVL	m(CX), BX
	CMPL	BX, $0
	JNE	6(PC)
	MOVL	sig+0(FP), BX
	MOVL	BX, 0(SP)
	MOVL	$runtime·badsignal(SB), AX
	CALL	AX
	RET

	// save g
	MOVL	g(CX), DI
	MOVL	DI, 20(SP)

	// g = m->gsignal
	MOVL	m(CX), BX
	MOVL	m_gsignal(BX), BX
	MOVL	BX, g(CX)

	// copy arguments for call to sighandler
	MOVL	sig+0(FP), BX
	MOVL	BX, 0(SP)
	MOVL	info+4(FP), BX
	MOVL	BX, 4(SP)
	MOVL	context+8(FP), BX
	MOVL	BX, 8(SP)
	MOVL	DI, 12(SP)

	CALL	runtime·sighandler(SB)

	// restore g
	get_tls(CX)
	MOVL	20(SP), BX
	MOVL	BX, g(CX)

	RET

TEXT runtime·sigreturn(SB),NOSPLIT,$0
	MOVL	$173, AX	// rt_sigreturn
	// Sigreturn expects same SP as signal handler,
	// so cannot CALL *runtime._vsdo(SB) here.
	INT	$0x80
	INT $3	// not reached
	RET

TEXT runtime·mmap(SB),NOSPLIT,$0
	MOVL	$192, AX	// mmap2
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	MOVL	16(SP), SI
	MOVL	20(SP), DI
	MOVL	24(SP), BP
	SHRL	$12, BP
	CALL	*runtime·_vdso(SB)
	CMPL	AX, $0xfffff001
	JLS	3(PC)
	NOTL	AX
	INCL	AX
	RET

TEXT runtime·munmap(SB),NOSPLIT,$0
	MOVL	$91, AX	// munmap
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	CALL	*runtime·_vdso(SB)
	CMPL	AX, $0xfffff001
	JLS	2(PC)
	INT $3
	RET

TEXT runtime·madvise(SB),NOSPLIT,$0
	MOVL	$219, AX	// madvise
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	CALL	*runtime·_vdso(SB)
	// ignore failure - maybe pages are locked
	RET

// int32 futex(int32 *uaddr, int32 op, int32 val,
//	struct timespec *timeout, int32 *uaddr2, int32 val2);
TEXT runtime·futex(SB),NOSPLIT,$0
	MOVL	$240, AX	// futex
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	MOVL	16(SP), SI
	MOVL	20(SP), DI
	MOVL	24(SP), BP
	CALL	*runtime·_vdso(SB)
	RET

// int32 clone(int32 flags, void *stack, M *mp, G *gp, void (*fn)(void));
TEXT runtime·clone(SB),NOSPLIT,$0
	MOVL	$120, AX	// clone
	MOVL	flags+4(SP), BX
	MOVL	stack+8(SP), CX
	MOVL	$0, DX	// parent tid ptr
	MOVL	$0, DI	// child tid ptr

	// Copy mp, gp, fn off parent stack for use by child.
	SUBL	$16, CX
	MOVL	mm+12(SP), SI
	MOVL	SI, 0(CX)
	MOVL	gg+16(SP), SI
	MOVL	SI, 4(CX)
	MOVL	fn+20(SP), SI
	MOVL	SI, 8(CX)
	MOVL	$1234, 12(CX)

	// cannot use CALL *runtime·_vdso(SB) here, because
	// the stack changes during the system call (after
	// CALL *runtime·_vdso(SB), the child is still using
	// the parent's stack when executing its RET instruction).
	INT	$0x80

	// In parent, return.
	CMPL	AX, $0
	JEQ	2(PC)
	RET

	// Paranoia: check that SP is as we expect.
	MOVL	12(SP), BP
	CMPL	BP, $1234
	JEQ	2(PC)
	INT	$3

	// Initialize AX to Linux tid
	MOVL	$224, AX
	CALL	*runtime·_vdso(SB)

	// In child on new stack.  Reload registers (paranoia).
	MOVL	0(SP), BX	// m
	MOVL	4(SP), DX	// g
	MOVL	8(SP), SI	// fn

	MOVL	AX, m_procid(BX)	// save tid as m->procid

	// set up ldt 7+id to point at m->tls.
	// newosproc left the id in tls[0].
	LEAL	m_tls(BX), BP
	MOVL	0(BP), DI
	ADDL	$7, DI	// m0 is LDT#7. count up.
	// setldt(tls#, &tls, sizeof tls)
	PUSHAL	// save registers
	PUSHL	$32	// sizeof tls
	PUSHL	BP	// &tls
	PUSHL	DI	// tls #
	CALL	runtime·setldt(SB)
	POPL	AX
	POPL	AX
	POPL	AX
	POPAL

	// Now segment is established.  Initialize m, g.
	get_tls(AX)
	MOVL	DX, g(AX)
	MOVL	BX, m(AX)

	CALL	runtime·stackcheck(SB)	// smashes AX, CX
	MOVL	0(DX), DX	// paranoia; check they are not nil
	MOVL	0(BX), BX

	// more paranoia; check that stack splitting code works
	PUSHAL
	CALL	runtime·emptyfunc(SB)
	POPAL

	CALL	SI	// fn()
	CALL	runtime·exit1(SB)
	MOVL	$0x1234, 0x1005
	RET

TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
	MOVL	$186, AX	// sigaltstack
	MOVL	new+4(SP), BX
	MOVL	old+8(SP), CX
	CALL	*runtime·_vdso(SB)
	CMPL	AX, $0xfffff001
	JLS	2(PC)
	INT	$3
	RET

// <asm-i386/ldt.h>
// struct user_desc {
//	unsigned int  entry_number;
//	unsigned long base_addr;
//	unsigned int  limit;
//	unsigned int  seg_32bit:1;
//	unsigned int  contents:2;
//	unsigned int  read_exec_only:1;
//	unsigned int  limit_in_pages:1;
//	unsigned int  seg_not_present:1;
//	unsigned int  useable:1;
// };
#define SEG_32BIT 0x01
// contents are the 2 bits 0x02 and 0x04.
#define CONTENTS_DATA 0x00
#define CONTENTS_STACK 0x02
#define CONTENTS_CODE 0x04
#define READ_EXEC_ONLY 0x08
#define LIMIT_IN_PAGES 0x10
#define SEG_NOT_PRESENT 0x20
#define USEABLE 0x40

// setldt(int entry, int address, int limit)
TEXT runtime·setldt(SB),NOSPLIT,$32
	MOVL	entry+0(FP), BX	// entry
	MOVL	address+4(FP), CX	// base address

	/*
	 * When linking against the system libraries,
	 * we use its pthread_create and let it set up %gs
	 * for us.  When we do that, the private storage
	 * we get is not at 0(GS), 4(GS), but -8(GS), -4(GS).
	 * To insulate the rest of the tool chain from this
	 * ugliness, 8l rewrites 0(GS) into -8(GS) for us.
	 * To accommodate that rewrite, we translate
	 * the address here and bump the limit to 0xffffffff (no limit)
	 * so that -8(GS) maps to 0(address).
	 * Also, the final 0(GS) (current 8(CX)) has to point
	 * to itself, to mimic ELF.
	 */
	ADDL	$0x8, CX	// address
	MOVL	CX, 0(CX)

	// set up user_desc
	LEAL	16(SP), AX	// struct user_desc
	MOVL	BX, 0(AX)
	MOVL	CX, 4(AX)
	MOVL	$0xfffff, 8(AX)
	MOVL	$(SEG_32BIT|LIMIT_IN_PAGES|USEABLE|CONTENTS_DATA), 12(AX)	// flag bits

	// call modify_ldt
	MOVL	$1, BX	// func = 1 (write)
	MOVL	AX, CX	// user_desc
	MOVL	$16, DX	// sizeof(user_desc)
	MOVL	$123, AX	// syscall - modify_ldt
	CALL	*runtime·_vdso(SB)

	// breakpoint on error
	CMPL AX, $0xfffff001
	JLS 2(PC)
	INT $3

	// compute segment selector - (entry*8+7)
	MOVL	entry+0(FP), AX
	SHLL	$3, AX
	ADDL	$7, AX
	MOVW	AX, GS

	RET

TEXT runtime·osyield(SB),NOSPLIT,$0
	MOVL	$158, AX
	CALL	*runtime·_vdso(SB)
	RET

TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
	MOVL	$242, AX		// syscall - sched_getaffinity
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	CALL	*runtime·_vdso(SB)
	RET

// int32 runtime·epollcreate(int32 size);
TEXT runtime·epollcreate(SB),NOSPLIT,$0
	MOVL    $254, AX
	MOVL	4(SP), BX
	CALL	*runtime·_vdso(SB)
	RET

// int32 runtime·epollcreate1(int32 flags);
TEXT runtime·epollcreate1(SB),NOSPLIT,$0
	MOVL    $329, AX
	MOVL	4(SP), BX
	CALL	*runtime·_vdso(SB)
	RET

// int32 runtime·epollctl(int32 epfd, int32 op, int32 fd, EpollEvent *ev);
TEXT runtime·epollctl(SB),NOSPLIT,$0
	MOVL	$255, AX
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	MOVL	16(SP), SI
	CALL	*runtime·_vdso(SB)
	RET

// int32 runtime·epollwait(int32 epfd, EpollEvent *ev, int32 nev, int32 timeout);
TEXT runtime·epollwait(SB),NOSPLIT,$0
	MOVL	$256, AX
	MOVL	4(SP), BX
	MOVL	8(SP), CX
	MOVL	12(SP), DX
	MOVL	16(SP), SI
	CALL	*runtime·_vdso(SB)
	RET

// void runtime·closeonexec(int32 fd);
TEXT runtime·closeonexec(SB),NOSPLIT,$0
	MOVL	$55, AX  // fcntl
	MOVL	4(SP), BX  // fd
	MOVL	$2, CX  // F_SETFD
	MOVL	$1, DX  // FD_CLOEXEC
	CALL	*runtime·_vdso(SB)
	RET