Text file
src/runtime/asm_amd64.s
Documentation: runtime
1// Copyright 2009 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5#include "go_asm.h"
6#include "go_tls.h"
7#include "funcdata.h"
8#include "textflag.h"
9#include "cgo/abi_amd64.h"
10
11// _rt0_amd64 is common startup code for most amd64 systems when using
12// internal linking. This is the entry point for the program from the
13// kernel for an ordinary -buildmode=exe program. The stack holds the
14// number of arguments and the C-style argv.
15TEXT _rt0_amd64(SB),NOSPLIT,$-8
16 MOVQ 0(SP), DI // argc
17 LEAQ 8(SP), SI // argv
18 JMP runtime·rt0_go(SB)
19
20// main is common startup code for most amd64 systems when using
21// external linking. The C startup code will call the symbol "main"
22// passing argc and argv in the usual C ABI registers DI and SI.
23TEXT main(SB),NOSPLIT,$-8
24 JMP runtime·rt0_go(SB)
25
26// _rt0_amd64_lib is common startup code for most amd64 systems when
27// using -buildmode=c-archive or -buildmode=c-shared. The linker will
28// arrange to invoke this function as a global constructor (for
29// c-archive) or when the shared library is loaded (for c-shared).
30// We expect argc and argv to be passed in the usual C ABI registers
31// DI and SI.
32TEXT _rt0_amd64_lib(SB),NOSPLIT|NOFRAME,$0
33 // Transition from C ABI to Go ABI.
34 PUSH_REGS_HOST_TO_ABI0()
35
36 MOVQ DI, _rt0_amd64_lib_argc<>(SB)
37 MOVQ SI, _rt0_amd64_lib_argv<>(SB)
38
39 // Synchronous initialization.
40 CALL runtime·libpreinit(SB)
41
42 // Create a new thread to finish Go runtime initialization.
43 MOVQ _cgo_sys_thread_create(SB), AX
44 TESTQ AX, AX
45 JZ nocgo
46
47 // We're calling back to C.
48 // Align stack per ELF ABI requirements.
49 MOVQ SP, BX // Callee-save in C ABI
50 ANDQ $~15, SP
51 MOVQ $_rt0_amd64_lib_go(SB), DI
52 MOVQ $0, SI
53 CALL AX
54 MOVQ BX, SP
55 JMP restore
56
57nocgo:
58 ADJSP $16
59 MOVQ $0x800000, 0(SP) // stacksize
60 MOVQ $_rt0_amd64_lib_go(SB), AX
61 MOVQ AX, 8(SP) // fn
62 CALL runtime·newosproc0(SB)
63 ADJSP $-16
64
65restore:
66 POP_REGS_HOST_TO_ABI0()
67 RET
68
69// _rt0_amd64_lib_go initializes the Go runtime.
70// This is started in a separate thread by _rt0_amd64_lib.
71TEXT _rt0_amd64_lib_go(SB),NOSPLIT,$0
72 MOVQ _rt0_amd64_lib_argc<>(SB), DI
73 MOVQ _rt0_amd64_lib_argv<>(SB), SI
74 JMP runtime·rt0_go(SB)
75
76DATA _rt0_amd64_lib_argc<>(SB)/8, $0
77GLOBL _rt0_amd64_lib_argc<>(SB),NOPTR, $8
78DATA _rt0_amd64_lib_argv<>(SB)/8, $0
79GLOBL _rt0_amd64_lib_argv<>(SB),NOPTR, $8
80
81#ifdef GOAMD64_v2
82DATA bad_cpu_msg<>+0x00(SB)/84, $"This program can only be run on AMD64 processors with v2 microarchitecture support.\n"
83#endif
84
85#ifdef GOAMD64_v3
86DATA bad_cpu_msg<>+0x00(SB)/84, $"This program can only be run on AMD64 processors with v3 microarchitecture support.\n"
87#endif
88
89#ifdef GOAMD64_v4
90DATA bad_cpu_msg<>+0x00(SB)/84, $"This program can only be run on AMD64 processors with v4 microarchitecture support.\n"
91#endif
92
93GLOBL bad_cpu_msg<>(SB), RODATA, $84
94
95// Define a list of AMD64 microarchitecture level features
96// https://en.wikipedia.org/wiki/X86-64#Microarchitecture_levels
97
98 // SSE3 SSSE3 CMPXCHNG16 SSE4.1 SSE4.2 POPCNT
99#define V2_FEATURES_CX (1 << 0 | 1 << 9 | 1 << 13 | 1 << 19 | 1 << 20 | 1 << 23)
100 // LAHF/SAHF
101#define V2_EXT_FEATURES_CX (1 << 0)
102 // FMA MOVBE OSXSAVE AVX F16C
103#define V3_FEATURES_CX (V2_FEATURES_CX | 1 << 12 | 1 << 22 | 1 << 27 | 1 << 28 | 1 << 29)
104 // ABM (FOR LZNCT)
105#define V3_EXT_FEATURES_CX (V2_EXT_FEATURES_CX | 1 << 5)
106 // BMI1 AVX2 BMI2
107#define V3_EXT_FEATURES_BX (1 << 3 | 1 << 5 | 1 << 8)
108 // XMM YMM
109#define V3_OS_SUPPORT_AX (1 << 1 | 1 << 2)
110
111#define V4_FEATURES_CX V3_FEATURES_CX
112
113#define V4_EXT_FEATURES_CX V3_EXT_FEATURES_CX
114 // AVX512F AVX512DQ AVX512CD AVX512BW AVX512VL
115#define V4_EXT_FEATURES_BX (V3_EXT_FEATURES_BX | 1 << 16 | 1 << 17 | 1 << 28 | 1 << 30 | 1 << 31)
116 // OPMASK ZMM
117#define V4_OS_SUPPORT_AX (V3_OS_SUPPORT_AX | 1 << 5 | (1 << 6 | 1 << 7))
118
119#ifdef GOAMD64_v2
120#define NEED_MAX_CPUID 0x80000001
121#define NEED_FEATURES_CX V2_FEATURES_CX
122#define NEED_EXT_FEATURES_CX V2_EXT_FEATURES_CX
123#endif
124
125#ifdef GOAMD64_v3
126#define NEED_MAX_CPUID 0x80000001
127#define NEED_FEATURES_CX V3_FEATURES_CX
128#define NEED_EXT_FEATURES_CX V3_EXT_FEATURES_CX
129#define NEED_EXT_FEATURES_BX V3_EXT_FEATURES_BX
130#define NEED_OS_SUPPORT_AX V3_OS_SUPPORT_AX
131#endif
132
133#ifdef GOAMD64_v4
134#define NEED_MAX_CPUID 0x80000001
135#define NEED_FEATURES_CX V4_FEATURES_CX
136#define NEED_EXT_FEATURES_CX V4_EXT_FEATURES_CX
137#define NEED_EXT_FEATURES_BX V4_EXT_FEATURES_BX
138
139// Darwin requires a different approach to check AVX512 support, see CL 285572.
140#ifdef GOOS_darwin
141#define NEED_OS_SUPPORT_AX V3_OS_SUPPORT_AX
142// These values are from:
143// https://github.com/apple/darwin-xnu/blob/xnu-4570.1.46/osfmk/i386/cpu_capabilities.h
144#define commpage64_base_address 0x00007fffffe00000
145#define commpage64_cpu_capabilities64 (commpage64_base_address+0x010)
146#define commpage64_version (commpage64_base_address+0x01E)
147#define AVX512F 0x0000004000000000
148#define AVX512CD 0x0000008000000000
149#define AVX512DQ 0x0000010000000000
150#define AVX512BW 0x0000020000000000
151#define AVX512VL 0x0000100000000000
152#define NEED_DARWIN_SUPPORT (AVX512F | AVX512DQ | AVX512CD | AVX512BW | AVX512VL)
153#else
154#define NEED_OS_SUPPORT_AX V4_OS_SUPPORT_AX
155#endif
156
157#endif
158
159TEXT runtime·rt0_go(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
160 // copy arguments forward on an even stack
161 MOVQ DI, AX // argc
162 MOVQ SI, BX // argv
163 SUBQ $(5*8), SP // 3args 2auto
164 ANDQ $~15, SP
165 MOVQ AX, 24(SP)
166 MOVQ BX, 32(SP)
167
168 // create istack out of the given (operating system) stack.
169 // _cgo_init may update stackguard.
170 MOVQ $runtime·g0(SB), DI
171 LEAQ (-64*1024)(SP), BX
172 MOVQ BX, g_stackguard0(DI)
173 MOVQ BX, g_stackguard1(DI)
174 MOVQ BX, (g_stack+stack_lo)(DI)
175 MOVQ SP, (g_stack+stack_hi)(DI)
176
177 // find out information about the processor we're on
178 MOVL $0, AX
179 CPUID
180 CMPL AX, $0
181 JE nocpuinfo
182
183 CMPL BX, $0x756E6547 // "Genu"
184 JNE notintel
185 CMPL DX, $0x49656E69 // "ineI"
186 JNE notintel
187 CMPL CX, $0x6C65746E // "ntel"
188 JNE notintel
189 MOVB $1, runtime·isIntel(SB)
190
191notintel:
192 // Load EAX=1 cpuid flags
193 MOVL $1, AX
194 CPUID
195 MOVL AX, runtime·processorVersionInfo(SB)
196
197nocpuinfo:
198 // if there is an _cgo_init, call it.
199 MOVQ _cgo_init(SB), AX
200 TESTQ AX, AX
201 JZ needtls
202 // arg 1: g0, already in DI
203 MOVQ $setg_gcc<>(SB), SI // arg 2: setg_gcc
204 MOVQ $0, DX // arg 3, 4: not used when using platform's TLS
205 MOVQ $0, CX
206#ifdef GOOS_android
207 MOVQ $runtime·tls_g(SB), DX // arg 3: &tls_g
208 // arg 4: TLS base, stored in slot 0 (Android's TLS_SLOT_SELF).
209 // Compensate for tls_g (+16).
210 MOVQ -16(TLS), CX
211#endif
212#ifdef GOOS_windows
213 MOVQ $runtime·tls_g(SB), DX // arg 3: &tls_g
214 // Adjust for the Win64 calling convention.
215 MOVQ CX, R9 // arg 4
216 MOVQ DX, R8 // arg 3
217 MOVQ SI, DX // arg 2
218 MOVQ DI, CX // arg 1
219#endif
220 CALL AX
221
222 // update stackguard after _cgo_init
223 MOVQ $runtime·g0(SB), CX
224 MOVQ (g_stack+stack_lo)(CX), AX
225 ADDQ $const_stackGuard, AX
226 MOVQ AX, g_stackguard0(CX)
227 MOVQ AX, g_stackguard1(CX)
228
229#ifndef GOOS_windows
230 JMP ok
231#endif
232needtls:
233#ifdef GOOS_plan9
234 // skip TLS setup on Plan 9
235 JMP ok
236#endif
237#ifdef GOOS_solaris
238 // skip TLS setup on Solaris
239 JMP ok
240#endif
241#ifdef GOOS_illumos
242 // skip TLS setup on illumos
243 JMP ok
244#endif
245#ifdef GOOS_darwin
246 // skip TLS setup on Darwin
247 JMP ok
248#endif
249#ifdef GOOS_openbsd
250 // skip TLS setup on OpenBSD
251 JMP ok
252#endif
253
254#ifdef GOOS_windows
255 CALL runtime·wintls(SB)
256#endif
257
258 LEAQ runtime·m0+m_tls(SB), DI
259 CALL runtime·settls(SB)
260
261 // store through it, to make sure it works
262 get_tls(BX)
263 MOVQ $0x123, g(BX)
264 MOVQ runtime·m0+m_tls(SB), AX
265 CMPQ AX, $0x123
266 JEQ 2(PC)
267 CALL runtime·abort(SB)
268ok:
269 // set the per-goroutine and per-mach "registers"
270 get_tls(BX)
271 LEAQ runtime·g0(SB), CX
272 MOVQ CX, g(BX)
273 LEAQ runtime·m0(SB), AX
274
275 // save m->g0 = g0
276 MOVQ CX, m_g0(AX)
277 // save m0 to g0->m
278 MOVQ AX, g_m(CX)
279
280 CLD // convention is D is always left cleared
281
282 // Check GOAMD64 requirements
283 // We need to do this after setting up TLS, so that
284 // we can report an error if there is a failure. See issue 49586.
285#ifdef NEED_FEATURES_CX
286 MOVL $0, AX
287 CPUID
288 CMPL AX, $0
289 JE bad_cpu
290 MOVL $1, AX
291 CPUID
292 ANDL $NEED_FEATURES_CX, CX
293 CMPL CX, $NEED_FEATURES_CX
294 JNE bad_cpu
295#endif
296
297#ifdef NEED_MAX_CPUID
298 MOVL $0x80000000, AX
299 CPUID
300 CMPL AX, $NEED_MAX_CPUID
301 JL bad_cpu
302#endif
303
304#ifdef NEED_EXT_FEATURES_BX
305 MOVL $7, AX
306 MOVL $0, CX
307 CPUID
308 ANDL $NEED_EXT_FEATURES_BX, BX
309 CMPL BX, $NEED_EXT_FEATURES_BX
310 JNE bad_cpu
311#endif
312
313#ifdef NEED_EXT_FEATURES_CX
314 MOVL $0x80000001, AX
315 CPUID
316 ANDL $NEED_EXT_FEATURES_CX, CX
317 CMPL CX, $NEED_EXT_FEATURES_CX
318 JNE bad_cpu
319#endif
320
321#ifdef NEED_OS_SUPPORT_AX
322 XORL CX, CX
323 XGETBV
324 ANDL $NEED_OS_SUPPORT_AX, AX
325 CMPL AX, $NEED_OS_SUPPORT_AX
326 JNE bad_cpu
327#endif
328
329#ifdef NEED_DARWIN_SUPPORT
330 MOVQ $commpage64_version, BX
331 CMPW (BX), $13 // cpu_capabilities64 undefined in versions < 13
332 JL bad_cpu
333 MOVQ $commpage64_cpu_capabilities64, BX
334 MOVQ (BX), BX
335 MOVQ $NEED_DARWIN_SUPPORT, CX
336 ANDQ CX, BX
337 CMPQ BX, CX
338 JNE bad_cpu
339#endif
340
341 CALL runtime·check(SB)
342
343 MOVL 24(SP), AX // copy argc
344 MOVL AX, 0(SP)
345 MOVQ 32(SP), AX // copy argv
346 MOVQ AX, 8(SP)
347 CALL runtime·args(SB)
348 CALL runtime·osinit(SB)
349 CALL runtime·schedinit(SB)
350
351 // create a new goroutine to start program
352 MOVQ $runtime·mainPC(SB), AX // entry
353 PUSHQ AX
354 CALL runtime·newproc(SB)
355 POPQ AX
356
357 // start this M
358 CALL runtime·mstart(SB)
359
360 CALL runtime·abort(SB) // mstart should never return
361 RET
362
363bad_cpu: // show that the program requires a certain microarchitecture level.
364 MOVQ $2, 0(SP)
365 MOVQ $bad_cpu_msg<>(SB), AX
366 MOVQ AX, 8(SP)
367 MOVQ $84, 16(SP)
368 CALL runtime·write(SB)
369 MOVQ $1, 0(SP)
370 CALL runtime·exit(SB)
371 CALL runtime·abort(SB)
372 RET
373
374 // Prevent dead-code elimination of debugCallV2 and debugPinnerV1, which are
375 // intended to be called by debuggers.
376 MOVQ $runtime·debugPinnerV1<ABIInternal>(SB), AX
377 MOVQ $runtime·debugCallV2<ABIInternal>(SB), AX
378 RET
379
380// mainPC is a function value for runtime.main, to be passed to newproc.
381// The reference to runtime.main is made via ABIInternal, since the
382// actual function (not the ABI0 wrapper) is needed by newproc.
383DATA runtime·mainPC+0(SB)/8,$runtime·main<ABIInternal>(SB)
384GLOBL runtime·mainPC(SB),RODATA,$8
385
386TEXT runtime·breakpoint(SB),NOSPLIT,$0-0
387 BYTE $0xcc
388 RET
389
390TEXT runtime·asminit(SB),NOSPLIT,$0-0
391 // No per-thread init.
392 RET
393
394TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME|NOFRAME,$0
395 CALL runtime·mstart0(SB)
396 RET // not reached
397
398/*
399 * go-routine
400 */
401
402// func gogo(buf *gobuf)
403// restore state from Gobuf; longjmp
404TEXT runtime·gogo(SB), NOSPLIT, $0-8
405 MOVQ buf+0(FP), BX // gobuf
406 MOVQ gobuf_g(BX), DX
407 MOVQ 0(DX), CX // make sure g != nil
408 JMP gogo<>(SB)
409
410TEXT gogo<>(SB), NOSPLIT, $0
411 get_tls(CX)
412 MOVQ DX, g(CX)
413 MOVQ DX, R14 // set the g register
414 MOVQ gobuf_sp(BX), SP // restore SP
415 MOVQ gobuf_ret(BX), AX
416 MOVQ gobuf_ctxt(BX), DX
417 MOVQ gobuf_bp(BX), BP
418 MOVQ $0, gobuf_sp(BX) // clear to help garbage collector
419 MOVQ $0, gobuf_ret(BX)
420 MOVQ $0, gobuf_ctxt(BX)
421 MOVQ $0, gobuf_bp(BX)
422 MOVQ gobuf_pc(BX), BX
423 JMP BX
424
425// func mcall(fn func(*g))
426// Switch to m->g0's stack, call fn(g).
427// Fn must never return. It should gogo(&g->sched)
428// to keep running g.
429TEXT runtime·mcall<ABIInternal>(SB), NOSPLIT, $0-8
430 MOVQ AX, DX // DX = fn
431
432 // Save state in g->sched. The caller's SP and PC are restored by gogo to
433 // resume execution in the caller's frame (implicit return). The caller's BP
434 // is also restored to support frame pointer unwinding.
435 MOVQ SP, BX // hide (SP) reads from vet
436 MOVQ 8(BX), BX // caller's PC
437 MOVQ BX, (g_sched+gobuf_pc)(R14)
438 LEAQ fn+0(FP), BX // caller's SP
439 MOVQ BX, (g_sched+gobuf_sp)(R14)
440 // Get the caller's frame pointer by dereferencing BP. Storing BP as it is
441 // can cause a frame pointer cycle, see CL 476235.
442 MOVQ (BP), BX // caller's BP
443 MOVQ BX, (g_sched+gobuf_bp)(R14)
444
445 // switch to m->g0 & its stack, call fn
446 MOVQ g_m(R14), BX
447 MOVQ m_g0(BX), SI // SI = g.m.g0
448 CMPQ SI, R14 // if g == m->g0 call badmcall
449 JNE goodm
450 JMP runtime·badmcall(SB)
451goodm:
452 MOVQ R14, AX // AX (and arg 0) = g
453 MOVQ SI, R14 // g = g.m.g0
454 get_tls(CX) // Set G in TLS
455 MOVQ R14, g(CX)
456 MOVQ (g_sched+gobuf_sp)(R14), SP // sp = g0.sched.sp
457 PUSHQ AX // open up space for fn's arg spill slot
458 MOVQ 0(DX), R12
459 CALL R12 // fn(g)
460 // The Windows native stack unwinder incorrectly classifies the next instruction
461 // as part of the function epilogue, producing a wrong call stack.
462 // Add a NOP to work around this issue. See go.dev/issue/67007.
463 BYTE $0x90
464 POPQ AX
465 JMP runtime·badmcall2(SB)
466 RET
467
468// systemstack_switch is a dummy routine that systemstack leaves at the bottom
469// of the G stack. We need to distinguish the routine that
470// lives at the bottom of the G stack from the one that lives
471// at the top of the system stack because the one at the top of
472// the system stack terminates the stack walk (see topofstack()).
473// The frame layout needs to match systemstack
474// so that it can pretend to be systemstack_switch.
475TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0
476 UNDEF
477 // Make sure this function is not leaf,
478 // so the frame is saved.
479 CALL runtime·abort(SB)
480 RET
481
482// func systemstack(fn func())
483TEXT runtime·systemstack(SB), NOSPLIT, $0-8
484 MOVQ fn+0(FP), DI // DI = fn
485 get_tls(CX)
486 MOVQ g(CX), AX // AX = g
487 MOVQ g_m(AX), BX // BX = m
488
489 CMPQ AX, m_gsignal(BX)
490 JEQ noswitch
491
492 MOVQ m_g0(BX), DX // DX = g0
493 CMPQ AX, DX
494 JEQ noswitch
495
496 CMPQ AX, m_curg(BX)
497 JNE bad
498
499 // Switch stacks.
500 // The original frame pointer is stored in BP,
501 // which is useful for stack unwinding.
502 // Save our state in g->sched. Pretend to
503 // be systemstack_switch if the G stack is scanned.
504 CALL gosave_systemstack_switch<>(SB)
505
506 // switch to g0
507 MOVQ DX, g(CX)
508 MOVQ DX, R14 // set the g register
509 MOVQ (g_sched+gobuf_sp)(DX), SP
510
511 // call target function
512 MOVQ DI, DX
513 MOVQ 0(DI), DI
514 CALL DI
515
516 // switch back to g
517 get_tls(CX)
518 MOVQ g(CX), AX
519 MOVQ g_m(AX), BX
520 MOVQ m_curg(BX), AX
521 MOVQ AX, g(CX)
522 MOVQ (g_sched+gobuf_sp)(AX), SP
523 MOVQ (g_sched+gobuf_bp)(AX), BP
524 MOVQ $0, (g_sched+gobuf_sp)(AX)
525 MOVQ $0, (g_sched+gobuf_bp)(AX)
526 RET
527
528noswitch:
529 // already on m stack; tail call the function
530 // Using a tail call here cleans up tracebacks since we won't stop
531 // at an intermediate systemstack.
532 MOVQ DI, DX
533 MOVQ 0(DI), DI
534 // The function epilogue is not called on a tail call.
535 // Pop BP from the stack to simulate it.
536 POPQ BP
537 JMP DI
538
539bad:
540 // Bad: g is not gsignal, not g0, not curg. What is it?
541 MOVQ $runtime·badsystemstack(SB), AX
542 CALL AX
543 INT $3
544
545// func switchToCrashStack0(fn func())
546TEXT runtime·switchToCrashStack0<ABIInternal>(SB), NOSPLIT, $0-8
547 MOVQ g_m(R14), BX // curm
548
549 // set g to gcrash
550 LEAQ runtime·gcrash(SB), R14 // g = &gcrash
551 MOVQ BX, g_m(R14) // g.m = curm
552 MOVQ R14, m_g0(BX) // curm.g0 = g
553 get_tls(CX)
554 MOVQ R14, g(CX)
555
556 // switch to crashstack
557 MOVQ (g_stack+stack_hi)(R14), BX
558 SUBQ $(4*8), BX
559 MOVQ BX, SP
560
561 // call target function
562 MOVQ AX, DX
563 MOVQ 0(AX), AX
564 CALL AX
565
566 // should never return
567 CALL runtime·abort(SB)
568 UNDEF
569
570/*
571 * support for morestack
572 */
573
574// Called during function prolog when more stack is needed.
575//
576// The traceback routines see morestack on a g0 as being
577// the top of a stack (for example, morestack calling newstack
578// calling the scheduler calling newm calling gc), so we must
579// record an argument size. For that purpose, it has no arguments.
580TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0
581 // Cannot grow scheduler stack (m->g0).
582 get_tls(CX)
583 MOVQ g(CX), DI // DI = g
584 MOVQ g_m(DI), BX // BX = m
585
586 // Set g->sched to context in f.
587 MOVQ 0(SP), AX // f's PC
588 MOVQ AX, (g_sched+gobuf_pc)(DI)
589 LEAQ 8(SP), AX // f's SP
590 MOVQ AX, (g_sched+gobuf_sp)(DI)
591 MOVQ BP, (g_sched+gobuf_bp)(DI)
592 MOVQ DX, (g_sched+gobuf_ctxt)(DI)
593
594 MOVQ m_g0(BX), SI // SI = m.g0
595 CMPQ DI, SI
596 JNE 3(PC)
597 CALL runtime·badmorestackg0(SB)
598 CALL runtime·abort(SB)
599
600 // Cannot grow signal stack (m->gsignal).
601 MOVQ m_gsignal(BX), SI
602 CMPQ DI, SI
603 JNE 3(PC)
604 CALL runtime·badmorestackgsignal(SB)
605 CALL runtime·abort(SB)
606
607 // Called from f.
608 // Set m->morebuf to f's caller.
609 NOP SP // tell vet SP changed - stop checking offsets
610 MOVQ 8(SP), AX // f's caller's PC
611 MOVQ AX, (m_morebuf+gobuf_pc)(BX)
612 LEAQ 16(SP), AX // f's caller's SP
613 MOVQ AX, (m_morebuf+gobuf_sp)(BX)
614 MOVQ DI, (m_morebuf+gobuf_g)(BX)
615
616 // Call newstack on m->g0's stack.
617 MOVQ m_g0(BX), BX
618 MOVQ BX, g(CX)
619 MOVQ (g_sched+gobuf_sp)(BX), SP
620 MOVQ (g_sched+gobuf_bp)(BX), BP
621 CALL runtime·newstack(SB)
622 CALL runtime·abort(SB) // crash if newstack returns
623 RET
624
625// morestack but not preserving ctxt.
626TEXT runtime·morestack_noctxt(SB),NOSPLIT,$0
627 MOVL $0, DX
628 JMP runtime·morestack(SB)
629
630// spillArgs stores return values from registers to a *internal/abi.RegArgs in R12.
631TEXT ·spillArgs(SB),NOSPLIT,$0-0
632 MOVQ AX, 0(R12)
633 MOVQ BX, 8(R12)
634 MOVQ CX, 16(R12)
635 MOVQ DI, 24(R12)
636 MOVQ SI, 32(R12)
637 MOVQ R8, 40(R12)
638 MOVQ R9, 48(R12)
639 MOVQ R10, 56(R12)
640 MOVQ R11, 64(R12)
641 MOVQ X0, 72(R12)
642 MOVQ X1, 80(R12)
643 MOVQ X2, 88(R12)
644 MOVQ X3, 96(R12)
645 MOVQ X4, 104(R12)
646 MOVQ X5, 112(R12)
647 MOVQ X6, 120(R12)
648 MOVQ X7, 128(R12)
649 MOVQ X8, 136(R12)
650 MOVQ X9, 144(R12)
651 MOVQ X10, 152(R12)
652 MOVQ X11, 160(R12)
653 MOVQ X12, 168(R12)
654 MOVQ X13, 176(R12)
655 MOVQ X14, 184(R12)
656 RET
657
658// unspillArgs loads args into registers from a *internal/abi.RegArgs in R12.
659TEXT ·unspillArgs(SB),NOSPLIT,$0-0
660 MOVQ 0(R12), AX
661 MOVQ 8(R12), BX
662 MOVQ 16(R12), CX
663 MOVQ 24(R12), DI
664 MOVQ 32(R12), SI
665 MOVQ 40(R12), R8
666 MOVQ 48(R12), R9
667 MOVQ 56(R12), R10
668 MOVQ 64(R12), R11
669 MOVQ 72(R12), X0
670 MOVQ 80(R12), X1
671 MOVQ 88(R12), X2
672 MOVQ 96(R12), X3
673 MOVQ 104(R12), X4
674 MOVQ 112(R12), X5
675 MOVQ 120(R12), X6
676 MOVQ 128(R12), X7
677 MOVQ 136(R12), X8
678 MOVQ 144(R12), X9
679 MOVQ 152(R12), X10
680 MOVQ 160(R12), X11
681 MOVQ 168(R12), X12
682 MOVQ 176(R12), X13
683 MOVQ 184(R12), X14
684 RET
685
686// reflectcall: call a function with the given argument list
687// func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
688// we don't have variable-sized frames, so we use a small number
689// of constant-sized-frame functions to encode a few bits of size in the pc.
690// Caution: ugly multiline assembly macros in your future!
691
692#define DISPATCH(NAME,MAXSIZE) \
693 CMPQ CX, $MAXSIZE; \
694 JA 3(PC); \
695 MOVQ $NAME(SB), AX; \
696 JMP AX
697// Note: can't just "JMP NAME(SB)" - bad inlining results.
698
699TEXT ·reflectcall(SB), NOSPLIT, $0-48
700 MOVLQZX frameSize+32(FP), CX
701 DISPATCH(runtime·call16, 16)
702 DISPATCH(runtime·call32, 32)
703 DISPATCH(runtime·call64, 64)
704 DISPATCH(runtime·call128, 128)
705 DISPATCH(runtime·call256, 256)
706 DISPATCH(runtime·call512, 512)
707 DISPATCH(runtime·call1024, 1024)
708 DISPATCH(runtime·call2048, 2048)
709 DISPATCH(runtime·call4096, 4096)
710 DISPATCH(runtime·call8192, 8192)
711 DISPATCH(runtime·call16384, 16384)
712 DISPATCH(runtime·call32768, 32768)
713 DISPATCH(runtime·call65536, 65536)
714 DISPATCH(runtime·call131072, 131072)
715 DISPATCH(runtime·call262144, 262144)
716 DISPATCH(runtime·call524288, 524288)
717 DISPATCH(runtime·call1048576, 1048576)
718 DISPATCH(runtime·call2097152, 2097152)
719 DISPATCH(runtime·call4194304, 4194304)
720 DISPATCH(runtime·call8388608, 8388608)
721 DISPATCH(runtime·call16777216, 16777216)
722 DISPATCH(runtime·call33554432, 33554432)
723 DISPATCH(runtime·call67108864, 67108864)
724 DISPATCH(runtime·call134217728, 134217728)
725 DISPATCH(runtime·call268435456, 268435456)
726 DISPATCH(runtime·call536870912, 536870912)
727 DISPATCH(runtime·call1073741824, 1073741824)
728 MOVQ $runtime·badreflectcall(SB), AX
729 JMP AX
730
731#define CALLFN(NAME,MAXSIZE) \
732TEXT NAME(SB), WRAPPER, $MAXSIZE-48; \
733 NO_LOCAL_POINTERS; \
734 /* copy arguments to stack */ \
735 MOVQ stackArgs+16(FP), SI; \
736 MOVLQZX stackArgsSize+24(FP), CX; \
737 MOVQ SP, DI; \
738 REP;MOVSB; \
739 /* set up argument registers */ \
740 MOVQ regArgs+40(FP), R12; \
741 CALL ·unspillArgs(SB); \
742 /* call function */ \
743 MOVQ f+8(FP), DX; \
744 PCDATA $PCDATA_StackMapIndex, $0; \
745 MOVQ (DX), R12; \
746 CALL R12; \
747 /* copy register return values back */ \
748 MOVQ regArgs+40(FP), R12; \
749 CALL ·spillArgs(SB); \
750 MOVLQZX stackArgsSize+24(FP), CX; \
751 MOVLQZX stackRetOffset+28(FP), BX; \
752 MOVQ stackArgs+16(FP), DI; \
753 MOVQ stackArgsType+0(FP), DX; \
754 MOVQ SP, SI; \
755 ADDQ BX, DI; \
756 ADDQ BX, SI; \
757 SUBQ BX, CX; \
758 CALL callRet<>(SB); \
759 RET
760
761// callRet copies return values back at the end of call*. This is a
762// separate function so it can allocate stack space for the arguments
763// to reflectcallmove. It does not follow the Go ABI; it expects its
764// arguments in registers.
765TEXT callRet<>(SB), NOSPLIT, $40-0
766 NO_LOCAL_POINTERS
767 MOVQ DX, 0(SP)
768 MOVQ DI, 8(SP)
769 MOVQ SI, 16(SP)
770 MOVQ CX, 24(SP)
771 MOVQ R12, 32(SP)
772 CALL runtime·reflectcallmove(SB)
773 RET
774
775CALLFN(·call16, 16)
776CALLFN(·call32, 32)
777CALLFN(·call64, 64)
778CALLFN(·call128, 128)
779CALLFN(·call256, 256)
780CALLFN(·call512, 512)
781CALLFN(·call1024, 1024)
782CALLFN(·call2048, 2048)
783CALLFN(·call4096, 4096)
784CALLFN(·call8192, 8192)
785CALLFN(·call16384, 16384)
786CALLFN(·call32768, 32768)
787CALLFN(·call65536, 65536)
788CALLFN(·call131072, 131072)
789CALLFN(·call262144, 262144)
790CALLFN(·call524288, 524288)
791CALLFN(·call1048576, 1048576)
792CALLFN(·call2097152, 2097152)
793CALLFN(·call4194304, 4194304)
794CALLFN(·call8388608, 8388608)
795CALLFN(·call16777216, 16777216)
796CALLFN(·call33554432, 33554432)
797CALLFN(·call67108864, 67108864)
798CALLFN(·call134217728, 134217728)
799CALLFN(·call268435456, 268435456)
800CALLFN(·call536870912, 536870912)
801CALLFN(·call1073741824, 1073741824)
802
803TEXT runtime·procyield(SB),NOSPLIT,$0-0
804 MOVL cycles+0(FP), AX
805again:
806 PAUSE
807 SUBL $1, AX
808 JNZ again
809 RET
810
811
812TEXT ·publicationBarrier<ABIInternal>(SB),NOSPLIT,$0-0
813 // Stores are already ordered on x86, so this is just a
814 // compile barrier.
815 RET
816
817// Save state of caller into g->sched,
818// but using fake PC from systemstack_switch.
819// Must only be called from functions with frame pointer
820// and without locals ($0) or else unwinding from
821// systemstack_switch is incorrect.
822// Smashes R9.
823TEXT gosave_systemstack_switch<>(SB),NOSPLIT|NOFRAME,$0
824 // Take systemstack_switch PC and add 8 bytes to skip
825 // the prologue. The final location does not matter
826 // as long as we are between the prologue and the epilogue.
827 MOVQ $runtime·systemstack_switch+8(SB), R9
828 MOVQ R9, (g_sched+gobuf_pc)(R14)
829 LEAQ 8(SP), R9
830 MOVQ R9, (g_sched+gobuf_sp)(R14)
831 MOVQ $0, (g_sched+gobuf_ret)(R14)
832 MOVQ BP, (g_sched+gobuf_bp)(R14)
833 // Assert ctxt is zero. See func save.
834 MOVQ (g_sched+gobuf_ctxt)(R14), R9
835 TESTQ R9, R9
836 JZ 2(PC)
837 CALL runtime·abort(SB)
838 RET
839
840// func asmcgocall_no_g(fn, arg unsafe.Pointer)
841// Call fn(arg) aligned appropriately for the gcc ABI.
842// Called on a system stack, and there may be no g yet (during needm).
843TEXT ·asmcgocall_no_g(SB),NOSPLIT,$32-16
844 MOVQ fn+0(FP), AX
845 MOVQ arg+8(FP), BX
846 MOVQ SP, DX
847 ANDQ $~15, SP // alignment
848 MOVQ DX, 8(SP)
849 MOVQ BX, DI // DI = first argument in AMD64 ABI
850 MOVQ BX, CX // CX = first argument in Win64
851 CALL AX
852 MOVQ 8(SP), DX
853 MOVQ DX, SP
854 RET
855
856// asmcgocall_landingpad calls AX with BX as argument.
857// Must be called on the system stack.
858TEXT ·asmcgocall_landingpad(SB),NOSPLIT,$0-0
859#ifdef GOOS_windows
860 // Make sure we have enough room for 4 stack-backed fast-call
861 // registers as per Windows amd64 calling convention.
862 ADJSP $32
863 // On Windows, asmcgocall_landingpad acts as landing pad for exceptions
864 // thrown in the cgo call. Exceptions that reach this function will be
865 // handled by runtime.sehtramp thanks to the SEH metadata added
866 // by the compiler.
867 // Note that runtime.sehtramp can't be attached directly to asmcgocall
868 // because its initial stack pointer can be outside the system stack bounds,
869 // and Windows stops the stack unwinding without calling the exception handler
870 // when it reaches that point.
871 MOVQ BX, CX // CX = first argument in Win64
872 CALL AX
873 // The exception handler is not called if the next instruction is part of
874 // the epilogue, which includes the RET instruction, so we need to add a NOP here.
875 BYTE $0x90
876 ADJSP $-32
877 RET
878#endif
879 // Tail call AX on non-Windows, as the extra stack frame is not needed.
880 MOVQ BX, DI // DI = first argument in AMD64 ABI
881 JMP AX
882
883// func asmcgocall(fn, arg unsafe.Pointer) int32
884// Call fn(arg) on the scheduler stack,
885// aligned appropriately for the gcc ABI.
886// See cgocall.go for more details.
887TEXT ·asmcgocall(SB),NOSPLIT,$0-20
888 MOVQ fn+0(FP), AX
889 MOVQ arg+8(FP), BX
890
891 MOVQ SP, DX
892
893 // Figure out if we need to switch to m->g0 stack.
894 // We get called to create new OS threads too, and those
895 // come in on the m->g0 stack already. Or we might already
896 // be on the m->gsignal stack.
897 get_tls(CX)
898 MOVQ g(CX), DI
899 CMPQ DI, $0
900 JEQ nosave
901 MOVQ g_m(DI), R8
902 MOVQ m_gsignal(R8), SI
903 CMPQ DI, SI
904 JEQ nosave
905 MOVQ m_g0(R8), SI
906 CMPQ DI, SI
907 JEQ nosave
908
909 // Switch to system stack.
910 // The original frame pointer is stored in BP,
911 // which is useful for stack unwinding.
912 CALL gosave_systemstack_switch<>(SB)
913 MOVQ SI, g(CX)
914 MOVQ (g_sched+gobuf_sp)(SI), SP
915
916 // Now on a scheduling stack (a pthread-created stack).
917 SUBQ $16, SP
918 ANDQ $~15, SP // alignment for gcc ABI
919 MOVQ DI, 8(SP) // save g
920 MOVQ (g_stack+stack_hi)(DI), DI
921 SUBQ DX, DI
922 MOVQ DI, 0(SP) // save depth in stack (can't just save SP, as stack might be copied during a callback)
923 CALL runtime·asmcgocall_landingpad(SB)
924
925 // Restore registers, g, stack pointer.
926 get_tls(CX)
927 MOVQ 8(SP), DI
928 MOVQ (g_stack+stack_hi)(DI), SI
929 SUBQ 0(SP), SI
930 MOVQ DI, g(CX)
931 MOVQ SI, SP
932
933 MOVL AX, ret+16(FP)
934 RET
935
936nosave:
937 // Running on a system stack, perhaps even without a g.
938 // Having no g can happen during thread creation or thread teardown
939 // (see needm/dropm on Solaris, for example).
940 // This code is like the above sequence but without saving/restoring g
941 // and without worrying about the stack moving out from under us
942 // (because we're on a system stack, not a goroutine stack).
943 // The above code could be used directly if already on a system stack,
944 // but then the only path through this code would be a rare case on Solaris.
945 // Using this code for all "already on system stack" calls exercises it more,
946 // which should help keep it correct.
947 SUBQ $16, SP
948 ANDQ $~15, SP
949 MOVQ $0, 8(SP) // where above code stores g, in case someone looks during debugging
950 MOVQ DX, 0(SP) // save original stack pointer
951 CALL runtime·asmcgocall_landingpad(SB)
952 MOVQ 0(SP), SI // restore original stack pointer
953 MOVQ SI, SP
954 MOVL AX, ret+16(FP)
955 RET
956
957#ifdef GOOS_windows
958// Dummy TLS that's used on Windows so that we don't crash trying
959// to restore the G register in needm. needm and its callees are
960// very careful never to actually use the G, the TLS just can't be
961// unset since we're in Go code.
962GLOBL zeroTLS<>(SB),RODATA,$const_tlsSize
963#endif
964
965// func cgocallback(fn, frame unsafe.Pointer, ctxt uintptr)
966// See cgocall.go for more details.
967TEXT ·cgocallback(SB),NOSPLIT,$24-24
968 NO_LOCAL_POINTERS
969
970 // Skip cgocallbackg, just dropm when fn is nil, and frame is the saved g.
971 // It is used to dropm while thread is exiting.
972 MOVQ fn+0(FP), AX
973 CMPQ AX, $0
974 JNE loadg
975 // Restore the g from frame.
976 get_tls(CX)
977 MOVQ frame+8(FP), BX
978 MOVQ BX, g(CX)
979 JMP dropm
980
981loadg:
982 // If g is nil, Go did not create the current thread,
983 // or if this thread never called into Go on pthread platforms.
984 // Call needm to obtain one m for temporary use.
985 // In this case, we're running on the thread stack, so there's
986 // lots of space, but the linker doesn't know. Hide the call from
987 // the linker analysis by using an indirect call through AX.
988 get_tls(CX)
989#ifdef GOOS_windows
990 MOVL $0, BX
991 CMPQ CX, $0
992 JEQ 2(PC)
993#endif
994 MOVQ g(CX), BX
995 CMPQ BX, $0
996 JEQ needm
997 MOVQ g_m(BX), BX
998 MOVQ BX, savedm-8(SP) // saved copy of oldm
999 JMP havem
1000needm:
1001#ifdef GOOS_windows
1002 // Set up a dummy TLS value. needm is careful not to use it,
1003 // but it needs to be there to prevent autogenerated code from
1004 // crashing when it loads from it.
1005 // We don't need to clear it or anything later because needm
1006 // will set up TLS properly.
1007 MOVQ $zeroTLS<>(SB), DI
1008 CALL runtime·settls(SB)
1009#endif
1010 // On some platforms (Windows) we cannot call needm through
1011 // an ABI wrapper because there's no TLS set up, and the ABI
1012 // wrapper will try to restore the G register (R14) from TLS.
1013 // Clear X15 because Go expects it and we're not calling
1014 // through a wrapper, but otherwise avoid setting the G
1015 // register in the wrapper and call needm directly. It
1016 // takes no arguments and doesn't return any values so
1017 // there's no need to handle that. Clear R14 so that there's
1018 // a bad value in there, in case needm tries to use it.
1019 XORPS X15, X15
1020 XORQ R14, R14
1021 MOVQ $runtime·needAndBindM<ABIInternal>(SB), AX
1022 CALL AX
1023 MOVQ $0, savedm-8(SP)
1024 get_tls(CX)
1025 MOVQ g(CX), BX
1026 MOVQ g_m(BX), BX
1027
1028 // Set m->sched.sp = SP, so that if a panic happens
1029 // during the function we are about to execute, it will
1030 // have a valid SP to run on the g0 stack.
1031 // The next few lines (after the havem label)
1032 // will save this SP onto the stack and then write
1033 // the same SP back to m->sched.sp. That seems redundant,
1034 // but if an unrecovered panic happens, unwindm will
1035 // restore the g->sched.sp from the stack location
1036 // and then systemstack will try to use it. If we don't set it here,
1037 // that restored SP will be uninitialized (typically 0) and
1038 // will not be usable.
1039 MOVQ m_g0(BX), SI
1040 MOVQ SP, (g_sched+gobuf_sp)(SI)
1041
1042havem:
1043 // Now there's a valid m, and we're running on its m->g0.
1044 // Save current m->g0->sched.sp on stack and then set it to SP.
1045 // Save current sp in m->g0->sched.sp in preparation for
1046 // switch back to m->curg stack.
1047 // NOTE: unwindm knows that the saved g->sched.sp is at 0(SP).
1048 MOVQ m_g0(BX), SI
1049 MOVQ (g_sched+gobuf_sp)(SI), AX
1050 MOVQ AX, 0(SP)
1051 MOVQ SP, (g_sched+gobuf_sp)(SI)
1052
1053 // Switch to m->curg stack and call runtime.cgocallbackg.
1054 // Because we are taking over the execution of m->curg
1055 // but *not* resuming what had been running, we need to
1056 // save that information (m->curg->sched) so we can restore it.
1057 // We can restore m->curg->sched.sp easily, because calling
1058 // runtime.cgocallbackg leaves SP unchanged upon return.
1059 // To save m->curg->sched.pc, we push it onto the curg stack and
1060 // open a frame the same size as cgocallback's g0 frame.
1061 // Once we switch to the curg stack, the pushed PC will appear
1062 // to be the return PC of cgocallback, so that the traceback
1063 // will seamlessly trace back into the earlier calls.
1064 MOVQ m_curg(BX), SI
1065 MOVQ SI, g(CX)
1066 MOVQ (g_sched+gobuf_sp)(SI), DI // prepare stack as DI
1067 MOVQ (g_sched+gobuf_pc)(SI), BX
1068 MOVQ BX, -8(DI) // "push" return PC on the g stack
1069 // Gather our arguments into registers.
1070 MOVQ fn+0(FP), BX
1071 MOVQ frame+8(FP), CX
1072 MOVQ ctxt+16(FP), DX
1073 // Compute the size of the frame, including return PC and, if
1074 // GOEXPERIMENT=framepointer, the saved base pointer
1075 LEAQ fn+0(FP), AX
1076 SUBQ SP, AX // AX is our actual frame size
1077 SUBQ AX, DI // Allocate the same frame size on the g stack
1078 MOVQ DI, SP
1079
1080 MOVQ BX, 0(SP)
1081 MOVQ CX, 8(SP)
1082 MOVQ DX, 16(SP)
1083 MOVQ $runtime·cgocallbackg(SB), AX
1084 CALL AX // indirect call to bypass nosplit check. We're on a different stack now.
1085
1086 // Compute the size of the frame again. FP and SP have
1087 // completely different values here than they did above,
1088 // but only their difference matters.
1089 LEAQ fn+0(FP), AX
1090 SUBQ SP, AX
1091
1092 // Restore g->sched (== m->curg->sched) from saved values.
1093 get_tls(CX)
1094 MOVQ g(CX), SI
1095 MOVQ SP, DI
1096 ADDQ AX, DI
1097 MOVQ -8(DI), BX
1098 MOVQ BX, (g_sched+gobuf_pc)(SI)
1099 MOVQ DI, (g_sched+gobuf_sp)(SI)
1100
1101 // Switch back to m->g0's stack and restore m->g0->sched.sp.
1102 // (Unlike m->curg, the g0 goroutine never uses sched.pc,
1103 // so we do not have to restore it.)
1104 MOVQ g(CX), BX
1105 MOVQ g_m(BX), BX
1106 MOVQ m_g0(BX), SI
1107 MOVQ SI, g(CX)
1108 MOVQ (g_sched+gobuf_sp)(SI), SP
1109 MOVQ 0(SP), AX
1110 MOVQ AX, (g_sched+gobuf_sp)(SI)
1111
1112 // If the m on entry was nil, we called needm above to borrow an m,
1113 // 1. for the duration of the call on non-pthread platforms,
1114 // 2. or the duration of the C thread alive on pthread platforms.
1115 // If the m on entry wasn't nil,
1116 // 1. the thread might be a Go thread,
1117 // 2. or it wasn't the first call from a C thread on pthread platforms,
1118 // since then we skip dropm to reuse the m in the first call.
1119 MOVQ savedm-8(SP), BX
1120 CMPQ BX, $0
1121 JNE done
1122
1123 // Skip dropm to reuse it in the next call, when a pthread key has been created.
1124 MOVQ _cgo_pthread_key_created(SB), AX
1125 // It means cgo is disabled when _cgo_pthread_key_created is a nil pointer, need dropm.
1126 CMPQ AX, $0
1127 JEQ dropm
1128 CMPQ (AX), $0
1129 JNE done
1130
1131dropm:
1132 MOVQ $runtime·dropm(SB), AX
1133 CALL AX
1134#ifdef GOOS_windows
1135 // We need to clear the TLS pointer in case the next
1136 // thread that comes into Go tries to reuse that space
1137 // but uses the same M.
1138 XORQ DI, DI
1139 CALL runtime·settls(SB)
1140#endif
1141done:
1142
1143 // Done!
1144 RET
1145
1146// func setg(gg *g)
1147// set g. for use by needm.
1148TEXT runtime·setg(SB), NOSPLIT, $0-8
1149 MOVQ gg+0(FP), BX
1150 get_tls(CX)
1151 MOVQ BX, g(CX)
1152 RET
1153
1154// void setg_gcc(G*); set g called from gcc.
1155TEXT setg_gcc<>(SB),NOSPLIT,$0
1156 get_tls(AX)
1157 MOVQ DI, g(AX)
1158 MOVQ DI, R14 // set the g register
1159 RET
1160
1161TEXT runtime·abort(SB),NOSPLIT,$0-0
1162 INT $3
1163loop:
1164 JMP loop
1165
1166// check that SP is in range [g->stack.lo, g->stack.hi)
1167TEXT runtime·stackcheck(SB), NOSPLIT|NOFRAME, $0-0
1168 get_tls(CX)
1169 MOVQ g(CX), AX
1170 CMPQ (g_stack+stack_hi)(AX), SP
1171 JHI 2(PC)
1172 CALL runtime·abort(SB)
1173 CMPQ SP, (g_stack+stack_lo)(AX)
1174 JHI 2(PC)
1175 CALL runtime·abort(SB)
1176 RET
1177
1178// func cputicks() int64
1179TEXT runtime·cputicks(SB),NOSPLIT,$0-0
1180 CMPB internal∕cpu·X86+const_offsetX86HasRDTSCP(SB), $1
1181 JNE fences
1182 // Instruction stream serializing RDTSCP is supported.
1183 // RDTSCP is supported by Intel Nehalem (2008) and
1184 // AMD K8 Rev. F (2006) and newer.
1185 RDTSCP
1186done:
1187 SHLQ $32, DX
1188 ADDQ DX, AX
1189 MOVQ AX, ret+0(FP)
1190 RET
1191fences:
1192 // MFENCE is instruction stream serializing and flushes the
1193 // store buffers on AMD. The serialization semantics of LFENCE on AMD
1194 // are dependent on MSR C001_1029 and CPU generation.
1195 // LFENCE on Intel does wait for all previous instructions to have executed.
1196 // Intel recommends MFENCE;LFENCE in its manuals before RDTSC to have all
1197 // previous instructions executed and all previous loads and stores to globally visible.
1198 // Using MFENCE;LFENCE here aligns the serializing properties without
1199 // runtime detection of CPU manufacturer.
1200 MFENCE
1201 LFENCE
1202 RDTSC
1203 JMP done
1204
1205// func memhash(p unsafe.Pointer, h, s uintptr) uintptr
1206// hash function using AES hardware instructions
1207TEXT runtime·memhash<ABIInternal>(SB),NOSPLIT,$0-32
1208 // AX = ptr to data
1209 // BX = seed
1210 // CX = size
1211 CMPB runtime·useAeshash(SB), $0
1212 JEQ noaes
1213 JMP aeshashbody<>(SB)
1214noaes:
1215 JMP runtime·memhashFallback<ABIInternal>(SB)
1216
1217// func strhash(p unsafe.Pointer, h uintptr) uintptr
1218TEXT runtime·strhash<ABIInternal>(SB),NOSPLIT,$0-24
1219 // AX = ptr to string struct
1220 // BX = seed
1221 CMPB runtime·useAeshash(SB), $0
1222 JEQ noaes
1223 MOVQ 8(AX), CX // length of string
1224 MOVQ (AX), AX // string data
1225 JMP aeshashbody<>(SB)
1226noaes:
1227 JMP runtime·strhashFallback<ABIInternal>(SB)
1228
1229// AX: data
1230// BX: hash seed
1231// CX: length
1232// At return: AX = return value
1233TEXT aeshashbody<>(SB),NOSPLIT,$0-0
1234 // Fill an SSE register with our seeds.
1235 MOVQ BX, X0 // 64 bits of per-table hash seed
1236 PINSRW $4, CX, X0 // 16 bits of length
1237 PSHUFHW $0, X0, X0 // repeat length 4 times total
1238 MOVO X0, X1 // save unscrambled seed
1239 PXOR runtime·aeskeysched(SB), X0 // xor in per-process seed
1240 AESENC X0, X0 // scramble seed
1241
1242 CMPQ CX, $16
1243 JB aes0to15
1244 JE aes16
1245 CMPQ CX, $32
1246 JBE aes17to32
1247 CMPQ CX, $64
1248 JBE aes33to64
1249 CMPQ CX, $128
1250 JBE aes65to128
1251 JMP aes129plus
1252
1253aes0to15:
1254 TESTQ CX, CX
1255 JE aes0
1256
1257 ADDQ $16, AX
1258 TESTW $0xff0, AX
1259 JE endofpage
1260
1261 // 16 bytes loaded at this address won't cross
1262 // a page boundary, so we can load it directly.
1263 MOVOU -16(AX), X1
1264 ADDQ CX, CX
1265 MOVQ $masks<>(SB), AX
1266 PAND (AX)(CX*8), X1
1267final1:
1268 PXOR X0, X1 // xor data with seed
1269 AESENC X1, X1 // scramble combo 3 times
1270 AESENC X1, X1
1271 AESENC X1, X1
1272 MOVQ X1, AX // return X1
1273 RET
1274
1275endofpage:
1276 // address ends in 1111xxxx. Might be up against
1277 // a page boundary, so load ending at last byte.
1278 // Then shift bytes down using pshufb.
1279 MOVOU -32(AX)(CX*1), X1
1280 ADDQ CX, CX
1281 MOVQ $shifts<>(SB), AX
1282 PSHUFB (AX)(CX*8), X1
1283 JMP final1
1284
1285aes0:
1286 // Return scrambled input seed
1287 AESENC X0, X0
1288 MOVQ X0, AX // return X0
1289 RET
1290
1291aes16:
1292 MOVOU (AX), X1
1293 JMP final1
1294
1295aes17to32:
1296 // make second starting seed
1297 PXOR runtime·aeskeysched+16(SB), X1
1298 AESENC X1, X1
1299
1300 // load data to be hashed
1301 MOVOU (AX), X2
1302 MOVOU -16(AX)(CX*1), X3
1303
1304 // xor with seed
1305 PXOR X0, X2
1306 PXOR X1, X3
1307
1308 // scramble 3 times
1309 AESENC X2, X2
1310 AESENC X3, X3
1311 AESENC X2, X2
1312 AESENC X3, X3
1313 AESENC X2, X2
1314 AESENC X3, X3
1315
1316 // combine results
1317 PXOR X3, X2
1318 MOVQ X2, AX // return X2
1319 RET
1320
1321aes33to64:
1322 // make 3 more starting seeds
1323 MOVO X1, X2
1324 MOVO X1, X3
1325 PXOR runtime·aeskeysched+16(SB), X1
1326 PXOR runtime·aeskeysched+32(SB), X2
1327 PXOR runtime·aeskeysched+48(SB), X3
1328 AESENC X1, X1
1329 AESENC X2, X2
1330 AESENC X3, X3
1331
1332 MOVOU (AX), X4
1333 MOVOU 16(AX), X5
1334 MOVOU -32(AX)(CX*1), X6
1335 MOVOU -16(AX)(CX*1), X7
1336
1337 PXOR X0, X4
1338 PXOR X1, X5
1339 PXOR X2, X6
1340 PXOR X3, X7
1341
1342 AESENC X4, X4
1343 AESENC X5, X5
1344 AESENC X6, X6
1345 AESENC X7, X7
1346
1347 AESENC X4, X4
1348 AESENC X5, X5
1349 AESENC X6, X6
1350 AESENC X7, X7
1351
1352 AESENC X4, X4
1353 AESENC X5, X5
1354 AESENC X6, X6
1355 AESENC X7, X7
1356
1357 PXOR X6, X4
1358 PXOR X7, X5
1359 PXOR X5, X4
1360 MOVQ X4, AX // return X4
1361 RET
1362
1363aes65to128:
1364 // make 7 more starting seeds
1365 MOVO X1, X2
1366 MOVO X1, X3
1367 MOVO X1, X4
1368 MOVO X1, X5
1369 MOVO X1, X6
1370 MOVO X1, X7
1371 PXOR runtime·aeskeysched+16(SB), X1
1372 PXOR runtime·aeskeysched+32(SB), X2
1373 PXOR runtime·aeskeysched+48(SB), X3
1374 PXOR runtime·aeskeysched+64(SB), X4
1375 PXOR runtime·aeskeysched+80(SB), X5
1376 PXOR runtime·aeskeysched+96(SB), X6
1377 PXOR runtime·aeskeysched+112(SB), X7
1378 AESENC X1, X1
1379 AESENC X2, X2
1380 AESENC X3, X3
1381 AESENC X4, X4
1382 AESENC X5, X5
1383 AESENC X6, X6
1384 AESENC X7, X7
1385
1386 // load data
1387 MOVOU (AX), X8
1388 MOVOU 16(AX), X9
1389 MOVOU 32(AX), X10
1390 MOVOU 48(AX), X11
1391 MOVOU -64(AX)(CX*1), X12
1392 MOVOU -48(AX)(CX*1), X13
1393 MOVOU -32(AX)(CX*1), X14
1394 MOVOU -16(AX)(CX*1), X15
1395
1396 // xor with seed
1397 PXOR X0, X8
1398 PXOR X1, X9
1399 PXOR X2, X10
1400 PXOR X3, X11
1401 PXOR X4, X12
1402 PXOR X5, X13
1403 PXOR X6, X14
1404 PXOR X7, X15
1405
1406 // scramble 3 times
1407 AESENC X8, X8
1408 AESENC X9, X9
1409 AESENC X10, X10
1410 AESENC X11, X11
1411 AESENC X12, X12
1412 AESENC X13, X13
1413 AESENC X14, X14
1414 AESENC X15, X15
1415
1416 AESENC X8, X8
1417 AESENC X9, X9
1418 AESENC X10, X10
1419 AESENC X11, X11
1420 AESENC X12, X12
1421 AESENC X13, X13
1422 AESENC X14, X14
1423 AESENC X15, X15
1424
1425 AESENC X8, X8
1426 AESENC X9, X9
1427 AESENC X10, X10
1428 AESENC X11, X11
1429 AESENC X12, X12
1430 AESENC X13, X13
1431 AESENC X14, X14
1432 AESENC X15, X15
1433
1434 // combine results
1435 PXOR X12, X8
1436 PXOR X13, X9
1437 PXOR X14, X10
1438 PXOR X15, X11
1439 PXOR X10, X8
1440 PXOR X11, X9
1441 PXOR X9, X8
1442 // X15 must be zero on return
1443 PXOR X15, X15
1444 MOVQ X8, AX // return X8
1445 RET
1446
1447aes129plus:
1448 // make 7 more starting seeds
1449 MOVO X1, X2
1450 MOVO X1, X3
1451 MOVO X1, X4
1452 MOVO X1, X5
1453 MOVO X1, X6
1454 MOVO X1, X7
1455 PXOR runtime·aeskeysched+16(SB), X1
1456 PXOR runtime·aeskeysched+32(SB), X2
1457 PXOR runtime·aeskeysched+48(SB), X3
1458 PXOR runtime·aeskeysched+64(SB), X4
1459 PXOR runtime·aeskeysched+80(SB), X5
1460 PXOR runtime·aeskeysched+96(SB), X6
1461 PXOR runtime·aeskeysched+112(SB), X7
1462 AESENC X1, X1
1463 AESENC X2, X2
1464 AESENC X3, X3
1465 AESENC X4, X4
1466 AESENC X5, X5
1467 AESENC X6, X6
1468 AESENC X7, X7
1469
1470 // start with last (possibly overlapping) block
1471 MOVOU -128(AX)(CX*1), X8
1472 MOVOU -112(AX)(CX*1), X9
1473 MOVOU -96(AX)(CX*1), X10
1474 MOVOU -80(AX)(CX*1), X11
1475 MOVOU -64(AX)(CX*1), X12
1476 MOVOU -48(AX)(CX*1), X13
1477 MOVOU -32(AX)(CX*1), X14
1478 MOVOU -16(AX)(CX*1), X15
1479
1480 // xor in seed
1481 PXOR X0, X8
1482 PXOR X1, X9
1483 PXOR X2, X10
1484 PXOR X3, X11
1485 PXOR X4, X12
1486 PXOR X5, X13
1487 PXOR X6, X14
1488 PXOR X7, X15
1489
1490 // compute number of remaining 128-byte blocks
1491 DECQ CX
1492 SHRQ $7, CX
1493
1494 PCALIGN $16
1495aesloop:
1496 // scramble state
1497 AESENC X8, X8
1498 AESENC X9, X9
1499 AESENC X10, X10
1500 AESENC X11, X11
1501 AESENC X12, X12
1502 AESENC X13, X13
1503 AESENC X14, X14
1504 AESENC X15, X15
1505
1506 // scramble state, xor in a block
1507 MOVOU (AX), X0
1508 MOVOU 16(AX), X1
1509 MOVOU 32(AX), X2
1510 MOVOU 48(AX), X3
1511 AESENC X0, X8
1512 AESENC X1, X9
1513 AESENC X2, X10
1514 AESENC X3, X11
1515 MOVOU 64(AX), X4
1516 MOVOU 80(AX), X5
1517 MOVOU 96(AX), X6
1518 MOVOU 112(AX), X7
1519 AESENC X4, X12
1520 AESENC X5, X13
1521 AESENC X6, X14
1522 AESENC X7, X15
1523
1524 ADDQ $128, AX
1525 DECQ CX
1526 JNE aesloop
1527
1528 // 3 more scrambles to finish
1529 AESENC X8, X8
1530 AESENC X9, X9
1531 AESENC X10, X10
1532 AESENC X11, X11
1533 AESENC X12, X12
1534 AESENC X13, X13
1535 AESENC X14, X14
1536 AESENC X15, X15
1537 AESENC X8, X8
1538 AESENC X9, X9
1539 AESENC X10, X10
1540 AESENC X11, X11
1541 AESENC X12, X12
1542 AESENC X13, X13
1543 AESENC X14, X14
1544 AESENC X15, X15
1545 AESENC X8, X8
1546 AESENC X9, X9
1547 AESENC X10, X10
1548 AESENC X11, X11
1549 AESENC X12, X12
1550 AESENC X13, X13
1551 AESENC X14, X14
1552 AESENC X15, X15
1553
1554 PXOR X12, X8
1555 PXOR X13, X9
1556 PXOR X14, X10
1557 PXOR X15, X11
1558 PXOR X10, X8
1559 PXOR X11, X9
1560 PXOR X9, X8
1561 // X15 must be zero on return
1562 PXOR X15, X15
1563 MOVQ X8, AX // return X8
1564 RET
1565
1566// func memhash32(p unsafe.Pointer, h uintptr) uintptr
1567// ABIInternal for performance.
1568TEXT runtime·memhash32<ABIInternal>(SB),NOSPLIT,$0-24
1569 // AX = ptr to data
1570 // BX = seed
1571 CMPB runtime·useAeshash(SB), $0
1572 JEQ noaes
1573 MOVQ BX, X0 // X0 = seed
1574 PINSRD $2, (AX), X0 // data
1575 AESENC runtime·aeskeysched+0(SB), X0
1576 AESENC runtime·aeskeysched+16(SB), X0
1577 AESENC runtime·aeskeysched+32(SB), X0
1578 MOVQ X0, AX // return X0
1579 RET
1580noaes:
1581 JMP runtime·memhash32Fallback<ABIInternal>(SB)
1582
1583// func memhash64(p unsafe.Pointer, h uintptr) uintptr
1584// ABIInternal for performance.
1585TEXT runtime·memhash64<ABIInternal>(SB),NOSPLIT,$0-24
1586 // AX = ptr to data
1587 // BX = seed
1588 CMPB runtime·useAeshash(SB), $0
1589 JEQ noaes
1590 MOVQ BX, X0 // X0 = seed
1591 PINSRQ $1, (AX), X0 // data
1592 AESENC runtime·aeskeysched+0(SB), X0
1593 AESENC runtime·aeskeysched+16(SB), X0
1594 AESENC runtime·aeskeysched+32(SB), X0
1595 MOVQ X0, AX // return X0
1596 RET
1597noaes:
1598 JMP runtime·memhash64Fallback<ABIInternal>(SB)
1599
1600// simple mask to get rid of data in the high part of the register.
1601DATA masks<>+0x00(SB)/8, $0x0000000000000000
1602DATA masks<>+0x08(SB)/8, $0x0000000000000000
1603DATA masks<>+0x10(SB)/8, $0x00000000000000ff
1604DATA masks<>+0x18(SB)/8, $0x0000000000000000
1605DATA masks<>+0x20(SB)/8, $0x000000000000ffff
1606DATA masks<>+0x28(SB)/8, $0x0000000000000000
1607DATA masks<>+0x30(SB)/8, $0x0000000000ffffff
1608DATA masks<>+0x38(SB)/8, $0x0000000000000000
1609DATA masks<>+0x40(SB)/8, $0x00000000ffffffff
1610DATA masks<>+0x48(SB)/8, $0x0000000000000000
1611DATA masks<>+0x50(SB)/8, $0x000000ffffffffff
1612DATA masks<>+0x58(SB)/8, $0x0000000000000000
1613DATA masks<>+0x60(SB)/8, $0x0000ffffffffffff
1614DATA masks<>+0x68(SB)/8, $0x0000000000000000
1615DATA masks<>+0x70(SB)/8, $0x00ffffffffffffff
1616DATA masks<>+0x78(SB)/8, $0x0000000000000000
1617DATA masks<>+0x80(SB)/8, $0xffffffffffffffff
1618DATA masks<>+0x88(SB)/8, $0x0000000000000000
1619DATA masks<>+0x90(SB)/8, $0xffffffffffffffff
1620DATA masks<>+0x98(SB)/8, $0x00000000000000ff
1621DATA masks<>+0xa0(SB)/8, $0xffffffffffffffff
1622DATA masks<>+0xa8(SB)/8, $0x000000000000ffff
1623DATA masks<>+0xb0(SB)/8, $0xffffffffffffffff
1624DATA masks<>+0xb8(SB)/8, $0x0000000000ffffff
1625DATA masks<>+0xc0(SB)/8, $0xffffffffffffffff
1626DATA masks<>+0xc8(SB)/8, $0x00000000ffffffff
1627DATA masks<>+0xd0(SB)/8, $0xffffffffffffffff
1628DATA masks<>+0xd8(SB)/8, $0x000000ffffffffff
1629DATA masks<>+0xe0(SB)/8, $0xffffffffffffffff
1630DATA masks<>+0xe8(SB)/8, $0x0000ffffffffffff
1631DATA masks<>+0xf0(SB)/8, $0xffffffffffffffff
1632DATA masks<>+0xf8(SB)/8, $0x00ffffffffffffff
1633GLOBL masks<>(SB),RODATA,$256
1634
1635// func checkASM() bool
1636TEXT ·checkASM(SB),NOSPLIT,$0-1
1637 // check that masks<>(SB) and shifts<>(SB) are aligned to 16-byte
1638 MOVQ $masks<>(SB), AX
1639 MOVQ $shifts<>(SB), BX
1640 ORQ BX, AX
1641 TESTQ $15, AX
1642 SETEQ ret+0(FP)
1643 RET
1644
1645// these are arguments to pshufb. They move data down from
1646// the high bytes of the register to the low bytes of the register.
1647// index is how many bytes to move.
1648DATA shifts<>+0x00(SB)/8, $0x0000000000000000
1649DATA shifts<>+0x08(SB)/8, $0x0000000000000000
1650DATA shifts<>+0x10(SB)/8, $0xffffffffffffff0f
1651DATA shifts<>+0x18(SB)/8, $0xffffffffffffffff
1652DATA shifts<>+0x20(SB)/8, $0xffffffffffff0f0e
1653DATA shifts<>+0x28(SB)/8, $0xffffffffffffffff
1654DATA shifts<>+0x30(SB)/8, $0xffffffffff0f0e0d
1655DATA shifts<>+0x38(SB)/8, $0xffffffffffffffff
1656DATA shifts<>+0x40(SB)/8, $0xffffffff0f0e0d0c
1657DATA shifts<>+0x48(SB)/8, $0xffffffffffffffff
1658DATA shifts<>+0x50(SB)/8, $0xffffff0f0e0d0c0b
1659DATA shifts<>+0x58(SB)/8, $0xffffffffffffffff
1660DATA shifts<>+0x60(SB)/8, $0xffff0f0e0d0c0b0a
1661DATA shifts<>+0x68(SB)/8, $0xffffffffffffffff
1662DATA shifts<>+0x70(SB)/8, $0xff0f0e0d0c0b0a09
1663DATA shifts<>+0x78(SB)/8, $0xffffffffffffffff
1664DATA shifts<>+0x80(SB)/8, $0x0f0e0d0c0b0a0908
1665DATA shifts<>+0x88(SB)/8, $0xffffffffffffffff
1666DATA shifts<>+0x90(SB)/8, $0x0e0d0c0b0a090807
1667DATA shifts<>+0x98(SB)/8, $0xffffffffffffff0f
1668DATA shifts<>+0xa0(SB)/8, $0x0d0c0b0a09080706
1669DATA shifts<>+0xa8(SB)/8, $0xffffffffffff0f0e
1670DATA shifts<>+0xb0(SB)/8, $0x0c0b0a0908070605
1671DATA shifts<>+0xb8(SB)/8, $0xffffffffff0f0e0d
1672DATA shifts<>+0xc0(SB)/8, $0x0b0a090807060504
1673DATA shifts<>+0xc8(SB)/8, $0xffffffff0f0e0d0c
1674DATA shifts<>+0xd0(SB)/8, $0x0a09080706050403
1675DATA shifts<>+0xd8(SB)/8, $0xffffff0f0e0d0c0b
1676DATA shifts<>+0xe0(SB)/8, $0x0908070605040302
1677DATA shifts<>+0xe8(SB)/8, $0xffff0f0e0d0c0b0a
1678DATA shifts<>+0xf0(SB)/8, $0x0807060504030201
1679DATA shifts<>+0xf8(SB)/8, $0xff0f0e0d0c0b0a09
1680GLOBL shifts<>(SB),RODATA,$256
1681
1682TEXT runtime·return0(SB), NOSPLIT, $0
1683 MOVL $0, AX
1684 RET
1685
1686
1687// Called from cgo wrappers, this function returns g->m->curg.stack.hi.
1688// Must obey the gcc calling convention.
1689TEXT _cgo_topofstack(SB),NOSPLIT,$0
1690 get_tls(CX)
1691 MOVQ g(CX), AX
1692 MOVQ g_m(AX), AX
1693 MOVQ m_curg(AX), AX
1694 MOVQ (g_stack+stack_hi)(AX), AX
1695 RET
1696
1697// The top-most function running on a goroutine
1698// returns to goexit+PCQuantum.
1699TEXT runtime·goexit(SB),NOSPLIT|TOPFRAME|NOFRAME,$0-0
1700 BYTE $0x90 // NOP
1701 CALL runtime·goexit1(SB) // does not return
1702 // traceback from goexit1 must hit code range of goexit
1703 BYTE $0x90 // NOP
1704
1705// This is called from .init_array and follows the platform, not Go, ABI.
1706TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0
1707 PUSHQ R15 // The access to global variables below implicitly uses R15, which is callee-save
1708 MOVQ runtime·lastmoduledatap(SB), AX
1709 MOVQ DI, moduledata_next(AX)
1710 MOVQ DI, runtime·lastmoduledatap(SB)
1711 POPQ R15
1712 RET
1713
1714// Initialize special registers then jump to sigpanic.
1715// This function is injected from the signal handler for panicking
1716// signals. It is quite painful to set X15 in the signal context,
1717// so we do it here.
1718TEXT ·sigpanic0(SB),NOSPLIT,$0-0
1719 get_tls(R14)
1720 MOVQ g(R14), R14
1721#ifndef GOOS_plan9
1722 XORPS X15, X15
1723#endif
1724 JMP ·sigpanic<ABIInternal>(SB)
1725
1726// gcWriteBarrier informs the GC about heap pointer writes.
1727//
1728// gcWriteBarrier returns space in a write barrier buffer which
1729// should be filled in by the caller.
1730// gcWriteBarrier does NOT follow the Go ABI. It accepts the
1731// number of bytes of buffer needed in R11, and returns a pointer
1732// to the buffer space in R11.
1733// It clobbers FLAGS. It does not clobber any general-purpose registers,
1734// but may clobber others (e.g., SSE registers).
1735// Typical use would be, when doing *(CX+88) = AX
1736// CMPL $0, runtime.writeBarrier(SB)
1737// JEQ dowrite
1738// CALL runtime.gcBatchBarrier2(SB)
1739// MOVQ AX, (R11)
1740// MOVQ 88(CX), DX
1741// MOVQ DX, 8(R11)
1742// dowrite:
1743// MOVQ AX, 88(CX)
1744TEXT gcWriteBarrier<>(SB),NOSPLIT,$112
1745 // Save the registers clobbered by the fast path. This is slightly
1746 // faster than having the caller spill these.
1747 MOVQ R12, 96(SP)
1748 MOVQ R13, 104(SP)
1749retry:
1750 // TODO: Consider passing g.m.p in as an argument so they can be shared
1751 // across a sequence of write barriers.
1752 MOVQ g_m(R14), R13
1753 MOVQ m_p(R13), R13
1754 // Get current buffer write position.
1755 MOVQ (p_wbBuf+wbBuf_next)(R13), R12 // original next position
1756 ADDQ R11, R12 // new next position
1757 // Is the buffer full?
1758 CMPQ R12, (p_wbBuf+wbBuf_end)(R13)
1759 JA flush
1760 // Commit to the larger buffer.
1761 MOVQ R12, (p_wbBuf+wbBuf_next)(R13)
1762 // Make return value (the original next position)
1763 SUBQ R11, R12
1764 MOVQ R12, R11
1765 // Restore registers.
1766 MOVQ 96(SP), R12
1767 MOVQ 104(SP), R13
1768 RET
1769
1770flush:
1771 // Save all general purpose registers since these could be
1772 // clobbered by wbBufFlush and were not saved by the caller.
1773 // It is possible for wbBufFlush to clobber other registers
1774 // (e.g., SSE registers), but the compiler takes care of saving
1775 // those in the caller if necessary. This strikes a balance
1776 // with registers that are likely to be used.
1777 //
1778 // We don't have type information for these, but all code under
1779 // here is NOSPLIT, so nothing will observe these.
1780 //
1781 // TODO: We could strike a different balance; e.g., saving X0
1782 // and not saving GP registers that are less likely to be used.
1783 MOVQ DI, 0(SP)
1784 MOVQ AX, 8(SP)
1785 MOVQ BX, 16(SP)
1786 MOVQ CX, 24(SP)
1787 MOVQ DX, 32(SP)
1788 // DI already saved
1789 MOVQ SI, 40(SP)
1790 MOVQ BP, 48(SP)
1791 MOVQ R8, 56(SP)
1792 MOVQ R9, 64(SP)
1793 MOVQ R10, 72(SP)
1794 MOVQ R11, 80(SP)
1795 // R12 already saved
1796 // R13 already saved
1797 // R14 is g
1798 MOVQ R15, 88(SP)
1799
1800 CALL runtime·wbBufFlush(SB)
1801
1802 MOVQ 0(SP), DI
1803 MOVQ 8(SP), AX
1804 MOVQ 16(SP), BX
1805 MOVQ 24(SP), CX
1806 MOVQ 32(SP), DX
1807 MOVQ 40(SP), SI
1808 MOVQ 48(SP), BP
1809 MOVQ 56(SP), R8
1810 MOVQ 64(SP), R9
1811 MOVQ 72(SP), R10
1812 MOVQ 80(SP), R11
1813 MOVQ 88(SP), R15
1814 JMP retry
1815
1816TEXT runtime·gcWriteBarrier1<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1817 MOVL $8, R11
1818 JMP gcWriteBarrier<>(SB)
1819TEXT runtime·gcWriteBarrier2<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1820 MOVL $16, R11
1821 JMP gcWriteBarrier<>(SB)
1822TEXT runtime·gcWriteBarrier3<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1823 MOVL $24, R11
1824 JMP gcWriteBarrier<>(SB)
1825TEXT runtime·gcWriteBarrier4<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1826 MOVL $32, R11
1827 JMP gcWriteBarrier<>(SB)
1828TEXT runtime·gcWriteBarrier5<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1829 MOVL $40, R11
1830 JMP gcWriteBarrier<>(SB)
1831TEXT runtime·gcWriteBarrier6<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1832 MOVL $48, R11
1833 JMP gcWriteBarrier<>(SB)
1834TEXT runtime·gcWriteBarrier7<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1835 MOVL $56, R11
1836 JMP gcWriteBarrier<>(SB)
1837TEXT runtime·gcWriteBarrier8<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
1838 MOVL $64, R11
1839 JMP gcWriteBarrier<>(SB)
1840
1841DATA debugCallFrameTooLarge<>+0x00(SB)/20, $"call frame too large"
1842GLOBL debugCallFrameTooLarge<>(SB), RODATA, $20 // Size duplicated below
1843
1844// debugCallV2 is the entry point for debugger-injected function
1845// calls on running goroutines. It informs the runtime that a
1846// debug call has been injected and creates a call frame for the
1847// debugger to fill in.
1848//
1849// To inject a function call, a debugger should:
1850// 1. Check that the goroutine is in state _Grunning and that
1851// there are at least 256 bytes free on the stack.
1852// 2. Push the current PC on the stack (updating SP).
1853// 3. Write the desired argument frame size at SP-16 (using the SP
1854// after step 2).
1855// 4. Save all machine registers (including flags and XMM registers)
1856// so they can be restored later by the debugger.
1857// 5. Set the PC to debugCallV2 and resume execution.
1858//
1859// If the goroutine is in state _Grunnable, then it's not generally
1860// safe to inject a call because it may return out via other runtime
1861// operations. Instead, the debugger should unwind the stack to find
1862// the return to non-runtime code, add a temporary breakpoint there,
1863// and inject the call once that breakpoint is hit.
1864//
1865// If the goroutine is in any other state, it's not safe to inject a call.
1866//
1867// This function communicates back to the debugger by setting R12 and
1868// invoking INT3 to raise a breakpoint signal. See the comments in the
1869// implementation for the protocol the debugger is expected to
1870// follow. InjectDebugCall in the runtime tests demonstrates this protocol.
1871//
1872// The debugger must ensure that any pointers passed to the function
1873// obey escape analysis requirements. Specifically, it must not pass
1874// a stack pointer to an escaping argument. debugCallV2 cannot check
1875// this invariant.
1876//
1877// This is ABIInternal because Go code injects its PC directly into new
1878// goroutine stacks.
1879TEXT runtime·debugCallV2<ABIInternal>(SB),NOSPLIT,$152-0
1880 // Save all registers that may contain pointers so they can be
1881 // conservatively scanned.
1882 //
1883 // We can't do anything that might clobber any of these
1884 // registers before this.
1885 MOVQ R15, r15-(14*8+8)(SP)
1886 MOVQ R14, r14-(13*8+8)(SP)
1887 MOVQ R13, r13-(12*8+8)(SP)
1888 MOVQ R12, r12-(11*8+8)(SP)
1889 MOVQ R11, r11-(10*8+8)(SP)
1890 MOVQ R10, r10-(9*8+8)(SP)
1891 MOVQ R9, r9-(8*8+8)(SP)
1892 MOVQ R8, r8-(7*8+8)(SP)
1893 MOVQ DI, di-(6*8+8)(SP)
1894 MOVQ SI, si-(5*8+8)(SP)
1895 MOVQ BP, bp-(4*8+8)(SP)
1896 MOVQ BX, bx-(3*8+8)(SP)
1897 MOVQ DX, dx-(2*8+8)(SP)
1898 // Save the frame size before we clobber it. Either of the last
1899 // saves could clobber this depending on whether there's a saved BP.
1900 MOVQ frameSize-24(FP), DX // aka -16(RSP) before prologue
1901 MOVQ CX, cx-(1*8+8)(SP)
1902 MOVQ AX, ax-(0*8+8)(SP)
1903
1904 // Save the argument frame size.
1905 MOVQ DX, frameSize-128(SP)
1906
1907 // Perform a safe-point check.
1908 MOVQ retpc-8(FP), AX // Caller's PC
1909 MOVQ AX, 0(SP)
1910 CALL runtime·debugCallCheck(SB)
1911 MOVQ 8(SP), AX
1912 TESTQ AX, AX
1913 JZ good
1914 // The safety check failed. Put the reason string at the top
1915 // of the stack.
1916 MOVQ AX, 0(SP)
1917 MOVQ 16(SP), AX
1918 MOVQ AX, 8(SP)
1919 // Set R12 to 8 and invoke INT3. The debugger should get the
1920 // reason a call can't be injected from the top of the stack
1921 // and resume execution.
1922 MOVQ $8, R12
1923 BYTE $0xcc
1924 JMP restore
1925
1926good:
1927 // Registers are saved and it's safe to make a call.
1928 // Open up a call frame, moving the stack if necessary.
1929 //
1930 // Once the frame is allocated, this will set R12 to 0 and
1931 // invoke INT3. The debugger should write the argument
1932 // frame for the call at SP, set up argument registers, push
1933 // the trapping PC on the stack, set the PC to the function to
1934 // call, set RDX to point to the closure (if a closure call),
1935 // and resume execution.
1936 //
1937 // If the function returns, this will set R12 to 1 and invoke
1938 // INT3. The debugger can then inspect any return value saved
1939 // on the stack at SP and in registers and resume execution again.
1940 //
1941 // If the function panics, this will set R12 to 2 and invoke INT3.
1942 // The interface{} value of the panic will be at SP. The debugger
1943 // can inspect the panic value and resume execution again.
1944#define DEBUG_CALL_DISPATCH(NAME,MAXSIZE) \
1945 CMPQ AX, $MAXSIZE; \
1946 JA 5(PC); \
1947 MOVQ $NAME(SB), AX; \
1948 MOVQ AX, 0(SP); \
1949 CALL runtime·debugCallWrap(SB); \
1950 JMP restore
1951
1952 MOVQ frameSize-128(SP), AX
1953 DEBUG_CALL_DISPATCH(debugCall32<>, 32)
1954 DEBUG_CALL_DISPATCH(debugCall64<>, 64)
1955 DEBUG_CALL_DISPATCH(debugCall128<>, 128)
1956 DEBUG_CALL_DISPATCH(debugCall256<>, 256)
1957 DEBUG_CALL_DISPATCH(debugCall512<>, 512)
1958 DEBUG_CALL_DISPATCH(debugCall1024<>, 1024)
1959 DEBUG_CALL_DISPATCH(debugCall2048<>, 2048)
1960 DEBUG_CALL_DISPATCH(debugCall4096<>, 4096)
1961 DEBUG_CALL_DISPATCH(debugCall8192<>, 8192)
1962 DEBUG_CALL_DISPATCH(debugCall16384<>, 16384)
1963 DEBUG_CALL_DISPATCH(debugCall32768<>, 32768)
1964 DEBUG_CALL_DISPATCH(debugCall65536<>, 65536)
1965 // The frame size is too large. Report the error.
1966 MOVQ $debugCallFrameTooLarge<>(SB), AX
1967 MOVQ AX, 0(SP)
1968 MOVQ $20, 8(SP) // length of debugCallFrameTooLarge string
1969 MOVQ $8, R12
1970 BYTE $0xcc
1971 JMP restore
1972
1973restore:
1974 // Calls and failures resume here.
1975 //
1976 // Set R12 to 16 and invoke INT3. The debugger should restore
1977 // all registers except RIP and RSP and resume execution.
1978 MOVQ $16, R12
1979 BYTE $0xcc
1980 // We must not modify flags after this point.
1981
1982 // Restore pointer-containing registers, which may have been
1983 // modified from the debugger's copy by stack copying.
1984 MOVQ ax-(0*8+8)(SP), AX
1985 MOVQ cx-(1*8+8)(SP), CX
1986 MOVQ dx-(2*8+8)(SP), DX
1987 MOVQ bx-(3*8+8)(SP), BX
1988 MOVQ bp-(4*8+8)(SP), BP
1989 MOVQ si-(5*8+8)(SP), SI
1990 MOVQ di-(6*8+8)(SP), DI
1991 MOVQ r8-(7*8+8)(SP), R8
1992 MOVQ r9-(8*8+8)(SP), R9
1993 MOVQ r10-(9*8+8)(SP), R10
1994 MOVQ r11-(10*8+8)(SP), R11
1995 MOVQ r12-(11*8+8)(SP), R12
1996 MOVQ r13-(12*8+8)(SP), R13
1997 MOVQ r14-(13*8+8)(SP), R14
1998 MOVQ r15-(14*8+8)(SP), R15
1999
2000 RET
2001
2002// runtime.debugCallCheck assumes that functions defined with the
2003// DEBUG_CALL_FN macro are safe points to inject calls.
2004#define DEBUG_CALL_FN(NAME,MAXSIZE) \
2005TEXT NAME(SB),WRAPPER,$MAXSIZE-0; \
2006 NO_LOCAL_POINTERS; \
2007 MOVQ $0, R12; \
2008 BYTE $0xcc; \
2009 MOVQ $1, R12; \
2010 BYTE $0xcc; \
2011 RET
2012DEBUG_CALL_FN(debugCall32<>, 32)
2013DEBUG_CALL_FN(debugCall64<>, 64)
2014DEBUG_CALL_FN(debugCall128<>, 128)
2015DEBUG_CALL_FN(debugCall256<>, 256)
2016DEBUG_CALL_FN(debugCall512<>, 512)
2017DEBUG_CALL_FN(debugCall1024<>, 1024)
2018DEBUG_CALL_FN(debugCall2048<>, 2048)
2019DEBUG_CALL_FN(debugCall4096<>, 4096)
2020DEBUG_CALL_FN(debugCall8192<>, 8192)
2021DEBUG_CALL_FN(debugCall16384<>, 16384)
2022DEBUG_CALL_FN(debugCall32768<>, 32768)
2023DEBUG_CALL_FN(debugCall65536<>, 65536)
2024
2025// func debugCallPanicked(val interface{})
2026TEXT runtime·debugCallPanicked(SB),NOSPLIT,$16-16
2027 // Copy the panic value to the top of stack.
2028 MOVQ val_type+0(FP), AX
2029 MOVQ AX, 0(SP)
2030 MOVQ val_data+8(FP), AX
2031 MOVQ AX, 8(SP)
2032 MOVQ $2, R12
2033 BYTE $0xcc
2034 RET
2035
2036// Note: these functions use a special calling convention to save generated code space.
2037// Arguments are passed in registers, but the space for those arguments are allocated
2038// in the caller's stack frame. These stubs write the args into that stack space and
2039// then tail call to the corresponding runtime handler.
2040// The tail call makes these stubs disappear in backtraces.
2041// Defined as ABIInternal since they do not use the stack-based Go ABI.
2042TEXT runtime·panicIndex<ABIInternal>(SB),NOSPLIT,$0-16
2043 MOVQ CX, BX
2044 JMP runtime·goPanicIndex<ABIInternal>(SB)
2045TEXT runtime·panicIndexU<ABIInternal>(SB),NOSPLIT,$0-16
2046 MOVQ CX, BX
2047 JMP runtime·goPanicIndexU<ABIInternal>(SB)
2048TEXT runtime·panicSliceAlen<ABIInternal>(SB),NOSPLIT,$0-16
2049 MOVQ CX, AX
2050 MOVQ DX, BX
2051 JMP runtime·goPanicSliceAlen<ABIInternal>(SB)
2052TEXT runtime·panicSliceAlenU<ABIInternal>(SB),NOSPLIT,$0-16
2053 MOVQ CX, AX
2054 MOVQ DX, BX
2055 JMP runtime·goPanicSliceAlenU<ABIInternal>(SB)
2056TEXT runtime·panicSliceAcap<ABIInternal>(SB),NOSPLIT,$0-16
2057 MOVQ CX, AX
2058 MOVQ DX, BX
2059 JMP runtime·goPanicSliceAcap<ABIInternal>(SB)
2060TEXT runtime·panicSliceAcapU<ABIInternal>(SB),NOSPLIT,$0-16
2061 MOVQ CX, AX
2062 MOVQ DX, BX
2063 JMP runtime·goPanicSliceAcapU<ABIInternal>(SB)
2064TEXT runtime·panicSliceB<ABIInternal>(SB),NOSPLIT,$0-16
2065 MOVQ CX, BX
2066 JMP runtime·goPanicSliceB<ABIInternal>(SB)
2067TEXT runtime·panicSliceBU<ABIInternal>(SB),NOSPLIT,$0-16
2068 MOVQ CX, BX
2069 JMP runtime·goPanicSliceBU<ABIInternal>(SB)
2070TEXT runtime·panicSlice3Alen<ABIInternal>(SB),NOSPLIT,$0-16
2071 MOVQ DX, AX
2072 JMP runtime·goPanicSlice3Alen<ABIInternal>(SB)
2073TEXT runtime·panicSlice3AlenU<ABIInternal>(SB),NOSPLIT,$0-16
2074 MOVQ DX, AX
2075 JMP runtime·goPanicSlice3AlenU<ABIInternal>(SB)
2076TEXT runtime·panicSlice3Acap<ABIInternal>(SB),NOSPLIT,$0-16
2077 MOVQ DX, AX
2078 JMP runtime·goPanicSlice3Acap<ABIInternal>(SB)
2079TEXT runtime·panicSlice3AcapU<ABIInternal>(SB),NOSPLIT,$0-16
2080 MOVQ DX, AX
2081 JMP runtime·goPanicSlice3AcapU<ABIInternal>(SB)
2082TEXT runtime·panicSlice3B<ABIInternal>(SB),NOSPLIT,$0-16
2083 MOVQ CX, AX
2084 MOVQ DX, BX
2085 JMP runtime·goPanicSlice3B<ABIInternal>(SB)
2086TEXT runtime·panicSlice3BU<ABIInternal>(SB),NOSPLIT,$0-16
2087 MOVQ CX, AX
2088 MOVQ DX, BX
2089 JMP runtime·goPanicSlice3BU<ABIInternal>(SB)
2090TEXT runtime·panicSlice3C<ABIInternal>(SB),NOSPLIT,$0-16
2091 MOVQ CX, BX
2092 JMP runtime·goPanicSlice3C<ABIInternal>(SB)
2093TEXT runtime·panicSlice3CU<ABIInternal>(SB),NOSPLIT,$0-16
2094 MOVQ CX, BX
2095 JMP runtime·goPanicSlice3CU<ABIInternal>(SB)
2096TEXT runtime·panicSliceConvert<ABIInternal>(SB),NOSPLIT,$0-16
2097 MOVQ DX, AX
2098 JMP runtime·goPanicSliceConvert<ABIInternal>(SB)
2099
2100#ifdef GOOS_android
2101// Use the free TLS_SLOT_APP slot #2 on Android Q.
2102// Earlier androids are set up in gcc_android.c.
2103DATA runtime·tls_g+0(SB)/8, $16
2104GLOBL runtime·tls_g+0(SB), NOPTR, $8
2105#endif
2106#ifdef GOOS_windows
2107GLOBL runtime·tls_g+0(SB), NOPTR, $8
2108#endif
2109
2110// The compiler and assembler's -spectre=ret mode rewrites
2111// all indirect CALL AX / JMP AX instructions to be
2112// CALL retpolineAX / JMP retpolineAX.
2113// See https://support.google.com/faqs/answer/7625886.
2114#define RETPOLINE(reg) \
2115 /* CALL setup */ BYTE $0xE8; BYTE $(2+2); BYTE $0; BYTE $0; BYTE $0; \
2116 /* nospec: */ \
2117 /* PAUSE */ BYTE $0xF3; BYTE $0x90; \
2118 /* JMP nospec */ BYTE $0xEB; BYTE $-(2+2); \
2119 /* setup: */ \
2120 /* MOVQ AX, 0(SP) */ BYTE $0x48|((reg&8)>>1); BYTE $0x89; \
2121 BYTE $0x04|((reg&7)<<3); BYTE $0x24; \
2122 /* RET */ BYTE $0xC3
2123
2124TEXT runtime·retpolineAX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(0)
2125TEXT runtime·retpolineCX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(1)
2126TEXT runtime·retpolineDX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(2)
2127TEXT runtime·retpolineBX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(3)
2128/* SP is 4, can't happen / magic encodings */
2129TEXT runtime·retpolineBP(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(5)
2130TEXT runtime·retpolineSI(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(6)
2131TEXT runtime·retpolineDI(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(7)
2132TEXT runtime·retpolineR8(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(8)
2133TEXT runtime·retpolineR9(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(9)
2134TEXT runtime·retpolineR10(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(10)
2135TEXT runtime·retpolineR11(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(11)
2136TEXT runtime·retpolineR12(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(12)
2137TEXT runtime·retpolineR13(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(13)
2138TEXT runtime·retpolineR14(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(14)
2139TEXT runtime·retpolineR15(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(15)
2140
2141TEXT ·getfp<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
2142 MOVQ BP, AX
2143 RET
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