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Diffstat (limited to 'src/runtime/asm_amd64.s')
| -rw-r--r-- | src/runtime/asm_amd64.s | 1833 |
1 files changed, 1833 insertions, 0 deletions
diff --git a/src/runtime/asm_amd64.s b/src/runtime/asm_amd64.s new file mode 100644 index 0000000..4ac8708 --- /dev/null +++ b/src/runtime/asm_amd64.s @@ -0,0 +1,1833 @@ +// 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. + +#include "go_asm.h" +#include "go_tls.h" +#include "funcdata.h" +#include "textflag.h" + +// _rt0_amd64 is common startup code for most amd64 systems when using +// internal linking. This is the entry point for the program from the +// kernel for an ordinary -buildmode=exe program. The stack holds the +// number of arguments and the C-style argv. +TEXT _rt0_amd64(SB),NOSPLIT,$-8 + MOVQ 0(SP), DI // argc + LEAQ 8(SP), SI // argv + JMP runtime·rt0_go(SB) + +// main is common startup code for most amd64 systems when using +// external linking. The C startup code will call the symbol "main" +// passing argc and argv in the usual C ABI registers DI and SI. +TEXT main(SB),NOSPLIT,$-8 + JMP runtime·rt0_go(SB) + +// _rt0_amd64_lib is common startup code for most amd64 systems when +// using -buildmode=c-archive or -buildmode=c-shared. The linker will +// arrange to invoke this function as a global constructor (for +// c-archive) or when the shared library is loaded (for c-shared). +// We expect argc and argv to be passed in the usual C ABI registers +// DI and SI. +TEXT _rt0_amd64_lib(SB),NOSPLIT,$0x50 + // Align stack per ELF ABI requirements. + MOVQ SP, AX + ANDQ $~15, SP + // Save C ABI callee-saved registers, as caller may need them. + MOVQ BX, 0x10(SP) + MOVQ BP, 0x18(SP) + MOVQ R12, 0x20(SP) + MOVQ R13, 0x28(SP) + MOVQ R14, 0x30(SP) + MOVQ R15, 0x38(SP) + MOVQ AX, 0x40(SP) + + MOVQ DI, _rt0_amd64_lib_argc<>(SB) + MOVQ SI, _rt0_amd64_lib_argv<>(SB) + + // Synchronous initialization. + CALL runtime·libpreinit(SB) + + // Create a new thread to finish Go runtime initialization. + MOVQ _cgo_sys_thread_create(SB), AX + TESTQ AX, AX + JZ nocgo + MOVQ $_rt0_amd64_lib_go(SB), DI + MOVQ $0, SI + CALL AX + JMP restore + +nocgo: + MOVQ $0x800000, 0(SP) // stacksize + MOVQ $_rt0_amd64_lib_go(SB), AX + MOVQ AX, 8(SP) // fn + CALL runtime·newosproc0(SB) + +restore: + MOVQ 0x10(SP), BX + MOVQ 0x18(SP), BP + MOVQ 0x20(SP), R12 + MOVQ 0x28(SP), R13 + MOVQ 0x30(SP), R14 + MOVQ 0x38(SP), R15 + MOVQ 0x40(SP), SP + RET + +// _rt0_amd64_lib_go initializes the Go runtime. +// This is started in a separate thread by _rt0_amd64_lib. +TEXT _rt0_amd64_lib_go(SB),NOSPLIT,$0 + MOVQ _rt0_amd64_lib_argc<>(SB), DI + MOVQ _rt0_amd64_lib_argv<>(SB), SI + JMP runtime·rt0_go(SB) + +DATA _rt0_amd64_lib_argc<>(SB)/8, $0 +GLOBL _rt0_amd64_lib_argc<>(SB),NOPTR, $8 +DATA _rt0_amd64_lib_argv<>(SB)/8, $0 +GLOBL _rt0_amd64_lib_argv<>(SB),NOPTR, $8 + +// Defined as ABIInternal since it does not use the stack-based Go ABI (and +// in addition there are no calls to this entry point from Go code). +TEXT runtime·rt0_go<ABIInternal>(SB),NOSPLIT,$0 + // copy arguments forward on an even stack + MOVQ DI, AX // argc + MOVQ SI, BX // argv + SUBQ $(4*8+7), SP // 2args 2auto + ANDQ $~15, SP + MOVQ AX, 16(SP) + MOVQ BX, 24(SP) + + // create istack out of the given (operating system) stack. + // _cgo_init may update stackguard. + MOVQ $runtime·g0(SB), DI + LEAQ (-64*1024+104)(SP), BX + MOVQ BX, g_stackguard0(DI) + MOVQ BX, g_stackguard1(DI) + MOVQ BX, (g_stack+stack_lo)(DI) + MOVQ SP, (g_stack+stack_hi)(DI) + + // find out information about the processor we're on + MOVL $0, AX + CPUID + MOVL AX, SI + CMPL AX, $0 + JE nocpuinfo + + // Figure out how to serialize RDTSC. + // On Intel processors LFENCE is enough. AMD requires MFENCE. + // Don't know about the rest, so let's do MFENCE. + CMPL BX, $0x756E6547 // "Genu" + JNE notintel + CMPL DX, $0x49656E69 // "ineI" + JNE notintel + CMPL CX, $0x6C65746E // "ntel" + JNE notintel + MOVB $1, runtime·isIntel(SB) + MOVB $1, runtime·lfenceBeforeRdtsc(SB) +notintel: + + // Load EAX=1 cpuid flags + MOVL $1, AX + CPUID + MOVL AX, runtime·processorVersionInfo(SB) + +nocpuinfo: + // if there is an _cgo_init, call it. + MOVQ _cgo_init(SB), AX + TESTQ AX, AX + JZ needtls + // arg 1: g0, already in DI + MOVQ $setg_gcc<>(SB), SI // arg 2: setg_gcc +#ifdef GOOS_android + MOVQ $runtime·tls_g(SB), DX // arg 3: &tls_g + // arg 4: TLS base, stored in slot 0 (Android's TLS_SLOT_SELF). + // Compensate for tls_g (+16). + MOVQ -16(TLS), CX +#else + MOVQ $0, DX // arg 3, 4: not used when using platform's TLS + MOVQ $0, CX +#endif +#ifdef GOOS_windows + // Adjust for the Win64 calling convention. + MOVQ CX, R9 // arg 4 + MOVQ DX, R8 // arg 3 + MOVQ SI, DX // arg 2 + MOVQ DI, CX // arg 1 +#endif + CALL AX + + // update stackguard after _cgo_init + MOVQ $runtime·g0(SB), CX + MOVQ (g_stack+stack_lo)(CX), AX + ADDQ $const__StackGuard, AX + MOVQ AX, g_stackguard0(CX) + MOVQ AX, g_stackguard1(CX) + +#ifndef GOOS_windows + JMP ok +#endif +needtls: +#ifdef GOOS_plan9 + // skip TLS setup on Plan 9 + JMP ok +#endif +#ifdef GOOS_solaris + // skip TLS setup on Solaris + JMP ok +#endif +#ifdef GOOS_illumos + // skip TLS setup on illumos + JMP ok +#endif +#ifdef GOOS_darwin + // skip TLS setup on Darwin + JMP ok +#endif +#ifdef GOOS_openbsd + // skip TLS setup on OpenBSD + JMP ok +#endif + + LEAQ runtime·m0+m_tls(SB), DI + CALL runtime·settls(SB) + + // store through it, to make sure it works + get_tls(BX) + MOVQ $0x123, g(BX) + MOVQ runtime·m0+m_tls(SB), AX + CMPQ AX, $0x123 + JEQ 2(PC) + CALL runtime·abort(SB) +ok: + // set the per-goroutine and per-mach "registers" + get_tls(BX) + LEAQ runtime·g0(SB), CX + MOVQ CX, g(BX) + LEAQ runtime·m0(SB), AX + + // save m->g0 = g0 + MOVQ CX, m_g0(AX) + // save m0 to g0->m + MOVQ AX, g_m(CX) + + CLD // convention is D is always left cleared + CALL runtime·check(SB) + + MOVL 16(SP), AX // copy argc + MOVL AX, 0(SP) + MOVQ 24(SP), AX // copy argv + MOVQ AX, 8(SP) + CALL runtime·args(SB) + CALL runtime·osinit(SB) + CALL runtime·schedinit(SB) + + // create a new goroutine to start program + MOVQ $runtime·mainPC(SB), AX // entry + PUSHQ AX + PUSHQ $0 // arg size + CALL runtime·newproc(SB) + POPQ AX + POPQ AX + + // start this M + CALL runtime·mstart(SB) + + CALL runtime·abort(SB) // mstart should never return + RET + + // Prevent dead-code elimination of debugCallV1, which is + // intended to be called by debuggers. + MOVQ $runtime·debugCallV1<ABIInternal>(SB), AX + RET + +// mainPC is a function value for runtime.main, to be passed to newproc. +// The reference to runtime.main is made via ABIInternal, since the +// actual function (not the ABI0 wrapper) is needed by newproc. +DATA runtime·mainPC+0(SB)/8,$runtime·main<ABIInternal>(SB) +GLOBL runtime·mainPC(SB),RODATA,$8 + +TEXT runtime·breakpoint(SB),NOSPLIT,$0-0 + BYTE $0xcc + RET + +TEXT runtime·asminit(SB),NOSPLIT,$0-0 + // No per-thread init. + RET + +/* + * go-routine + */ + +// func gosave(buf *gobuf) +// save state in Gobuf; setjmp +TEXT runtime·gosave(SB), NOSPLIT, $0-8 + MOVQ buf+0(FP), AX // gobuf + LEAQ buf+0(FP), BX // caller's SP + MOVQ BX, gobuf_sp(AX) + MOVQ 0(SP), BX // caller's PC + MOVQ BX, gobuf_pc(AX) + MOVQ $0, gobuf_ret(AX) + MOVQ BP, gobuf_bp(AX) + // Assert ctxt is zero. See func save. + MOVQ gobuf_ctxt(AX), BX + TESTQ BX, BX + JZ 2(PC) + CALL runtime·badctxt(SB) + get_tls(CX) + MOVQ g(CX), BX + MOVQ BX, gobuf_g(AX) + RET + +// func gogo(buf *gobuf) +// restore state from Gobuf; longjmp +TEXT runtime·gogo(SB), NOSPLIT, $16-8 + MOVQ buf+0(FP), BX // gobuf + MOVQ gobuf_g(BX), DX + MOVQ 0(DX), CX // make sure g != nil + get_tls(CX) + MOVQ DX, g(CX) + MOVQ gobuf_sp(BX), SP // restore SP + MOVQ gobuf_ret(BX), AX + MOVQ gobuf_ctxt(BX), DX + MOVQ gobuf_bp(BX), BP + MOVQ $0, gobuf_sp(BX) // clear to help garbage collector + MOVQ $0, gobuf_ret(BX) + MOVQ $0, gobuf_ctxt(BX) + MOVQ $0, gobuf_bp(BX) + MOVQ gobuf_pc(BX), BX + JMP BX + +// func mcall(fn func(*g)) +// Switch to m->g0's stack, call fn(g). +// Fn must never return. It should gogo(&g->sched) +// to keep running g. +TEXT runtime·mcall(SB), NOSPLIT, $0-8 + MOVQ fn+0(FP), DI + + get_tls(CX) + MOVQ g(CX), AX // save state in g->sched + MOVQ 0(SP), BX // caller's PC + MOVQ BX, (g_sched+gobuf_pc)(AX) + LEAQ fn+0(FP), BX // caller's SP + MOVQ BX, (g_sched+gobuf_sp)(AX) + MOVQ AX, (g_sched+gobuf_g)(AX) + MOVQ BP, (g_sched+gobuf_bp)(AX) + + // switch to m->g0 & its stack, call fn + MOVQ g(CX), BX + MOVQ g_m(BX), BX + MOVQ m_g0(BX), SI + CMPQ SI, AX // if g == m->g0 call badmcall + JNE 3(PC) + MOVQ $runtime·badmcall(SB), AX + JMP AX + MOVQ SI, g(CX) // g = m->g0 + MOVQ (g_sched+gobuf_sp)(SI), SP // sp = m->g0->sched.sp + PUSHQ AX + MOVQ DI, DX + MOVQ 0(DI), DI + CALL DI + POPQ AX + MOVQ $runtime·badmcall2(SB), AX + JMP AX + RET + +// systemstack_switch is a dummy routine that systemstack leaves at the bottom +// of the G stack. We need to distinguish the routine that +// lives at the bottom of the G stack from the one that lives +// at the top of the system stack because the one at the top of +// the system stack terminates the stack walk (see topofstack()). +TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0 + RET + +// func systemstack(fn func()) +TEXT runtime·systemstack(SB), NOSPLIT, $0-8 + MOVQ fn+0(FP), DI // DI = fn + get_tls(CX) + MOVQ g(CX), AX // AX = g + MOVQ g_m(AX), BX // BX = m + + CMPQ AX, m_gsignal(BX) + JEQ noswitch + + MOVQ m_g0(BX), DX // DX = g0 + CMPQ AX, DX + JEQ noswitch + + CMPQ AX, m_curg(BX) + JNE bad + + // switch stacks + // save our state in g->sched. Pretend to + // be systemstack_switch if the G stack is scanned. + MOVQ $runtime·systemstack_switch(SB), SI + MOVQ SI, (g_sched+gobuf_pc)(AX) + MOVQ SP, (g_sched+gobuf_sp)(AX) + MOVQ AX, (g_sched+gobuf_g)(AX) + MOVQ BP, (g_sched+gobuf_bp)(AX) + + // switch to g0 + MOVQ DX, g(CX) + MOVQ (g_sched+gobuf_sp)(DX), BX + // make it look like mstart called systemstack on g0, to stop traceback + SUBQ $8, BX + MOVQ $runtime·mstart(SB), DX + MOVQ DX, 0(BX) + MOVQ BX, SP + + // call target function + MOVQ DI, DX + MOVQ 0(DI), DI + CALL DI + + // switch back to g + get_tls(CX) + MOVQ g(CX), AX + MOVQ g_m(AX), BX + MOVQ m_curg(BX), AX + MOVQ AX, g(CX) + MOVQ (g_sched+gobuf_sp)(AX), SP + MOVQ $0, (g_sched+gobuf_sp)(AX) + RET + +noswitch: + // already on m stack; tail call the function + // Using a tail call here cleans up tracebacks since we won't stop + // at an intermediate systemstack. + MOVQ DI, DX + MOVQ 0(DI), DI + JMP DI + +bad: + // Bad: g is not gsignal, not g0, not curg. What is it? + MOVQ $runtime·badsystemstack(SB), AX + CALL AX + INT $3 + + +/* + * support for morestack + */ + +// Called during function prolog when more stack is needed. +// +// The traceback routines see morestack on a g0 as being +// the top of a stack (for example, morestack calling newstack +// calling the scheduler calling newm calling gc), so we must +// record an argument size. For that purpose, it has no arguments. +TEXT runtime·morestack(SB),NOSPLIT,$0-0 + // Cannot grow scheduler stack (m->g0). + get_tls(CX) + MOVQ g(CX), BX + MOVQ g_m(BX), BX + MOVQ m_g0(BX), SI + CMPQ g(CX), SI + JNE 3(PC) + CALL runtime·badmorestackg0(SB) + CALL runtime·abort(SB) + + // Cannot grow signal stack (m->gsignal). + MOVQ m_gsignal(BX), SI + CMPQ g(CX), SI + JNE 3(PC) + CALL runtime·badmorestackgsignal(SB) + CALL runtime·abort(SB) + + // Called from f. + // Set m->morebuf to f's caller. + NOP SP // tell vet SP changed - stop checking offsets + MOVQ 8(SP), AX // f's caller's PC + MOVQ AX, (m_morebuf+gobuf_pc)(BX) + LEAQ 16(SP), AX // f's caller's SP + MOVQ AX, (m_morebuf+gobuf_sp)(BX) + get_tls(CX) + MOVQ g(CX), SI + MOVQ SI, (m_morebuf+gobuf_g)(BX) + + // Set g->sched to context in f. + MOVQ 0(SP), AX // f's PC + MOVQ AX, (g_sched+gobuf_pc)(SI) + MOVQ SI, (g_sched+gobuf_g)(SI) + LEAQ 8(SP), AX // f's SP + MOVQ AX, (g_sched+gobuf_sp)(SI) + MOVQ BP, (g_sched+gobuf_bp)(SI) + MOVQ DX, (g_sched+gobuf_ctxt)(SI) + + // Call newstack on m->g0's stack. + MOVQ m_g0(BX), BX + MOVQ BX, g(CX) + MOVQ (g_sched+gobuf_sp)(BX), SP + CALL runtime·newstack(SB) + CALL runtime·abort(SB) // crash if newstack returns + RET + +// morestack but not preserving ctxt. +TEXT runtime·morestack_noctxt(SB),NOSPLIT,$0 + MOVL $0, DX + JMP runtime·morestack(SB) + +// reflectcall: call a function with the given argument list +// func call(argtype *_type, f *FuncVal, arg *byte, argsize, retoffset uint32). +// we don't have variable-sized frames, so we use a small number +// of constant-sized-frame functions to encode a few bits of size in the pc. +// Caution: ugly multiline assembly macros in your future! + +#define DISPATCH(NAME,MAXSIZE) \ + CMPQ CX, $MAXSIZE; \ + JA 3(PC); \ + MOVQ $NAME(SB), AX; \ + JMP AX +// Note: can't just "JMP NAME(SB)" - bad inlining results. + +TEXT ·reflectcall<ABIInternal>(SB), NOSPLIT, $0-32 + MOVLQZX argsize+24(FP), CX + DISPATCH(runtime·call16, 16) + DISPATCH(runtime·call32, 32) + DISPATCH(runtime·call64, 64) + DISPATCH(runtime·call128, 128) + DISPATCH(runtime·call256, 256) + DISPATCH(runtime·call512, 512) + DISPATCH(runtime·call1024, 1024) + DISPATCH(runtime·call2048, 2048) + DISPATCH(runtime·call4096, 4096) + DISPATCH(runtime·call8192, 8192) + DISPATCH(runtime·call16384, 16384) + DISPATCH(runtime·call32768, 32768) + DISPATCH(runtime·call65536, 65536) + DISPATCH(runtime·call131072, 131072) + DISPATCH(runtime·call262144, 262144) + DISPATCH(runtime·call524288, 524288) + DISPATCH(runtime·call1048576, 1048576) + DISPATCH(runtime·call2097152, 2097152) + DISPATCH(runtime·call4194304, 4194304) + DISPATCH(runtime·call8388608, 8388608) + DISPATCH(runtime·call16777216, 16777216) + DISPATCH(runtime·call33554432, 33554432) + DISPATCH(runtime·call67108864, 67108864) + DISPATCH(runtime·call134217728, 134217728) + DISPATCH(runtime·call268435456, 268435456) + DISPATCH(runtime·call536870912, 536870912) + DISPATCH(runtime·call1073741824, 1073741824) + MOVQ $runtime·badreflectcall(SB), AX + JMP AX + +#define CALLFN(NAME,MAXSIZE) \ +TEXT NAME(SB), WRAPPER, $MAXSIZE-32; \ + NO_LOCAL_POINTERS; \ + /* copy arguments to stack */ \ + MOVQ argptr+16(FP), SI; \ + MOVLQZX argsize+24(FP), CX; \ + MOVQ SP, DI; \ + REP;MOVSB; \ + /* call function */ \ + MOVQ f+8(FP), DX; \ + PCDATA $PCDATA_StackMapIndex, $0; \ + MOVQ (DX), AX; \ + CALL AX; \ + /* copy return values back */ \ + MOVQ argtype+0(FP), DX; \ + MOVQ argptr+16(FP), DI; \ + MOVLQZX argsize+24(FP), CX; \ + MOVLQZX retoffset+28(FP), BX; \ + MOVQ SP, SI; \ + ADDQ BX, DI; \ + ADDQ BX, SI; \ + SUBQ BX, CX; \ + CALL callRet<>(SB); \ + RET + +// callRet copies return values back at the end of call*. This is a +// separate function so it can allocate stack space for the arguments +// to reflectcallmove. It does not follow the Go ABI; it expects its +// arguments in registers. +TEXT callRet<>(SB), NOSPLIT, $32-0 + NO_LOCAL_POINTERS + MOVQ DX, 0(SP) + MOVQ DI, 8(SP) + MOVQ SI, 16(SP) + MOVQ CX, 24(SP) + CALL runtime·reflectcallmove(SB) + RET + +CALLFN(·call16, 16) +CALLFN(·call32, 32) +CALLFN(·call64, 64) +CALLFN(·call128, 128) +CALLFN(·call256, 256) +CALLFN(·call512, 512) +CALLFN(·call1024, 1024) +CALLFN(·call2048, 2048) +CALLFN(·call4096, 4096) +CALLFN(·call8192, 8192) +CALLFN(·call16384, 16384) +CALLFN(·call32768, 32768) +CALLFN(·call65536, 65536) +CALLFN(·call131072, 131072) +CALLFN(·call262144, 262144) +CALLFN(·call524288, 524288) +CALLFN(·call1048576, 1048576) +CALLFN(·call2097152, 2097152) +CALLFN(·call4194304, 4194304) +CALLFN(·call8388608, 8388608) +CALLFN(·call16777216, 16777216) +CALLFN(·call33554432, 33554432) +CALLFN(·call67108864, 67108864) +CALLFN(·call134217728, 134217728) +CALLFN(·call268435456, 268435456) +CALLFN(·call536870912, 536870912) +CALLFN(·call1073741824, 1073741824) + +TEXT runtime·procyield(SB),NOSPLIT,$0-0 + MOVL cycles+0(FP), AX +again: + PAUSE + SUBL $1, AX + JNZ again + RET + + +TEXT ·publicationBarrier(SB),NOSPLIT,$0-0 + // Stores are already ordered on x86, so this is just a + // compile barrier. + RET + +// func jmpdefer(fv *funcval, argp uintptr) +// argp is a caller SP. +// called from deferreturn. +// 1. pop the caller +// 2. sub 5 bytes from the callers return +// 3. jmp to the argument +TEXT runtime·jmpdefer(SB), NOSPLIT, $0-16 + MOVQ fv+0(FP), DX // fn + MOVQ argp+8(FP), BX // caller sp + LEAQ -8(BX), SP // caller sp after CALL + MOVQ -8(SP), BP // restore BP as if deferreturn returned (harmless if framepointers not in use) + SUBQ $5, (SP) // return to CALL again + MOVQ 0(DX), BX + JMP BX // but first run the deferred function + +// Save state of caller into g->sched. Smashes R8, R9. +TEXT gosave<>(SB),NOSPLIT,$0 + get_tls(R8) + MOVQ g(R8), R8 + MOVQ 0(SP), R9 + MOVQ R9, (g_sched+gobuf_pc)(R8) + LEAQ 8(SP), R9 + MOVQ R9, (g_sched+gobuf_sp)(R8) + MOVQ $0, (g_sched+gobuf_ret)(R8) + MOVQ BP, (g_sched+gobuf_bp)(R8) + // Assert ctxt is zero. See func save. + MOVQ (g_sched+gobuf_ctxt)(R8), R9 + TESTQ R9, R9 + JZ 2(PC) + CALL runtime·badctxt(SB) + RET + +// func asmcgocall(fn, arg unsafe.Pointer) int32 +// Call fn(arg) on the scheduler stack, +// aligned appropriately for the gcc ABI. +// See cgocall.go for more details. +TEXT ·asmcgocall(SB),NOSPLIT,$0-20 + MOVQ fn+0(FP), AX + MOVQ arg+8(FP), BX + + MOVQ SP, DX + + // Figure out if we need to switch to m->g0 stack. + // We get called to create new OS threads too, and those + // come in on the m->g0 stack already. + get_tls(CX) + MOVQ g(CX), R8 + CMPQ R8, $0 + JEQ nosave + MOVQ g_m(R8), R8 + MOVQ m_g0(R8), SI + MOVQ g(CX), DI + CMPQ SI, DI + JEQ nosave + MOVQ m_gsignal(R8), SI + CMPQ SI, DI + JEQ nosave + + // Switch to system stack. + MOVQ m_g0(R8), SI + CALL gosave<>(SB) + MOVQ SI, g(CX) + MOVQ (g_sched+gobuf_sp)(SI), SP + + // Now on a scheduling stack (a pthread-created stack). + // Make sure we have enough room for 4 stack-backed fast-call + // registers as per windows amd64 calling convention. + SUBQ $64, SP + ANDQ $~15, SP // alignment for gcc ABI + MOVQ DI, 48(SP) // save g + MOVQ (g_stack+stack_hi)(DI), DI + SUBQ DX, DI + MOVQ DI, 40(SP) // save depth in stack (can't just save SP, as stack might be copied during a callback) + MOVQ BX, DI // DI = first argument in AMD64 ABI + MOVQ BX, CX // CX = first argument in Win64 + CALL AX + + // Restore registers, g, stack pointer. + get_tls(CX) + MOVQ 48(SP), DI + MOVQ (g_stack+stack_hi)(DI), SI + SUBQ 40(SP), SI + MOVQ DI, g(CX) + MOVQ SI, SP + + MOVL AX, ret+16(FP) + RET + +nosave: + // Running on a system stack, perhaps even without a g. + // Having no g can happen during thread creation or thread teardown + // (see needm/dropm on Solaris, for example). + // This code is like the above sequence but without saving/restoring g + // and without worrying about the stack moving out from under us + // (because we're on a system stack, not a goroutine stack). + // The above code could be used directly if already on a system stack, + // but then the only path through this code would be a rare case on Solaris. + // Using this code for all "already on system stack" calls exercises it more, + // which should help keep it correct. + SUBQ $64, SP + ANDQ $~15, SP + MOVQ $0, 48(SP) // where above code stores g, in case someone looks during debugging + MOVQ DX, 40(SP) // save original stack pointer + MOVQ BX, DI // DI = first argument in AMD64 ABI + MOVQ BX, CX // CX = first argument in Win64 + CALL AX + MOVQ 40(SP), SI // restore original stack pointer + MOVQ SI, SP + MOVL AX, ret+16(FP) + RET + +// func cgocallback(fn, frame unsafe.Pointer, ctxt uintptr) +// See cgocall.go for more details. +TEXT ·cgocallback(SB),NOSPLIT,$24-24 + NO_LOCAL_POINTERS + + // If g is nil, Go did not create the current thread. + // Call needm to obtain one m for temporary use. + // In this case, we're running on the thread stack, so there's + // lots of space, but the linker doesn't know. Hide the call from + // the linker analysis by using an indirect call through AX. + get_tls(CX) +#ifdef GOOS_windows + MOVL $0, BX + CMPQ CX, $0 + JEQ 2(PC) +#endif + MOVQ g(CX), BX + CMPQ BX, $0 + JEQ needm + MOVQ g_m(BX), BX + MOVQ BX, savedm-8(SP) // saved copy of oldm + JMP havem +needm: + MOVQ $runtime·needm(SB), AX + CALL AX + MOVQ $0, savedm-8(SP) // dropm on return + get_tls(CX) + MOVQ g(CX), BX + MOVQ g_m(BX), BX + + // Set m->sched.sp = SP, so that if a panic happens + // during the function we are about to execute, it will + // have a valid SP to run on the g0 stack. + // The next few lines (after the havem label) + // will save this SP onto the stack and then write + // the same SP back to m->sched.sp. That seems redundant, + // but if an unrecovered panic happens, unwindm will + // restore the g->sched.sp from the stack location + // and then systemstack will try to use it. If we don't set it here, + // that restored SP will be uninitialized (typically 0) and + // will not be usable. + MOVQ m_g0(BX), SI + MOVQ SP, (g_sched+gobuf_sp)(SI) + +havem: + // Now there's a valid m, and we're running on its m->g0. + // Save current m->g0->sched.sp on stack and then set it to SP. + // Save current sp in m->g0->sched.sp in preparation for + // switch back to m->curg stack. + // NOTE: unwindm knows that the saved g->sched.sp is at 0(SP). + MOVQ m_g0(BX), SI + MOVQ (g_sched+gobuf_sp)(SI), AX + MOVQ AX, 0(SP) + MOVQ SP, (g_sched+gobuf_sp)(SI) + + // Switch to m->curg stack and call runtime.cgocallbackg. + // Because we are taking over the execution of m->curg + // but *not* resuming what had been running, we need to + // save that information (m->curg->sched) so we can restore it. + // We can restore m->curg->sched.sp easily, because calling + // runtime.cgocallbackg leaves SP unchanged upon return. + // To save m->curg->sched.pc, we push it onto the curg stack and + // open a frame the same size as cgocallback's g0 frame. + // Once we switch to the curg stack, the pushed PC will appear + // to be the return PC of cgocallback, so that the traceback + // will seamlessly trace back into the earlier calls. + MOVQ m_curg(BX), SI + MOVQ SI, g(CX) + MOVQ (g_sched+gobuf_sp)(SI), DI // prepare stack as DI + MOVQ (g_sched+gobuf_pc)(SI), BX + MOVQ BX, -8(DI) // "push" return PC on the g stack + // Gather our arguments into registers. + MOVQ fn+0(FP), BX + MOVQ frame+8(FP), CX + MOVQ ctxt+16(FP), DX + // Compute the size of the frame, including return PC and, if + // GOEXPERIMENT=framepointer, the saved base pointer + LEAQ fn+0(FP), AX + SUBQ SP, AX // AX is our actual frame size + SUBQ AX, DI // Allocate the same frame size on the g stack + MOVQ DI, SP + + MOVQ BX, 0(SP) + MOVQ CX, 8(SP) + MOVQ DX, 16(SP) + CALL runtime·cgocallbackg(SB) + + // Compute the size of the frame again. FP and SP have + // completely different values here than they did above, + // but only their difference matters. + LEAQ fn+0(FP), AX + SUBQ SP, AX + + // Restore g->sched (== m->curg->sched) from saved values. + get_tls(CX) + MOVQ g(CX), SI + MOVQ SP, DI + ADDQ AX, DI + MOVQ -8(DI), BX + MOVQ BX, (g_sched+gobuf_pc)(SI) + MOVQ DI, (g_sched+gobuf_sp)(SI) + + // Switch back to m->g0's stack and restore m->g0->sched.sp. + // (Unlike m->curg, the g0 goroutine never uses sched.pc, + // so we do not have to restore it.) + MOVQ g(CX), BX + MOVQ g_m(BX), BX + MOVQ m_g0(BX), SI + MOVQ SI, g(CX) + MOVQ (g_sched+gobuf_sp)(SI), SP + MOVQ 0(SP), AX + MOVQ AX, (g_sched+gobuf_sp)(SI) + + // If the m on entry was nil, we called needm above to borrow an m + // for the duration of the call. Since the call is over, return it with dropm. + MOVQ savedm-8(SP), BX + CMPQ BX, $0 + JNE 3(PC) + MOVQ $runtime·dropm(SB), AX + CALL AX + + // Done! + RET + +// func setg(gg *g) +// set g. for use by needm. +TEXT runtime·setg(SB), NOSPLIT, $0-8 + MOVQ gg+0(FP), BX +#ifdef GOOS_windows + CMPQ BX, $0 + JNE settls + MOVQ $0, 0x28(GS) + RET +settls: + MOVQ g_m(BX), AX + LEAQ m_tls(AX), AX + MOVQ AX, 0x28(GS) +#endif + get_tls(CX) + MOVQ BX, g(CX) + RET + +// void setg_gcc(G*); set g called from gcc. +TEXT setg_gcc<>(SB),NOSPLIT,$0 + get_tls(AX) + MOVQ DI, g(AX) + RET + +TEXT runtime·abort(SB),NOSPLIT,$0-0 + INT $3 +loop: + JMP loop + +// check that SP is in range [g->stack.lo, g->stack.hi) +TEXT runtime·stackcheck(SB), NOSPLIT, $0-0 + get_tls(CX) + MOVQ g(CX), AX + CMPQ (g_stack+stack_hi)(AX), SP + JHI 2(PC) + CALL runtime·abort(SB) + CMPQ SP, (g_stack+stack_lo)(AX) + JHI 2(PC) + CALL runtime·abort(SB) + RET + +// func cputicks() int64 +TEXT runtime·cputicks(SB),NOSPLIT,$0-0 + CMPB runtime·lfenceBeforeRdtsc(SB), $1 + JNE mfence + LFENCE + JMP done +mfence: + MFENCE +done: + RDTSC + SHLQ $32, DX + ADDQ DX, AX + MOVQ AX, ret+0(FP) + RET + +// func memhash(p unsafe.Pointer, h, s uintptr) uintptr +// hash function using AES hardware instructions +TEXT runtime·memhash(SB),NOSPLIT,$0-32 + CMPB runtime·useAeshash(SB), $0 + JEQ noaes + MOVQ p+0(FP), AX // ptr to data + MOVQ s+16(FP), CX // size + LEAQ ret+24(FP), DX + JMP aeshashbody<>(SB) +noaes: + JMP runtime·memhashFallback(SB) + +// func strhash(p unsafe.Pointer, h uintptr) uintptr +TEXT runtime·strhash(SB),NOSPLIT,$0-24 + CMPB runtime·useAeshash(SB), $0 + JEQ noaes + MOVQ p+0(FP), AX // ptr to string struct + MOVQ 8(AX), CX // length of string + MOVQ (AX), AX // string data + LEAQ ret+16(FP), DX + JMP aeshashbody<>(SB) +noaes: + JMP runtime·strhashFallback(SB) + +// AX: data +// CX: length +// DX: address to put return value +TEXT aeshashbody<>(SB),NOSPLIT,$0-0 + // Fill an SSE register with our seeds. + MOVQ h+8(FP), X0 // 64 bits of per-table hash seed + PINSRW $4, CX, X0 // 16 bits of length + PSHUFHW $0, X0, X0 // repeat length 4 times total + MOVO X0, X1 // save unscrambled seed + PXOR runtime·aeskeysched(SB), X0 // xor in per-process seed + AESENC X0, X0 // scramble seed + + CMPQ CX, $16 + JB aes0to15 + JE aes16 + CMPQ CX, $32 + JBE aes17to32 + CMPQ CX, $64 + JBE aes33to64 + CMPQ CX, $128 + JBE aes65to128 + JMP aes129plus + +aes0to15: + TESTQ CX, CX + JE aes0 + + ADDQ $16, AX + TESTW $0xff0, AX + JE endofpage + + // 16 bytes loaded at this address won't cross + // a page boundary, so we can load it directly. + MOVOU -16(AX), X1 + ADDQ CX, CX + MOVQ $masks<>(SB), AX + PAND (AX)(CX*8), X1 +final1: + PXOR X0, X1 // xor data with seed + AESENC X1, X1 // scramble combo 3 times + AESENC X1, X1 + AESENC X1, X1 + MOVQ X1, (DX) + RET + +endofpage: + // address ends in 1111xxxx. Might be up against + // a page boundary, so load ending at last byte. + // Then shift bytes down using pshufb. + MOVOU -32(AX)(CX*1), X1 + ADDQ CX, CX + MOVQ $shifts<>(SB), AX + PSHUFB (AX)(CX*8), X1 + JMP final1 + +aes0: + // Return scrambled input seed + AESENC X0, X0 + MOVQ X0, (DX) + RET + +aes16: + MOVOU (AX), X1 + JMP final1 + +aes17to32: + // make second starting seed + PXOR runtime·aeskeysched+16(SB), X1 + AESENC X1, X1 + + // load data to be hashed + MOVOU (AX), X2 + MOVOU -16(AX)(CX*1), X3 + + // xor with seed + PXOR X0, X2 + PXOR X1, X3 + + // scramble 3 times + AESENC X2, X2 + AESENC X3, X3 + AESENC X2, X2 + AESENC X3, X3 + AESENC X2, X2 + AESENC X3, X3 + + // combine results + PXOR X3, X2 + MOVQ X2, (DX) + RET + +aes33to64: + // make 3 more starting seeds + MOVO X1, X2 + MOVO X1, X3 + PXOR runtime·aeskeysched+16(SB), X1 + PXOR runtime·aeskeysched+32(SB), X2 + PXOR runtime·aeskeysched+48(SB), X3 + AESENC X1, X1 + AESENC X2, X2 + AESENC X3, X3 + + MOVOU (AX), X4 + MOVOU 16(AX), X5 + MOVOU -32(AX)(CX*1), X6 + MOVOU -16(AX)(CX*1), X7 + + PXOR X0, X4 + PXOR X1, X5 + PXOR X2, X6 + PXOR X3, X7 + + AESENC X4, X4 + AESENC X5, X5 + AESENC X6, X6 + AESENC X7, X7 + + AESENC X4, X4 + AESENC X5, X5 + AESENC X6, X6 + AESENC X7, X7 + + AESENC X4, X4 + AESENC X5, X5 + AESENC X6, X6 + AESENC X7, X7 + + PXOR X6, X4 + PXOR X7, X5 + PXOR X5, X4 + MOVQ X4, (DX) + RET + +aes65to128: + // make 7 more starting seeds + MOVO X1, X2 + MOVO X1, X3 + MOVO X1, X4 + MOVO X1, X5 + MOVO X1, X6 + MOVO X1, X7 + PXOR runtime·aeskeysched+16(SB), X1 + PXOR runtime·aeskeysched+32(SB), X2 + PXOR runtime·aeskeysched+48(SB), X3 + PXOR runtime·aeskeysched+64(SB), X4 + PXOR runtime·aeskeysched+80(SB), X5 + PXOR runtime·aeskeysched+96(SB), X6 + PXOR runtime·aeskeysched+112(SB), X7 + AESENC X1, X1 + AESENC X2, X2 + AESENC X3, X3 + AESENC X4, X4 + AESENC X5, X5 + AESENC X6, X6 + AESENC X7, X7 + + // load data + MOVOU (AX), X8 + MOVOU 16(AX), X9 + MOVOU 32(AX), X10 + MOVOU 48(AX), X11 + MOVOU -64(AX)(CX*1), X12 + MOVOU -48(AX)(CX*1), X13 + MOVOU -32(AX)(CX*1), X14 + MOVOU -16(AX)(CX*1), X15 + + // xor with seed + PXOR X0, X8 + PXOR X1, X9 + PXOR X2, X10 + PXOR X3, X11 + PXOR X4, X12 + PXOR X5, X13 + PXOR X6, X14 + PXOR X7, X15 + + // scramble 3 times + AESENC X8, X8 + AESENC X9, X9 + AESENC X10, X10 + AESENC X11, X11 + AESENC X12, X12 + AESENC X13, X13 + AESENC X14, X14 + AESENC X15, X15 + + AESENC X8, X8 + AESENC X9, X9 + AESENC X10, X10 + AESENC X11, X11 + AESENC X12, X12 + AESENC X13, X13 + AESENC X14, X14 + AESENC X15, X15 + + AESENC X8, X8 + AESENC X9, X9 + AESENC X10, X10 + AESENC X11, X11 + AESENC X12, X12 + AESENC X13, X13 + AESENC X14, X14 + AESENC X15, X15 + + // combine results + PXOR X12, X8 + PXOR X13, X9 + PXOR X14, X10 + PXOR X15, X11 + PXOR X10, X8 + PXOR X11, X9 + PXOR X9, X8 + MOVQ X8, (DX) + RET + +aes129plus: + // make 7 more starting seeds + MOVO X1, X2 + MOVO X1, X3 + MOVO X1, X4 + MOVO X1, X5 + MOVO X1, X6 + MOVO X1, X7 + PXOR runtime·aeskeysched+16(SB), X1 + PXOR runtime·aeskeysched+32(SB), X2 + PXOR runtime·aeskeysched+48(SB), X3 + PXOR runtime·aeskeysched+64(SB), X4 + PXOR runtime·aeskeysched+80(SB), X5 + PXOR runtime·aeskeysched+96(SB), X6 + PXOR runtime·aeskeysched+112(SB), X7 + AESENC X1, X1 + AESENC X2, X2 + AESENC X3, X3 + AESENC X4, X4 + AESENC X5, X5 + AESENC X6, X6 + AESENC X7, X7 + + // start with last (possibly overlapping) block + MOVOU -128(AX)(CX*1), X8 + MOVOU -112(AX)(CX*1), X9 + MOVOU -96(AX)(CX*1), X10 + MOVOU -80(AX)(CX*1), X11 + MOVOU -64(AX)(CX*1), X12 + MOVOU -48(AX)(CX*1), X13 + MOVOU -32(AX)(CX*1), X14 + MOVOU -16(AX)(CX*1), X15 + + // xor in seed + PXOR X0, X8 + PXOR X1, X9 + PXOR X2, X10 + PXOR X3, X11 + PXOR X4, X12 + PXOR X5, X13 + PXOR X6, X14 + PXOR X7, X15 + + // compute number of remaining 128-byte blocks + DECQ CX + SHRQ $7, CX + +aesloop: + // scramble state + AESENC X8, X8 + AESENC X9, X9 + AESENC X10, X10 + AESENC X11, X11 + AESENC X12, X12 + AESENC X13, X13 + AESENC X14, X14 + AESENC X15, X15 + + // scramble state, xor in a block + MOVOU (AX), X0 + MOVOU 16(AX), X1 + MOVOU 32(AX), X2 + MOVOU 48(AX), X3 + AESENC X0, X8 + AESENC X1, X9 + AESENC X2, X10 + AESENC X3, X11 + MOVOU 64(AX), X4 + MOVOU 80(AX), X5 + MOVOU 96(AX), X6 + MOVOU 112(AX), X7 + AESENC X4, X12 + AESENC X5, X13 + AESENC X6, X14 + AESENC X7, X15 + + ADDQ $128, AX + DECQ CX + JNE aesloop + + // 3 more scrambles to finish + AESENC X8, X8 + AESENC X9, X9 + AESENC X10, X10 + AESENC X11, X11 + AESENC X12, X12 + AESENC X13, X13 + AESENC X14, X14 + AESENC X15, X15 + AESENC X8, X8 + AESENC X9, X9 + AESENC X10, X10 + AESENC X11, X11 + AESENC X12, X12 + AESENC X13, X13 + AESENC X14, X14 + AESENC X15, X15 + AESENC X8, X8 + AESENC X9, X9 + AESENC X10, X10 + AESENC X11, X11 + AESENC X12, X12 + AESENC X13, X13 + AESENC X14, X14 + AESENC X15, X15 + + PXOR X12, X8 + PXOR X13, X9 + PXOR X14, X10 + PXOR X15, X11 + PXOR X10, X8 + PXOR X11, X9 + PXOR X9, X8 + MOVQ X8, (DX) + RET + +// func memhash32(p unsafe.Pointer, h uintptr) uintptr +TEXT runtime·memhash32(SB),NOSPLIT,$0-24 + CMPB runtime·useAeshash(SB), $0 + JEQ noaes + MOVQ p+0(FP), AX // ptr to data + MOVQ h+8(FP), X0 // seed + PINSRD $2, (AX), X0 // data + AESENC runtime·aeskeysched+0(SB), X0 + AESENC runtime·aeskeysched+16(SB), X0 + AESENC runtime·aeskeysched+32(SB), X0 + MOVQ X0, ret+16(FP) + RET +noaes: + JMP runtime·memhash32Fallback(SB) + +// func memhash64(p unsafe.Pointer, h uintptr) uintptr +TEXT runtime·memhash64(SB),NOSPLIT,$0-24 + CMPB runtime·useAeshash(SB), $0 + JEQ noaes + MOVQ p+0(FP), AX // ptr to data + MOVQ h+8(FP), X0 // seed + PINSRQ $1, (AX), X0 // data + AESENC runtime·aeskeysched+0(SB), X0 + AESENC runtime·aeskeysched+16(SB), X0 + AESENC runtime·aeskeysched+32(SB), X0 + MOVQ X0, ret+16(FP) + RET +noaes: + JMP runtime·memhash64Fallback(SB) + +// simple mask to get rid of data in the high part of the register. +DATA masks<>+0x00(SB)/8, $0x0000000000000000 +DATA masks<>+0x08(SB)/8, $0x0000000000000000 +DATA masks<>+0x10(SB)/8, $0x00000000000000ff +DATA masks<>+0x18(SB)/8, $0x0000000000000000 +DATA masks<>+0x20(SB)/8, $0x000000000000ffff +DATA masks<>+0x28(SB)/8, $0x0000000000000000 +DATA masks<>+0x30(SB)/8, $0x0000000000ffffff +DATA masks<>+0x38(SB)/8, $0x0000000000000000 +DATA masks<>+0x40(SB)/8, $0x00000000ffffffff +DATA masks<>+0x48(SB)/8, $0x0000000000000000 +DATA masks<>+0x50(SB)/8, $0x000000ffffffffff +DATA masks<>+0x58(SB)/8, $0x0000000000000000 +DATA masks<>+0x60(SB)/8, $0x0000ffffffffffff +DATA masks<>+0x68(SB)/8, $0x0000000000000000 +DATA masks<>+0x70(SB)/8, $0x00ffffffffffffff +DATA masks<>+0x78(SB)/8, $0x0000000000000000 +DATA masks<>+0x80(SB)/8, $0xffffffffffffffff +DATA masks<>+0x88(SB)/8, $0x0000000000000000 +DATA masks<>+0x90(SB)/8, $0xffffffffffffffff +DATA masks<>+0x98(SB)/8, $0x00000000000000ff +DATA masks<>+0xa0(SB)/8, $0xffffffffffffffff +DATA masks<>+0xa8(SB)/8, $0x000000000000ffff +DATA masks<>+0xb0(SB)/8, $0xffffffffffffffff +DATA masks<>+0xb8(SB)/8, $0x0000000000ffffff +DATA masks<>+0xc0(SB)/8, $0xffffffffffffffff +DATA masks<>+0xc8(SB)/8, $0x00000000ffffffff +DATA masks<>+0xd0(SB)/8, $0xffffffffffffffff +DATA masks<>+0xd8(SB)/8, $0x000000ffffffffff +DATA masks<>+0xe0(SB)/8, $0xffffffffffffffff +DATA masks<>+0xe8(SB)/8, $0x0000ffffffffffff +DATA masks<>+0xf0(SB)/8, $0xffffffffffffffff +DATA masks<>+0xf8(SB)/8, $0x00ffffffffffffff +GLOBL masks<>(SB),RODATA,$256 + +// func checkASM() bool +TEXT ·checkASM(SB),NOSPLIT,$0-1 + // check that masks<>(SB) and shifts<>(SB) are aligned to 16-byte + MOVQ $masks<>(SB), AX + MOVQ $shifts<>(SB), BX + ORQ BX, AX + TESTQ $15, AX + SETEQ ret+0(FP) + RET + +// these are arguments to pshufb. They move data down from +// the high bytes of the register to the low bytes of the register. +// index is how many bytes to move. +DATA shifts<>+0x00(SB)/8, $0x0000000000000000 +DATA shifts<>+0x08(SB)/8, $0x0000000000000000 +DATA shifts<>+0x10(SB)/8, $0xffffffffffffff0f +DATA shifts<>+0x18(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x20(SB)/8, $0xffffffffffff0f0e +DATA shifts<>+0x28(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x30(SB)/8, $0xffffffffff0f0e0d +DATA shifts<>+0x38(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x40(SB)/8, $0xffffffff0f0e0d0c +DATA shifts<>+0x48(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x50(SB)/8, $0xffffff0f0e0d0c0b +DATA shifts<>+0x58(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x60(SB)/8, $0xffff0f0e0d0c0b0a +DATA shifts<>+0x68(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x70(SB)/8, $0xff0f0e0d0c0b0a09 +DATA shifts<>+0x78(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x80(SB)/8, $0x0f0e0d0c0b0a0908 +DATA shifts<>+0x88(SB)/8, $0xffffffffffffffff +DATA shifts<>+0x90(SB)/8, $0x0e0d0c0b0a090807 +DATA shifts<>+0x98(SB)/8, $0xffffffffffffff0f +DATA shifts<>+0xa0(SB)/8, $0x0d0c0b0a09080706 +DATA shifts<>+0xa8(SB)/8, $0xffffffffffff0f0e +DATA shifts<>+0xb0(SB)/8, $0x0c0b0a0908070605 +DATA shifts<>+0xb8(SB)/8, $0xffffffffff0f0e0d +DATA shifts<>+0xc0(SB)/8, $0x0b0a090807060504 +DATA shifts<>+0xc8(SB)/8, $0xffffffff0f0e0d0c +DATA shifts<>+0xd0(SB)/8, $0x0a09080706050403 +DATA shifts<>+0xd8(SB)/8, $0xffffff0f0e0d0c0b +DATA shifts<>+0xe0(SB)/8, $0x0908070605040302 +DATA shifts<>+0xe8(SB)/8, $0xffff0f0e0d0c0b0a +DATA shifts<>+0xf0(SB)/8, $0x0807060504030201 +DATA shifts<>+0xf8(SB)/8, $0xff0f0e0d0c0b0a09 +GLOBL shifts<>(SB),RODATA,$256 + +TEXT runtime·return0(SB), NOSPLIT, $0 + MOVL $0, AX + RET + + +// Called from cgo wrappers, this function returns g->m->curg.stack.hi. +// Must obey the gcc calling convention. +TEXT _cgo_topofstack(SB),NOSPLIT,$0 + get_tls(CX) + MOVQ g(CX), AX + MOVQ g_m(AX), AX + MOVQ m_curg(AX), AX + MOVQ (g_stack+stack_hi)(AX), AX + RET + +// The top-most function running on a goroutine +// returns to goexit+PCQuantum. Defined as ABIInternal +// so as to make it identifiable to traceback (this +// function it used as a sentinel; traceback wants to +// see the func PC, not a wrapper PC). +TEXT runtime·goexit<ABIInternal>(SB),NOSPLIT,$0-0 + BYTE $0x90 // NOP + CALL runtime·goexit1(SB) // does not return + // traceback from goexit1 must hit code range of goexit + BYTE $0x90 // NOP + +// This is called from .init_array and follows the platform, not Go, ABI. +TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0 + PUSHQ R15 // The access to global variables below implicitly uses R15, which is callee-save + MOVQ runtime·lastmoduledatap(SB), AX + MOVQ DI, moduledata_next(AX) + MOVQ DI, runtime·lastmoduledatap(SB) + POPQ R15 + RET + +// gcWriteBarrier performs a heap pointer write and informs the GC. +// +// gcWriteBarrier does NOT follow the Go ABI. It takes two arguments: +// - DI is the destination of the write +// - AX is the value being written at DI +// It clobbers FLAGS. It does not clobber any general-purpose registers, +// but may clobber others (e.g., SSE registers). +// Defined as ABIInternal since it does not use the stack-based Go ABI. +TEXT runtime·gcWriteBarrier<ABIInternal>(SB),NOSPLIT,$120 + // Save the registers clobbered by the fast path. This is slightly + // faster than having the caller spill these. + MOVQ R14, 104(SP) + MOVQ R13, 112(SP) + // TODO: Consider passing g.m.p in as an argument so they can be shared + // across a sequence of write barriers. + get_tls(R13) + MOVQ g(R13), R13 + MOVQ g_m(R13), R13 + MOVQ m_p(R13), R13 + MOVQ (p_wbBuf+wbBuf_next)(R13), R14 + // Increment wbBuf.next position. + LEAQ 16(R14), R14 + MOVQ R14, (p_wbBuf+wbBuf_next)(R13) + CMPQ R14, (p_wbBuf+wbBuf_end)(R13) + // Record the write. + MOVQ AX, -16(R14) // Record value + // Note: This turns bad pointer writes into bad + // pointer reads, which could be confusing. We could avoid + // reading from obviously bad pointers, which would + // take care of the vast majority of these. We could + // patch this up in the signal handler, or use XCHG to + // combine the read and the write. + MOVQ (DI), R13 + MOVQ R13, -8(R14) // Record *slot + // Is the buffer full? (flags set in CMPQ above) + JEQ flush +ret: + MOVQ 104(SP), R14 + MOVQ 112(SP), R13 + // Do the write. + MOVQ AX, (DI) + RET + +flush: + // Save all general purpose registers since these could be + // clobbered by wbBufFlush and were not saved by the caller. + // It is possible for wbBufFlush to clobber other registers + // (e.g., SSE registers), but the compiler takes care of saving + // those in the caller if necessary. This strikes a balance + // with registers that are likely to be used. + // + // We don't have type information for these, but all code under + // here is NOSPLIT, so nothing will observe these. + // + // TODO: We could strike a different balance; e.g., saving X0 + // and not saving GP registers that are less likely to be used. + MOVQ DI, 0(SP) // Also first argument to wbBufFlush + MOVQ AX, 8(SP) // Also second argument to wbBufFlush + MOVQ BX, 16(SP) + MOVQ CX, 24(SP) + MOVQ DX, 32(SP) + // DI already saved + MOVQ SI, 40(SP) + MOVQ BP, 48(SP) + MOVQ R8, 56(SP) + MOVQ R9, 64(SP) + MOVQ R10, 72(SP) + MOVQ R11, 80(SP) + MOVQ R12, 88(SP) + // R13 already saved + // R14 already saved + MOVQ R15, 96(SP) + + // This takes arguments DI and AX + CALL runtime·wbBufFlush(SB) + + MOVQ 0(SP), DI + MOVQ 8(SP), AX + MOVQ 16(SP), BX + MOVQ 24(SP), CX + MOVQ 32(SP), DX + MOVQ 40(SP), SI + MOVQ 48(SP), BP + MOVQ 56(SP), R8 + MOVQ 64(SP), R9 + MOVQ 72(SP), R10 + MOVQ 80(SP), R11 + MOVQ 88(SP), R12 + MOVQ 96(SP), R15 + JMP ret + +// gcWriteBarrierCX is gcWriteBarrier, but with args in DI and CX. +// Defined as ABIInternal since it does not use the stable Go ABI. +TEXT runtime·gcWriteBarrierCX<ABIInternal>(SB),NOSPLIT,$0 + XCHGQ CX, AX + CALL runtime·gcWriteBarrier<ABIInternal>(SB) + XCHGQ CX, AX + RET + +// gcWriteBarrierDX is gcWriteBarrier, but with args in DI and DX. +// Defined as ABIInternal since it does not use the stable Go ABI. +TEXT runtime·gcWriteBarrierDX<ABIInternal>(SB),NOSPLIT,$0 + XCHGQ DX, AX + CALL runtime·gcWriteBarrier<ABIInternal>(SB) + XCHGQ DX, AX + RET + +// gcWriteBarrierBX is gcWriteBarrier, but with args in DI and BX. +// Defined as ABIInternal since it does not use the stable Go ABI. +TEXT runtime·gcWriteBarrierBX<ABIInternal>(SB),NOSPLIT,$0 + XCHGQ BX, AX + CALL runtime·gcWriteBarrier<ABIInternal>(SB) + XCHGQ BX, AX + RET + +// gcWriteBarrierBP is gcWriteBarrier, but with args in DI and BP. +// Defined as ABIInternal since it does not use the stable Go ABI. +TEXT runtime·gcWriteBarrierBP<ABIInternal>(SB),NOSPLIT,$0 + XCHGQ BP, AX + CALL runtime·gcWriteBarrier<ABIInternal>(SB) + XCHGQ BP, AX + RET + +// gcWriteBarrierSI is gcWriteBarrier, but with args in DI and SI. +// Defined as ABIInternal since it does not use the stable Go ABI. +TEXT runtime·gcWriteBarrierSI<ABIInternal>(SB),NOSPLIT,$0 + XCHGQ SI, AX + CALL runtime·gcWriteBarrier<ABIInternal>(SB) + XCHGQ SI, AX + RET + +// gcWriteBarrierR8 is gcWriteBarrier, but with args in DI and R8. +// Defined as ABIInternal since it does not use the stable Go ABI. +TEXT runtime·gcWriteBarrierR8<ABIInternal>(SB),NOSPLIT,$0 + XCHGQ R8, AX + CALL runtime·gcWriteBarrier<ABIInternal>(SB) + XCHGQ R8, AX + RET + +// gcWriteBarrierR9 is gcWriteBarrier, but with args in DI and R9. +// Defined as ABIInternal since it does not use the stable Go ABI. +TEXT runtime·gcWriteBarrierR9<ABIInternal>(SB),NOSPLIT,$0 + XCHGQ R9, AX + CALL runtime·gcWriteBarrier<ABIInternal>(SB) + XCHGQ R9, AX + RET + +DATA debugCallFrameTooLarge<>+0x00(SB)/20, $"call frame too large" +GLOBL debugCallFrameTooLarge<>(SB), RODATA, $20 // Size duplicated below + +// debugCallV1 is the entry point for debugger-injected function +// calls on running goroutines. It informs the runtime that a +// debug call has been injected and creates a call frame for the +// debugger to fill in. +// +// To inject a function call, a debugger should: +// 1. Check that the goroutine is in state _Grunning and that +// there are at least 256 bytes free on the stack. +// 2. Push the current PC on the stack (updating SP). +// 3. Write the desired argument frame size at SP-16 (using the SP +// after step 2). +// 4. Save all machine registers (including flags and XMM reigsters) +// so they can be restored later by the debugger. +// 5. Set the PC to debugCallV1 and resume execution. +// +// If the goroutine is in state _Grunnable, then it's not generally +// safe to inject a call because it may return out via other runtime +// operations. Instead, the debugger should unwind the stack to find +// the return to non-runtime code, add a temporary breakpoint there, +// and inject the call once that breakpoint is hit. +// +// If the goroutine is in any other state, it's not safe to inject a call. +// +// This function communicates back to the debugger by setting RAX and +// invoking INT3 to raise a breakpoint signal. See the comments in the +// implementation for the protocol the debugger is expected to +// follow. InjectDebugCall in the runtime tests demonstrates this protocol. +// +// The debugger must ensure that any pointers passed to the function +// obey escape analysis requirements. Specifically, it must not pass +// a stack pointer to an escaping argument. debugCallV1 cannot check +// this invariant. +// +// This is ABIInternal because Go code injects its PC directly into new +// goroutine stacks. +TEXT runtime·debugCallV1<ABIInternal>(SB),NOSPLIT,$152-0 + // Save all registers that may contain pointers so they can be + // conservatively scanned. + // + // We can't do anything that might clobber any of these + // registers before this. + MOVQ R15, r15-(14*8+8)(SP) + MOVQ R14, r14-(13*8+8)(SP) + MOVQ R13, r13-(12*8+8)(SP) + MOVQ R12, r12-(11*8+8)(SP) + MOVQ R11, r11-(10*8+8)(SP) + MOVQ R10, r10-(9*8+8)(SP) + MOVQ R9, r9-(8*8+8)(SP) + MOVQ R8, r8-(7*8+8)(SP) + MOVQ DI, di-(6*8+8)(SP) + MOVQ SI, si-(5*8+8)(SP) + MOVQ BP, bp-(4*8+8)(SP) + MOVQ BX, bx-(3*8+8)(SP) + MOVQ DX, dx-(2*8+8)(SP) + // Save the frame size before we clobber it. Either of the last + // saves could clobber this depending on whether there's a saved BP. + MOVQ frameSize-24(FP), DX // aka -16(RSP) before prologue + MOVQ CX, cx-(1*8+8)(SP) + MOVQ AX, ax-(0*8+8)(SP) + + // Save the argument frame size. + MOVQ DX, frameSize-128(SP) + + // Perform a safe-point check. + MOVQ retpc-8(FP), AX // Caller's PC + MOVQ AX, 0(SP) + CALL runtime·debugCallCheck(SB) + MOVQ 8(SP), AX + TESTQ AX, AX + JZ good + // The safety check failed. Put the reason string at the top + // of the stack. + MOVQ AX, 0(SP) + MOVQ 16(SP), AX + MOVQ AX, 8(SP) + // Set AX to 8 and invoke INT3. The debugger should get the + // reason a call can't be injected from the top of the stack + // and resume execution. + MOVQ $8, AX + BYTE $0xcc + JMP restore + +good: + // Registers are saved and it's safe to make a call. + // Open up a call frame, moving the stack if necessary. + // + // Once the frame is allocated, this will set AX to 0 and + // invoke INT3. The debugger should write the argument + // frame for the call at SP, push the trapping PC on the + // stack, set the PC to the function to call, set RCX to point + // to the closure (if a closure call), and resume execution. + // + // If the function returns, this will set AX to 1 and invoke + // INT3. The debugger can then inspect any return value saved + // on the stack at SP and resume execution again. + // + // If the function panics, this will set AX to 2 and invoke INT3. + // The interface{} value of the panic will be at SP. The debugger + // can inspect the panic value and resume execution again. +#define DEBUG_CALL_DISPATCH(NAME,MAXSIZE) \ + CMPQ AX, $MAXSIZE; \ + JA 5(PC); \ + MOVQ $NAME(SB), AX; \ + MOVQ AX, 0(SP); \ + CALL runtime·debugCallWrap(SB); \ + JMP restore + + MOVQ frameSize-128(SP), AX + DEBUG_CALL_DISPATCH(debugCall32<>, 32) + DEBUG_CALL_DISPATCH(debugCall64<>, 64) + DEBUG_CALL_DISPATCH(debugCall128<>, 128) + DEBUG_CALL_DISPATCH(debugCall256<>, 256) + DEBUG_CALL_DISPATCH(debugCall512<>, 512) + DEBUG_CALL_DISPATCH(debugCall1024<>, 1024) + DEBUG_CALL_DISPATCH(debugCall2048<>, 2048) + DEBUG_CALL_DISPATCH(debugCall4096<>, 4096) + DEBUG_CALL_DISPATCH(debugCall8192<>, 8192) + DEBUG_CALL_DISPATCH(debugCall16384<>, 16384) + DEBUG_CALL_DISPATCH(debugCall32768<>, 32768) + DEBUG_CALL_DISPATCH(debugCall65536<>, 65536) + // The frame size is too large. Report the error. + MOVQ $debugCallFrameTooLarge<>(SB), AX + MOVQ AX, 0(SP) + MOVQ $20, 8(SP) // length of debugCallFrameTooLarge string + MOVQ $8, AX + BYTE $0xcc + JMP restore + +restore: + // Calls and failures resume here. + // + // Set AX to 16 and invoke INT3. The debugger should restore + // all registers except RIP and RSP and resume execution. + MOVQ $16, AX + BYTE $0xcc + // We must not modify flags after this point. + + // Restore pointer-containing registers, which may have been + // modified from the debugger's copy by stack copying. + MOVQ ax-(0*8+8)(SP), AX + MOVQ cx-(1*8+8)(SP), CX + MOVQ dx-(2*8+8)(SP), DX + MOVQ bx-(3*8+8)(SP), BX + MOVQ bp-(4*8+8)(SP), BP + MOVQ si-(5*8+8)(SP), SI + MOVQ di-(6*8+8)(SP), DI + MOVQ r8-(7*8+8)(SP), R8 + MOVQ r9-(8*8+8)(SP), R9 + MOVQ r10-(9*8+8)(SP), R10 + MOVQ r11-(10*8+8)(SP), R11 + MOVQ r12-(11*8+8)(SP), R12 + MOVQ r13-(12*8+8)(SP), R13 + MOVQ r14-(13*8+8)(SP), R14 + MOVQ r15-(14*8+8)(SP), R15 + + RET + +// runtime.debugCallCheck assumes that functions defined with the +// DEBUG_CALL_FN macro are safe points to inject calls. +#define DEBUG_CALL_FN(NAME,MAXSIZE) \ +TEXT NAME(SB),WRAPPER,$MAXSIZE-0; \ + NO_LOCAL_POINTERS; \ + MOVQ $0, AX; \ + BYTE $0xcc; \ + MOVQ $1, AX; \ + BYTE $0xcc; \ + RET +DEBUG_CALL_FN(debugCall32<>, 32) +DEBUG_CALL_FN(debugCall64<>, 64) +DEBUG_CALL_FN(debugCall128<>, 128) +DEBUG_CALL_FN(debugCall256<>, 256) +DEBUG_CALL_FN(debugCall512<>, 512) +DEBUG_CALL_FN(debugCall1024<>, 1024) +DEBUG_CALL_FN(debugCall2048<>, 2048) +DEBUG_CALL_FN(debugCall4096<>, 4096) +DEBUG_CALL_FN(debugCall8192<>, 8192) +DEBUG_CALL_FN(debugCall16384<>, 16384) +DEBUG_CALL_FN(debugCall32768<>, 32768) +DEBUG_CALL_FN(debugCall65536<>, 65536) + +// func debugCallPanicked(val interface{}) +TEXT runtime·debugCallPanicked(SB),NOSPLIT,$16-16 + // Copy the panic value to the top of stack. + MOVQ val_type+0(FP), AX + MOVQ AX, 0(SP) + MOVQ val_data+8(FP), AX + MOVQ AX, 8(SP) + MOVQ $2, AX + BYTE $0xcc + RET + +// Note: these functions use a special calling convention to save generated code space. +// Arguments are passed in registers, but the space for those arguments are allocated +// in the caller's stack frame. These stubs write the args into that stack space and +// then tail call to the corresponding runtime handler. +// The tail call makes these stubs disappear in backtraces. +// Defined as ABIInternal since they do not use the stack-based Go ABI. +TEXT runtime·panicIndex<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ AX, x+0(FP) + MOVQ CX, y+8(FP) + JMP runtime·goPanicIndex(SB) +TEXT runtime·panicIndexU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ AX, x+0(FP) + MOVQ CX, y+8(FP) + JMP runtime·goPanicIndexU(SB) +TEXT runtime·panicSliceAlen<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ CX, x+0(FP) + MOVQ DX, y+8(FP) + JMP runtime·goPanicSliceAlen(SB) +TEXT runtime·panicSliceAlenU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ CX, x+0(FP) + MOVQ DX, y+8(FP) + JMP runtime·goPanicSliceAlenU(SB) +TEXT runtime·panicSliceAcap<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ CX, x+0(FP) + MOVQ DX, y+8(FP) + JMP runtime·goPanicSliceAcap(SB) +TEXT runtime·panicSliceAcapU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ CX, x+0(FP) + MOVQ DX, y+8(FP) + JMP runtime·goPanicSliceAcapU(SB) +TEXT runtime·panicSliceB<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ AX, x+0(FP) + MOVQ CX, y+8(FP) + JMP runtime·goPanicSliceB(SB) +TEXT runtime·panicSliceBU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ AX, x+0(FP) + MOVQ CX, y+8(FP) + JMP runtime·goPanicSliceBU(SB) +TEXT runtime·panicSlice3Alen<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ DX, x+0(FP) + MOVQ BX, y+8(FP) + JMP runtime·goPanicSlice3Alen(SB) +TEXT runtime·panicSlice3AlenU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ DX, x+0(FP) + MOVQ BX, y+8(FP) + JMP runtime·goPanicSlice3AlenU(SB) +TEXT runtime·panicSlice3Acap<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ DX, x+0(FP) + MOVQ BX, y+8(FP) + JMP runtime·goPanicSlice3Acap(SB) +TEXT runtime·panicSlice3AcapU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ DX, x+0(FP) + MOVQ BX, y+8(FP) + JMP runtime·goPanicSlice3AcapU(SB) +TEXT runtime·panicSlice3B<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ CX, x+0(FP) + MOVQ DX, y+8(FP) + JMP runtime·goPanicSlice3B(SB) +TEXT runtime·panicSlice3BU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ CX, x+0(FP) + MOVQ DX, y+8(FP) + JMP runtime·goPanicSlice3BU(SB) +TEXT runtime·panicSlice3C<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ AX, x+0(FP) + MOVQ CX, y+8(FP) + JMP runtime·goPanicSlice3C(SB) +TEXT runtime·panicSlice3CU<ABIInternal>(SB),NOSPLIT,$0-16 + MOVQ AX, x+0(FP) + MOVQ CX, y+8(FP) + JMP runtime·goPanicSlice3CU(SB) + +#ifdef GOOS_android +// Use the free TLS_SLOT_APP slot #2 on Android Q. +// Earlier androids are set up in gcc_android.c. +DATA runtime·tls_g+0(SB)/8, $16 +GLOBL runtime·tls_g+0(SB), NOPTR, $8 +#endif + +// The compiler and assembler's -spectre=ret mode rewrites +// all indirect CALL AX / JMP AX instructions to be +// CALL retpolineAX / JMP retpolineAX. +// See https://support.google.com/faqs/answer/7625886. +#define RETPOLINE(reg) \ + /* CALL setup */ BYTE $0xE8; BYTE $(2+2); BYTE $0; BYTE $0; BYTE $0; \ + /* nospec: */ \ + /* PAUSE */ BYTE $0xF3; BYTE $0x90; \ + /* JMP nospec */ BYTE $0xEB; BYTE $-(2+2); \ + /* setup: */ \ + /* MOVQ AX, 0(SP) */ BYTE $0x48|((reg&8)>>1); BYTE $0x89; \ + BYTE $0x04|((reg&7)<<3); BYTE $0x24; \ + /* RET */ BYTE $0xC3 + +TEXT runtime·retpolineAX(SB),NOSPLIT,$0; RETPOLINE(0) +TEXT runtime·retpolineCX(SB),NOSPLIT,$0; RETPOLINE(1) +TEXT runtime·retpolineDX(SB),NOSPLIT,$0; RETPOLINE(2) +TEXT runtime·retpolineBX(SB),NOSPLIT,$0; RETPOLINE(3) +/* SP is 4, can't happen / magic encodings */ +TEXT runtime·retpolineBP(SB),NOSPLIT,$0; RETPOLINE(5) +TEXT runtime·retpolineSI(SB),NOSPLIT,$0; RETPOLINE(6) +TEXT runtime·retpolineDI(SB),NOSPLIT,$0; RETPOLINE(7) +TEXT runtime·retpolineR8(SB),NOSPLIT,$0; RETPOLINE(8) +TEXT runtime·retpolineR9(SB),NOSPLIT,$0; RETPOLINE(9) +TEXT runtime·retpolineR10(SB),NOSPLIT,$0; RETPOLINE(10) +TEXT runtime·retpolineR11(SB),NOSPLIT,$0; RETPOLINE(11) +TEXT runtime·retpolineR12(SB),NOSPLIT,$0; RETPOLINE(12) +TEXT runtime·retpolineR13(SB),NOSPLIT,$0; RETPOLINE(13) +TEXT runtime·retpolineR14(SB),NOSPLIT,$0; RETPOLINE(14) +TEXT runtime·retpolineR15(SB),NOSPLIT,$0; RETPOLINE(15) |