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// Copyright 2013 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.
// +build race
#include "zasm_GOOS_GOARCH.h"
#include "funcdata.h"
#include "../../cmd/ld/textflag.h"
// The following thunks allow calling the gcc-compiled race runtime directly
// from Go code without going all the way through cgo.
// First, it's much faster (up to 50% speedup for real Go programs).
// Second, it eliminates race-related special cases from cgocall and scheduler.
// Third, in long-term it will allow to remove cyclic runtime/race dependency on cmd/go.
// A brief recap of the amd64 calling convention.
// Arguments are passed in DI, SI, DX, CX, R8, R9, the rest is on stack.
// Callee-saved registers are: BX, BP, R12-R15.
// SP must be 16-byte aligned.
// On Windows:
// Arguments are passed in CX, DX, R8, R9, the rest is on stack.
// Callee-saved registers are: BX, BP, DI, SI, R12-R15.
// SP must be 16-byte aligned. Windows also requires "stack-backing" for the 4 register arguments:
// http://msdn.microsoft.com/en-us/library/ms235286.aspx
// We do not do this, because it seems to be intended for vararg/unprototyped functions.
// Gcc-compiled race runtime does not try to use that space.
#ifdef GOOS_windows
#define RARG0 CX
#define RARG1 DX
#define RARG2 R8
#define RARG3 R9
#else
#define RARG0 DI
#define RARG1 SI
#define RARG2 DX
#define RARG3 CX
#endif
// func runtime·raceread(addr uintptr)
// Called from instrumented code.
TEXT runtime·raceread(SB), NOSPLIT, $0-8
MOVQ addr+0(FP), RARG1
MOVQ (SP), RARG2
// void __tsan_read(ThreadState *thr, void *addr, void *pc);
MOVQ $__tsan_read(SB), AX
JMP racecalladdr<>(SB)
// func runtime·RaceRead(addr uintptr)
TEXT runtime·RaceRead(SB), NOSPLIT, $0-8
// This needs to be a tail call, because raceread reads caller pc.
JMP runtime·raceread(SB)
// void runtime·racereadpc(void *addr, void *callpc, void *pc)
TEXT runtime·racereadpc(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ callpc+8(FP), RARG2
MOVQ pc+16(FP), RARG3
// void __tsan_read_pc(ThreadState *thr, void *addr, void *callpc, void *pc);
MOVQ $__tsan_read_pc(SB), AX
JMP racecalladdr<>(SB)
// func runtime·racewrite(addr uintptr)
// Called from instrumented code.
TEXT runtime·racewrite(SB), NOSPLIT, $0-8
MOVQ addr+0(FP), RARG1
MOVQ (SP), RARG2
// void __tsan_write(ThreadState *thr, void *addr, void *pc);
MOVQ $__tsan_write(SB), AX
JMP racecalladdr<>(SB)
// func runtime·RaceWrite(addr uintptr)
TEXT runtime·RaceWrite(SB), NOSPLIT, $0-8
// This needs to be a tail call, because racewrite reads caller pc.
JMP runtime·racewrite(SB)
// void runtime·racewritepc(void *addr, void *callpc, void *pc)
TEXT runtime·racewritepc(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ callpc+8(FP), RARG2
MOVQ cp+16(FP), RARG3
// void __tsan_write_pc(ThreadState *thr, void *addr, void *callpc, void *pc);
MOVQ $__tsan_write_pc(SB), AX
JMP racecalladdr<>(SB)
// func runtime·racereadrange(addr, size uintptr)
// Called from instrumented code.
TEXT runtime·racereadrange(SB), NOSPLIT, $0-16
MOVQ addr+0(FP), RARG1
MOVQ size+8(FP), RARG2
MOVQ (SP), RARG3
// void __tsan_read_range(ThreadState *thr, void *addr, uintptr size, void *pc);
MOVQ $__tsan_read_range(SB), AX
JMP racecalladdr<>(SB)
// func runtime·RaceReadRange(addr, size uintptr)
TEXT runtime·RaceReadRange(SB), NOSPLIT, $0-16
// This needs to be a tail call, because racereadrange reads caller pc.
JMP runtime·racereadrange(SB)
// void runtime·racereadrangepc1(void *addr, uintptr sz, void *pc)
TEXT runtime·racereadrangepc1(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ size+8(FP), RARG2
MOVQ pc+16(FP), RARG3
// void __tsan_read_range(ThreadState *thr, void *addr, uintptr size, void *pc);
MOVQ $__tsan_read_range(SB), AX
JMP racecalladdr<>(SB)
// func runtime·racewriterange(addr, size uintptr)
// Called from instrumented code.
TEXT runtime·racewriterange(SB), NOSPLIT, $0-16
MOVQ addr+0(FP), RARG1
MOVQ size+8(FP), RARG2
MOVQ (SP), RARG3
// void __tsan_write_range(ThreadState *thr, void *addr, uintptr size, void *pc);
MOVQ $__tsan_write_range(SB), AX
JMP racecalladdr<>(SB)
// func runtime·RaceWriteRange(addr, size uintptr)
TEXT runtime·RaceWriteRange(SB), NOSPLIT, $0-16
// This needs to be a tail call, because racewriterange reads caller pc.
JMP runtime·racewriterange(SB)
// void runtime·racewriterangepc1(void *addr, uintptr sz, void *pc)
TEXT runtime·racewriterangepc1(SB), NOSPLIT, $0-24
MOVQ addr+0(FP), RARG1
MOVQ size+8(FP), RARG2
MOVQ pc+16(FP), RARG3
// void __tsan_write_range(ThreadState *thr, void *addr, uintptr size, void *pc);
MOVQ $__tsan_write_range(SB), AX
JMP racecalladdr<>(SB)
// If addr (RARG1) is out of range, do nothing.
// Otherwise, setup goroutine context and invoke racecall. Other arguments already set.
TEXT racecalladdr<>(SB), NOSPLIT, $0-0
get_tls(R12)
MOVQ g(R12), R14
MOVQ g_racectx(R14), RARG0 // goroutine context
// Check that addr is within [arenastart, arenaend) or within [noptrdata, enoptrbss).
CMPQ RARG1, runtime·racearenastart(SB)
JB racecalladdr_data
CMPQ RARG1, runtime·racearenaend(SB)
JB racecalladdr_call
racecalladdr_data:
CMPQ RARG1, $noptrdata(SB)
JB racecalladdr_ret
CMPQ RARG1, $enoptrbss(SB)
JAE racecalladdr_ret
racecalladdr_call:
MOVQ AX, AX // w/o this 6a miscompiles this function
JMP racecall<>(SB)
racecalladdr_ret:
RET
// func runtime·racefuncenter(pc uintptr)
// Called from instrumented code.
TEXT runtime·racefuncenter(SB), NOSPLIT, $0-8
MOVQ DX, R15 // save function entry context (for closures)
get_tls(R12)
MOVQ g(R12), R14
MOVQ g_racectx(R14), RARG0 // goroutine context
MOVQ callpc+0(FP), RARG1
// void __tsan_func_enter(ThreadState *thr, void *pc);
MOVQ $__tsan_func_enter(SB), AX
CALL racecall<>(SB)
MOVQ R15, DX // restore function entry context
RET
// func runtime·racefuncexit()
// Called from instrumented code.
TEXT runtime·racefuncexit(SB), NOSPLIT, $0-0
get_tls(R12)
MOVQ g(R12), R14
MOVQ g_racectx(R14), RARG0 // goroutine context
// void __tsan_func_exit(ThreadState *thr);
MOVQ $__tsan_func_exit(SB), AX
JMP racecall<>(SB)
// void runtime·racecall(void(*f)(...), ...)
// Calls C function f from race runtime and passes up to 4 arguments to it.
// The arguments are never heap-object-preserving pointers, so we pretend there are no arguments.
TEXT runtime·racecall(SB), NOSPLIT, $0-0
MOVQ fn+0(FP), AX
MOVQ arg0+8(FP), RARG0
MOVQ arg1+16(FP), RARG1
MOVQ arg2+24(FP), RARG2
MOVQ arg3+32(FP), RARG3
JMP racecall<>(SB)
// Switches SP to g0 stack and calls (AX). Arguments already set.
TEXT racecall<>(SB), NOSPLIT, $0-0
get_tls(R12)
MOVQ m(R12), R13
MOVQ g(R12), R14
// Switch to g0 stack.
MOVQ SP, R12 // callee-saved, preserved across the CALL
MOVQ m_g0(R13), R10
CMPQ R10, R14
JE racecall_cont // already on g0
MOVQ (g_sched+gobuf_sp)(R10), SP
racecall_cont:
ANDQ $~15, SP // alignment for gcc ABI
CALL AX
MOVQ R12, SP
RET
// C->Go callback thunk that allows to call runtime·racesymbolize from C code.
// Direct Go->C race call has only switched SP, finish g->g0 switch by setting correct g.
// The overall effect of Go->C->Go call chain is similar to that of mcall.
TEXT runtime·racesymbolizethunk(SB), NOSPLIT, $56-8
// Save callee-saved registers (Go code won't respect that).
// This is superset of darwin/linux/windows registers.
PUSHQ BX
PUSHQ BP
PUSHQ DI
PUSHQ SI
PUSHQ R12
PUSHQ R13
PUSHQ R14
PUSHQ R15
// Set g = g0.
get_tls(R12)
MOVQ m(R12), R13
MOVQ m_g0(R13), R14
MOVQ R14, g(R12) // g = m->g0
MOVQ RARG0, 0(SP) // func arg
CALL runtime·racesymbolize(SB)
// All registers are smashed after Go code, reload.
get_tls(R12)
MOVQ m(R12), R13
MOVQ m_curg(R13), R14
MOVQ R14, g(R12) // g = m->curg
// Restore callee-saved registers.
POPQ R15
POPQ R14
POPQ R13
POPQ R12
POPQ SI
POPQ DI
POPQ BP
POPQ BX
RET
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