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75 lines
1.9 KiB
Go
75 lines
1.9 KiB
Go
//go:build darwin || linux
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// +build darwin linux
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/*
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* Copyright 2021 ByteDance Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package loader
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import (
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`fmt`
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`os`
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`reflect`
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`syscall`
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`unsafe`
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)
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const (
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_AP = syscall.MAP_ANON | syscall.MAP_PRIVATE
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_RX = syscall.PROT_READ | syscall.PROT_EXEC
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_RW = syscall.PROT_READ | syscall.PROT_WRITE
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)
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type Loader []byte
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type Function unsafe.Pointer
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func (self Loader) Load(fn string, fp int, args int, argPtrs []bool, localPtrs []bool) (f Function) {
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p := os.Getpagesize()
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n := (((len(self) - 1) / p) + 1) * p
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/* register the function */
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m := mmap(n)
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v := fmt.Sprintf("runtime.__%s_%x", fn, m)
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registerFunction(v, m, uintptr(n), fp, args, uintptr(len(self)), argPtrs, localPtrs)
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/* reference as a slice */
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s := *(*[]byte)(unsafe.Pointer(&reflect.SliceHeader {
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Data : m,
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Cap : n,
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Len : len(self),
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}))
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/* copy the machine code, and make it executable */
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copy(s, self)
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mprotect(m, n)
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return Function(&m)
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}
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func mmap(nb int) uintptr {
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if m, _, e := syscall.RawSyscall6(syscall.SYS_MMAP, 0, uintptr(nb), _RW, _AP, 0, 0); e != 0 {
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panic(e)
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} else {
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return m
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}
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}
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func mprotect(p uintptr, nb int) {
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if _, _, err := syscall.RawSyscall(syscall.SYS_MPROTECT, p, uintptr(nb), _RX); err != 0 {
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panic(err)
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}
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}
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