github.com/bytedance/mockey@v1.2.10/internal/monkey/inst/inst_amd64.go (about)

     1  /*
     2   * Copyright 2022 ByteDance Inc.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package inst
    18  
    19  import "unsafe"
    20  
    21  func BranchTo(to uintptr) (res []byte) {
    22  	res = append(res, rdxMOV(to)...)         // MOVABS RDX, to
    23  	res = append(res, []byte{0xff, 0xe2}...) // JMP RDX
    24  	return
    25  }
    26  
    27  func BranchInto(to uintptr) (res []byte) {
    28  	res = append(res, rdxMOV(to)...)         // MOVABS RDX, to
    29  	res = append(res, []byte{0xff, 0x22}...) // JMP [RDX]
    30  	return
    31  }
    32  
    33  // rdxMOV moves the 64bit value to rdx register, using the following instruction:
    34  // MOVABS RDX, val
    35  func rdxMOV(val uintptr) []byte {
    36  	res := make([]byte, unsafe.Sizeof(val))
    37  	*(*uintptr)(unsafe.Pointer(&res[0])) = val
    38  	res = append([]byte{0x48, 0xba}, res...)
    39  	return res
    40  }