github.com/ttpreport/gvisor-ligolo@v0.0.0-20240123134145-a858404967ba/pkg/sentry/arch/fpu/fpu_unsafe.go (about)

     1  // Copyright 2021 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package fpu
    16  
    17  import (
    18  	"unsafe"
    19  )
    20  
    21  // alignedBytes returns a slice of size bytes, aligned in memory to the given
    22  // alignment. This is used because we require certain structures to be aligned
    23  // in a specific way (for example, the X86 floating point data).
    24  func alignedBytes(size, alignment uint) []byte {
    25  	data := make([]byte, size+alignment-1)
    26  	offset := uint(uintptr(unsafe.Pointer(&data[0])) % uintptr(alignment))
    27  	if offset == 0 {
    28  		return data[:size:size]
    29  	}
    30  	return data[alignment-offset:][:size:size]
    31  }