1// Copyright 2018 The Fuchsia Authors 2// 3// Use of this source code is governed by a MIT-style 4// license that can be found in the LICENSE file or at 5// https://opensource.org/licenses/MIT 6 7#include <object/buffer_chain.h> 8 9// Makes a const void* look like a user_in_ptr<const void>. 10// 11// Sometimes we need to copy data from kernel space. KernelPtrAdapter allows us to implement the 12// copy logic once for both const void* and user_in_ptr<const void>. 13class KernelPtrAdapter { 14public: 15 explicit KernelPtrAdapter(const void* p) 16 : p_(p) {} 17 zx_status_t copy_array_from_user(void* dst, size_t count) const { 18 memcpy(dst, p_, count); 19 return ZX_OK; 20 } 21 KernelPtrAdapter byte_offset(size_t offset) const { 22 return KernelPtrAdapter(reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(p_) + offset)); 23 } 24 25private: 26 const void* p_; 27}; 28 29zx_status_t BufferChain::CopyInKernel(const void* src, size_t dst_offset, size_t size) { 30 return CopyInCommon(KernelPtrAdapter(src), dst_offset, size); 31} 32 33template zx_status_t BufferChain::CopyInCommon(user_in_ptr<const void> src, size_t dst_offset, 34 size_t size); 35