1 /*
2  * Copyright (C) 2020 The Android Open Source Project
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 #pragma once
18 
19 /*
20  * hwasan_tag_memory() - tag a given a chunk of memory
21  * @ptr: pointer to the memory region being tagged
22  * @size: size of the memory region being tagged
23  *
24  * Generate a tag for the memory region and record it in the corresponding
25  * shadow memory locations.
26  *
27  * Return: pointer to the same memory pointed to by @ptr, but with the generated
28  *         tag placed in the top byte.
29  */
30 void* hwasan_tag_memory(void* ptr, size_t size);
31 
32 /*
33  * hwasan_untag_memory() - untag a given a chunk of memory
34  * @ptr: pointer to the memory region being untagged
35  * @size: size of the memory region being untagged
36  *
37  * Find shadow memory location corresponding to the given memory region and
38  * clear its contents.
39  */
40 void hwasan_untag_memory(void* ptr, size_t size);
41 
42 /*
43  * hwasan_remove_ptr_tag() - clear the tag from the given pointer
44  * @ptr: pointer being untagged
45  *
46  * Return: pointer to memory pointed to by @ptr, but with the tag cleared.
47  */
48 void* hwasan_remove_ptr_tag(void* ptr);
49