1 /*
2  * Copyright (C) 2018 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 #include <sys/mman.h>
18 
19 #include <lk/err_ptr.h>
20 #include <stddef.h>
21 #include <stdint.h>
22 #include <trusty/sys/mman.h>
23 #include <trusty_syscalls.h>
24 #ifdef HWASAN_ENABLED
25 #include <lib/hwasan/hwasan_shadow.h>
26 #endif /* HWASAN_ENABLED */
27 
28 #include <trusty_log.h>
29 #define TLOG_TAG "mman"
30 
mmap(void * uaddr,size_t size,int prot,int flags,int handle,off_t offset)31 void* mmap(void* uaddr,
32            size_t size,
33            int prot,
34            int flags,
35            int handle,
36            off_t offset) {
37     void* result;
38 
39     if (offset != 0) {
40         return MAP_FAILED;
41     }
42 
43     /*
44      * or the flags together for now since the syscall doesn't have enough
45      * arguments and now that we have real mappable handles, we have to dispatch
46      * on the flags to switch between regions and handles
47      */
48     result = (void*)_trusty_mmap(uaddr, size, (uint32_t)prot | flags,
49                                  (int32_t)handle);
50     if (IS_ERR(result)) {
51         return MAP_FAILED;
52     }
53 #ifdef HWASAN_ENABLED
54     /*
55      * Assume _trusty_mmap() call above gives us a valid region of memory that
56      * is mapped into user address space. For such regions hwasan_tag_memory()
57      * can not fail.
58      */
59     result = hwasan_tag_memory(result, size);
60 #endif
61     return result;
62 }
63 
munmap(void * uaddr,size_t size)64 int munmap(void* uaddr, size_t size) {
65 #ifdef HWASAN_ENABLED
66     /* HWASan memory will be unmapped. No need to worry about untagging it. */
67     uaddr = hwasan_remove_ptr_tag(uaddr);
68 #endif
69     return _trusty_munmap(uaddr, size);
70 }
71 
prepare_dma(void * uaddr,uint32_t size,uint32_t flags,struct dma_pmem * pmem)72 int prepare_dma(void* uaddr,
73                 uint32_t size,
74                 uint32_t flags,
75                 struct dma_pmem* pmem) {
76 #ifdef HWASAN_ENABLED
77     uaddr = hwasan_remove_ptr_tag(uaddr);
78 #endif
79     return _trusty_prepare_dma(uaddr, size, flags, pmem);
80 }
81 
finish_dma(void * uaddr,uint32_t size,uint32_t flags)82 int finish_dma(void* uaddr, uint32_t size, uint32_t flags) {
83 #ifdef HWASAN_ENABLED
84     uaddr = hwasan_remove_ptr_tag(uaddr);
85 #endif
86     return _trusty_finish_dma(uaddr, size, flags);
87 }
88 
prepare_input_output_dma(void * input,uint32_t input_len,void * output,uint32_t output_len,struct dma_pmem * input_pmem,struct dma_pmem * output_pmem)89 int prepare_input_output_dma(void* input,
90                              uint32_t input_len,
91                              void* output,
92                              uint32_t output_len,
93                              struct dma_pmem* input_pmem,
94                              struct dma_pmem* output_pmem) {
95     if (input == output && input_len != output_len) {
96         return ERR_INVALID_ARGS;
97     }
98 
99     int rc = NO_ERROR;
100     if (input == output && input_len == output_len) {
101         rc = prepare_dma(input, input_len, DMA_FLAG_BIDIRECTION, input_pmem);
102         if (rc < 0) {
103             TLOGE("Couldn't prepare input/output dma - rc(%d)\n", rc);
104             return rc;
105         }
106         *output_pmem = *input_pmem;
107     } else {
108         rc = prepare_dma(input, input_len, DMA_FLAG_TO_DEVICE, input_pmem);
109         if (rc < 0) {
110             TLOGE("Couldn't prepare input dma - rc(%d)\n", rc);
111             return rc;
112         }
113         rc = prepare_dma(output, output_len, DMA_FLAG_FROM_DEVICE, output_pmem);
114         if (rc < 0) {
115             TLOGE("Couldn't prepare output dma - rc(%d)\n", rc);
116             finish_dma(input, input_len, DMA_FLAG_TO_DEVICE);  // Clean DMA
117             return rc;
118         }
119     }
120     return NO_ERROR;
121 }
122 
finish_input_output_dma(void * input,uint32_t input_len,void * output,uint32_t output_len)123 int finish_input_output_dma(void* input,
124                             uint32_t input_len,
125                             void* output,
126                             uint32_t output_len) {
127     if (input == output && input_len != output_len) {
128         return ERR_INVALID_ARGS;
129     }
130 
131     if (input == output && input_len == output_len) {
132         return finish_dma(input, input_len, DMA_FLAG_BIDIRECTION);
133     } else {
134         int rc_in = finish_dma(input, input_len, DMA_FLAG_TO_DEVICE);
135         int rc_out = finish_dma(output, output_len, DMA_FLAG_FROM_DEVICE);
136 
137         /* Return an error if it exists */
138         return rc_in == NO_ERROR ? rc_out : rc_in;
139     }
140 }
141