1 /*
2  * Copyright (c) 2022, Google Inc. All rights reserved
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files
6  * (the "Software"), to deal in the Software without restriction,
7  * including without limitation the rights to use, copy, modify, merge,
8  * publish, distribute, sublicense, and/or sell copies of the Software,
9  * and to permit persons to whom the Software is furnished to do so,
10  * subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22  */
23 
24 #include <err.h>
25 #include <kernel/vm.h>
26 #include <lib/dtb_service/dtb_service.h>
27 #include <lib/ktipc/ktipc.h>
28 #include <lib/shared/binder_discover/binder_discover.h>
29 #include <lib/shared/device_tree/service/device_tree_service.h>
30 #include <lib/trusty/ipc.h>
31 #include <lib/vmm_obj_service/vmm_obj_service.h>
32 #include <libfdt.h>
33 #include <lk/trace.h>
34 #include <string.h>
35 
36 #define LOCAL_TRACE (0)
37 
38 /* UUID: 185b4dbc-8935-4a1e-89ee-df027b89bc7a */
39 const static struct uuid device_tree_service_uuid = {
40         0x185b4dbc,
41         0x8935,
42         0x4a1e,
43         {0x89, 0xee, 0xdf, 0x02, 0x7b, 0x89, 0xbc, 0x7a},
44 };
45 
46 const static struct uuid* dtb_service_uuids[] = {
47         &device_tree_service_uuid,
48 };
49 
50 const static struct ktipc_port_acl dtb_service_port_acl = {
51         .flags = IPC_PORT_ALLOW_TA_CONNECT,
52         .uuid_num = countof(dtb_service_uuids),
53         .uuids = dtb_service_uuids,
54         .extra_data = NULL,
55 };
56 
dtb_service_add_user(const void * dtb,size_t dtb_size,const char * dtb_port,struct ktipc_server * server)57 static int dtb_service_add_user(const void* dtb,
58                                 size_t dtb_size,
59                                 const char* dtb_port,
60                                 struct ktipc_server* server) {
61     int rc;
62     vmm_aspace_t* kas = vmm_get_kernel_aspace();
63     struct vmm_obj_slice slice = VMM_OBJ_SLICE_INITIAL_VALUE(slice);
64 
65     uint64_t aligned_size = round_up(dtb_size, PAGE_SIZE);
66     void* dtb_copy;
67     rc = vmm_alloc(kas, "dtb copy", aligned_size, &dtb_copy, PAGE_SIZE_SHIFT, 0,
68                    ARCH_MMU_FLAG_PERM_NO_EXECUTE);
69     if (rc != NO_ERROR) {
70         TRACEF("error allocating memory (%d)\n", rc);
71         goto err_alloc;
72     }
73 
74     /*
75      * We need to make a copy because calling memref_create_from_aspace
76      * directly on dtb returns ERR_OUT_OF_RANGE because there is no backing
77      * vmm_obj for the kernel image
78      */
79     rc = fdt_move(dtb, dtb_copy, aligned_size);
80     if (rc) {
81         TRACEF("failed (%d) to move fdt\n", rc);
82         goto err_fdt_move;
83     }
84 
85     rc = vmm_get_obj(kas, (vaddr_t)dtb_copy, aligned_size, &slice);
86     if (rc < 0) {
87         TRACEF("failed (%d) to get vmm_obj\n", rc);
88         goto err_get_obj;
89     }
90 
91     struct vmm_obj_service* srv;
92     rc = vmm_obj_service_create_ro(dtb_port, &dtb_service_port_acl, slice.obj,
93                                    slice.offset, slice.size, &srv);
94     if (rc < 0) {
95         TRACEF("failed (%d) to create vmm_obj_service\n", rc);
96         goto err_create_service;
97     }
98 
99     rc = vmm_obj_service_add(srv, server);
100     if (rc < 0) {
101         TRACEF("error (%d) adding new service\n", rc);
102         goto err_add_service;
103     }
104 
105     /* vmm_obj_service_create_ro incremented the reference count of slice.obj */
106     vmm_obj_slice_release(&slice);
107     /* We can free the allocation now that we have the slice */
108     vmm_free_region(kas, (vaddr_t)dtb_copy);
109     return NO_ERROR;
110 
111 err_add_service:
112     vmm_obj_service_destroy(&srv);
113 err_create_service:
114     vmm_obj_slice_release(&slice);
115 err_get_obj:
116 err_fdt_move:
117     vmm_free_region(kas, (vaddr_t)dtb_copy);
118 err_alloc:
119     return rc;
120 }
121 
dtb_service_add(const void * dtb,size_t dtb_size,const char * dt_port,const char * dtb_port,struct ktipc_server * server)122 int dtb_service_add(const void* dtb,
123                     size_t dtb_size,
124                     const char* dt_port,
125                     const char* dtb_port,
126                     struct ktipc_server* server) {
127     if (!dtb) {
128         TRACEF("invalid dtb pointer\n");
129         return ERR_INVALID_ARGS;
130     }
131     if (!dtb_size) {
132         TRACEF("invalid dtb size\n");
133         return ERR_INVALID_ARGS;
134     }
135     if (fdt_check_full(dtb, dtb_size)) {
136         TRACEF("invalid dtb contents");
137         return ERR_INVALID_ARGS;
138     }
139     if (!dt_port) {
140         TRACEF("invalid kernel port name\n");
141         return ERR_INVALID_ARGS;
142     }
143     if (!dtb_port) {
144         TRACEF("invalid user port name\n");
145         return ERR_INVALID_ARGS;
146     }
147     if (!server) {
148         TRACEF("invalid server pointer\n");
149         return ERR_INVALID_ARGS;
150     }
151 
152     auto dt = android::sp<com::android::trusty::device_tree::DeviceTree>::make(
153             static_cast<const unsigned char*>(dtb), dtb_size);
154     int err = binder_discover_add_service(dt_port, dt);
155     if (err != android::OK) {
156         TRACEF("error adding service (%d)\n", err);
157         return ERR_GENERIC;
158     }
159 
160     int rc = dtb_service_add_user(dtb, dtb_size, dtb_port, server);
161     if (rc < 0) {
162         binder_discover_remove_service(dt_port);
163         return rc;
164     }
165 
166     return NO_ERROR;
167 }
168