1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (c) 2014, STMicroelectronics International N.V.
4 */
5
6 #include <kernel/mutex.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <tee/tee_pobj.h>
10
11 static TAILQ_HEAD(tee_pobjs, tee_pobj) tee_pobjs =
12 TAILQ_HEAD_INITIALIZER(tee_pobjs);
13 static struct mutex pobjs_mutex = MUTEX_INITIALIZER;
14 static struct mutex pobjs_usage_mutex = MUTEX_INITIALIZER;
15
pobj_need_usage_lock(struct tee_pobj * obj)16 static bool pobj_need_usage_lock(struct tee_pobj *obj)
17 {
18 /* Only lock if we don't have exclusive access to the object */
19 return obj->flags & (TEE_DATA_FLAG_SHARE_WRITE |
20 TEE_DATA_FLAG_SHARE_READ);
21 }
22
tee_pobj_lock_usage(struct tee_pobj * obj)23 void tee_pobj_lock_usage(struct tee_pobj *obj)
24 {
25 if (pobj_need_usage_lock(obj))
26 mutex_lock(&pobjs_usage_mutex);
27 }
28
tee_pobj_unlock_usage(struct tee_pobj * obj)29 void tee_pobj_unlock_usage(struct tee_pobj *obj)
30 {
31 if (pobj_need_usage_lock(obj))
32 mutex_unlock(&pobjs_usage_mutex);
33 }
34
tee_pobj_check_access(uint32_t oflags,uint32_t nflags)35 static TEE_Result tee_pobj_check_access(uint32_t oflags, uint32_t nflags)
36 {
37 /* meta is exclusive */
38 if ((oflags & TEE_DATA_FLAG_ACCESS_WRITE_META) ||
39 (nflags & TEE_DATA_FLAG_ACCESS_WRITE_META))
40 return TEE_ERROR_ACCESS_CONFLICT;
41
42 /*
43 * Excerpt of TEE Internal Core API Specification v1.1:
44 * If more than one handle is opened on the same object, and if any
45 * of these object handles was opened with the flag
46 * TEE_DATA_FLAG_ACCESS_READ, then all the object handles MUST have been
47 * opened with the flag TEE_DATA_FLAG_SHARE_READ
48 */
49 if (((oflags & TEE_DATA_FLAG_ACCESS_READ) ||
50 (nflags & TEE_DATA_FLAG_ACCESS_READ)) &&
51 !((nflags & TEE_DATA_FLAG_SHARE_READ) &&
52 (oflags & TEE_DATA_FLAG_SHARE_READ)))
53 return TEE_ERROR_ACCESS_CONFLICT;
54
55 /*
56 * Excerpt of TEE Internal Core API Specification v1.1:
57 * An object can be opened with only share flags, which locks the access
58 * to an object against a given mode.
59 * An object can be opened with no flag set, which completely locks all
60 * subsequent attempts to access the object
61 */
62 if ((nflags & TEE_DATA_FLAG_SHARE_READ) !=
63 (oflags & TEE_DATA_FLAG_SHARE_READ))
64 return TEE_ERROR_ACCESS_CONFLICT;
65
66 /* Same on WRITE access */
67 if (((oflags & TEE_DATA_FLAG_ACCESS_WRITE) ||
68 (nflags & TEE_DATA_FLAG_ACCESS_WRITE)) &&
69 !((nflags & TEE_DATA_FLAG_SHARE_WRITE) &&
70 (oflags & TEE_DATA_FLAG_SHARE_WRITE)))
71 return TEE_ERROR_ACCESS_CONFLICT;
72 if ((nflags & TEE_DATA_FLAG_SHARE_WRITE) !=
73 (oflags & TEE_DATA_FLAG_SHARE_WRITE))
74 return TEE_ERROR_ACCESS_CONFLICT;
75
76 return TEE_SUCCESS;
77 }
78
tee_pobj_get(TEE_UUID * uuid,void * obj_id,uint32_t obj_id_len,uint32_t flags,enum tee_pobj_usage usage,const struct tee_file_operations * fops,struct tee_pobj ** obj)79 TEE_Result tee_pobj_get(TEE_UUID *uuid, void *obj_id, uint32_t obj_id_len,
80 uint32_t flags, enum tee_pobj_usage usage,
81 const struct tee_file_operations *fops,
82 struct tee_pobj **obj)
83 {
84 TEE_Result res = TEE_SUCCESS;
85 struct tee_pobj *o = NULL;
86
87 *obj = NULL;
88
89 mutex_lock(&pobjs_mutex);
90 /* Check if file is open */
91 TAILQ_FOREACH(o, &tee_pobjs, link) {
92 if ((obj_id_len == o->obj_id_len) &&
93 (memcmp(obj_id, o->obj_id, obj_id_len) == 0) &&
94 (memcmp(uuid, &o->uuid, sizeof(TEE_UUID)) == 0) &&
95 (fops == o->fops)) {
96 *obj = o;
97 }
98 }
99
100 if (*obj) {
101 if (usage == TEE_POBJ_USAGE_ENUM) {
102 (*obj)->refcnt++;
103 goto out;
104 }
105 if ((*obj)->creating || (usage == TEE_POBJ_USAGE_CREATE &&
106 !(flags & TEE_DATA_FLAG_OVERWRITE))) {
107 res = TEE_ERROR_ACCESS_CONFLICT;
108 goto out;
109 }
110 res = tee_pobj_check_access((*obj)->flags, flags);
111 if (res == TEE_SUCCESS)
112 (*obj)->refcnt++;
113 goto out;
114 }
115
116 /* new file */
117 o = calloc(1, sizeof(struct tee_pobj));
118 if (!o) {
119 res = TEE_ERROR_OUT_OF_MEMORY;
120 goto out;
121 }
122
123 o->refcnt = 1;
124 memcpy(&o->uuid, uuid, sizeof(TEE_UUID));
125 o->flags = flags;
126 o->fops = fops;
127
128 if (usage == TEE_POBJ_USAGE_CREATE) {
129 o->temporary = true;
130 o->creating = true;
131 }
132
133 o->obj_id = malloc(obj_id_len);
134 if (o->obj_id == NULL) {
135 free(o);
136 res = TEE_ERROR_OUT_OF_MEMORY;
137 goto out;
138 }
139 memcpy(o->obj_id, obj_id, obj_id_len);
140 o->obj_id_len = obj_id_len;
141
142 TAILQ_INSERT_TAIL(&tee_pobjs, o, link);
143 *obj = o;
144
145 res = TEE_SUCCESS;
146 out:
147 if (res != TEE_SUCCESS)
148 *obj = NULL;
149 mutex_unlock(&pobjs_mutex);
150 return res;
151 }
152
tee_pobj_create_final(struct tee_pobj * po)153 void tee_pobj_create_final(struct tee_pobj *po)
154 {
155 mutex_lock(&pobjs_mutex);
156 po->temporary = false;
157 po->creating = false;
158 mutex_unlock(&pobjs_mutex);
159 }
160
tee_pobj_release(struct tee_pobj * obj)161 TEE_Result tee_pobj_release(struct tee_pobj *obj)
162 {
163 if (obj == NULL)
164 return TEE_ERROR_BAD_PARAMETERS;
165
166 mutex_lock(&pobjs_mutex);
167 obj->refcnt--;
168 if (obj->refcnt == 0) {
169 TAILQ_REMOVE(&tee_pobjs, obj, link);
170 free(obj->obj_id);
171 free(obj);
172 }
173 mutex_unlock(&pobjs_mutex);
174
175 return TEE_SUCCESS;
176 }
177
tee_pobj_rename(struct tee_pobj * obj,void * obj_id,uint32_t obj_id_len)178 TEE_Result tee_pobj_rename(struct tee_pobj *obj, void *obj_id,
179 uint32_t obj_id_len)
180 {
181 TEE_Result res = TEE_SUCCESS;
182 void *new_obj_id = NULL;
183
184 if (obj == NULL || obj_id == NULL)
185 return TEE_ERROR_BAD_PARAMETERS;
186
187 mutex_lock(&pobjs_mutex);
188 if (obj->refcnt != 1) {
189 res = TEE_ERROR_BAD_STATE;
190 goto exit;
191 }
192
193 new_obj_id = malloc(obj_id_len);
194 if (new_obj_id == NULL) {
195 res = TEE_ERROR_OUT_OF_MEMORY;
196 goto exit;
197 }
198 memcpy(new_obj_id, obj_id, obj_id_len);
199
200 /* update internal data */
201 free(obj->obj_id);
202 obj->obj_id = new_obj_id;
203 obj->obj_id_len = obj_id_len;
204 new_obj_id = NULL;
205
206 exit:
207 mutex_unlock(&pobjs_mutex);
208 free(new_obj_id);
209 return res;
210 }
211