xref: /optee_os/core/tee/tee_pobj.c (revision 5a913ee74d3c71af2a2860ce8a4e7aeab2916f9b)
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 #include <trace.h>
11 
12 static TAILQ_HEAD(tee_pobjs, tee_pobj) tee_pobjs =
13 		TAILQ_HEAD_INITIALIZER(tee_pobjs);
14 static struct mutex pobjs_mutex = MUTEX_INITIALIZER;
15 
16 static TEE_Result tee_pobj_check_access(uint32_t oflags, uint32_t nflags)
17 {
18 	/* meta is exclusive */
19 	if ((oflags & TEE_DATA_FLAG_ACCESS_WRITE_META) ||
20 	    (nflags & TEE_DATA_FLAG_ACCESS_WRITE_META))
21 		return TEE_ERROR_ACCESS_CONFLICT;
22 
23 	/*
24 	 * Excerpt of TEE Internal Core API Specification v1.1:
25 	 * If more than one handle is opened on the same  object, and if any
26 	 * of these object handles was opened with the flag
27 	 * TEE_DATA_FLAG_ACCESS_READ, then all the object handles MUST have been
28 	 * opened with the flag TEE_DATA_FLAG_SHARE_READ
29 	 */
30 	if (((oflags & TEE_DATA_FLAG_ACCESS_READ) ||
31 	     (nflags & TEE_DATA_FLAG_ACCESS_READ)) &&
32 	    !((nflags & TEE_DATA_FLAG_SHARE_READ) &&
33 	      (oflags & TEE_DATA_FLAG_SHARE_READ)))
34 		return TEE_ERROR_ACCESS_CONFLICT;
35 
36 	/*
37 	 * Excerpt of TEE Internal Core API Specification v1.1:
38 	 * An object can be opened with only share flags, which locks the access
39 	 * to an object against a given mode.
40 	 * An object can be opened with no flag set, which completely locks all
41 	 * subsequent attempts to access the object
42 	 */
43 	if ((nflags & TEE_DATA_FLAG_SHARE_READ) !=
44 	    (oflags & TEE_DATA_FLAG_SHARE_READ))
45 		return TEE_ERROR_ACCESS_CONFLICT;
46 
47 	/* Same on WRITE access */
48 	if (((oflags & TEE_DATA_FLAG_ACCESS_WRITE) ||
49 	     (nflags & TEE_DATA_FLAG_ACCESS_WRITE)) &&
50 	    !((nflags & TEE_DATA_FLAG_SHARE_WRITE) &&
51 	      (oflags & TEE_DATA_FLAG_SHARE_WRITE)))
52 		return TEE_ERROR_ACCESS_CONFLICT;
53 	if ((nflags & TEE_DATA_FLAG_SHARE_WRITE) !=
54 	    (oflags & TEE_DATA_FLAG_SHARE_WRITE))
55 		return TEE_ERROR_ACCESS_CONFLICT;
56 
57 	return TEE_SUCCESS;
58 }
59 
60 TEE_Result tee_pobj_get(TEE_UUID *uuid, void *obj_id, uint32_t obj_id_len,
61 			uint32_t flags, bool temporary,
62 			const struct tee_file_operations *fops,
63 			struct tee_pobj **obj)
64 {
65 	struct tee_pobj *o;
66 	TEE_Result res;
67 
68 	*obj = NULL;
69 
70 	mutex_lock(&pobjs_mutex);
71 	/* Check if file is open */
72 	TAILQ_FOREACH(o, &tee_pobjs, link) {
73 		if ((obj_id_len == o->obj_id_len) &&
74 		    (memcmp(obj_id, o->obj_id, obj_id_len) == 0) &&
75 		    (memcmp(uuid, &o->uuid, sizeof(TEE_UUID)) == 0) &&
76 		    (fops == o->fops)) {
77 			*obj = o;
78 		}
79 	}
80 
81 	if (*obj) {
82 		if (temporary != (*obj)->temporary) {
83 			res = TEE_ERROR_ACCESS_CONFLICT;
84 			goto out;
85 		}
86 		res = tee_pobj_check_access((*obj)->flags, flags);
87 		if (res == TEE_SUCCESS)
88 			(*obj)->refcnt++;
89 		goto out;
90 	}
91 
92 	/* new file */
93 	o = calloc(1, sizeof(struct tee_pobj));
94 	if (!o) {
95 		res = TEE_ERROR_OUT_OF_MEMORY;
96 		goto out;
97 	}
98 
99 	o->refcnt = 1;
100 	memcpy(&o->uuid, uuid, sizeof(TEE_UUID));
101 	o->flags = flags;
102 	o->fops = fops;
103 	o->temporary = temporary;
104 
105 	o->obj_id = malloc(obj_id_len);
106 	if (o->obj_id == NULL) {
107 		free(o);
108 		res = TEE_ERROR_OUT_OF_MEMORY;
109 		goto out;
110 	}
111 	memcpy(o->obj_id, obj_id, obj_id_len);
112 	o->obj_id_len = obj_id_len;
113 
114 	TAILQ_INSERT_TAIL(&tee_pobjs, o, link);
115 	*obj = o;
116 
117 	res = TEE_SUCCESS;
118 out:
119 	if (res != TEE_SUCCESS)
120 		*obj = NULL;
121 	mutex_unlock(&pobjs_mutex);
122 	return res;
123 }
124 
125 TEE_Result tee_pobj_release(struct tee_pobj *obj)
126 {
127 	if (obj == NULL)
128 		return TEE_ERROR_BAD_PARAMETERS;
129 
130 	mutex_lock(&pobjs_mutex);
131 	obj->refcnt--;
132 	if (obj->refcnt == 0) {
133 		TAILQ_REMOVE(&tee_pobjs, obj, link);
134 		free(obj->obj_id);
135 		free(obj);
136 	}
137 	mutex_unlock(&pobjs_mutex);
138 
139 	return TEE_SUCCESS;
140 }
141 
142 TEE_Result tee_pobj_rename(struct tee_pobj *obj, void *obj_id,
143 			   uint32_t obj_id_len)
144 {
145 	TEE_Result res = TEE_SUCCESS;
146 	void *new_obj_id = NULL;
147 
148 	if (obj == NULL || obj_id == NULL)
149 		return TEE_ERROR_BAD_PARAMETERS;
150 
151 	mutex_lock(&pobjs_mutex);
152 	if (obj->refcnt != 1) {
153 		res = TEE_ERROR_BAD_STATE;
154 		goto exit;
155 	}
156 
157 	new_obj_id = malloc(obj_id_len);
158 	if (new_obj_id == NULL) {
159 		res = TEE_ERROR_OUT_OF_MEMORY;
160 		goto exit;
161 	}
162 	memcpy(new_obj_id, obj_id, obj_id_len);
163 
164 	/* update internal data */
165 	free(obj->obj_id);
166 	obj->obj_id = new_obj_id;
167 	obj->obj_id_len = obj_id_len;
168 	new_obj_id = NULL;
169 
170 exit:
171 	mutex_unlock(&pobjs_mutex);
172 	free(new_obj_id);
173 	return res;
174 }
175