xref: /optee_os/core/tee/tee_pobj.c (revision 6885abf2f7ef758b0a9c5f3580af167a53ec28dd)
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, enum tee_pobj_usage usage,
62 			const struct tee_file_operations *fops,
63 			struct tee_pobj **obj)
64 {
65 	bool temporary = (usage == TEE_POBJ_USAGE_CREATE);
66 	TEE_Result res = TEE_SUCCESS;
67 	struct tee_pobj *o = NULL;
68 
69 	*obj = NULL;
70 
71 	mutex_lock(&pobjs_mutex);
72 	/* Check if file is open */
73 	TAILQ_FOREACH(o, &tee_pobjs, link) {
74 		if ((obj_id_len == o->obj_id_len) &&
75 		    (memcmp(obj_id, o->obj_id, obj_id_len) == 0) &&
76 		    (memcmp(uuid, &o->uuid, sizeof(TEE_UUID)) == 0) &&
77 		    (fops == o->fops)) {
78 			*obj = o;
79 		}
80 	}
81 
82 	if (*obj) {
83 		if (temporary != (*obj)->temporary) {
84 			res = TEE_ERROR_ACCESS_CONFLICT;
85 			goto out;
86 		}
87 		res = tee_pobj_check_access((*obj)->flags, flags);
88 		if (res == TEE_SUCCESS)
89 			(*obj)->refcnt++;
90 		goto out;
91 	}
92 
93 	/* new file */
94 	o = calloc(1, sizeof(struct tee_pobj));
95 	if (!o) {
96 		res = TEE_ERROR_OUT_OF_MEMORY;
97 		goto out;
98 	}
99 
100 	o->refcnt = 1;
101 	memcpy(&o->uuid, uuid, sizeof(TEE_UUID));
102 	o->flags = flags;
103 	o->fops = fops;
104 	o->temporary = temporary;
105 
106 	o->obj_id = malloc(obj_id_len);
107 	if (o->obj_id == NULL) {
108 		free(o);
109 		res = TEE_ERROR_OUT_OF_MEMORY;
110 		goto out;
111 	}
112 	memcpy(o->obj_id, obj_id, obj_id_len);
113 	o->obj_id_len = obj_id_len;
114 
115 	TAILQ_INSERT_TAIL(&tee_pobjs, o, link);
116 	*obj = o;
117 
118 	res = TEE_SUCCESS;
119 out:
120 	if (res != TEE_SUCCESS)
121 		*obj = NULL;
122 	mutex_unlock(&pobjs_mutex);
123 	return res;
124 }
125 
126 TEE_Result tee_pobj_release(struct tee_pobj *obj)
127 {
128 	if (obj == NULL)
129 		return TEE_ERROR_BAD_PARAMETERS;
130 
131 	mutex_lock(&pobjs_mutex);
132 	obj->refcnt--;
133 	if (obj->refcnt == 0) {
134 		TAILQ_REMOVE(&tee_pobjs, obj, link);
135 		free(obj->obj_id);
136 		free(obj);
137 	}
138 	mutex_unlock(&pobjs_mutex);
139 
140 	return TEE_SUCCESS;
141 }
142 
143 TEE_Result tee_pobj_rename(struct tee_pobj *obj, void *obj_id,
144 			   uint32_t obj_id_len)
145 {
146 	TEE_Result res = TEE_SUCCESS;
147 	void *new_obj_id = NULL;
148 
149 	if (obj == NULL || obj_id == NULL)
150 		return TEE_ERROR_BAD_PARAMETERS;
151 
152 	mutex_lock(&pobjs_mutex);
153 	if (obj->refcnt != 1) {
154 		res = TEE_ERROR_BAD_STATE;
155 		goto exit;
156 	}
157 
158 	new_obj_id = malloc(obj_id_len);
159 	if (new_obj_id == NULL) {
160 		res = TEE_ERROR_OUT_OF_MEMORY;
161 		goto exit;
162 	}
163 	memcpy(new_obj_id, obj_id, obj_id_len);
164 
165 	/* update internal data */
166 	free(obj->obj_id);
167 	obj->obj_id = new_obj_id;
168 	obj->obj_id_len = obj_id_len;
169 	new_obj_id = NULL;
170 
171 exit:
172 	mutex_unlock(&pobjs_mutex);
173 	free(new_obj_id);
174 	return res;
175 }
176