1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (c) 2014-2020, Linaro Limited
4 */
5
6 #include <stdlib.h>
7 #include <tee_internal_api.h>
8
9 #include "handle.h"
10
11 /*
12 * Define the initial capacity of the database. It should be a low number
13 * multiple of 2 since some databases a likely to only use a few handles.
14 * Since the algorithm is to doubles up when growing it shouldn't cause a
15 * noticeable overhead on large databases.
16 */
17 #define HANDLE_DB_INITIAL_MAX_PTRS 4
18
19 /* Specific pointer ~0 denotes a still allocated but invalid handle */
20 #define INVALID_HANDLE_PTR ((void *)~0)
21
handle_db_init(struct handle_db * db)22 void handle_db_init(struct handle_db *db)
23 {
24 TEE_MemFill(db, 0, sizeof(*db));
25 }
26
handle_db_destroy(struct handle_db * db)27 void handle_db_destroy(struct handle_db *db)
28 {
29 if (db) {
30 TEE_Free(db->ptrs);
31 db->ptrs = NULL;
32 db->max_ptrs = 0;
33 }
34 }
35
handle_get(struct handle_db * db,void * ptr)36 uint32_t handle_get(struct handle_db *db, void *ptr)
37 {
38 uint32_t n = 0;
39 void *p = NULL;
40 uint32_t new_max_ptrs = 0;
41
42 if (!db || !ptr || ptr == INVALID_HANDLE_PTR)
43 return 0;
44
45 /* Try to find an empty location (index 0 is reserved as invalid) */
46 for (n = 1; n < db->max_ptrs; n++) {
47 if (!db->ptrs[n]) {
48 db->ptrs[n] = ptr;
49 return n;
50 }
51 }
52
53 /* No location available, grow the ptrs array */
54 if (db->max_ptrs)
55 new_max_ptrs = db->max_ptrs * 2;
56 else
57 new_max_ptrs = HANDLE_DB_INITIAL_MAX_PTRS;
58
59 p = TEE_Realloc(db->ptrs, new_max_ptrs * sizeof(void *));
60 if (!p)
61 return 0;
62 db->ptrs = p;
63 TEE_MemFill(db->ptrs + db->max_ptrs, 0,
64 (new_max_ptrs - db->max_ptrs) * sizeof(void *));
65 db->max_ptrs = new_max_ptrs;
66
67 /* Since n stopped at db->max_ptrs there is an empty location there */
68 db->ptrs[n] = ptr;
69 return n;
70 }
71
handle_is_valid(struct handle_db * db,uint32_t handle)72 static bool handle_is_valid(struct handle_db *db, uint32_t handle)
73 {
74 return db && handle && handle < db->max_ptrs;
75 }
76
handle_put(struct handle_db * db,uint32_t handle)77 void *handle_put(struct handle_db *db, uint32_t handle)
78 {
79 void *p = NULL;
80
81 if (!handle_is_valid(db, handle))
82 return NULL;
83
84 p = db->ptrs[handle];
85 db->ptrs[handle] = NULL;
86 return p;
87 }
88
handle_lookup(struct handle_db * db,uint32_t handle)89 void *handle_lookup(struct handle_db *db, uint32_t handle)
90 {
91 if (!handle_is_valid(db, handle) ||
92 db->ptrs[handle] == INVALID_HANDLE_PTR)
93 return NULL;
94
95 return db->ptrs[handle];
96 }
97
handle_invalidate(struct handle_db * db,uint32_t handle)98 void handle_invalidate(struct handle_db *db, uint32_t handle)
99 {
100 if (handle_is_valid(db, handle)) {
101 if (!db->ptrs[handle])
102 TEE_Panic(TEE_ERROR_GENERIC);
103
104 db->ptrs[handle] = INVALID_HANDLE_PTR;
105 }
106 }
107
handle_lookup_handle(struct handle_db * db,void * ptr)108 uint32_t handle_lookup_handle(struct handle_db *db, void *ptr)
109 {
110 uint32_t n = 0;
111
112 if (ptr && ptr != INVALID_HANDLE_PTR) {
113 for (n = 1; n < db->max_ptrs; n++)
114 if (db->ptrs[n] == ptr)
115 return n;
116 }
117
118 return 0;
119 }
120