1 // SPDX-License-Identifier: BSD-2-Clause 2 /* 3 * Copyright (c) 2014, STMicroelectronics International N.V. 4 * Copyright (c) 2015-2020, 2022 Linaro Limited 5 */ 6 7 #include <initcall.h> 8 #include <kernel/linker.h> 9 #include <kernel/user_access.h> 10 #include <kernel/user_mode_ctx.h> 11 #include <memtag.h> 12 #include <mm/vm.h> 13 #include <string.h> 14 #include <tee_api_types.h> 15 #include <types_ext.h> 16 17 #define BB_ALIGNMENT (sizeof(long) * 2) 18 19 static struct user_mode_ctx *get_current_uctx(void) 20 { 21 struct ts_session *s = ts_get_current_session(); 22 23 if (!is_user_mode_ctx(s->ctx)) { 24 /* 25 * We may be called within a PTA session, which doesn't 26 * have a user_mode_ctx. Here, try to retrieve the 27 * user_mode_ctx associated with the calling session. 28 */ 29 s = TAILQ_NEXT(s, link_tsd); 30 if (!s || !is_user_mode_ctx(s->ctx)) 31 return NULL; 32 } 33 34 return to_user_mode_ctx(s->ctx); 35 } 36 37 TEE_Result check_user_access(uint32_t flags, const void *uaddr, size_t len) 38 { 39 struct user_mode_ctx *uctx = get_current_uctx(); 40 41 if (!uctx) 42 return TEE_ERROR_GENERIC; 43 44 return vm_check_access_rights(uctx, flags, (vaddr_t)uaddr, len); 45 } 46 47 TEE_Result copy_from_user(void *kaddr, const void *uaddr, size_t len) 48 { 49 uint32_t flags = TEE_MEMORY_ACCESS_READ | TEE_MEMORY_ACCESS_ANY_OWNER; 50 TEE_Result res = TEE_SUCCESS; 51 52 uaddr = memtag_strip_tag_const(uaddr); 53 res = check_user_access(flags, uaddr, len); 54 if (!res) { 55 enter_user_access(); 56 memcpy(kaddr, uaddr, len); 57 exit_user_access(); 58 } 59 60 return res; 61 } 62 63 TEE_Result copy_to_user(void *uaddr, const void *kaddr, size_t len) 64 { 65 uint32_t flags = TEE_MEMORY_ACCESS_WRITE | TEE_MEMORY_ACCESS_ANY_OWNER; 66 TEE_Result res = TEE_SUCCESS; 67 68 uaddr = memtag_strip_tag(uaddr); 69 res = check_user_access(flags, uaddr, len); 70 if (!res) { 71 enter_user_access(); 72 memcpy(uaddr, kaddr, len); 73 exit_user_access(); 74 } 75 76 return res; 77 } 78 79 TEE_Result copy_from_user_private(void *kaddr, const void *uaddr, size_t len) 80 { 81 uint32_t flags = TEE_MEMORY_ACCESS_READ; 82 TEE_Result res = TEE_SUCCESS; 83 84 uaddr = memtag_strip_tag_const(uaddr); 85 res = check_user_access(flags, uaddr, len); 86 if (!res) { 87 enter_user_access(); 88 memcpy(kaddr, uaddr, len); 89 exit_user_access(); 90 } 91 92 return res; 93 } 94 95 TEE_Result copy_to_user_private(void *uaddr, const void *kaddr, size_t len) 96 { 97 uint32_t flags = TEE_MEMORY_ACCESS_WRITE; 98 TEE_Result res = TEE_SUCCESS; 99 100 uaddr = memtag_strip_tag(uaddr); 101 res = check_user_access(flags, uaddr, len); 102 if (!res) { 103 enter_user_access(); 104 memcpy(uaddr, kaddr, len); 105 exit_user_access(); 106 } 107 108 return res; 109 } 110 111 void *bb_alloc(size_t len) 112 { 113 struct user_mode_ctx *uctx = get_current_uctx(); 114 size_t offs = 0; 115 void *bb = NULL; 116 117 if (uctx && !ADD_OVERFLOW(uctx->bbuf_offs, len, &offs) && 118 offs <= uctx->bbuf_size) { 119 bb = uctx->bbuf + uctx->bbuf_offs; 120 uctx->bbuf_offs = ROUNDUP(offs, BB_ALIGNMENT); 121 } 122 return bb; 123 } 124 125 static void bb_free_helper(struct user_mode_ctx *uctx, vaddr_t bb, size_t len) 126 { 127 vaddr_t bbuf = (vaddr_t)uctx->bbuf; 128 129 if (bb >= bbuf && IS_ALIGNED(bb, BB_ALIGNMENT)) { 130 size_t prev_offs = bb - bbuf; 131 132 if (prev_offs + ROUNDUP(len, BB_ALIGNMENT) == uctx->bbuf_offs) 133 uctx->bbuf_offs = prev_offs; 134 } 135 } 136 137 void bb_free(void *bb, size_t len) 138 { 139 struct user_mode_ctx *uctx = get_current_uctx(); 140 141 if (uctx) 142 bb_free_helper(uctx, (vaddr_t)bb, len); 143 } 144 145 void bb_reset(void) 146 { 147 struct user_mode_ctx *uctx = get_current_uctx(); 148 149 if (uctx) 150 uctx->bbuf_offs = 0; 151 } 152 153 TEE_Result clear_user(void *uaddr, size_t n) 154 { 155 uint32_t flags = TEE_MEMORY_ACCESS_WRITE | TEE_MEMORY_ACCESS_ANY_OWNER; 156 TEE_Result res = TEE_SUCCESS; 157 158 uaddr = memtag_strip_tag(uaddr); 159 res = check_user_access(flags, uaddr, n); 160 if (res) 161 return res; 162 163 enter_user_access(); 164 memset(uaddr, 0, n); 165 exit_user_access(); 166 167 return TEE_SUCCESS; 168 } 169 170 size_t strnlen_user(const void *uaddr, size_t len) 171 { 172 uint32_t flags = TEE_MEMORY_ACCESS_READ | TEE_MEMORY_ACCESS_ANY_OWNER; 173 TEE_Result res = TEE_SUCCESS; 174 size_t n = 0; 175 176 uaddr = memtag_strip_tag_const(uaddr); 177 res = check_user_access(flags, uaddr, len); 178 if (!res) { 179 enter_user_access(); 180 n = strnlen(uaddr, len); 181 exit_user_access(); 182 } 183 184 return n; 185 } 186 187 TEE_Result bb_memdup_user(const void *src, size_t len, void **p) 188 { 189 TEE_Result res = TEE_SUCCESS; 190 void *buf = NULL; 191 192 buf = bb_alloc(len); 193 if (!buf) 194 return TEE_ERROR_OUT_OF_MEMORY; 195 196 res = copy_from_user(buf, src, len); 197 if (res) 198 bb_free(buf, len); 199 else 200 *p = buf; 201 202 return res; 203 } 204 205 TEE_Result bb_memdup_user_private(const void *src, size_t len, void **p) 206 { 207 TEE_Result res = TEE_SUCCESS; 208 void *buf = NULL; 209 210 buf = bb_alloc(len); 211 if (!buf) 212 return TEE_ERROR_OUT_OF_MEMORY; 213 214 res = copy_from_user_private(buf, src, len); 215 if (res) 216 bb_free(buf, len); 217 else 218 *p = buf; 219 220 return res; 221 } 222 223 TEE_Result bb_strndup_user(const char *src, size_t maxlen, char **dst, 224 size_t *dstlen) 225 { 226 uint32_t flags = TEE_MEMORY_ACCESS_READ | TEE_MEMORY_ACCESS_ANY_OWNER; 227 TEE_Result res = TEE_SUCCESS; 228 size_t l = 0; 229 char *d = NULL; 230 231 src = memtag_strip_tag_const(src); 232 res = check_user_access(flags, src, maxlen); 233 if (res) 234 return res; 235 236 enter_user_access(); 237 l = strnlen(src, maxlen); 238 exit_user_access(); 239 240 d = bb_alloc(l + 1); 241 if (!d) 242 return TEE_ERROR_OUT_OF_MEMORY; 243 244 enter_user_access(); 245 memcpy(d, src, l); 246 exit_user_access(); 247 248 d[l] = 0; 249 250 *dst = d; 251 *dstlen = l; 252 return TEE_SUCCESS; 253 } 254 255 TEE_Result copy_kaddr_to_uref(uint32_t *uref, void *kaddr) 256 { 257 uint32_t ref = kaddr_to_uref(kaddr); 258 259 return copy_to_user_private(uref, &ref, sizeof(ref)); 260 } 261 262 uint32_t kaddr_to_uref(void *kaddr) 263 { 264 if (MEMTAG_IS_ENABLED) { 265 unsigned int uref_tag_shift = 32 - MEMTAG_TAG_WIDTH; 266 vaddr_t uref = memtag_strip_tag_vaddr(kaddr); 267 268 uref -= VCORE_START_VA; 269 assert(uref < (UINT32_MAX >> MEMTAG_TAG_WIDTH)); 270 uref |= memtag_get_tag(kaddr) << uref_tag_shift; 271 return uref; 272 } 273 274 assert(((vaddr_t)kaddr - VCORE_START_VA) < UINT32_MAX); 275 return (vaddr_t)kaddr - VCORE_START_VA; 276 } 277 278 vaddr_t uref_to_vaddr(uint32_t uref) 279 { 280 if (MEMTAG_IS_ENABLED) { 281 vaddr_t u = uref & (UINT32_MAX >> MEMTAG_TAG_WIDTH); 282 unsigned int uref_tag_shift = 32 - MEMTAG_TAG_WIDTH; 283 uint8_t tag = uref >> uref_tag_shift; 284 285 return memtag_insert_tag_vaddr(VCORE_START_VA + u, tag); 286 } 287 288 return VCORE_START_VA + uref; 289 } 290