1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2020 ARM Limited 3 4 #include <fcntl.h> 5 #include <sched.h> 6 #include <signal.h> 7 #include <stdio.h> 8 #include <stdlib.h> 9 #include <unistd.h> 10 11 #include <linux/auxvec.h> 12 #include <sys/auxv.h> 13 #include <sys/mman.h> 14 #include <sys/prctl.h> 15 16 #include <asm/hwcap.h> 17 18 #include "kselftest.h" 19 #include "mte_common_util.h" 20 #include "mte_def.h" 21 22 #define INIT_BUFFER_SIZE 256 23 24 struct mte_fault_cxt cur_mte_cxt; 25 static unsigned int mte_cur_mode; 26 static unsigned int mte_cur_pstate_tco; 27 28 void mte_default_handler(int signum, siginfo_t *si, void *uc) 29 { 30 unsigned long addr = (unsigned long)si->si_addr; 31 32 if (signum == SIGSEGV) { 33 #ifdef DEBUG 34 ksft_print_msg("INFO: SIGSEGV signal at pc=%lx, fault addr=%lx, si_code=%lx\n", 35 ((ucontext_t *)uc)->uc_mcontext.pc, addr, si->si_code); 36 #endif 37 if (si->si_code == SEGV_MTEAERR) { 38 if (cur_mte_cxt.trig_si_code == si->si_code) 39 cur_mte_cxt.fault_valid = true; 40 else 41 ksft_print_msg("Got unexpected SEGV_MTEAERR at pc=%llx, fault addr=%lx\n", 42 ((ucontext_t *)uc)->uc_mcontext.pc, 43 addr); 44 return; 45 } 46 /* Compare the context for precise error */ 47 else if (si->si_code == SEGV_MTESERR) { 48 if (cur_mte_cxt.trig_si_code == si->si_code && 49 ((cur_mte_cxt.trig_range >= 0 && 50 addr >= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) && 51 addr <= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range)) || 52 (cur_mte_cxt.trig_range < 0 && 53 addr <= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) && 54 addr >= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range)))) { 55 cur_mte_cxt.fault_valid = true; 56 /* Adjust the pc by 4 */ 57 ((ucontext_t *)uc)->uc_mcontext.pc += 4; 58 } else { 59 ksft_print_msg("Invalid MTE synchronous exception caught!\n"); 60 exit(1); 61 } 62 } else { 63 ksft_print_msg("Unknown SIGSEGV exception caught!\n"); 64 exit(1); 65 } 66 } else if (signum == SIGBUS) { 67 ksft_print_msg("INFO: SIGBUS signal at pc=%llx, fault addr=%lx, si_code=%x\n", 68 ((ucontext_t *)uc)->uc_mcontext.pc, addr, si->si_code); 69 if ((cur_mte_cxt.trig_range >= 0 && 70 addr >= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) && 71 addr <= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range)) || 72 (cur_mte_cxt.trig_range < 0 && 73 addr <= MT_CLEAR_TAG(cur_mte_cxt.trig_addr) && 74 addr >= (MT_CLEAR_TAG(cur_mte_cxt.trig_addr) + cur_mte_cxt.trig_range))) { 75 cur_mte_cxt.fault_valid = true; 76 /* Adjust the pc by 4 */ 77 ((ucontext_t *)uc)->uc_mcontext.pc += 4; 78 } 79 } 80 } 81 82 void mte_register_signal(int signal, void (*handler)(int, siginfo_t *, void *)) 83 { 84 struct sigaction sa; 85 86 sa.sa_sigaction = handler; 87 sa.sa_flags = SA_SIGINFO; 88 sigemptyset(&sa.sa_mask); 89 sigaction(signal, &sa, NULL); 90 } 91 92 void mte_wait_after_trig(void) 93 { 94 sched_yield(); 95 } 96 97 void *mte_insert_tags(void *ptr, size_t size) 98 { 99 void *tag_ptr; 100 int align_size; 101 102 if (!ptr || (unsigned long)(ptr) & MT_ALIGN_GRANULE) { 103 ksft_print_msg("FAIL: Addr=%p: invalid\n", ptr); 104 return NULL; 105 } 106 align_size = MT_ALIGN_UP(size); 107 tag_ptr = mte_insert_random_tag(ptr); 108 mte_set_tag_address_range(tag_ptr, align_size); 109 return tag_ptr; 110 } 111 112 void mte_clear_tags(void *ptr, size_t size) 113 { 114 if (!ptr || (unsigned long)(ptr) & MT_ALIGN_GRANULE) { 115 ksft_print_msg("FAIL: Addr=%p: invalid\n", ptr); 116 return; 117 } 118 size = MT_ALIGN_UP(size); 119 ptr = (void *)MT_CLEAR_TAG((unsigned long)ptr); 120 mte_clear_tag_address_range(ptr, size); 121 } 122 123 static void *__mte_allocate_memory_range(size_t size, int mem_type, int mapping, 124 size_t range_before, size_t range_after, 125 bool tags, int fd) 126 { 127 void *ptr; 128 int prot_flag, map_flag; 129 size_t entire_size = size + range_before + range_after; 130 131 switch (mem_type) { 132 case USE_MALLOC: 133 return malloc(entire_size) + range_before; 134 case USE_MMAP: 135 case USE_MPROTECT: 136 break; 137 default: 138 ksft_print_msg("FAIL: Invalid allocate request\n"); 139 return NULL; 140 } 141 142 prot_flag = PROT_READ | PROT_WRITE; 143 if (mem_type == USE_MMAP) 144 prot_flag |= PROT_MTE; 145 146 map_flag = mapping; 147 if (fd == -1) 148 map_flag = MAP_ANONYMOUS | map_flag; 149 if (!(mapping & MAP_SHARED)) 150 map_flag |= MAP_PRIVATE; 151 ptr = mmap(NULL, entire_size, prot_flag, map_flag, fd, 0); 152 if (ptr == MAP_FAILED) { 153 ksft_perror("mmap()"); 154 return NULL; 155 } 156 if (mem_type == USE_MPROTECT) { 157 if (mprotect(ptr, entire_size, prot_flag | PROT_MTE)) { 158 ksft_perror("mprotect(PROT_MTE)"); 159 munmap(ptr, size); 160 return NULL; 161 } 162 } 163 if (tags) 164 ptr = mte_insert_tags(ptr + range_before, size); 165 return ptr; 166 } 167 168 void *mte_allocate_memory_tag_range(size_t size, int mem_type, int mapping, 169 size_t range_before, size_t range_after) 170 { 171 return __mte_allocate_memory_range(size, mem_type, mapping, range_before, 172 range_after, true, -1); 173 } 174 175 void *mte_allocate_memory(size_t size, int mem_type, int mapping, bool tags) 176 { 177 return __mte_allocate_memory_range(size, mem_type, mapping, 0, 0, tags, -1); 178 } 179 180 void *mte_allocate_file_memory(size_t size, int mem_type, int mapping, bool tags, int fd) 181 { 182 int index; 183 char buffer[INIT_BUFFER_SIZE]; 184 185 if (mem_type != USE_MPROTECT && mem_type != USE_MMAP) { 186 ksft_print_msg("FAIL: Invalid mmap file request\n"); 187 return NULL; 188 } 189 /* Initialize the file for mappable size */ 190 lseek(fd, 0, SEEK_SET); 191 for (index = INIT_BUFFER_SIZE; index < size; index += INIT_BUFFER_SIZE) { 192 if (write(fd, buffer, INIT_BUFFER_SIZE) != INIT_BUFFER_SIZE) { 193 ksft_perror("initialising buffer"); 194 return NULL; 195 } 196 } 197 index -= INIT_BUFFER_SIZE; 198 if (write(fd, buffer, size - index) != size - index) { 199 ksft_perror("initialising buffer"); 200 return NULL; 201 } 202 return __mte_allocate_memory_range(size, mem_type, mapping, 0, 0, tags, fd); 203 } 204 205 void *mte_allocate_file_memory_tag_range(size_t size, int mem_type, int mapping, 206 size_t range_before, size_t range_after, int fd) 207 { 208 int index; 209 char buffer[INIT_BUFFER_SIZE]; 210 int map_size = size + range_before + range_after; 211 212 if (mem_type != USE_MPROTECT && mem_type != USE_MMAP) { 213 ksft_print_msg("FAIL: Invalid mmap file request\n"); 214 return NULL; 215 } 216 /* Initialize the file for mappable size */ 217 lseek(fd, 0, SEEK_SET); 218 for (index = INIT_BUFFER_SIZE; index < map_size; index += INIT_BUFFER_SIZE) 219 if (write(fd, buffer, INIT_BUFFER_SIZE) != INIT_BUFFER_SIZE) { 220 ksft_perror("initialising buffer"); 221 return NULL; 222 } 223 index -= INIT_BUFFER_SIZE; 224 if (write(fd, buffer, map_size - index) != map_size - index) { 225 ksft_perror("initialising buffer"); 226 return NULL; 227 } 228 return __mte_allocate_memory_range(size, mem_type, mapping, range_before, 229 range_after, true, fd); 230 } 231 232 static void __mte_free_memory_range(void *ptr, size_t size, int mem_type, 233 size_t range_before, size_t range_after, bool tags) 234 { 235 switch (mem_type) { 236 case USE_MALLOC: 237 free(ptr - range_before); 238 break; 239 case USE_MMAP: 240 case USE_MPROTECT: 241 if (tags) 242 mte_clear_tags(ptr, size); 243 munmap(ptr - range_before, size + range_before + range_after); 244 break; 245 default: 246 ksft_print_msg("FAIL: Invalid free request\n"); 247 break; 248 } 249 } 250 251 void mte_free_memory_tag_range(void *ptr, size_t size, int mem_type, 252 size_t range_before, size_t range_after) 253 { 254 __mte_free_memory_range(ptr, size, mem_type, range_before, range_after, true); 255 } 256 257 void mte_free_memory(void *ptr, size_t size, int mem_type, bool tags) 258 { 259 __mte_free_memory_range(ptr, size, mem_type, 0, 0, tags); 260 } 261 262 void mte_initialize_current_context(int mode, uintptr_t ptr, ssize_t range) 263 { 264 cur_mte_cxt.fault_valid = false; 265 cur_mte_cxt.trig_addr = ptr; 266 cur_mte_cxt.trig_range = range; 267 if (mode == MTE_SYNC_ERR) 268 cur_mte_cxt.trig_si_code = SEGV_MTESERR; 269 else if (mode == MTE_ASYNC_ERR) 270 cur_mte_cxt.trig_si_code = SEGV_MTEAERR; 271 else 272 cur_mte_cxt.trig_si_code = 0; 273 } 274 275 int mte_switch_mode(int mte_option, unsigned long incl_mask) 276 { 277 unsigned long en = 0; 278 279 switch (mte_option) { 280 case MTE_NONE_ERR: 281 case MTE_SYNC_ERR: 282 case MTE_ASYNC_ERR: 283 break; 284 default: 285 ksft_print_msg("FAIL: Invalid MTE option %x\n", mte_option); 286 return -EINVAL; 287 } 288 289 if (incl_mask & ~MT_INCLUDE_TAG_MASK) { 290 ksft_print_msg("FAIL: Invalid incl_mask %lx\n", incl_mask); 291 return -EINVAL; 292 } 293 294 en = PR_TAGGED_ADDR_ENABLE; 295 switch (mte_option) { 296 case MTE_SYNC_ERR: 297 en |= PR_MTE_TCF_SYNC; 298 break; 299 case MTE_ASYNC_ERR: 300 en |= PR_MTE_TCF_ASYNC; 301 break; 302 case MTE_NONE_ERR: 303 en |= PR_MTE_TCF_NONE; 304 break; 305 } 306 307 en |= (incl_mask << PR_MTE_TAG_SHIFT); 308 /* Enable address tagging ABI, mte error reporting mode and tag inclusion mask. */ 309 if (prctl(PR_SET_TAGGED_ADDR_CTRL, en, 0, 0, 0) != 0) { 310 ksft_print_msg("FAIL:prctl PR_SET_TAGGED_ADDR_CTRL for mte mode\n"); 311 return -EINVAL; 312 } 313 return 0; 314 } 315 316 int mte_default_setup(void) 317 { 318 unsigned long hwcaps2 = getauxval(AT_HWCAP2); 319 unsigned long en = 0; 320 int ret; 321 322 if (!(hwcaps2 & HWCAP2_MTE)) 323 ksft_exit_skip("MTE features unavailable\n"); 324 325 /* Get current mte mode */ 326 ret = prctl(PR_GET_TAGGED_ADDR_CTRL, en, 0, 0, 0); 327 if (ret < 0) { 328 ksft_print_msg("FAIL:prctl PR_GET_TAGGED_ADDR_CTRL with error =%d\n", ret); 329 return KSFT_FAIL; 330 } 331 if (ret & PR_MTE_TCF_SYNC) 332 mte_cur_mode = MTE_SYNC_ERR; 333 else if (ret & PR_MTE_TCF_ASYNC) 334 mte_cur_mode = MTE_ASYNC_ERR; 335 else if (ret & PR_MTE_TCF_NONE) 336 mte_cur_mode = MTE_NONE_ERR; 337 338 mte_cur_pstate_tco = mte_get_pstate_tco(); 339 /* Disable PSTATE.TCO */ 340 mte_disable_pstate_tco(); 341 return 0; 342 } 343 344 void mte_restore_setup(void) 345 { 346 mte_switch_mode(mte_cur_mode, MTE_ALLOW_NON_ZERO_TAG); 347 if (mte_cur_pstate_tco == MT_PSTATE_TCO_EN) 348 mte_enable_pstate_tco(); 349 else if (mte_cur_pstate_tco == MT_PSTATE_TCO_DIS) 350 mte_disable_pstate_tco(); 351 } 352 353 int create_temp_file(void) 354 { 355 int fd; 356 char filename[] = "/dev/shm/tmp_XXXXXX"; 357 358 /* Create a file in the tmpfs filesystem */ 359 fd = mkstemp(&filename[0]); 360 if (fd == -1) { 361 ksft_perror(filename); 362 ksft_print_msg("FAIL: Unable to open temporary file\n"); 363 return 0; 364 } 365 unlink(&filename[0]); 366 return fd; 367 } 368