1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2020 ARM Limited 3 4 #define _GNU_SOURCE 5 6 #include <errno.h> 7 #include <fcntl.h> 8 #include <signal.h> 9 #include <stdlib.h> 10 #include <stdio.h> 11 #include <string.h> 12 #include <ucontext.h> 13 #include <unistd.h> 14 #include <sys/mman.h> 15 16 #include "kselftest.h" 17 #include "mte_common_util.h" 18 #include "mte_def.h" 19 20 static size_t page_sz; 21 22 static int check_usermem_access_fault(int mem_type, int mode, int mapping) 23 { 24 int fd, i, err; 25 char val = 'A'; 26 size_t len, read_len; 27 void *ptr, *ptr_next; 28 29 err = KSFT_FAIL; 30 len = 2 * page_sz; 31 mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG); 32 fd = create_temp_file(); 33 if (fd == -1) 34 return KSFT_FAIL; 35 for (i = 0; i < len; i++) 36 if (write(fd, &val, sizeof(val)) != sizeof(val)) 37 return KSFT_FAIL; 38 lseek(fd, 0, 0); 39 ptr = mte_allocate_memory(len, mem_type, mapping, true); 40 if (check_allocated_memory(ptr, len, mem_type, true) != KSFT_PASS) { 41 close(fd); 42 return KSFT_FAIL; 43 } 44 mte_initialize_current_context(mode, (uintptr_t)ptr, len); 45 /* Copy from file into buffer with valid tag */ 46 read_len = read(fd, ptr, len); 47 mte_wait_after_trig(); 48 if (cur_mte_cxt.fault_valid || read_len < len) 49 goto usermem_acc_err; 50 /* Verify same pattern is read */ 51 for (i = 0; i < len; i++) 52 if (*(char *)(ptr + i) != val) 53 break; 54 if (i < len) 55 goto usermem_acc_err; 56 57 /* Tag the next half of memory with different value */ 58 ptr_next = (void *)((unsigned long)ptr + page_sz); 59 ptr_next = mte_insert_new_tag(ptr_next); 60 mte_set_tag_address_range(ptr_next, page_sz); 61 62 lseek(fd, 0, 0); 63 /* Copy from file into buffer with invalid tag */ 64 read_len = read(fd, ptr, len); 65 mte_wait_after_trig(); 66 /* 67 * Accessing user memory in kernel with invalid tag should fail in sync 68 * mode without fault but may not fail in async mode as per the 69 * implemented MTE userspace support in Arm64 kernel. 70 */ 71 if (mode == MTE_SYNC_ERR && 72 !cur_mte_cxt.fault_valid && read_len < len) { 73 err = KSFT_PASS; 74 } else if (mode == MTE_ASYNC_ERR && 75 !cur_mte_cxt.fault_valid && read_len == len) { 76 err = KSFT_PASS; 77 } 78 usermem_acc_err: 79 mte_free_memory((void *)ptr, len, mem_type, true); 80 close(fd); 81 return err; 82 } 83 84 int main(int argc, char *argv[]) 85 { 86 int err; 87 88 page_sz = getpagesize(); 89 if (!page_sz) { 90 ksft_print_msg("ERR: Unable to get page size\n"); 91 return KSFT_FAIL; 92 } 93 err = mte_default_setup(); 94 if (err) 95 return err; 96 97 /* Register signal handlers */ 98 mte_register_signal(SIGSEGV, mte_default_handler); 99 100 /* Set test plan */ 101 ksft_set_plan(4); 102 103 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE), 104 "Check memory access from kernel in sync mode, private mapping and mmap memory\n"); 105 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED), 106 "Check memory access from kernel in sync mode, shared mapping and mmap memory\n"); 107 108 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE), 109 "Check memory access from kernel in async mode, private mapping and mmap memory\n"); 110 evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED), 111 "Check memory access from kernel in async mode, shared mapping and mmap memory\n"); 112 113 mte_restore_setup(); 114 ksft_print_cnts(); 115 return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL; 116 } 117