1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2017, Anshuman Khandual, IBM Corp. 4 * 5 * Works on architectures which support 128TB virtual 6 * address range and beyond. 7 */ 8 #include <stdio.h> 9 #include <stdlib.h> 10 #include <string.h> 11 #include <unistd.h> 12 #include <errno.h> 13 #include <sys/prctl.h> 14 #include <sys/mman.h> 15 #include <sys/time.h> 16 #include <fcntl.h> 17 18 #include "vm_util.h" 19 #include "../kselftest.h" 20 21 /* 22 * Maximum address range mapped with a single mmap() 23 * call is little bit more than 1GB. Hence 1GB is 24 * chosen as the single chunk size for address space 25 * mapping. 26 */ 27 28 #define SZ_1GB (1024 * 1024 * 1024UL) 29 #define SZ_1TB (1024 * 1024 * 1024 * 1024UL) 30 31 #define MAP_CHUNK_SIZE SZ_1GB 32 33 /* 34 * Address space till 128TB is mapped without any hint 35 * and is enabled by default. Address space beyond 128TB 36 * till 512TB is obtained by passing hint address as the 37 * first argument into mmap() system call. 38 * 39 * The process heap address space is divided into two 40 * different areas one below 128TB and one above 128TB 41 * till it reaches 512TB. One with size 128TB and the 42 * other being 384TB. 43 * 44 * On Arm64 the address space is 256TB and support for 45 * high mappings up to 4PB virtual address space has 46 * been added. 47 */ 48 49 #define NR_CHUNKS_128TB ((128 * SZ_1TB) / MAP_CHUNK_SIZE) /* Number of chunks for 128TB */ 50 #define NR_CHUNKS_256TB (NR_CHUNKS_128TB * 2UL) 51 #define NR_CHUNKS_384TB (NR_CHUNKS_128TB * 3UL) 52 #define NR_CHUNKS_3840TB (NR_CHUNKS_128TB * 30UL) 53 54 #define ADDR_MARK_128TB (1UL << 47) /* First address beyond 128TB */ 55 #define ADDR_MARK_256TB (1UL << 48) /* First address beyond 256TB */ 56 57 #ifdef __aarch64__ 58 #define HIGH_ADDR_MARK ADDR_MARK_256TB 59 #define HIGH_ADDR_SHIFT 49 60 #define NR_CHUNKS_LOW NR_CHUNKS_256TB 61 #define NR_CHUNKS_HIGH NR_CHUNKS_3840TB 62 #else 63 #define HIGH_ADDR_MARK ADDR_MARK_128TB 64 #define HIGH_ADDR_SHIFT 48 65 #define NR_CHUNKS_LOW NR_CHUNKS_128TB 66 #define NR_CHUNKS_HIGH NR_CHUNKS_384TB 67 #endif 68 69 static char *hint_addr(void) 70 { 71 int bits = HIGH_ADDR_SHIFT + rand() % (63 - HIGH_ADDR_SHIFT); 72 73 return (char *) (1UL << bits); 74 } 75 76 static void validate_addr(char *ptr, int high_addr) 77 { 78 unsigned long addr = (unsigned long) ptr; 79 80 if (high_addr) { 81 if (addr < HIGH_ADDR_MARK) 82 ksft_exit_fail_msg("Bad address %lx\n", addr); 83 return; 84 } 85 86 if (addr > HIGH_ADDR_MARK) 87 ksft_exit_fail_msg("Bad address %lx\n", addr); 88 } 89 90 static void mark_range(char *ptr, size_t size) 91 { 92 if (prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, "virtual_address_range") == -1) { 93 if (errno == EINVAL) { 94 /* Depends on CONFIG_ANON_VMA_NAME */ 95 ksft_test_result_skip("prctl(PR_SET_VMA_ANON_NAME) not supported\n"); 96 ksft_finished(); 97 } else { 98 ksft_exit_fail_perror("prctl(PR_SET_VMA_ANON_NAME) failed\n"); 99 } 100 } 101 } 102 103 static int is_marked_vma(const char *vma_name) 104 { 105 return vma_name && !strcmp(vma_name, "[anon:virtual_address_range]\n"); 106 } 107 108 static int validate_lower_address_hint(void) 109 { 110 char *ptr; 111 112 ptr = mmap((void *) (1UL << 45), MAP_CHUNK_SIZE, PROT_READ | 113 PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 114 115 if (ptr == MAP_FAILED) 116 return 0; 117 118 return 1; 119 } 120 121 static int validate_complete_va_space(void) 122 { 123 unsigned long start_addr, end_addr, prev_end_addr; 124 char line[400]; 125 char prot[6]; 126 FILE *file; 127 int fd; 128 129 fd = open("va_dump", O_CREAT | O_WRONLY, 0600); 130 unlink("va_dump"); 131 if (fd < 0) { 132 ksft_test_result_skip("cannot create or open dump file\n"); 133 ksft_finished(); 134 } 135 136 file = fopen("/proc/self/maps", "r"); 137 if (file == NULL) 138 ksft_exit_fail_msg("cannot open /proc/self/maps\n"); 139 140 prev_end_addr = 0; 141 while (fgets(line, sizeof(line), file)) { 142 const char *vma_name = NULL; 143 int vma_name_start = 0; 144 unsigned long hop; 145 146 if (sscanf(line, "%lx-%lx %4s %*s %*s %*s %n", 147 &start_addr, &end_addr, prot, &vma_name_start) != 3) 148 ksft_exit_fail_msg("cannot parse /proc/self/maps\n"); 149 150 if (vma_name_start) 151 vma_name = line + vma_name_start; 152 153 /* end of userspace mappings; ignore vsyscall mapping */ 154 if (start_addr & (1UL << 63)) 155 return 0; 156 157 /* /proc/self/maps must have gaps less than MAP_CHUNK_SIZE */ 158 if (start_addr - prev_end_addr >= MAP_CHUNK_SIZE) 159 return 1; 160 161 prev_end_addr = end_addr; 162 163 if (prot[0] != 'r') 164 continue; 165 166 if (check_vmflag_io((void *)start_addr)) 167 continue; 168 169 /* 170 * Confirm whether MAP_CHUNK_SIZE chunk can be found or not. 171 * If write succeeds, no need to check MAP_CHUNK_SIZE - 1 172 * addresses after that. If the address was not held by this 173 * process, write would fail with errno set to EFAULT. 174 * Anyways, if write returns anything apart from 1, exit the 175 * program since that would mean a bug in /proc/self/maps. 176 */ 177 hop = 0; 178 while (start_addr + hop < end_addr) { 179 if (write(fd, (void *)(start_addr + hop), 1) != 1) 180 return 1; 181 lseek(fd, 0, SEEK_SET); 182 183 if (is_marked_vma(vma_name)) 184 munmap((char *)(start_addr + hop), MAP_CHUNK_SIZE); 185 186 hop += MAP_CHUNK_SIZE; 187 } 188 } 189 return 0; 190 } 191 192 int main(int argc, char *argv[]) 193 { 194 char *ptr[NR_CHUNKS_LOW]; 195 char **hptr; 196 char *hint; 197 unsigned long i, lchunks, hchunks; 198 199 ksft_print_header(); 200 ksft_set_plan(1); 201 202 for (i = 0; i < NR_CHUNKS_LOW; i++) { 203 ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ, 204 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 205 206 if (ptr[i] == MAP_FAILED) { 207 if (validate_lower_address_hint()) 208 ksft_exit_fail_msg("mmap unexpectedly succeeded with hint\n"); 209 break; 210 } 211 212 mark_range(ptr[i], MAP_CHUNK_SIZE); 213 validate_addr(ptr[i], 0); 214 } 215 lchunks = i; 216 hptr = (char **) calloc(NR_CHUNKS_HIGH, sizeof(char *)); 217 if (hptr == NULL) { 218 ksft_test_result_skip("Memory constraint not fulfilled\n"); 219 ksft_finished(); 220 } 221 222 for (i = 0; i < NR_CHUNKS_HIGH; i++) { 223 hint = hint_addr(); 224 hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ, 225 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 226 227 if (hptr[i] == MAP_FAILED) 228 break; 229 230 mark_range(ptr[i], MAP_CHUNK_SIZE); 231 validate_addr(hptr[i], 1); 232 } 233 hchunks = i; 234 if (validate_complete_va_space()) { 235 ksft_test_result_fail("BUG in mmap() or /proc/self/maps\n"); 236 ksft_finished(); 237 } 238 239 for (i = 0; i < lchunks; i++) 240 munmap(ptr[i], MAP_CHUNK_SIZE); 241 242 for (i = 0; i < hchunks; i++) 243 munmap(hptr[i], MAP_CHUNK_SIZE); 244 245 free(hptr); 246 247 ksft_test_result_pass("Test\n"); 248 ksft_finished(); 249 } 250