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 && addr < HIGH_ADDR_MARK) 81 ksft_exit_fail_msg("Bad address %lx\n", addr); 82 83 if (addr > HIGH_ADDR_MARK) 84 ksft_exit_fail_msg("Bad address %lx\n", addr); 85 } 86 87 static void mark_range(char *ptr, size_t size) 88 { 89 if (prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, "virtual_address_range") == -1) { 90 if (errno == EINVAL) { 91 /* Depends on CONFIG_ANON_VMA_NAME */ 92 ksft_test_result_skip("prctl(PR_SET_VMA_ANON_NAME) not supported\n"); 93 ksft_finished(); 94 } else { 95 ksft_exit_fail_perror("prctl(PR_SET_VMA_ANON_NAME) failed\n"); 96 } 97 } 98 } 99 100 static int is_marked_vma(const char *vma_name) 101 { 102 return vma_name && !strcmp(vma_name, "[anon:virtual_address_range]\n"); 103 } 104 105 static int validate_lower_address_hint(void) 106 { 107 char *ptr; 108 109 ptr = mmap((void *) (1UL << 45), MAP_CHUNK_SIZE, PROT_READ | 110 PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 111 112 if (ptr == MAP_FAILED) 113 return 0; 114 115 return 1; 116 } 117 118 static int validate_complete_va_space(void) 119 { 120 unsigned long start_addr, end_addr, prev_end_addr; 121 char line[400]; 122 char prot[6]; 123 FILE *file; 124 int fd; 125 126 fd = open("va_dump", O_CREAT | O_WRONLY, 0600); 127 unlink("va_dump"); 128 if (fd < 0) { 129 ksft_test_result_skip("cannot create or open dump file\n"); 130 ksft_finished(); 131 } 132 133 file = fopen("/proc/self/maps", "r"); 134 if (file == NULL) 135 ksft_exit_fail_msg("cannot open /proc/self/maps\n"); 136 137 prev_end_addr = 0; 138 while (fgets(line, sizeof(line), file)) { 139 const char *vma_name = NULL; 140 int vma_name_start = 0; 141 unsigned long hop; 142 143 if (sscanf(line, "%lx-%lx %4s %*s %*s %*s %n", 144 &start_addr, &end_addr, prot, &vma_name_start) != 3) 145 ksft_exit_fail_msg("cannot parse /proc/self/maps\n"); 146 147 if (vma_name_start) 148 vma_name = line + vma_name_start; 149 150 /* end of userspace mappings; ignore vsyscall mapping */ 151 if (start_addr & (1UL << 63)) 152 return 0; 153 154 /* /proc/self/maps must have gaps less than MAP_CHUNK_SIZE */ 155 if (start_addr - prev_end_addr >= MAP_CHUNK_SIZE) 156 return 1; 157 158 prev_end_addr = end_addr; 159 160 if (prot[0] != 'r') 161 continue; 162 163 if (check_vmflag_io((void *)start_addr)) 164 continue; 165 166 /* 167 * Confirm whether MAP_CHUNK_SIZE chunk can be found or not. 168 * If write succeeds, no need to check MAP_CHUNK_SIZE - 1 169 * addresses after that. If the address was not held by this 170 * process, write would fail with errno set to EFAULT. 171 * Anyways, if write returns anything apart from 1, exit the 172 * program since that would mean a bug in /proc/self/maps. 173 */ 174 hop = 0; 175 while (start_addr + hop < end_addr) { 176 if (write(fd, (void *)(start_addr + hop), 1) != 1) 177 return 1; 178 lseek(fd, 0, SEEK_SET); 179 180 if (is_marked_vma(vma_name)) 181 munmap((char *)(start_addr + hop), MAP_CHUNK_SIZE); 182 183 hop += MAP_CHUNK_SIZE; 184 } 185 } 186 return 0; 187 } 188 189 int main(int argc, char *argv[]) 190 { 191 char *ptr[NR_CHUNKS_LOW]; 192 char **hptr; 193 char *hint; 194 unsigned long i, lchunks, hchunks; 195 196 ksft_print_header(); 197 ksft_set_plan(1); 198 199 for (i = 0; i < NR_CHUNKS_LOW; i++) { 200 ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ, 201 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 202 203 if (ptr[i] == MAP_FAILED) { 204 if (validate_lower_address_hint()) 205 ksft_exit_fail_msg("mmap unexpectedly succeeded with hint\n"); 206 break; 207 } 208 209 mark_range(ptr[i], MAP_CHUNK_SIZE); 210 validate_addr(ptr[i], 0); 211 } 212 lchunks = i; 213 hptr = (char **) calloc(NR_CHUNKS_HIGH, sizeof(char *)); 214 if (hptr == NULL) { 215 ksft_test_result_skip("Memory constraint not fulfilled\n"); 216 ksft_finished(); 217 } 218 219 for (i = 0; i < NR_CHUNKS_HIGH; i++) { 220 hint = hint_addr(); 221 hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ, 222 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 223 224 if (hptr[i] == MAP_FAILED) 225 break; 226 227 mark_range(ptr[i], MAP_CHUNK_SIZE); 228 validate_addr(hptr[i], 1); 229 } 230 hchunks = i; 231 if (validate_complete_va_space()) { 232 ksft_test_result_fail("BUG in mmap() or /proc/self/maps\n"); 233 ksft_finished(); 234 } 235 236 for (i = 0; i < lchunks; i++) 237 munmap(ptr[i], MAP_CHUNK_SIZE); 238 239 for (i = 0; i < hchunks; i++) 240 munmap(hptr[i], MAP_CHUNK_SIZE); 241 242 free(hptr); 243 244 ksft_test_result_pass("Test\n"); 245 ksft_finished(); 246 } 247