1 /* 2 * Copyright IBM Corp. 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of version 2.1 of the GNU Lesser General Public License 6 * as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it would be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 11 * 12 */ 13 14 #include <assert.h> 15 #include <errno.h> 16 #include <fcntl.h> 17 #include <signal.h> 18 #include <stdarg.h> 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <string.h> 22 #include <sys/mman.h> 23 #include <sys/ptrace.h> 24 #include <sys/syscall.h> 25 #include <ucontext.h> 26 #include <unistd.h> 27 28 #include "utils.h" 29 30 char *file_name; 31 32 int in_test; 33 volatile int faulted; 34 volatile void *dar; 35 int errors; 36 37 static void segv(int signum, siginfo_t *info, void *ctxt_v) 38 { 39 ucontext_t *ctxt = (ucontext_t *)ctxt_v; 40 struct pt_regs *regs = ctxt->uc_mcontext.regs; 41 42 if (!in_test) { 43 fprintf(stderr, "Segfault outside of test !\n"); 44 exit(1); 45 } 46 47 faulted = 1; 48 dar = (void *)regs->dar; 49 regs->nip += 4; 50 } 51 52 static inline void do_read(const volatile void *addr) 53 { 54 int ret; 55 56 asm volatile("lwz %0,0(%1); twi 0,%0,0; isync;\n" 57 : "=r" (ret) : "r" (addr) : "memory"); 58 } 59 60 static inline void do_write(const volatile void *addr) 61 { 62 int val = 0x1234567; 63 64 asm volatile("stw %0,0(%1); sync; \n" 65 : : "r" (val), "r" (addr) : "memory"); 66 } 67 68 static inline void check_faulted(void *addr, long page, long subpage, int write) 69 { 70 int want_fault = (subpage == ((page + 3) % 16)); 71 72 if (write) 73 want_fault |= (subpage == ((page + 1) % 16)); 74 75 if (faulted != want_fault) { 76 printf("Failed at %p (p=%ld,sp=%ld,w=%d), want=%s, got=%s !\n", 77 addr, page, subpage, write, 78 want_fault ? "fault" : "pass", 79 faulted ? "fault" : "pass"); 80 ++errors; 81 } 82 83 if (faulted) { 84 if (dar != addr) { 85 printf("Fault expected at %p and happened at %p !\n", 86 addr, dar); 87 } 88 faulted = 0; 89 asm volatile("sync" : : : "memory"); 90 } 91 } 92 93 static int run_test(void *addr, unsigned long size) 94 { 95 unsigned int *map; 96 long i, j, pages, err; 97 98 pages = size / 0x10000; 99 map = malloc(pages * 4); 100 assert(map); 101 102 /* 103 * for each page, mark subpage i % 16 read only and subpage 104 * (i + 3) % 16 inaccessible 105 */ 106 for (i = 0; i < pages; i++) { 107 map[i] = (0x40000000 >> (((i + 1) * 2) % 32)) | 108 (0xc0000000 >> (((i + 3) * 2) % 32)); 109 } 110 111 err = syscall(__NR_subpage_prot, addr, size, map); 112 if (err) { 113 perror("subpage_perm"); 114 return 1; 115 } 116 free(map); 117 118 in_test = 1; 119 errors = 0; 120 for (i = 0; i < pages; i++) { 121 for (j = 0; j < 16; j++, addr += 0x1000) { 122 do_read(addr); 123 check_faulted(addr, i, j, 0); 124 do_write(addr); 125 check_faulted(addr, i, j, 1); 126 } 127 } 128 129 in_test = 0; 130 if (errors) { 131 printf("%d errors detected\n", errors); 132 return 1; 133 } 134 135 return 0; 136 } 137 138 static int syscall_available(void) 139 { 140 int rc; 141 142 errno = 0; 143 rc = syscall(__NR_subpage_prot, 0, 0, 0); 144 145 return rc == 0 || (errno != ENOENT && errno != ENOSYS); 146 } 147 148 int test_anon(void) 149 { 150 unsigned long align; 151 struct sigaction act = { 152 .sa_sigaction = segv, 153 .sa_flags = SA_SIGINFO 154 }; 155 void *mallocblock; 156 unsigned long mallocsize; 157 158 SKIP_IF(!syscall_available()); 159 160 if (getpagesize() != 0x10000) { 161 fprintf(stderr, "Kernel page size must be 64K!\n"); 162 return 1; 163 } 164 165 sigaction(SIGSEGV, &act, NULL); 166 167 mallocsize = 4 * 16 * 1024 * 1024; 168 169 FAIL_IF(posix_memalign(&mallocblock, 64 * 1024, mallocsize)); 170 171 align = (unsigned long)mallocblock; 172 if (align & 0xffff) 173 align = (align | 0xffff) + 1; 174 175 mallocblock = (void *)align; 176 177 printf("allocated malloc block of 0x%lx bytes at %p\n", 178 mallocsize, mallocblock); 179 180 printf("testing malloc block...\n"); 181 182 return run_test(mallocblock, mallocsize); 183 } 184 185 int test_file(void) 186 { 187 struct sigaction act = { 188 .sa_sigaction = segv, 189 .sa_flags = SA_SIGINFO 190 }; 191 void *fileblock; 192 off_t filesize; 193 int fd; 194 195 SKIP_IF(!syscall_available()); 196 197 fd = open(file_name, O_RDWR); 198 if (fd == -1) { 199 perror("failed to open file"); 200 return 1; 201 } 202 sigaction(SIGSEGV, &act, NULL); 203 204 filesize = lseek(fd, 0, SEEK_END); 205 if (filesize & 0xffff) 206 filesize &= ~0xfffful; 207 208 fileblock = mmap(NULL, filesize, PROT_READ | PROT_WRITE, 209 MAP_SHARED, fd, 0); 210 if (fileblock == MAP_FAILED) { 211 perror("failed to map file"); 212 return 1; 213 } 214 printf("allocated %s for 0x%llx bytes at %p\n", 215 file_name, (long long)filesize, fileblock); 216 217 printf("testing file map...\n"); 218 219 return run_test(fileblock, filesize); 220 } 221 222 int main(int argc, char *argv[]) 223 { 224 int rc; 225 226 rc = test_harness(test_anon, "subpage_prot_anon"); 227 if (rc) 228 return rc; 229 230 if (argc > 1) 231 file_name = argv[1]; 232 else 233 file_name = "tempfile"; 234 235 return test_harness(test_file, "subpage_prot_file"); 236 } 237