237 lines · c
1/*2 * Copyright IBM Corp.3 *4 * This program is free software; you can redistribute it and/or modify it5 * under the terms of version 2.1 of the GNU Lesser General Public License6 * as published by the Free Software Foundation.7 *8 * This program is distributed in the hope that it would be useful, but9 * WITHOUT ANY WARRANTY; without even the implied warranty of10 * 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 30char *file_name;31 32int in_test;33volatile int faulted;34volatile void *dar;35int errors;36 37static 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 52static 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 60static 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 68static 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 93static 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 subpage104 * (i + 3) % 16 inaccessible105 */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 138static 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 148int test_anon(void)149{150 unsigned long align;151 struct sigaction act = {152 .sa_sigaction = segv,153 .sa_flags = SA_SIGINFO154 };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 185int test_file(void)186{187 struct sigaction act = {188 .sa_sigaction = segv,189 .sa_flags = SA_SIGINFO190 };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%lx bytes at %p\n",215 file_name, filesize, fileblock);216 217 printf("testing file map...\n");218 219 return run_test(fileblock, filesize);220}221 222int 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 else233 file_name = "tempfile";234 235 return test_harness(test_file, "subpage_prot_file");236}237