tools/testing/selftests/ia64/aliasing-test.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Exercise /dev/mem mmap cases that have been troublesome in the past
   4  *
   5  * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
   6  *      Bjorn Helgaas <bjorn.helgaas@hp.com>
   7  */
   8
   9 #include <stdlib.h>
  10 #include <stdio.h>
  11 #include <sys/types.h>
  12 #include <dirent.h>
  13 #include <fcntl.h>
  14 #include <fnmatch.h>
  15 #include <string.h>
  16 #include <sys/ioctl.h>
  17 #include <sys/mman.h>
  18 #include <sys/stat.h>
  19 #include <unistd.h>
  20 #include <linux/pci.h>
  21
  22 int sum;
  23
  24 static int map_mem(char *path, off_t offset, size_t length, int touch)
  25 {
  26         int fd, rc;
  27         void *addr;
  28         int *c;
  29
  30         fd = open(path, O_RDWR);
  31         if (fd == -1) {
  32                 perror(path);
  33                 return -1;
  34         }
  35
  36         if (fnmatch("/proc/bus/pci/*", path, 0) == 0) {
  37                 rc = ioctl(fd, PCIIOC_MMAP_IS_MEM);
  38                 if (rc == -1)
  39                         perror("PCIIOC_MMAP_IS_MEM ioctl");
  40         }
  41
  42         addr = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, offset);
  43         if (addr == MAP_FAILED)
  44                 return 1;
  45
  46         if (touch) {
  47                 c = (int *) addr;
  48                 while (c < (int *) (addr + length))
  49                         sum += *c++;
  50         }
  51
  52         rc = munmap(addr, length);
  53         if (rc == -1) {
  54                 perror("munmap");
  55                 return -1;
  56         }
  57
  58         close(fd);
  59         return 0;
  60 }
  61
  62 static int scan_tree(char *path, char *file, off_t offset, size_t length, int touch)
  63 {
  64         struct dirent **namelist;
  65         char *name, *path2;
  66         int i, n, r, rc = 0, result = 0;
  67         struct stat buf;
  68
  69         n = scandir(path, &namelist, 0, alphasort);
  70         if (n < 0) {
  71                 perror("scandir");
  72                 return -1;
  73         }
  74
  75         for (i = 0; i < n; i++) {
  76                 name = namelist[i]->d_name;
  77
  78                 if (fnmatch(".", name, 0) == 0)
  79                         goto skip;
  80                 if (fnmatch("..", name, 0) == 0)
  81                         goto skip;
  82
  83                 path2 = malloc(strlen(path) + strlen(name) + 3);
  84                 strcpy(path2, path);
  85                 strcat(path2, "/");
  86                 strcat(path2, name);
  87
  88                 if (fnmatch(file, name, 0) == 0) {
  89                         rc = map_mem(path2, offset, length, touch);
  90                         if (rc == 0)
  91                                 fprintf(stderr, "PASS: %s 0x%lx-0x%lx is %s\n", path2, offset, offset + length, touch ? "readable" : "mappable");
  92                         else if (rc > 0)
  93                                 fprintf(stderr, "PASS: %s 0x%lx-0x%lx not mappable\n", path2, offset, offset + length);
  94                         else {
  95                                 fprintf(stderr, "FAIL: %s 0x%lx-0x%lx not accessible\n", path2, offset, offset + length);
  96                                 return rc;
  97                         }
  98                 } else {
  99                         r = lstat(path2, &buf);
 100                         if (r == 0 && S_ISDIR(buf.st_mode)) {
 101                                 rc = scan_tree(path2, file, offset, length, touch);
 102                                 if (rc < 0)
 103                                         return rc;
 104                         }
 105                 }
 106
 107                 result |= rc;
 108                 free(path2);
 109
 110 skip:
 111                 free(namelist[i]);
 112         }
 113         free(namelist);
 114         return result;
 115 }
 116
 117 char buf[1024];
 118
 119 static int read_rom(char *path)
 120 {
 121         int fd, rc;
 122         size_t size = 0;
 123
 124         fd = open(path, O_RDWR);
 125         if (fd == -1) {
 126                 perror(path);
 127                 return -1;
 128         }
 129
 130         rc = write(fd, "1", 2);
 131         if (rc <= 0) {
 132                 close(fd);
 133                 perror("write");
 134                 return -1;
 135         }
 136
 137         do {
 138                 rc = read(fd, buf, sizeof(buf));
 139                 if (rc > 0)
 140                         size += rc;
 141         } while (rc > 0);
 142
 143         close(fd);
 144         return size;
 145 }
 146
 147 static int scan_rom(char *path, char *file)
 148 {
 149         struct dirent **namelist;
 150         char *name, *path2;
 151         int i, n, r, rc = 0, result = 0;
 152         struct stat buf;
 153
 154         n = scandir(path, &namelist, 0, alphasort);
 155         if (n < 0) {
 156                 perror("scandir");
 157                 return -1;
 158         }
 159
 160         for (i = 0; i < n; i++) {
 161                 name = namelist[i]->d_name;
 162
 163                 if (fnmatch(".", name, 0) == 0)
 164                         goto skip;
 165                 if (fnmatch("..", name, 0) == 0)
 166                         goto skip;
 167
 168                 path2 = malloc(strlen(path) + strlen(name) + 3);
 169                 strcpy(path2, path);
 170                 strcat(path2, "/");
 171                 strcat(path2, name);
 172
 173                 if (fnmatch(file, name, 0) == 0) {
 174                         rc = read_rom(path2);
 175
 176                         /*
 177                          * It's OK if the ROM is unreadable.  Maybe there
 178                          * is no ROM, or some other error occurred.  The
 179                          * important thing is that no MCA happened.
 180                          */
 181                         if (rc > 0)
 182                                 fprintf(stderr, "PASS: %s read %d bytes\n", path2, rc);
 183                         else {
 184                                 fprintf(stderr, "PASS: %s not readable\n", path2);
 185                                 return rc;
 186                         }
 187                 } else {
 188                         r = lstat(path2, &buf);
 189                         if (r == 0 && S_ISDIR(buf.st_mode)) {
 190                                 rc = scan_rom(path2, file);
 191                                 if (rc < 0)
 192                                         return rc;
 193                         }
 194                 }
 195
 196                 result |= rc;
 197                 free(path2);
 198
 199 skip:
 200                 free(namelist[i]);
 201         }
 202         free(namelist);
 203         return result;
 204 }
 205
 206 int main(void)
 207 {
 208         int rc;
 209
 210         if (map_mem("/dev/mem", 0, 0xA0000, 1) == 0)
 211                 fprintf(stderr, "PASS: /dev/mem 0x0-0xa0000 is readable\n");
 212         else
 213                 fprintf(stderr, "FAIL: /dev/mem 0x0-0xa0000 not accessible\n");
 214
 215         /*
 216          * It's not safe to blindly read the VGA frame buffer.  If you know
 217          * how to poke the card the right way, it should respond, but it's
 218          * not safe in general.  Many machines, e.g., Intel chipsets, cover
 219          * up a non-responding card by just returning -1, but others will
 220          * report the failure as a machine check.
 221          */
 222         if (map_mem("/dev/mem", 0xA0000, 0x20000, 0) == 0)
 223                 fprintf(stderr, "PASS: /dev/mem 0xa0000-0xc0000 is mappable\n");
 224         else
 225                 fprintf(stderr, "FAIL: /dev/mem 0xa0000-0xc0000 not accessible\n");
 226
 227         if (map_mem("/dev/mem", 0xC0000, 0x40000, 1) == 0)
 228                 fprintf(stderr, "PASS: /dev/mem 0xc0000-0x100000 is readable\n");
 229         else
 230                 fprintf(stderr, "FAIL: /dev/mem 0xc0000-0x100000 not accessible\n");
 231
 232         /*
 233          * Often you can map all the individual pieces above (0-0xA0000,
 234          * 0xA0000-0xC0000, and 0xC0000-0x100000), but can't map the whole
 235          * thing at once.  This is because the individual pieces use different
 236          * attributes, and there's no single attribute supported over the
 237          * whole region.
 238          */
 239         rc = map_mem("/dev/mem", 0, 1024*1024, 0);
 240         if (rc == 0)
 241                 fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 is mappable\n");
 242         else if (rc > 0)
 243                 fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 not mappable\n");
 244         else
 245                 fprintf(stderr, "FAIL: /dev/mem 0x0-0x100000 not accessible\n");
 246
 247         scan_tree("/sys/class/pci_bus", "legacy_mem", 0, 0xA0000, 1);
 248         scan_tree("/sys/class/pci_bus", "legacy_mem", 0xA0000, 0x20000, 0);
 249         scan_tree("/sys/class/pci_bus", "legacy_mem", 0xC0000, 0x40000, 1);
 250         scan_tree("/sys/class/pci_bus", "legacy_mem", 0, 1024*1024, 0);
 251
 252         scan_rom("/sys/devices", "rom");
 253
 254         scan_tree("/proc/bus/pci", "??.?", 0, 0xA0000, 1);
 255         scan_tree("/proc/bus/pci", "??.?", 0xA0000, 0x20000, 0);
 256         scan_tree("/proc/bus/pci", "??.?", 0xC0000, 0x40000, 1);
 257         scan_tree("/proc/bus/pci", "??.?", 0, 1024*1024, 0);
 258
 259         return rc;
 260 }