1 /*
2 * Exercise /dev/mem mmap cases that have been troublesome in the past
3 *
4 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
5 * Bjorn Helgaas <bjorn.helgaas@hp.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <stdlib.h>
13 #include <stdio.h>
14 #include <sys/types.h>
15 #include <dirent.h>
16 #include <fcntl.h>
17 #include <fnmatch.h>
18 #include <string.h>
19 #include <sys/ioctl.h>
20 #include <sys/mman.h>
21 #include <sys/stat.h>
22 #include <unistd.h>
23 #include <linux/pci.h>
24
25 int sum;
26
27 int map_mem(char *path, off_t offset, size_t length, int touch)
28 {
29 int fd, rc;
30 void *addr;
31 int *c;
32
33 fd = open(path, O_RDWR);
34 if (fd == -1) {
35 perror(path);
36 return -1;
37 }
38
39 if (fnmatch("/proc/bus/pci/*", path, 0) == 0) {
40 rc = ioctl(fd, PCIIOC_MMAP_IS_MEM);
41 if (rc == -1)
42 perror("PCIIOC_MMAP_IS_MEM ioctl");
43 }
44
45 addr = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, offset);
46 if (addr == MAP_FAILED)
47 return 1;
48
49 if (touch) {
50 c = (int *) addr;
51 while (c < (int *) (addr + length))
52 sum += *c++;
53 }
54
55 rc = munmap(addr, length);
56 if (rc == -1) {
57 perror("munmap");
58 return -1;
59 }
60
61 close(fd);
62 return 0;
63 }
64
65 int scan_tree(char *path, char *file, off_t offset, size_t length, int touch)
66 {
67 struct dirent **namelist;
68 char *name, *path2;
69 int i, n, r, rc = 0, result = 0;
70 struct stat buf;
71
72 n = scandir(path, &namelist, 0, alphasort);
73 if (n < 0) {
74 perror("scandir");
75 return -1;
76 }
77
78 for (i = 0; i < n; i++) {
79 name = namelist[i]->d_name;
80
81 if (fnmatch(".", name, 0) == 0)
82 goto skip;
83 if (fnmatch("..", name, 0) == 0)
84 goto skip;
85
86 path2 = malloc(strlen(path) + strlen(name) + 3);
87 strcpy(path2, path);
88 strcat(path2, "/");
89 strcat(path2, name);
90
91 if (fnmatch(file, name, 0) == 0) {
92 rc = map_mem(path2, offset, length, touch);
93 if (rc == 0)
94 fprintf(stderr, "PASS: %s 0x%lx-0x%lx is %s\n", path2, offset, offset + length, touch ? "readable" : "mappable");
95 else if (rc > 0)
96 fprintf(stderr, "PASS: %s 0x%lx-0x%lx not mappable\n", path2, offset, offset + length);
97 else {
98 fprintf(stderr, "FAIL: %s 0x%lx-0x%lx not accessible\n", path2, offset, offset + length);
99 return rc;
100 }
101 } else {
102 r = lstat(path2, &buf);
103 if (r == 0 && S_ISDIR(buf.st_mode)) {
104 rc = scan_tree(path2, file, offset, length, touch);
105 if (rc < 0)
106 return rc;
107 }
108 }
109
110 result |= rc;
111 free(path2);
112
113 skip:
114 free(namelist[i]);
115 }
116 free(namelist);
117 return result;
118 }
119
120 char buf[1024];
121
122 int read_rom(char *path)
123 {
124 int fd, rc;
125 size_t size = 0;
126
127 fd = open(path, O_RDWR);
128 if (fd == -1) {
129 perror(path);
130 return -1;
131 }
132
133 rc = write(fd, "1", 2);
134 if (rc <= 0) {
135 perror("write");
136 return -1;
137 }
138
139 do {
140 rc = read(fd, buf, sizeof(buf));
141 if (rc > 0)
142 size += rc;
143 } while (rc > 0);
144
145 close(fd);
146 return size;
147 }
148
149 int scan_rom(char *path, char *file)
150 {
151 struct dirent **namelist;
152 char *name, *path2;
153 int i, n, r, rc = 0, result = 0;
154 struct stat buf;
155
156 n = scandir(path, &namelist, 0, alphasort);
157 if (n < 0) {
158 perror("scandir");
159 return -1;
160 }
161
162 for (i = 0; i < n; i++) {
163 name = namelist[i]->d_name;
164
165 if (fnmatch(".", name, 0) == 0)
166 goto skip;
167 if (fnmatch("..", name, 0) == 0)
168 goto skip;
169
170 path2 = malloc(strlen(path) + strlen(name) + 3);
171 strcpy(path2, path);
172 strcat(path2, "/");
173 strcat(path2, name);
174
175 if (fnmatch(file, name, 0) == 0) {
176 rc = read_rom(path2);
177
178 /*
179 * It's OK if the ROM is unreadable. Maybe there
180 * is no ROM, or some other error ocurred. The
181 * important thing is that no MCA happened.
182 */
183 if (rc > 0)
184 fprintf(stderr, "PASS: %s read %d bytes\n", path2, rc);
185 else {
186 fprintf(stderr, "PASS: %s not readable\n", path2);
187 return rc;
188 }
189 } else {
190 r = lstat(path2, &buf);
191 if (r == 0 && S_ISDIR(buf.st_mode)) {
192 rc = scan_rom(path2, file);
193 if (rc < 0)
194 return rc;
195 }
196 }
197
198 result |= rc;
199 free(path2);
200
201 skip:
202 free(namelist[i]);
203 }
204 free(namelist);
205 return result;
206 }
207
208 int main(void)
209 {
210 int rc;
211
212 if (map_mem("/dev/mem", 0, 0xA0000, 1) == 0)
213 fprintf(stderr, "PASS: /dev/mem 0x0-0xa0000 is readable\n");
214 else
215 fprintf(stderr, "FAIL: /dev/mem 0x0-0xa0000 not accessible\n");
216
217 /*
218 * It's not safe to blindly read the VGA frame buffer. If you know
219 * how to poke the card the right way, it should respond, but it's
220 * not safe in general. Many machines, e.g., Intel chipsets, cover
221 * up a non-responding card by just returning -1, but others will
222 * report the failure as a machine check.
223 */
224 if (map_mem("/dev/mem", 0xA0000, 0x20000, 0) == 0)
225 fprintf(stderr, "PASS: /dev/mem 0xa0000-0xc0000 is mappable\n");
226 else
227 fprintf(stderr, "FAIL: /dev/mem 0xa0000-0xc0000 not accessible\n");
228
229 if (map_mem("/dev/mem", 0xC0000, 0x40000, 1) == 0)
230 fprintf(stderr, "PASS: /dev/mem 0xc0000-0x100000 is readable\n");
231 else
232 fprintf(stderr, "FAIL: /dev/mem 0xc0000-0x100000 not accessible\n");
233
234 /*
235 * Often you can map all the individual pieces above (0-0xA0000,
236 * 0xA0000-0xC0000, and 0xC0000-0x100000), but can't map the whole
237 * thing at once. This is because the individual pieces use different
238 * attributes, and there's no single attribute supported over the
239 * whole region.
240 */
241 rc = map_mem("/dev/mem", 0, 1024*1024, 0);
242 if (rc == 0)
243 fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 is mappable\n");
244 else if (rc > 0)
245 fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 not mappable\n");
246 else
247 fprintf(stderr, "FAIL: /dev/mem 0x0-0x100000 not accessible\n");
248
249 scan_tree("/sys/class/pci_bus", "legacy_mem", 0, 0xA0000, 1);
250 scan_tree("/sys/class/pci_bus", "legacy_mem", 0xA0000, 0x20000, 0);
251 scan_tree("/sys/class/pci_bus", "legacy_mem", 0xC0000, 0x40000, 1);
252 scan_tree("/sys/class/pci_bus", "legacy_mem", 0, 1024*1024, 0);
253
254 scan_rom("/sys/devices", "rom");
255
256 scan_tree("/proc/bus/pci", "??.?", 0, 0xA0000, 1);
257 scan_tree("/proc/bus/pci", "??.?", 0xA0000, 0x20000, 0);
258 scan_tree("/proc/bus/pci", "??.?", 0xC0000, 0x40000, 1);
259 scan_tree("/proc/bus/pci", "??.?", 0, 1024*1024, 0);
260
261 return rc;
262 }
263
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