1 /*
2 * proc01.c - Tests Linux /proc file reading.
3 *
4 * Copyright (C) 2001 Stephane Fillod <f4cfe@free.fr>
5 * Copyright (c) 2008, 2009 Red Hat, Inc.
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of version 2 of the GNU General Public License as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it would be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
14 *
15 * Further, this software is distributed without any warranty that it is
16 * free of the rightful claim of any third person regarding infringement
17 * or the like. Any license provided herein, whether implied or
18 * otherwise, applies only to this software file. Patent licenses, if
19 * any, provided herein do not apply to combinations of this program with
20 * other software, or any other product whatsoever.
21 *
22 * You should have received a copy of the GNU General Public License along
23 * with this program; if not, write the Free Software Foundation, Inc.,
24 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 *
26 */
27
28 #include "config.h"
29
30 #include <errno.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <limits.h>
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 #include <dirent.h>
38 #include <unistd.h>
39 #include <fcntl.h>
40 #include <fnmatch.h>
41
42 #ifdef HAVE_LIBSELINUX_DEVEL
43 #include <selinux/selinux.h>
44 #endif
45
46 #include "test.h"
47
48 #define MAX_BUFF_SIZE 65536
49 #define MAX_FUNC_NAME 256
50
51 char *TCID = "proc01";
52 int TST_TOTAL = 1;
53
54 static int opt_verbose;
55 static int opt_procpath;
56 static char *opt_procpathstr;
57 static int opt_buffsize;
58 static int opt_readirq;
59 static char *opt_buffsizestr;
60 static int opt_maxmbytes;
61 static char *opt_maxmbytesstr;
62
63 static char *procpath = "/proc";
64 static const char selfpath[] = "/proc/self";
65 size_t buffsize = 1024;
66 static unsigned long long maxbytes;
67
68 unsigned long long total_read;
69 unsigned int total_obj;
70
71 struct mapping {
72 char func[MAX_FUNC_NAME];
73 char file[PATH_MAX];
74 int err;
75 };
76
77 /* Those are known failures for 2.6.18 baremetal kernel and Xen dom0
78 kernel on i686, x86_64, ia64, ppc64 and s390x. In addition, It looks
79 like if SELinux is disabled, the test may still fail on some other
80 entries. */
81 static const struct mapping known_issues[] = {
82 {"open", "/proc/acpi/event", EBUSY},
83 {"open", "/proc/sal/cpe/data", EBUSY},
84 {"open", "/proc/sal/cmc/data", EBUSY},
85 {"open", "/proc/sal/init/data", EBUSY},
86 {"open", "/proc/sal/mca/data", EBUSY},
87 {"open", "/proc/fs/nfsd/pool_stats", ENODEV},
88 {"read", "/proc/fs/nfsd/clients/*/ctl", EINVAL},
89 {"read", "/proc/acpi/event", EAGAIN},
90 {"read", "/proc/kmsg", EAGAIN},
91 {"read", "/proc/sal/cpe/event", EAGAIN},
92 {"read", "/proc/sal/cmc/event", EAGAIN},
93 {"read", "/proc/sal/init/event", EAGAIN},
94 {"read", "/proc/sal/mca/event", EAGAIN},
95 {"read", "/proc/xen/privcmd", EIO},
96 {"read", "/proc/xen/privcmd", EINVAL},
97 {"read", "/proc/self/mem", EIO},
98 {"read", "/proc/self/task/[0-9]*/mem", EIO},
99 {"read", "/proc/self/attr/*", EINVAL},
100 {"read", "/proc/self/attr/selinux/*", EINVAL},
101 {"read", "/proc/self/attr/smack/*", EINVAL},
102 {"read", "/proc/self/attr/apparmor/*", EINVAL},
103 {"read", "/proc/self/task/[0-9]*/attr/*", EINVAL},
104 {"read", "/proc/self/task/[0-9]*/attr/smack/*", EINVAL},
105 {"read", "/proc/self/task/[0-9]*/attr/selinux/*", EINVAL},
106 {"read", "/proc/self/task/[0-9]*/attr/apparmor/*", EINVAL},
107 {"read", "/proc/self/ns/*", EINVAL},
108 {"read", "/proc/self/task/[0-9]*/ns/*", EINVAL},
109 {"read", "/proc/ppc64/rtas/error_log", EINVAL},
110 {"read", "/proc/powerpc/rtas/error_log", EINVAL},
111 {"read", "/proc/fs/nfsd/unlock_filesystem", EINVAL},
112 {"read", "/proc/fs/nfsd/unlock_ip", EINVAL},
113 {"read", "/proc/fs/nfsd/filehandle", EINVAL},
114 {"read", "/proc/fs/nfsd/.getfs", EINVAL},
115 {"read", "/proc/fs/nfsd/.getfd", EINVAL},
116 {"read", "/proc/self/net/rpc/use-gss-proxy", EAGAIN},
117 {"read", "/proc/sys/net/ipv6/conf/*/stable_secret", EIO},
118 {"read", "/proc/sys/vm/nr_hugepages", EOPNOTSUPP},
119 {"read", "/proc/sys/vm/nr_overcommit_hugepages", EOPNOTSUPP},
120 {"read", "/proc/sys/vm/nr_hugepages_mempolicy", EOPNOTSUPP},
121 {"read", "/proc/pressure/*", EOPNOTSUPP},
122 {"", "", 0}
123 };
124
125 /*
126 * If a particular LSM is enabled, it is expected that some entries can
127 * be read successfully. Otherwise, those entries will retrun some
128 * failures listed above. Here to add any LSM specific entries.
129 */
130
131 /*
132 * Test macro to indicate that SELinux libraries and headers are
133 * installed.
134 */
135 #ifdef HAVE_LIBSELINUX_DEVEL
136 static const char lsm_should_work[][PATH_MAX] = {
137 "/proc/self/attr/*",
138 "/proc/self/attr/selinux/*",
139 "/proc/self/task/[0-9]*/attr/*",
140 "/proc/self/task/[0-9]*/attr/selinux/*",
141 ""
142 };
143 #endif
144
145 /* Known files that does not honor O_NONBLOCK, so they will hang
146 the test while being read. */
147 static const char error_nonblock[][PATH_MAX] = {
148 "/proc/xen/xenbus",
149 ""
150 };
151
152 /*
153 * Verify expected failures, and then let the test to continue.
154 *
155 * Return 0 when a problem errno is found.
156 * Return 1 when a known issue is found.
157 *
158 */
found_errno(const char * syscall,const char * obj,int tmperr)159 static int found_errno(const char *syscall, const char *obj, int tmperr)
160 {
161 int i;
162
163 /* Should not see any error for certain entries if a LSM is enabled. */
164 #ifdef HAVE_LIBSELINUX_DEVEL
165 if (is_selinux_enabled()) {
166 for (i = 0; lsm_should_work[i][0] != '\0'; i++) {
167 if (!strcmp(obj, lsm_should_work[i]) ||
168 !fnmatch(lsm_should_work[i], obj, FNM_PATHNAME)) {
169 return 0;
170 }
171 }
172 }
173 #endif
174 for (i = 0; known_issues[i].err != 0; i++) {
175 if (tmperr == known_issues[i].err &&
176 (!strcmp(obj, known_issues[i].file) ||
177 !fnmatch(known_issues[i].file, obj, FNM_PATHNAME)) &&
178 !strcmp(syscall, known_issues[i].func)) {
179 /* Using strcmp / fnmatch could have messed up the
180 * errno value. */
181 errno = tmperr;
182 tst_resm(TINFO | TERRNO, "%s: known issue", obj);
183 return 1;
184 }
185 }
186 return 0;
187 }
188
cleanup(void)189 static void cleanup(void)
190 {
191 tst_rmdir();
192 }
193
setup(void)194 static void setup(void)
195 {
196 tst_sig(FORK, DEF_HANDLER, cleanup);
197 TEST_PAUSE;
198 tst_tmpdir();
199 }
200
help(void)201 void help(void)
202 {
203 printf(" -b x read byte count\n");
204 printf(" -m x max megabytes to read from single file\n");
205 printf(" -q read .../irq/... entries\n");
206 printf(" -r x proc pathname\n");
207 printf(" -v verbose mode\n");
208 }
209
210 /*
211 * add the -m option whose parameter is the
212 * pages that should be mapped.
213 */
214 static option_t options[] = {
215 {"b:", &opt_buffsize, &opt_buffsizestr},
216 {"m:", &opt_maxmbytes, &opt_maxmbytesstr},
217 {"q", &opt_readirq, NULL},
218 {"r:", &opt_procpath, &opt_procpathstr},
219 {"v", &opt_verbose, NULL},
220 {NULL, NULL, NULL}
221 };
222
223 /*
224 * NB: this function is recursive
225 * returns 0 if no error encountered, otherwise number of errors (objs)
226 *
227 * REM: Funny enough, while developing this function (actually replacing
228 * streamed fopen by standard open), I hit a real /proc bug.
229 * On a 2.2.13-SuSE kernel, "cat /proc/tty/driver/serial" would fail
230 * with EFAULT, while "cat /proc/tty/driver/serial > somefile" wouldn't.
231 * Okay, this might be due to a slight serial misconfiguration, but still.
232 * Analysis with strace showed up the difference was on the count size
233 * of read (1024 bytes vs 4096 bytes). So I tested further..
234 * read count of 512 bytes adds /proc/tty/drivers to the list
235 * of broken proc files, while 64 bytes reads removes
236 * /proc/tty/driver/serial from the list. Interesting, isn't it?
237 * Now, there's a -b option to this test, so you can try your luck. --SF
238 *
239 * It's more fun to run this test it as root, as all the files will be accessible!
240 * (however, be careful, there might be some bufferoverflow holes..)
241 * reading proc files might be also a good kernel latency killer.
242 */
readproc(const char * obj)243 static long readproc(const char *obj)
244 {
245 DIR *dir = NULL; /* pointer to a directory */
246 struct dirent *dir_ent; /* pointer to directory entries */
247 char dirobj[PATH_MAX]; /* object inside directory to modify */
248 struct stat statbuf; /* used to hold stat information */
249 int fd, tmperr, i;
250 ssize_t nread;
251 static char buf[MAX_BUFF_SIZE]; /* static kills reentrancy, but we don't care about the contents */
252 unsigned long long file_total_read = 0;
253
254 /* Determine the file type */
255 if (lstat(obj, &statbuf) < 0) {
256
257 /* permission denied is not considered as error */
258 if (errno != EACCES) {
259 tst_resm(TFAIL | TERRNO, "%s: lstat", obj);
260 return 1;
261 }
262 return 0;
263
264 }
265
266 /* Prevent loops, but read /proc/self. */
267 if (S_ISLNK(statbuf.st_mode) && strcmp(obj, selfpath))
268 return 0;
269
270 total_obj++;
271
272 /* Take appropriate action, depending on the file type */
273 if (S_ISDIR(statbuf.st_mode) || !strcmp(obj, selfpath)) {
274
275 /* object is a directory */
276
277 /*
278 * Skip over the /proc/irq directory, unless the user
279 * requested that we read the directory because it could
280 * map to a broken driver which effectively `hangs' the
281 * test.
282 */
283 if (!opt_readirq && !strcmp("/proc/irq", obj)) {
284 return 0;
285 /* Open the directory to get access to what is in it */
286 } else if ((dir = opendir(obj)) == NULL) {
287 if (errno != EACCES) {
288 tst_resm(TFAIL | TERRNO, "%s: opendir", obj);
289 return 1;
290 }
291 return 0;
292 } else {
293
294 long ret_val = 0;
295
296 /* Loop through the entries in the directory */
297 for (dir_ent = (struct dirent *)readdir(dir);
298 dir_ent != NULL;
299 dir_ent = (struct dirent *)readdir(dir)) {
300
301 /* Ignore ".", "..", "kcore", and
302 * "/proc/<pid>" (unless this is our
303 * starting point as directed by the
304 * user).
305 */
306 if (strcmp(dir_ent->d_name, ".") &&
307 strcmp(dir_ent->d_name, "..") &&
308 strcmp(dir_ent->d_name, "kcore") &&
309 (fnmatch("[0-9]*", dir_ent->d_name,
310 FNM_PATHNAME) ||
311 strcmp(obj, procpath))) {
312
313 if (opt_verbose) {
314 fprintf(stderr, "%s\n",
315 dir_ent->d_name);
316 }
317
318 /* Recursively call this routine to test the
319 * current entry */
320 snprintf(dirobj, PATH_MAX,
321 "%s/%s", obj, dir_ent->d_name);
322 ret_val += readproc(dirobj);
323
324 }
325
326 }
327
328 /* Close the directory */
329 if (dir)
330 (void)closedir(dir);
331
332 return ret_val;
333
334 }
335
336 } else { /* if it's not a dir, read it! */
337
338 if (!S_ISREG(statbuf.st_mode))
339 return 0;
340
341 #ifdef DEBUG
342 fprintf(stderr, "%s", obj);
343 #endif
344
345 /* is O_NONBLOCK enough to escape from FIFO's ? */
346 fd = open(obj, O_RDONLY | O_NONBLOCK);
347 if (fd < 0) {
348 tmperr = errno;
349
350 if (!found_errno("open", obj, tmperr)) {
351
352 errno = tmperr;
353
354 if (errno != EACCES) {
355 tst_resm(TFAIL | TERRNO,
356 "%s: open failed", obj);
357 return 1;
358 }
359
360 }
361 return 0;
362
363 }
364
365 /* Skip write-only files. */
366 if ((statbuf.st_mode & S_IRUSR) == 0 &&
367 (statbuf.st_mode & S_IWUSR) != 0) {
368 tst_resm(TINFO, "%s: is write-only.", obj);
369 (void)close(fd);
370 return 0;
371 }
372
373 /* Skip files does not honor O_NONBLOCK. */
374 for (i = 0; error_nonblock[i][0] != '\0'; i++) {
375 if (!strcmp(obj, error_nonblock[i])) {
376 tst_resm(TINFO, "%s: does not honor "
377 "O_NONBLOCK", obj);
378 (void)close(fd);
379 return 0;
380 }
381 }
382
383 file_total_read = 0;
384 do {
385
386 nread = read(fd, buf, buffsize);
387
388 if (nread < 0) {
389
390 tmperr = errno;
391 (void)close(fd);
392
393 /* ignore no perm (not root) and no
394 * process (terminated) errors */
395 if (!found_errno("read", obj, tmperr)) {
396
397 errno = tmperr;
398
399 if (errno != EACCES && errno != ESRCH) {
400 tst_resm(TFAIL | TERRNO,
401 "read failed: "
402 "%s", obj);
403 return 1;
404 }
405 return 0;
406
407 }
408
409 } else
410 file_total_read += nread;
411
412 if (opt_verbose) {
413 #ifdef DEBUG
414 fprintf(stderr, "%ld", nread);
415 #endif
416 fprintf(stderr, ".");
417 }
418
419 if ((maxbytes > 0) && (file_total_read > maxbytes)) {
420 tst_resm(TINFO, "%s: reached maxmbytes (-m)",
421 obj);
422 break;
423 }
424 } while (0 < nread);
425 total_read += file_total_read;
426
427 if (opt_verbose)
428 fprintf(stderr, "\n");
429
430 if (0 <= fd)
431 (void)close(fd);
432
433 }
434
435 /* It's better to assume success by default rather than failure. */
436 return 0;
437
438 }
439
main(int argc,char * argv[])440 int main(int argc, char *argv[])
441 {
442 int lc;
443
444 tst_parse_opts(argc, argv, options, help);
445
446 if (opt_buffsize) {
447 size_t bs;
448 bs = atoi(opt_buffsizestr);
449 if (bs <= MAX_BUFF_SIZE)
450 buffsize = bs;
451 else
452 tst_brkm(TBROK, cleanup,
453 "Invalid arg for -b (max: %u): %s",
454 MAX_BUFF_SIZE, opt_buffsizestr);
455 }
456 if (opt_maxmbytes)
457 maxbytes = atoi(opt_maxmbytesstr) * 1024 * 1024;
458
459 if (opt_procpath)
460 procpath = opt_procpathstr;
461
462 setup();
463
464 for (lc = 0; TEST_LOOPING(lc); lc++) {
465 tst_count = 0;
466
467 TEST(readproc(procpath));
468
469 if (TEST_RETURN != 0) {
470 tst_resm(TFAIL, "readproc() failed with %ld errors.",
471 TEST_RETURN);
472 } else {
473 tst_resm(TPASS, "readproc() completed successfully, "
474 "total read: %llu bytes, %u objs", total_read,
475 total_obj);
476 }
477 }
478
479 cleanup();
480 tst_exit();
481 }
482