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 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/acpi/event", EAGAIN},
89 {"read", "/proc/kmsg", EAGAIN},
90 {"read", "/proc/sal/cpe/event", EAGAIN},
91 {"read", "/proc/sal/cmc/event", EAGAIN},
92 {"read", "/proc/sal/init/event", EAGAIN},
93 {"read", "/proc/sal/mca/event", EAGAIN},
94 {"read", "/proc/xen/privcmd", EIO},
95 {"read", "/proc/xen/privcmd", EINVAL},
96 {"read", "/proc/self/mem", EIO},
97 {"read", "/proc/self/task/[0-9]*/mem", EIO},
98 {"read", "/proc/self/attr/*", EINVAL},
99 {"read", "/proc/self/task/[0-9]*/attr/*", EINVAL},
100 {"read", "/proc/self/ns/*", EINVAL},
101 {"read", "/proc/self/task/[0-9]*/ns/*", EINVAL},
102 {"read", "/proc/ppc64/rtas/error_log", EINVAL},
103 {"read", "/proc/powerpc/rtas/error_log", EINVAL},
104 {"read", "/proc/fs/nfsd/unlock_filesystem", EINVAL},
105 {"read", "/proc/fs/nfsd/unlock_ip", EINVAL},
106 {"read", "/proc/fs/nfsd/filehandle", EINVAL},
107 {"read", "/proc/fs/nfsd/.getfs", EINVAL},
108 {"read", "/proc/fs/nfsd/.getfd", EINVAL},
109 {"read", "/proc/self/net/rpc/use-gss-proxy", EAGAIN},
110 {"read", "/proc/sys/net/ipv6/conf/*/stable_secret", EIO},
111 {"read", "/proc/sys/vm/nr_hugepages", EOPNOTSUPP},
112 {"read", "/proc/sys/vm/nr_overcommit_hugepages", EOPNOTSUPP},
113 {"read", "/proc/sys/vm/nr_hugepages_mempolicy", EOPNOTSUPP},
114 {"read", "/proc/debug/fwdump", EINVAL},
115 {"read", "/proc/cid/athdiagpfs", EIO},
116 {"", "", 0}
117 };
118
119 /*
120 * If a particular LSM is enabled, it is expected that some entries can
121 * be read successfully. Otherwise, those entries will retrun some
122 * failures listed above. Here to add any LSM specific entries.
123 */
124
125 /*
126 * Test macro to indicate that SELinux libraries and headers are
127 * installed.
128 */
129 #ifdef HAVE_LIBSELINUX_DEVEL
130 static const char lsm_should_work[][PATH_MAX] = {
131 "/proc/self/attr/*",
132 "/proc/self/task/[0-9]*/attr/*",
133 ""
134 };
135
136 /* Place holder for none of LSM is detected. */
137 #else
138 static const char lsm_should_work[][PATH_MAX] = {
139 ""
140 };
141 #endif
142
143 /* Known files that does not honor O_NONBLOCK, so they will hang
144 the test while being read. */
145 static const char error_nonblock[][PATH_MAX] = {
146 "/proc/xen/xenbus",
147 ""
148 };
149
150 /*
151 * Verify expected failures, and then let the test to continue.
152 *
153 * Return 0 when a problem errno is found.
154 * Return 1 when a known issue is found.
155 *
156 */
found_errno(const char * syscall,const char * obj,int tmperr)157 static int found_errno(const char *syscall, const char *obj, int tmperr)
158 {
159 int i;
160
161 /* Should not see any error for certain entries if a LSM is enabled. */
162 #ifdef HAVE_LIBSELINUX_DEVEL
163 if (is_selinux_enabled()) {
164 for (i = 0; lsm_should_work[i][0] != '\0'; i++) {
165 if (!strcmp(obj, lsm_should_work[i]) ||
166 !fnmatch(lsm_should_work[i], obj, FNM_PATHNAME)) {
167 return 0;
168 }
169 }
170 }
171 #endif
172 for (i = 0; known_issues[i].err != 0; i++) {
173 if (tmperr == known_issues[i].err &&
174 (!strcmp(obj, known_issues[i].file) ||
175 !fnmatch(known_issues[i].file, obj, FNM_PATHNAME)) &&
176 !strcmp(syscall, known_issues[i].func)) {
177 /* Using strcmp / fnmatch could have messed up the
178 * errno value. */
179 errno = tmperr;
180 tst_resm(TINFO | TERRNO, "%s: known issue", obj);
181 return 1;
182 }
183 }
184 return 0;
185 }
186
cleanup(void)187 static void cleanup(void)
188 {
189 tst_rmdir();
190 }
191
setup(void)192 static void setup(void)
193 {
194 tst_sig(FORK, DEF_HANDLER, cleanup);
195 TEST_PAUSE;
196 tst_tmpdir();
197 }
198
help(void)199 void help(void)
200 {
201 printf(" -b x read byte count\n");
202 printf(" -m x max megabytes to read from single file\n");
203 printf(" -q read .../irq/... entries\n");
204 printf(" -r x proc pathname\n");
205 printf(" -v verbose mode\n");
206 }
207
208 /*
209 * add the -m option whose parameter is the
210 * pages that should be mapped.
211 */
212 static option_t options[] = {
213 {"b:", &opt_buffsize, &opt_buffsizestr},
214 {"m:", &opt_maxmbytes, &opt_maxmbytesstr},
215 {"q", &opt_readirq, NULL},
216 {"r:", &opt_procpath, &opt_procpathstr},
217 {"v", &opt_verbose, NULL},
218 {NULL, NULL, NULL}
219 };
220
221 /*
222 * NB: this function is recursive
223 * returns 0 if no error encountered, otherwise number of errors (objs)
224 *
225 * REM: Funny enough, while developing this function (actually replacing
226 * streamed fopen by standard open), I hit a real /proc bug.
227 * On a 2.2.13-SuSE kernel, "cat /proc/tty/driver/serial" would fail
228 * with EFAULT, while "cat /proc/tty/driver/serial > somefile" wouldn't.
229 * Okay, this might be due to a slight serial misconfiguration, but still.
230 * Analysis with strace showed up the difference was on the count size
231 * of read (1024 bytes vs 4096 bytes). So I tested further..
232 * read count of 512 bytes adds /proc/tty/drivers to the list
233 * of broken proc files, while 64 bytes reads removes
234 * /proc/tty/driver/serial from the list. Interesting, isn't it?
235 * Now, there's a -b option to this test, so you can try your luck. --SF
236 *
237 * It's more fun to run this test it as root, as all the files will be accessible!
238 * (however, be careful, there might be some bufferoverflow holes..)
239 * reading proc files might be also a good kernel latency killer.
240 */
readproc(const char * obj)241 static long readproc(const char *obj)
242 {
243 DIR *dir = NULL; /* pointer to a directory */
244 struct dirent *dir_ent; /* pointer to directory entries */
245 char dirobj[PATH_MAX]; /* object inside directory to modify */
246 struct stat statbuf; /* used to hold stat information */
247 int fd, tmperr, i;
248 ssize_t nread;
249 static char buf[MAX_BUFF_SIZE]; /* static kills reentrancy, but we don't care about the contents */
250 unsigned long long file_total_read = 0;
251
252 /* Determine the file type */
253 if (lstat(obj, &statbuf) < 0) {
254
255 /* permission denied is not considered as error */
256 if (errno != EACCES) {
257 tst_resm(TFAIL | TERRNO, "%s: lstat", obj);
258 return 1;
259 }
260 return 0;
261
262 }
263
264 /* Prevent loops, but read /proc/self. */
265 if (S_ISLNK(statbuf.st_mode) && strcmp(obj, selfpath))
266 return 0;
267
268 total_obj++;
269
270 /* Take appropriate action, depending on the file type */
271 if (S_ISDIR(statbuf.st_mode) || !strcmp(obj, selfpath)) {
272
273 /* object is a directory */
274
275 /*
276 * Skip over the /proc/irq directory, unless the user
277 * requested that we read the directory because it could
278 * map to a broken driver which effectively `hangs' the
279 * test.
280 */
281 if (!opt_readirq && !strcmp("/proc/irq", obj)) {
282 return 0;
283 /* Open the directory to get access to what is in it */
284 } else if ((dir = opendir(obj)) == NULL) {
285 if (errno != EACCES) {
286 tst_resm(TFAIL | TERRNO, "%s: opendir", obj);
287 return 1;
288 }
289 return 0;
290 } else {
291
292 long ret_val = 0;
293
294 /* Loop through the entries in the directory */
295 for (dir_ent = (struct dirent *)readdir(dir);
296 dir_ent != NULL;
297 dir_ent = (struct dirent *)readdir(dir)) {
298
299 /* Ignore ".", "..", "kcore", and
300 * "/proc/<pid>" (unless this is our
301 * starting point as directed by the
302 * user).
303 */
304 if (strcmp(dir_ent->d_name, ".") &&
305 strcmp(dir_ent->d_name, "..") &&
306 strcmp(dir_ent->d_name, "kcore") &&
307 (fnmatch("[0-9]*", dir_ent->d_name,
308 FNM_PATHNAME) ||
309 strcmp(obj, procpath))) {
310
311 if (opt_verbose) {
312 fprintf(stderr, "%s\n",
313 dir_ent->d_name);
314 }
315
316 /* Recursively call this routine to test the
317 * current entry */
318 snprintf(dirobj, PATH_MAX,
319 "%s/%s", obj, dir_ent->d_name);
320 ret_val += readproc(dirobj);
321
322 }
323
324 }
325
326 /* Close the directory */
327 if (dir)
328 (void)closedir(dir);
329
330 return ret_val;
331
332 }
333
334 } else { /* if it's not a dir, read it! */
335
336 if (!S_ISREG(statbuf.st_mode))
337 return 0;
338
339 #ifdef DEBUG
340 fprintf(stderr, "%s", obj);
341 #endif
342
343 /* is O_NONBLOCK enough to escape from FIFO's ? */
344 fd = open(obj, O_RDONLY | O_NONBLOCK);
345 if (fd < 0) {
346 tmperr = errno;
347
348 if (!found_errno("open", obj, tmperr)) {
349
350 errno = tmperr;
351
352 if (errno != EACCES) {
353 tst_resm(TFAIL | TERRNO,
354 "%s: open failed", obj);
355 return 1;
356 }
357
358 }
359 return 0;
360
361 }
362
363 /* Skip write-only files. */
364 if ((statbuf.st_mode & S_IRUSR) == 0 &&
365 (statbuf.st_mode & S_IWUSR) != 0) {
366 tst_resm(TINFO, "%s: is write-only.", obj);
367 return 0;
368 }
369
370 /* Skip files does not honor O_NONBLOCK. */
371 for (i = 0; error_nonblock[i][0] != '\0'; i++) {
372 if (!strcmp(obj, error_nonblock[i])) {
373 tst_resm(TINFO, "%s: does not honor "
374 "O_NONBLOCK", obj);
375 return 0;
376 }
377 }
378
379 file_total_read = 0;
380 do {
381
382 nread = read(fd, buf, buffsize);
383
384 if (nread < 0) {
385
386 tmperr = errno;
387 (void)close(fd);
388
389 /* ignore no perm (not root) and no
390 * process (terminated) errors */
391 if (!found_errno("read", obj, tmperr)) {
392
393 errno = tmperr;
394
395 if (errno != EACCES && errno != ESRCH) {
396 tst_resm(TFAIL | TERRNO,
397 "read failed: "
398 "%s", obj);
399 return 1;
400 }
401 return 0;
402
403 }
404
405 } else
406 file_total_read += nread;
407
408 if (opt_verbose) {
409 #ifdef DEBUG
410 fprintf(stderr, "%ld", nread);
411 #endif
412 fprintf(stderr, ".");
413 }
414
415 if ((maxbytes > 0) && (file_total_read > maxbytes)) {
416 tst_resm(TINFO, "%s: reached maxmbytes (-m)",
417 obj);
418 break;
419 }
420 } while (0 < nread);
421 total_read += file_total_read;
422
423 if (opt_verbose)
424 fprintf(stderr, "\n");
425
426 if (0 <= fd)
427 (void)close(fd);
428
429 }
430
431 /* It's better to assume success by default rather than failure. */
432 return 0;
433
434 }
435
main(int argc,char * argv[])436 int main(int argc, char *argv[])
437 {
438 int lc;
439
440 tst_parse_opts(argc, argv, options, help);
441
442 if (opt_buffsize) {
443 size_t bs;
444 bs = atoi(opt_buffsizestr);
445 if (bs <= MAX_BUFF_SIZE)
446 buffsize = bs;
447 else
448 tst_brkm(TBROK, cleanup,
449 "Invalid arg for -b (max: %u): %s",
450 MAX_BUFF_SIZE, opt_buffsizestr);
451 }
452 if (opt_maxmbytes)
453 maxbytes = atoi(opt_maxmbytesstr) * 1024 * 1024;
454
455 if (opt_procpath)
456 procpath = opt_procpathstr;
457
458 setup();
459
460 for (lc = 0; TEST_LOOPING(lc); lc++) {
461 tst_count = 0;
462
463 TEST(readproc(procpath));
464
465 if (TEST_RETURN != 0) {
466 tst_resm(TFAIL, "readproc() failed with %ld errors.",
467 TEST_RETURN);
468 } else {
469 tst_resm(TPASS, "readproc() completed successfully, "
470 "total read: %llu bytes, %u objs", total_read,
471 total_obj);
472 }
473 }
474
475 cleanup();
476 tst_exit();
477 }
478