1 | /* Miscellaneous support functions for dynamic linker |
2 | Copyright (C) 1997-2017 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <assert.h> |
20 | #include <fcntl.h> |
21 | #include <ldsodefs.h> |
22 | #include <limits.h> |
23 | #include <link.h> |
24 | #include <stdarg.h> |
25 | #include <stdlib.h> |
26 | #include <string.h> |
27 | #include <unistd.h> |
28 | #include <stdint.h> |
29 | #include <sys/mman.h> |
30 | #include <sys/param.h> |
31 | #include <sys/stat.h> |
32 | #include <sys/uio.h> |
33 | #include <sysdep.h> |
34 | #include <_itoa.h> |
35 | #include <dl-writev.h> |
36 | |
37 | |
38 | /* Read the whole contents of FILE into new mmap'd space with given |
39 | protections. *SIZEP gets the size of the file. On error MAP_FAILED |
40 | is returned. */ |
41 | |
42 | void * |
43 | internal_function |
44 | _dl_sysdep_read_whole_file (const char *file, size_t *sizep, int prot) |
45 | { |
46 | void *result = MAP_FAILED; |
47 | struct stat64 st; |
48 | int fd = __open (file, O_RDONLY | O_CLOEXEC); |
49 | if (fd >= 0) |
50 | { |
51 | if (__fxstat64 (_STAT_VER, fd, &st) >= 0) |
52 | { |
53 | *sizep = st.st_size; |
54 | |
55 | /* No need to map the file if it is empty. */ |
56 | if (*sizep != 0) |
57 | /* Map a copy of the file contents. */ |
58 | result = __mmap (NULL, *sizep, prot, |
59 | #ifdef MAP_COPY |
60 | MAP_COPY |
61 | #else |
62 | MAP_PRIVATE |
63 | #endif |
64 | #ifdef MAP_FILE |
65 | | MAP_FILE |
66 | #endif |
67 | , fd, 0); |
68 | } |
69 | __close (fd); |
70 | } |
71 | return result; |
72 | } |
73 | |
74 | |
75 | /* Bare-bones printf implementation. This function only knows about |
76 | the formats and flags needed and can handle only up to 64 stripes in |
77 | the output. */ |
78 | static void |
79 | _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg) |
80 | { |
81 | # define NIOVMAX 64 |
82 | struct iovec iov[NIOVMAX]; |
83 | int niov = 0; |
84 | pid_t pid = 0; |
85 | char pidbuf[12]; |
86 | |
87 | while (*fmt != '\0') |
88 | { |
89 | const char *startp = fmt; |
90 | |
91 | if (tag_p > 0) |
92 | { |
93 | /* Generate the tag line once. It consists of the PID and a |
94 | colon followed by a tab. */ |
95 | if (pid == 0) |
96 | { |
97 | char *p; |
98 | pid = __getpid (); |
99 | assert (pid >= 0 && sizeof (pid_t) <= 4); |
100 | p = _itoa (pid, &pidbuf[10], 10, 0); |
101 | while (p > pidbuf) |
102 | *--p = ' '; |
103 | pidbuf[10] = ':'; |
104 | pidbuf[11] = '\t'; |
105 | } |
106 | |
107 | /* Append to the output. */ |
108 | assert (niov < NIOVMAX); |
109 | iov[niov].iov_len = 12; |
110 | iov[niov++].iov_base = pidbuf; |
111 | |
112 | /* No more tags until we see the next newline. */ |
113 | tag_p = -1; |
114 | } |
115 | |
116 | /* Skip everything except % and \n (if tags are needed). */ |
117 | while (*fmt != '\0' && *fmt != '%' && (! tag_p || *fmt != '\n')) |
118 | ++fmt; |
119 | |
120 | /* Append constant string. */ |
121 | assert (niov < NIOVMAX); |
122 | if ((iov[niov].iov_len = fmt - startp) != 0) |
123 | iov[niov++].iov_base = (char *) startp; |
124 | |
125 | if (*fmt == '%') |
126 | { |
127 | /* It is a format specifier. */ |
128 | char fill = ' '; |
129 | int width = -1; |
130 | int prec = -1; |
131 | #if LONG_MAX != INT_MAX |
132 | int long_mod = 0; |
133 | #endif |
134 | |
135 | /* Recognize zero-digit fill flag. */ |
136 | if (*++fmt == '0') |
137 | { |
138 | fill = '0'; |
139 | ++fmt; |
140 | } |
141 | |
142 | /* See whether with comes from a parameter. Note that no other |
143 | way to specify the width is implemented. */ |
144 | if (*fmt == '*') |
145 | { |
146 | width = va_arg (arg, int); |
147 | ++fmt; |
148 | } |
149 | |
150 | /* Handle precision. */ |
151 | if (*fmt == '.' && fmt[1] == '*') |
152 | { |
153 | prec = va_arg (arg, int); |
154 | fmt += 2; |
155 | } |
156 | |
157 | /* Recognize the l modifier. It is only important on some |
158 | platforms where long and int have a different size. We |
159 | can use the same code for size_t. */ |
160 | if (*fmt == 'l' || *fmt == 'Z') |
161 | { |
162 | #if LONG_MAX != INT_MAX |
163 | long_mod = 1; |
164 | #endif |
165 | ++fmt; |
166 | } |
167 | |
168 | switch (*fmt) |
169 | { |
170 | /* Integer formatting. */ |
171 | case 'u': |
172 | case 'x': |
173 | { |
174 | /* We have to make a difference if long and int have a |
175 | different size. */ |
176 | #if LONG_MAX != INT_MAX |
177 | unsigned long int num = (long_mod |
178 | ? va_arg (arg, unsigned long int) |
179 | : va_arg (arg, unsigned int)); |
180 | #else |
181 | unsigned long int num = va_arg (arg, unsigned int); |
182 | #endif |
183 | /* We use alloca() to allocate the buffer with the most |
184 | pessimistic guess for the size. Using alloca() allows |
185 | having more than one integer formatting in a call. */ |
186 | char *buf = (char *) alloca (3 * sizeof (unsigned long int)); |
187 | char *endp = &buf[3 * sizeof (unsigned long int)]; |
188 | char *cp = _itoa (num, endp, *fmt == 'x' ? 16 : 10, 0); |
189 | |
190 | /* Pad to the width the user specified. */ |
191 | if (width != -1) |
192 | while (endp - cp < width) |
193 | *--cp = fill; |
194 | |
195 | iov[niov].iov_base = cp; |
196 | iov[niov].iov_len = endp - cp; |
197 | ++niov; |
198 | } |
199 | break; |
200 | |
201 | case 's': |
202 | /* Get the string argument. */ |
203 | iov[niov].iov_base = va_arg (arg, char *); |
204 | iov[niov].iov_len = strlen (iov[niov].iov_base); |
205 | if (prec != -1) |
206 | iov[niov].iov_len = MIN ((size_t) prec, iov[niov].iov_len); |
207 | ++niov; |
208 | break; |
209 | |
210 | case '%': |
211 | iov[niov].iov_base = (void *) fmt; |
212 | iov[niov].iov_len = 1; |
213 | ++niov; |
214 | break; |
215 | |
216 | default: |
217 | assert (! "invalid format specifier" ); |
218 | } |
219 | ++fmt; |
220 | } |
221 | else if (*fmt == '\n') |
222 | { |
223 | /* See whether we have to print a single newline character. */ |
224 | if (fmt == startp) |
225 | { |
226 | iov[niov].iov_base = (char *) startp; |
227 | iov[niov++].iov_len = 1; |
228 | } |
229 | else |
230 | /* No, just add it to the rest of the string. */ |
231 | ++iov[niov - 1].iov_len; |
232 | |
233 | /* Next line, print a tag again. */ |
234 | tag_p = 1; |
235 | ++fmt; |
236 | } |
237 | } |
238 | |
239 | /* Finally write the result. */ |
240 | _dl_writev (fd, iov, niov); |
241 | } |
242 | |
243 | |
244 | /* Write to debug file. */ |
245 | void |
246 | _dl_debug_printf (const char *fmt, ...) |
247 | { |
248 | va_list arg; |
249 | |
250 | va_start (arg, fmt); |
251 | _dl_debug_vdprintf (GLRO(dl_debug_fd), 1, fmt, arg); |
252 | va_end (arg); |
253 | } |
254 | |
255 | |
256 | /* Write to debug file but don't start with a tag. */ |
257 | void |
258 | _dl_debug_printf_c (const char *fmt, ...) |
259 | { |
260 | va_list arg; |
261 | |
262 | va_start (arg, fmt); |
263 | _dl_debug_vdprintf (GLRO(dl_debug_fd), -1, fmt, arg); |
264 | va_end (arg); |
265 | } |
266 | |
267 | |
268 | /* Write the given file descriptor. */ |
269 | void |
270 | _dl_dprintf (int fd, const char *fmt, ...) |
271 | { |
272 | va_list arg; |
273 | |
274 | va_start (arg, fmt); |
275 | _dl_debug_vdprintf (fd, 0, fmt, arg); |
276 | va_end (arg); |
277 | } |
278 | |
279 | |
280 | /* Test whether given NAME matches any of the names of the given object. */ |
281 | int |
282 | internal_function |
283 | _dl_name_match_p (const char *name, const struct link_map *map) |
284 | { |
285 | if (strcmp (name, map->l_name) == 0) |
286 | return 1; |
287 | |
288 | struct libname_list *runp = map->l_libname; |
289 | |
290 | while (runp != NULL) |
291 | if (strcmp (name, runp->name) == 0) |
292 | return 1; |
293 | else |
294 | runp = runp->next; |
295 | |
296 | return 0; |
297 | } |
298 | |
299 | |
300 | unsigned long int |
301 | internal_function |
302 | _dl_higher_prime_number (unsigned long int n) |
303 | { |
304 | /* These are primes that are near, but slightly smaller than, a |
305 | power of two. */ |
306 | static const uint32_t primes[] = { |
307 | UINT32_C (7), |
308 | UINT32_C (13), |
309 | UINT32_C (31), |
310 | UINT32_C (61), |
311 | UINT32_C (127), |
312 | UINT32_C (251), |
313 | UINT32_C (509), |
314 | UINT32_C (1021), |
315 | UINT32_C (2039), |
316 | UINT32_C (4093), |
317 | UINT32_C (8191), |
318 | UINT32_C (16381), |
319 | UINT32_C (32749), |
320 | UINT32_C (65521), |
321 | UINT32_C (131071), |
322 | UINT32_C (262139), |
323 | UINT32_C (524287), |
324 | UINT32_C (1048573), |
325 | UINT32_C (2097143), |
326 | UINT32_C (4194301), |
327 | UINT32_C (8388593), |
328 | UINT32_C (16777213), |
329 | UINT32_C (33554393), |
330 | UINT32_C (67108859), |
331 | UINT32_C (134217689), |
332 | UINT32_C (268435399), |
333 | UINT32_C (536870909), |
334 | UINT32_C (1073741789), |
335 | UINT32_C (2147483647), |
336 | /* 4294967291L */ |
337 | UINT32_C (2147483647) + UINT32_C (2147483644) |
338 | }; |
339 | |
340 | const uint32_t *low = &primes[0]; |
341 | const uint32_t *high = &primes[sizeof (primes) / sizeof (primes[0])]; |
342 | |
343 | while (low != high) |
344 | { |
345 | const uint32_t *mid = low + (high - low) / 2; |
346 | if (n > *mid) |
347 | low = mid + 1; |
348 | else |
349 | high = mid; |
350 | } |
351 | |
352 | #if 0 |
353 | /* If we've run out of primes, abort. */ |
354 | if (n > *low) |
355 | { |
356 | fprintf (stderr, "Cannot find prime bigger than %lu\n" , n); |
357 | abort (); |
358 | } |
359 | #endif |
360 | |
361 | return *low; |
362 | } |
363 | |
364 | /* A stripped down strtoul-like implementation for very early use. It |
365 | does not set errno if the result is outside bounds because it may get |
366 | called before errno may have been set up. */ |
367 | |
368 | uint64_t |
369 | internal_function |
370 | _dl_strtoul (const char *nptr, char **endptr) |
371 | { |
372 | uint64_t result = 0; |
373 | bool positive = true; |
374 | unsigned max_digit; |
375 | |
376 | while (*nptr == ' ' || *nptr == '\t') |
377 | ++nptr; |
378 | |
379 | if (*nptr == '-') |
380 | { |
381 | positive = false; |
382 | ++nptr; |
383 | } |
384 | else if (*nptr == '+') |
385 | ++nptr; |
386 | |
387 | if (*nptr < '0' || *nptr > '9') |
388 | { |
389 | if (endptr != NULL) |
390 | *endptr = (char *) nptr; |
391 | return 0UL; |
392 | } |
393 | |
394 | int base = 10; |
395 | max_digit = 9; |
396 | if (*nptr == '0') |
397 | { |
398 | if (nptr[1] == 'x' || nptr[1] == 'X') |
399 | { |
400 | base = 16; |
401 | nptr += 2; |
402 | } |
403 | else |
404 | { |
405 | base = 8; |
406 | max_digit = 7; |
407 | } |
408 | } |
409 | |
410 | while (1) |
411 | { |
412 | int digval; |
413 | if (*nptr >= '0' && *nptr <= '0' + max_digit) |
414 | digval = *nptr - '0'; |
415 | else if (base == 16) |
416 | { |
417 | if (*nptr >= 'a' && *nptr <= 'f') |
418 | digval = *nptr - 'a' + 10; |
419 | else if (*nptr >= 'A' && *nptr <= 'F') |
420 | digval = *nptr - 'A' + 10; |
421 | else |
422 | break; |
423 | } |
424 | else |
425 | break; |
426 | |
427 | if (result >= (UINT64_MAX - digval) / base) |
428 | { |
429 | if (endptr != NULL) |
430 | *endptr = (char *) nptr; |
431 | return UINT64_MAX; |
432 | } |
433 | result *= base; |
434 | result += digval; |
435 | ++nptr; |
436 | } |
437 | |
438 | if (endptr != NULL) |
439 | *endptr = (char *) nptr; |
440 | |
441 | /* Avoid 64-bit multiplication. */ |
442 | if (!positive) |
443 | result = -result; |
444 | |
445 | return result; |
446 | } |
447 | |