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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2011 The Chromium OS Authors.
4  */
5 
6 #include <dirent.h>
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <getopt.h>
10 #include <setjmp.h>
11 #include <stdio.h>
12 #include <stdint.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <termios.h>
16 #include <time.h>
17 #include <unistd.h>
18 #include <sys/mman.h>
19 #include <sys/stat.h>
20 #include <sys/time.h>
21 #include <sys/types.h>
22 #include <linux/types.h>
23 
24 #include <asm/getopt.h>
25 #include <asm/sections.h>
26 #include <asm/state.h>
27 #include <os.h>
28 #include <rtc_def.h>
29 
30 /* Operating System Interface */
31 
32 struct os_mem_hdr {
33 	size_t length;		/* number of bytes in the block */
34 };
35 
os_read(int fd,void * buf,size_t count)36 ssize_t os_read(int fd, void *buf, size_t count)
37 {
38 	return read(fd, buf, count);
39 }
40 
os_write(int fd,const void * buf,size_t count)41 ssize_t os_write(int fd, const void *buf, size_t count)
42 {
43 	return write(fd, buf, count);
44 }
45 
os_lseek(int fd,off_t offset,int whence)46 off_t os_lseek(int fd, off_t offset, int whence)
47 {
48 	if (whence == OS_SEEK_SET)
49 		whence = SEEK_SET;
50 	else if (whence == OS_SEEK_CUR)
51 		whence = SEEK_CUR;
52 	else if (whence == OS_SEEK_END)
53 		whence = SEEK_END;
54 	else
55 		os_exit(1);
56 	return lseek(fd, offset, whence);
57 }
58 
os_open(const char * pathname,int os_flags)59 int os_open(const char *pathname, int os_flags)
60 {
61 	int flags;
62 
63 	switch (os_flags & OS_O_MASK) {
64 	case OS_O_RDONLY:
65 	default:
66 		flags = O_RDONLY;
67 		break;
68 
69 	case OS_O_WRONLY:
70 		flags = O_WRONLY;
71 		break;
72 
73 	case OS_O_RDWR:
74 		flags = O_RDWR;
75 		break;
76 	}
77 
78 	if (os_flags & OS_O_CREAT)
79 		flags |= O_CREAT;
80 	if (os_flags & OS_O_TRUNC)
81 		flags |= O_TRUNC;
82 
83 	return open(pathname, flags, 0777);
84 }
85 
os_close(int fd)86 int os_close(int fd)
87 {
88 	return close(fd);
89 }
90 
os_unlink(const char * pathname)91 int os_unlink(const char *pathname)
92 {
93 	return unlink(pathname);
94 }
95 
os_exit(int exit_code)96 void os_exit(int exit_code)
97 {
98 	exit(exit_code);
99 }
100 
os_write_file(const char * fname,const void * buf,int size)101 int os_write_file(const char *fname, const void *buf, int size)
102 {
103 	int fd;
104 
105 	fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT | OS_O_TRUNC);
106 	if (fd < 0) {
107 		printf("Cannot open file '%s'\n", fname);
108 		return -EIO;
109 	}
110 	if (os_write(fd, buf, size) != size) {
111 		printf("Cannot write to file '%s'\n", fname);
112 		os_close(fd);
113 		return -EIO;
114 	}
115 	os_close(fd);
116 
117 	return 0;
118 }
119 
os_read_file(const char * fname,void ** bufp,int * sizep)120 int os_read_file(const char *fname, void **bufp, int *sizep)
121 {
122 	off_t size;
123 	int ret = -EIO;
124 	int fd;
125 
126 	fd = os_open(fname, OS_O_RDONLY);
127 	if (fd < 0) {
128 		printf("Cannot open file '%s'\n", fname);
129 		goto err;
130 	}
131 	size = os_lseek(fd, 0, OS_SEEK_END);
132 	if (size < 0) {
133 		printf("Cannot seek to end of file '%s'\n", fname);
134 		goto err;
135 	}
136 	if (os_lseek(fd, 0, OS_SEEK_SET) < 0) {
137 		printf("Cannot seek to start of file '%s'\n", fname);
138 		goto err;
139 	}
140 	*bufp = os_malloc(size);
141 	if (!*bufp) {
142 		printf("Not enough memory to read file '%s'\n", fname);
143 		ret = -ENOMEM;
144 		goto err;
145 	}
146 	if (os_read(fd, *bufp, size) != size) {
147 		printf("Cannot read from file '%s'\n", fname);
148 		goto err;
149 	}
150 	os_close(fd);
151 	*sizep = size;
152 
153 	return 0;
154 err:
155 	os_close(fd);
156 	return ret;
157 }
158 
159 /* Restore tty state when we exit */
160 static struct termios orig_term;
161 static bool term_setup;
162 static bool term_nonblock;
163 
os_fd_restore(void)164 void os_fd_restore(void)
165 {
166 	if (term_setup) {
167 		int flags;
168 
169 		tcsetattr(0, TCSANOW, &orig_term);
170 		if (term_nonblock) {
171 			flags = fcntl(0, F_GETFL, 0);
172 			fcntl(0, F_SETFL, flags & ~O_NONBLOCK);
173 		}
174 		term_setup = false;
175 	}
176 }
177 
178 /* Put tty into raw mode so <tab> and <ctrl+c> work */
os_tty_raw(int fd,bool allow_sigs)179 void os_tty_raw(int fd, bool allow_sigs)
180 {
181 	struct termios term;
182 	int flags;
183 
184 	if (term_setup)
185 		return;
186 
187 	/* If not a tty, don't complain */
188 	if (tcgetattr(fd, &orig_term))
189 		return;
190 
191 	term = orig_term;
192 	term.c_iflag = IGNBRK | IGNPAR;
193 	term.c_oflag = OPOST | ONLCR;
194 	term.c_cflag = CS8 | CREAD | CLOCAL;
195 	term.c_lflag = allow_sigs ? ISIG : 0;
196 	if (tcsetattr(fd, TCSANOW, &term))
197 		return;
198 
199 	flags = fcntl(fd, F_GETFL, 0);
200 	if (!(flags & O_NONBLOCK)) {
201 		if (fcntl(fd, F_SETFL, flags | O_NONBLOCK))
202 			return;
203 		term_nonblock = true;
204 	}
205 
206 	term_setup = true;
207 	atexit(os_fd_restore);
208 }
209 
os_malloc(size_t length)210 void *os_malloc(size_t length)
211 {
212 	int page_size = getpagesize();
213 	struct os_mem_hdr *hdr;
214 
215 	/*
216 	 * Use an address that is hopefully available to us so that pointers
217 	 * to this memory are fairly obvious. If we end up with a different
218 	 * address, that's fine too.
219 	 */
220 	hdr = mmap((void *)0x10000000, length + page_size,
221 		   PROT_READ | PROT_WRITE | PROT_EXEC,
222 		   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
223 	if (hdr == MAP_FAILED)
224 		return NULL;
225 	hdr->length = length;
226 
227 	return (void *)hdr + page_size;
228 }
229 
os_free(void * ptr)230 void os_free(void *ptr)
231 {
232 	int page_size = getpagesize();
233 	struct os_mem_hdr *hdr;
234 
235 	if (ptr) {
236 		hdr = ptr - page_size;
237 		munmap(hdr, hdr->length + page_size);
238 	}
239 }
240 
os_realloc(void * ptr,size_t length)241 void *os_realloc(void *ptr, size_t length)
242 {
243 	int page_size = getpagesize();
244 	struct os_mem_hdr *hdr;
245 	void *buf = NULL;
246 
247 	if (length) {
248 		buf = os_malloc(length);
249 		if (!buf)
250 			return buf;
251 		if (ptr) {
252 			hdr = ptr - page_size;
253 			if (length > hdr->length)
254 				length = hdr->length;
255 			memcpy(buf, ptr, length);
256 		}
257 	}
258 	if (ptr)
259 		os_free(ptr);
260 
261 	return buf;
262 }
263 
os_usleep(unsigned long usec)264 void os_usleep(unsigned long usec)
265 {
266 	usleep(usec);
267 }
268 
os_get_nsec(void)269 uint64_t __attribute__((no_instrument_function)) os_get_nsec(void)
270 {
271 #if defined(CLOCK_MONOTONIC) && defined(_POSIX_MONOTONIC_CLOCK)
272 	struct timespec tp;
273 	if (EINVAL == clock_gettime(CLOCK_MONOTONIC, &tp)) {
274 		struct timeval tv;
275 
276 		gettimeofday(&tv, NULL);
277 		tp.tv_sec = tv.tv_sec;
278 		tp.tv_nsec = tv.tv_usec * 1000;
279 	}
280 	return tp.tv_sec * 1000000000ULL + tp.tv_nsec;
281 #else
282 	struct timeval tv;
283 	gettimeofday(&tv, NULL);
284 	return tv.tv_sec * 1000000000ULL + tv.tv_usec * 1000;
285 #endif
286 }
287 
288 static char *short_opts;
289 static struct option *long_opts;
290 
os_parse_args(struct sandbox_state * state,int argc,char * argv[])291 int os_parse_args(struct sandbox_state *state, int argc, char *argv[])
292 {
293 	struct sandbox_cmdline_option **sb_opt = __u_boot_sandbox_option_start;
294 	size_t num_options = __u_boot_sandbox_option_count();
295 	size_t i;
296 
297 	int hidden_short_opt;
298 	size_t si;
299 
300 	int c;
301 
302 	if (short_opts || long_opts)
303 		return 1;
304 
305 	state->argc = argc;
306 	state->argv = argv;
307 
308 	/* dynamically construct the arguments to the system getopt_long */
309 	short_opts = os_malloc(sizeof(*short_opts) * num_options * 2 + 1);
310 	long_opts = os_malloc(sizeof(*long_opts) * num_options);
311 	if (!short_opts || !long_opts)
312 		return 1;
313 
314 	/*
315 	 * getopt_long requires "val" to be unique (since that is what the
316 	 * func returns), so generate unique values automatically for flags
317 	 * that don't have a short option.  pick 0x100 as that is above the
318 	 * single byte range (where ASCII/ISO-XXXX-X charsets live).
319 	 */
320 	hidden_short_opt = 0x100;
321 	si = 0;
322 	for (i = 0; i < num_options; ++i) {
323 		long_opts[i].name = sb_opt[i]->flag;
324 		long_opts[i].has_arg = sb_opt[i]->has_arg ?
325 			required_argument : no_argument;
326 		long_opts[i].flag = NULL;
327 
328 		if (sb_opt[i]->flag_short) {
329 			short_opts[si++] = long_opts[i].val = sb_opt[i]->flag_short;
330 			if (long_opts[i].has_arg == required_argument)
331 				short_opts[si++] = ':';
332 		} else
333 			long_opts[i].val = sb_opt[i]->flag_short = hidden_short_opt++;
334 	}
335 	short_opts[si] = '\0';
336 
337 	/* we need to handle output ourselves since u-boot provides printf */
338 	opterr = 0;
339 
340 	/*
341 	 * walk all of the options the user gave us on the command line,
342 	 * figure out what u-boot option structure they belong to (via
343 	 * the unique short val key), and call the appropriate callback.
344 	 */
345 	while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) {
346 		for (i = 0; i < num_options; ++i) {
347 			if (sb_opt[i]->flag_short == c) {
348 				if (sb_opt[i]->callback(state, optarg)) {
349 					state->parse_err = sb_opt[i]->flag;
350 					return 0;
351 				}
352 				break;
353 			}
354 		}
355 		if (i == num_options) {
356 			/*
357 			 * store the faulting flag for later display.  we have to
358 			 * store the flag itself as the getopt parsing itself is
359 			 * tricky: need to handle the following flags (assume all
360 			 * of the below are unknown):
361 			 *   -a        optopt='a' optind=<next>
362 			 *   -abbbb    optopt='a' optind=<this>
363 			 *   -aaaaa    optopt='a' optind=<this>
364 			 *   --a       optopt=0   optind=<this>
365 			 * as you can see, it is impossible to determine the exact
366 			 * faulting flag without doing the parsing ourselves, so
367 			 * we just report the specific flag that failed.
368 			 */
369 			if (optopt) {
370 				static char parse_err[3] = { '-', 0, '\0', };
371 				parse_err[1] = optopt;
372 				state->parse_err = parse_err;
373 			} else
374 				state->parse_err = argv[optind - 1];
375 			break;
376 		}
377 	}
378 
379 	return 0;
380 }
381 
os_dirent_free(struct os_dirent_node * node)382 void os_dirent_free(struct os_dirent_node *node)
383 {
384 	struct os_dirent_node *next;
385 
386 	while (node) {
387 		next = node->next;
388 		os_free(node);
389 		node = next;
390 	}
391 }
392 
os_dirent_ls(const char * dirname,struct os_dirent_node ** headp)393 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp)
394 {
395 	struct dirent *entry;
396 	struct os_dirent_node *head, *node, *next;
397 	struct stat buf;
398 	DIR *dir;
399 	int ret;
400 	char *fname;
401 	char *old_fname;
402 	int len;
403 	int dirlen;
404 
405 	*headp = NULL;
406 	dir = opendir(dirname);
407 	if (!dir)
408 		return -1;
409 
410 	/* Create a buffer upfront, with typically sufficient size */
411 	dirlen = strlen(dirname) + 2;
412 	len = dirlen + 256;
413 	fname = os_malloc(len);
414 	if (!fname) {
415 		ret = -ENOMEM;
416 		goto done;
417 	}
418 
419 	for (node = head = NULL;; node = next) {
420 		errno = 0;
421 		entry = readdir(dir);
422 		if (!entry) {
423 			ret = errno;
424 			break;
425 		}
426 		next = os_malloc(sizeof(*node) + strlen(entry->d_name) + 1);
427 		if (!next) {
428 			os_dirent_free(head);
429 			ret = -ENOMEM;
430 			goto done;
431 		}
432 		if (dirlen + strlen(entry->d_name) > len) {
433 			len = dirlen + strlen(entry->d_name);
434 			old_fname = fname;
435 			fname = os_realloc(fname, len);
436 			if (!fname) {
437 				os_free(old_fname);
438 				os_free(next);
439 				os_dirent_free(head);
440 				ret = -ENOMEM;
441 				goto done;
442 			}
443 		}
444 		next->next = NULL;
445 		strcpy(next->name, entry->d_name);
446 		switch (entry->d_type) {
447 		case DT_REG:
448 			next->type = OS_FILET_REG;
449 			break;
450 		case DT_DIR:
451 			next->type = OS_FILET_DIR;
452 			break;
453 		case DT_LNK:
454 			next->type = OS_FILET_LNK;
455 			break;
456 		default:
457 			next->type = OS_FILET_UNKNOWN;
458 		}
459 		next->size = 0;
460 		snprintf(fname, len, "%s/%s", dirname, next->name);
461 		if (!stat(fname, &buf))
462 			next->size = buf.st_size;
463 		if (node)
464 			node->next = next;
465 		else
466 			head = next;
467 	}
468 	*headp = head;
469 
470 done:
471 	closedir(dir);
472 	os_free(fname);
473 	return ret;
474 }
475 
476 const char *os_dirent_typename[OS_FILET_COUNT] = {
477 	"   ",
478 	"SYM",
479 	"DIR",
480 	"???",
481 };
482 
os_dirent_get_typename(enum os_dirent_t type)483 const char *os_dirent_get_typename(enum os_dirent_t type)
484 {
485 	if (type >= OS_FILET_REG && type < OS_FILET_COUNT)
486 		return os_dirent_typename[type];
487 
488 	return os_dirent_typename[OS_FILET_UNKNOWN];
489 }
490 
os_get_filesize(const char * fname,loff_t * size)491 int os_get_filesize(const char *fname, loff_t *size)
492 {
493 	struct stat buf;
494 	int ret;
495 
496 	ret = stat(fname, &buf);
497 	if (ret)
498 		return ret;
499 	*size = buf.st_size;
500 	return 0;
501 }
502 
os_putc(int ch)503 void os_putc(int ch)
504 {
505 	putchar(ch);
506 }
507 
os_puts(const char * str)508 void os_puts(const char *str)
509 {
510 	while (*str)
511 		os_putc(*str++);
512 }
513 
os_write_ram_buf(const char * fname)514 int os_write_ram_buf(const char *fname)
515 {
516 	struct sandbox_state *state = state_get_current();
517 	int fd, ret;
518 
519 	fd = open(fname, O_CREAT | O_WRONLY, 0777);
520 	if (fd < 0)
521 		return -ENOENT;
522 	ret = write(fd, state->ram_buf, state->ram_size);
523 	close(fd);
524 	if (ret != state->ram_size)
525 		return -EIO;
526 
527 	return 0;
528 }
529 
os_read_ram_buf(const char * fname)530 int os_read_ram_buf(const char *fname)
531 {
532 	struct sandbox_state *state = state_get_current();
533 	int fd, ret;
534 	loff_t size;
535 
536 	ret = os_get_filesize(fname, &size);
537 	if (ret < 0)
538 		return ret;
539 	if (size != state->ram_size)
540 		return -ENOSPC;
541 	fd = open(fname, O_RDONLY);
542 	if (fd < 0)
543 		return -ENOENT;
544 
545 	ret = read(fd, state->ram_buf, state->ram_size);
546 	close(fd);
547 	if (ret != state->ram_size)
548 		return -EIO;
549 
550 	return 0;
551 }
552 
make_exec(char * fname,const void * data,int size)553 static int make_exec(char *fname, const void *data, int size)
554 {
555 	int fd;
556 
557 	strcpy(fname, "/tmp/u-boot.jump.XXXXXX");
558 	fd = mkstemp(fname);
559 	if (fd < 0)
560 		return -ENOENT;
561 	if (write(fd, data, size) < 0)
562 		return -EIO;
563 	close(fd);
564 	if (chmod(fname, 0777))
565 		return -ENOEXEC;
566 
567 	return 0;
568 }
569 
570 /**
571  * add_args() - Allocate a new argv with the given args
572  *
573  * This is used to create a new argv array with all the old arguments and some
574  * new ones that are passed in
575  *
576  * @argvp:  Returns newly allocated args list
577  * @add_args: Arguments to add, each a string
578  * @count: Number of arguments in @add_args
579  * @return 0 if OK, -ENOMEM if out of memory
580  */
add_args(char *** argvp,char * add_args[],int count)581 static int add_args(char ***argvp, char *add_args[], int count)
582 {
583 	char **argv, **ap;
584 	int argc;
585 
586 	for (argc = 0; (*argvp)[argc]; argc++)
587 		;
588 
589 	argv = os_malloc((argc + count + 1) * sizeof(char *));
590 	if (!argv) {
591 		printf("Out of memory for %d argv\n", count);
592 		return -ENOMEM;
593 	}
594 	for (ap = *argvp, argc = 0; *ap; ap++) {
595 		char *arg = *ap;
596 
597 		/* Drop args that we don't want to propagate */
598 		if (*arg == '-' && strlen(arg) == 2) {
599 			switch (arg[1]) {
600 			case 'j':
601 			case 'm':
602 				ap++;
603 				continue;
604 			}
605 		} else if (!strcmp(arg, "--rm_memory")) {
606 			ap++;
607 			continue;
608 		}
609 		argv[argc++] = arg;
610 	}
611 
612 	memcpy(argv + argc, add_args, count * sizeof(char *));
613 	argv[argc + count] = NULL;
614 
615 	*argvp = argv;
616 	return 0;
617 }
618 
619 /**
620  * os_jump_to_file() - Jump to a new program
621  *
622  * This saves the memory buffer, sets up arguments to the new process, then
623  * execs it.
624  *
625  * @fname: Filename to exec
626  * @return does not return on success, any return value is an error
627  */
os_jump_to_file(const char * fname)628 static int os_jump_to_file(const char *fname)
629 {
630 	struct sandbox_state *state = state_get_current();
631 	char mem_fname[30];
632 	int fd, err;
633 	char *extra_args[5];
634 	char **argv = state->argv;
635 	int argc;
636 #ifdef DEBUG
637 	int i;
638 #endif
639 
640 	strcpy(mem_fname, "/tmp/u-boot.mem.XXXXXX");
641 	fd = mkstemp(mem_fname);
642 	if (fd < 0)
643 		return -ENOENT;
644 	close(fd);
645 	err = os_write_ram_buf(mem_fname);
646 	if (err)
647 		return err;
648 
649 	os_fd_restore();
650 
651 	extra_args[0] = "-j";
652 	extra_args[1] = (char *)fname;
653 	extra_args[2] = "-m";
654 	extra_args[3] = mem_fname;
655 	argc = 4;
656 	if (state->ram_buf_rm)
657 		extra_args[argc++] = "--rm_memory";
658 	err = add_args(&argv, extra_args, argc);
659 	if (err)
660 		return err;
661 	argv[0] = (char *)fname;
662 
663 #ifdef DEBUG
664 	for (i = 0; argv[i]; i++)
665 		printf("%d %s\n", i, argv[i]);
666 #endif
667 
668 	if (state_uninit())
669 		os_exit(2);
670 
671 	err = execv(fname, argv);
672 	os_free(argv);
673 	if (err) {
674 		perror("Unable to run image");
675 		printf("Image filename '%s'\n", fname);
676 		return err;
677 	}
678 
679 	return unlink(fname);
680 }
681 
os_jump_to_image(const void * dest,int size)682 int os_jump_to_image(const void *dest, int size)
683 {
684 	char fname[30];
685 	int err;
686 
687 	err = make_exec(fname, dest, size);
688 	if (err)
689 		return err;
690 
691 	return os_jump_to_file(fname);
692 }
693 
os_find_u_boot(char * fname,int maxlen)694 int os_find_u_boot(char *fname, int maxlen)
695 {
696 	struct sandbox_state *state = state_get_current();
697 	const char *progname = state->argv[0];
698 	int len = strlen(progname);
699 	const char *suffix;
700 	char *p;
701 	int fd;
702 
703 	if (len >= maxlen || len < 4)
704 		return -ENOSPC;
705 
706 	strcpy(fname, progname);
707 	suffix = fname + len - 4;
708 
709 	/* If we are TPL, boot to SPL */
710 	if (!strcmp(suffix, "-tpl")) {
711 		fname[len - 3] = 's';
712 		fd = os_open(fname, O_RDONLY);
713 		if (fd >= 0) {
714 			close(fd);
715 			return 0;
716 		}
717 
718 		/* Look for 'u-boot-tpl' in the tpl/ directory */
719 		p = strstr(fname, "/tpl/");
720 		if (p) {
721 			p[1] = 's';
722 			fd = os_open(fname, O_RDONLY);
723 			if (fd >= 0) {
724 				close(fd);
725 				return 0;
726 			}
727 		}
728 		return -ENOENT;
729 	}
730 
731 	/* Look for 'u-boot' in the same directory as 'u-boot-spl' */
732 	if (!strcmp(suffix, "-spl")) {
733 		fname[len - 4] = '\0';
734 		fd = os_open(fname, O_RDONLY);
735 		if (fd >= 0) {
736 			close(fd);
737 			return 0;
738 		}
739 	}
740 
741 	/* Look for 'u-boot' in the parent directory of spl/ */
742 	p = strstr(fname, "spl/");
743 	if (p) {
744 		/* Remove the "spl" characters */
745 		memmove(p, p + 4, strlen(p + 4) + 1);
746 		fd = os_open(fname, O_RDONLY);
747 		if (fd >= 0) {
748 			close(fd);
749 			return 0;
750 		}
751 	}
752 
753 	return -ENOENT;
754 }
755 
os_spl_to_uboot(const char * fname)756 int os_spl_to_uboot(const char *fname)
757 {
758 	return os_jump_to_file(fname);
759 }
760 
os_localtime(struct rtc_time * rt)761 void os_localtime(struct rtc_time *rt)
762 {
763 	time_t t = time(NULL);
764 	struct tm *tm;
765 
766 	tm = localtime(&t);
767 	rt->tm_sec = tm->tm_sec;
768 	rt->tm_min = tm->tm_min;
769 	rt->tm_hour = tm->tm_hour;
770 	rt->tm_mday = tm->tm_mday;
771 	rt->tm_mon = tm->tm_mon + 1;
772 	rt->tm_year = tm->tm_year + 1900;
773 	rt->tm_wday = tm->tm_wday;
774 	rt->tm_yday = tm->tm_yday;
775 	rt->tm_isdst = tm->tm_isdst;
776 }
777 
os_abort(void)778 void os_abort(void)
779 {
780 	abort();
781 }
782 
os_mprotect_allow(void * start,size_t len)783 int os_mprotect_allow(void *start, size_t len)
784 {
785 	int page_size = getpagesize();
786 
787 	/* Move start to the start of a page, len to the end */
788 	start = (void *)(((ulong)start) & ~(page_size - 1));
789 	len = (len + page_size * 2) & ~(page_size - 1);
790 
791 	return mprotect(start, len, PROT_READ | PROT_WRITE);
792 }
793 
os_find_text_base(void)794 void *os_find_text_base(void)
795 {
796 	char line[500];
797 	void *base = NULL;
798 	int len;
799 	int fd;
800 
801 	/*
802 	 * This code assumes that the first line of /proc/self/maps holds
803 	 * information about the text, for example:
804 	 *
805 	 * 5622d9907000-5622d9a55000 r-xp 00000000 08:01 15067168   u-boot
806 	 *
807 	 * The first hex value is assumed to be the address.
808 	 *
809 	 * This is tested in Linux 4.15.
810 	 */
811 	fd = open("/proc/self/maps", O_RDONLY);
812 	if (fd == -1)
813 		return NULL;
814 	len = read(fd, line, sizeof(line));
815 	if (len > 0) {
816 		char *end = memchr(line, '-', len);
817 
818 		if (end) {
819 			uintptr_t addr;
820 
821 			*end = '\0';
822 			if (sscanf(line, "%zx", &addr) == 1)
823 				base = (void *)addr;
824 		}
825 	}
826 	close(fd);
827 
828 	return base;
829 }
830