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      1 /*
      2  * Copyright  2018 Alexey Dobriyan <adobriyan (at) gmail.com>
      3  *
      4  * Permission to use, copy, modify, and distribute this software for any
      5  * purpose with or without fee is hereby granted, provided that the above
      6  * copyright notice and this permission notice appear in all copies.
      7  *
      8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     15  */
     16 /* Test readlink /proc/self/map_files/... */
     17 #include <errno.h>
     18 #include <sys/types.h>
     19 #include <sys/stat.h>
     20 #include <fcntl.h>
     21 #include <stdio.h>
     22 #include <unistd.h>
     23 #include <sys/mman.h>
     24 #include <stdlib.h>
     25 
     26 static void pass(const char *fmt, unsigned long a, unsigned long b)
     27 {
     28 	char name[64];
     29 	char buf[64];
     30 
     31 	snprintf(name, sizeof(name), fmt, a, b);
     32 	if (readlink(name, buf, sizeof(buf)) == -1)
     33 		exit(1);
     34 }
     35 
     36 static void fail(const char *fmt, unsigned long a, unsigned long b)
     37 {
     38 	char name[64];
     39 	char buf[64];
     40 
     41 	snprintf(name, sizeof(name), fmt, a, b);
     42 	if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT)
     43 		return;
     44 	exit(1);
     45 }
     46 
     47 int main(void)
     48 {
     49 	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
     50 	void *p;
     51 	int fd;
     52 	unsigned long a, b;
     53 
     54 	fd = open("/dev/zero", O_RDONLY);
     55 	if (fd == -1)
     56 		return 1;
     57 
     58 	p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE, fd, 0);
     59 	if (p == MAP_FAILED)
     60 		return 1;
     61 
     62 	a = (unsigned long)p;
     63 	b = (unsigned long)p + PAGE_SIZE;
     64 
     65 	pass("/proc/self/map_files/%lx-%lx", a, b);
     66 	fail("/proc/self/map_files/ %lx-%lx", a, b);
     67 	fail("/proc/self/map_files/%lx -%lx", a, b);
     68 	fail("/proc/self/map_files/%lx- %lx", a, b);
     69 	fail("/proc/self/map_files/%lx-%lx ", a, b);
     70 	fail("/proc/self/map_files/0%lx-%lx", a, b);
     71 	fail("/proc/self/map_files/%lx-0%lx", a, b);
     72 	if (sizeof(long) == 4) {
     73 		fail("/proc/self/map_files/100000000%lx-%lx", a, b);
     74 		fail("/proc/self/map_files/%lx-100000000%lx", a, b);
     75 	} else if (sizeof(long) == 8) {
     76 		fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b);
     77 		fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b);
     78 	} else
     79 		return 1;
     80 
     81 	return 0;
     82 }
     83