xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/mmap/mmap04.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) International Business Machines  Corp., 2001
4  *  07/2001 Ported by Wayne Boyer
5  * Copyright (c) 2023 SUSE LLC Avinesh Kumar <[email protected]>
6  */
7 
8 /*\
9  * [Description]
10  *
11  * Verify that, after a successful mmap() call, permission bits of the new
12  * mapping in /proc/pid/maps file matches the prot and flags arguments in
13  * mmap() call.
14  */
15 
16 #include <inttypes.h>
17 #include "tst_test.h"
18 #include <stdio.h>
19 
20 static char *addr1;
21 static char *addr2;
22 
23 static struct tcase {
24 	int prot;
25 	int flags;
26 	char *exp_perms;
27 } tcases[] = {
28 	{PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, "---p"},
29 	{PROT_NONE, MAP_ANONYMOUS | MAP_SHARED, "---s"},
30 	{PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, "r--p"},
31 	{PROT_READ, MAP_ANONYMOUS | MAP_SHARED, "r--s"},
32 	{PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, "-w-p"},
33 	{PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, "-w-s"},
34 	{PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, "rw-p"},
35 	{PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, "rw-s"},
36 	{PROT_READ | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, "r-xp"},
37 	{PROT_READ | PROT_EXEC, MAP_ANONYMOUS | MAP_SHARED, "r-xs"},
38 	{PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, "-wxp"},
39 	{PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_SHARED, "-wxs"},
40 	{PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, "rwxp"},
41 	{PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_SHARED, "rwxs"}
42 };
43 
run(unsigned int i)44 static void run(unsigned int i)
45 {
46 	struct tcase *tc = &tcases[i];
47 	char perms[8];
48 	char fmt[1024];
49 	unsigned int pagesize;
50 	int flag;
51 
52 	pagesize = SAFE_SYSCONF(_SC_PAGESIZE);
53 
54 	/* To avoid new mapping getting merged with existing mappings, we first
55 	 * create a 2-page mapping with the different permissions, and then remap
56 	 * the 2nd page with the perms being tested.
57 	 */
58 	flag = (tc->flags & MAP_PRIVATE) ? MAP_SHARED : MAP_PRIVATE;
59 	addr1 = SAFE_MMAP(NULL, pagesize * 2, PROT_NONE, MAP_ANONYMOUS | flag, -1, 0);
60 
61 	addr2 = SAFE_MMAP(addr1 + pagesize, pagesize, tc->prot, tc->flags | MAP_FIXED, -1, 0);
62 
63 	sprintf(fmt, "%" PRIxPTR "-%%*x %%s", (uintptr_t)addr2);
64 	SAFE_FILE_LINES_SCANF("/proc/self/maps", fmt, perms);
65 
66 	if (!strcmp(perms, tc->exp_perms)) {
67 		tst_res(TPASS, "mapping permissions in /proc matched: %s", perms);
68 	} else {
69 		tst_res(TFAIL, "mapping permissions in /proc mismatched, expected: %s, found: %s",
70 						tc->exp_perms, perms);
71 	}
72 
73 	SAFE_MUNMAP(addr1, pagesize * 2);
74 }
75 
76 static struct tst_test test = {
77 	.test = run,
78 	.tcnt = ARRAY_SIZE(tcases),
79 };
80