1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2013 FNST, DAN LI <[email protected]>
4 * Copyright (c) 2024 SUSE LLC Avinesh Kumar <[email protected]>
5 */
6
7 /*\
8 * [Description]
9 *
10 * Verify that, mmap() call succeeds to create a file mapping with length
11 * argument greater than the file size but any attempt to reference the
12 * memory region which does not correspond to the file causes SIGBUS signal.
13 */
14
15 #include <stdlib.h>
16 #include <setjmp.h>
17 #include "tst_test.h"
18
19 #define TEMPFILE "mmapfile"
20 static size_t page_sz;
21 static char *addr;
22 static int fd;
23 static volatile sig_atomic_t pass;
24 static sigjmp_buf env;
25
sig_handler(int sig)26 static void sig_handler(int sig)
27 {
28 if (sig == SIGBUS) {
29 pass = 1;
30 siglongjmp(env, 1);
31 }
32 }
33
setup(void)34 static void setup(void)
35 {
36 SAFE_SIGNAL(SIGBUS, sig_handler);
37
38 page_sz = getpagesize();
39
40 fd = SAFE_OPEN(TEMPFILE, O_RDWR | O_CREAT, 0666);
41 SAFE_FTRUNCATE(fd, page_sz / 2);
42 }
43
run(void)44 static void run(void)
45 {
46 char *ch;
47
48 addr = mmap(0, page_sz * 2, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, fd, 0);
49 if (addr == MAP_FAILED) {
50 tst_res(TFAIL | TERRNO, "mmap() of %s failed", TEMPFILE);
51 return;
52 }
53
54 if (sigsetjmp(env, 1) == 0) {
55 ch = addr + page_sz + 1;
56 *ch = 0;
57 }
58
59 if (pass == 1)
60 tst_res(TPASS, "Received SIGBUS signal as expected");
61 else
62 tst_res(TFAIL, "SIGBUS signal not received");
63
64 SAFE_MUNMAP(addr, page_sz * 2);
65 }
66
cleanup(void)67 static void cleanup(void)
68 {
69 if (fd > 0)
70 SAFE_CLOSE(fd);
71 }
72
73 static struct tst_test test = {
74 .setup = setup,
75 .cleanup = cleanup,
76 .test_all = run,
77 .needs_tmpdir = 1
78 };
79