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0256a6ac PA |
1 | /* This testcase is part of GDB, the GNU debugger. |
2 | ||
618f726f | 3 | Copyright 2012-2016 Free Software Foundation, Inc. |
0256a6ac PA |
4 | |
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 3 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program 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 | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
17 | ||
18 | #include <stdlib.h> | |
19 | #include <stdio.h> | |
20 | #include <sys/mman.h> | |
21 | #include <unistd.h> | |
22 | #include <string.h> | |
23 | ||
24 | size_t pg_size; | |
25 | void *first_mapped_page; | |
26 | void *last_mapped_page; | |
27 | ||
28 | void | |
29 | breakpt (void) | |
30 | { | |
31 | /* Nothing. */ | |
32 | } | |
33 | ||
34 | int | |
35 | main (void) | |
36 | { | |
37 | void *p; | |
38 | int pg_count; | |
39 | size_t i; | |
40 | ||
41 | /* Map 6 contiguous pages, and then unmap all second first, and | |
42 | second last. | |
43 | ||
44 | From GDB we will disassemble each of the _mapped_ pages, with a | |
45 | code-cache (dcache) line size bigger than the page size (twice | |
46 | bigger). This makes GDB try to read one page before the mapped | |
47 | page once, and the page after another time. GDB should give no | |
48 | error in either case. | |
49 | ||
50 | That is, depending on where the kernel aligns the pages, we get | |
51 | either: | |
52 | ||
53 | .---.---.---.---.---.---. | |
54 | | U | M | U | U | M | U | | |
55 | '---'---'---'---'---'---. | |
56 | | | | | <- line alignment | |
57 | ^^^^^^^ ^^^^^^^ | |
58 | | | | |
59 | + line1 + line2 | |
60 | ||
61 | Or: | |
62 | ||
63 | .---.---.---.---.---.---. | |
64 | | U | M | U | U | M | U | | |
65 | '---'---'---'---'---'---. | |
66 | | | | <- line alignment | |
67 | ^^^^^^^ ^^^^^^^ | |
68 | | | | |
69 | line1 + + line2 | |
70 | ||
71 | Note we really want to test that dcache behaves correctly when | |
72 | reading a cache line fails. We're just using unmapped memory as | |
73 | proxy for any kind of error. */ | |
74 | ||
75 | pg_size = getpagesize (); | |
76 | pg_count = 6; | |
77 | ||
78 | p = mmap (0, pg_count * pg_size, PROT_READ|PROT_WRITE, | |
79 | MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); | |
80 | if (p == MAP_FAILED) | |
81 | { | |
82 | perror ("mmap"); | |
83 | return EXIT_FAILURE; | |
84 | } | |
85 | ||
86 | /* Leave memory zero-initialized. Disassembling 0s should behave on | |
87 | all targets. */ | |
88 | ||
89 | for (i = 0; i < pg_count; i++) | |
90 | { | |
91 | if (i == 1 || i == 4) | |
92 | continue; | |
93 | ||
94 | if (munmap (p + (i * pg_size), pg_size) == -1) | |
95 | { | |
96 | perror ("munmap"); | |
97 | return EXIT_FAILURE; | |
98 | } | |
99 | } | |
100 | ||
101 | first_mapped_page = p + 1 * pg_size;; | |
102 | last_mapped_page = p + 4 * pg_size; | |
103 | ||
104 | breakpt (); | |
105 | ||
106 | return EXIT_SUCCESS; | |
107 | } |