1 /*
2 * Copyright (c) 2015 Red Hat, Inc.
3 *
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 /*
19 * DESCRIPTION
20 * shmget()/shmat() fails to allocate huge pages shared memory segment
21 * with EINVAL if its size is not in the range [ N*HUGE_PAGE_SIZE - 4095,
22 * N*HUGE_PAGE_SIZE ]. This is a problem in the memory segment size round
23 * up algorithm. The requested size is rounded up to PAGE_SIZE (4096), but
24 * if this roundup does not match HUGE_PAGE_SIZE (2Mb) boundary - the
25 * allocation fails.
26 *
27 * This bug is present in all RHEL6 versions, but not in RHEL7. It looks
28 * like this was fixed in mainline kernel > v3.3 by the following patches:
29 *
30 * 091d0d5 (shm: fix null pointer deref when userspace specifies
31 * invalid hugepage size)
32 * af73e4d (hugetlbfs: fix mmap failure in unaligned size request)
33 * 42d7395 (mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB)
34 * 40716e2 (hugetlbfs: fix alignment of huge page requests)
35 *
36 * AUTHORS
37 * Vladislav Dronov <vdronov@redhat.com>
38 * Li Wang <liwang@redhat.com>
39 *
40 */
41
42 #include <stdlib.h>
43 #include <stdio.h>
44 #include <sys/types.h>
45 #include <sys/ipc.h>
46 #include <sys/shm.h>
47 #include <sys/mman.h>
48 #include <fcntl.h>
49
50 #include "test.h"
51 #include "mem.h"
52 #include "hugetlb.h"
53
54 char *TCID = "hugeshmat05";
55 int TST_TOTAL = 1;
56
57 static long page_size;
58 static long hpage_size;
59 static long hugepages;
60
61 #define N 4
62
setup(void)63 void setup(void)
64 {
65 tst_require_root();
66 check_hugepage();
67
68 orig_hugepages = get_sys_tune("nr_hugepages");
69 page_size = getpagesize();
70 hpage_size = read_meminfo("Hugepagesize:") * 1024;
71
72 hugepages = N + 1;
73 set_sys_tune("nr_hugepages", hugepages, 1);
74
75 TEST_PAUSE;
76 }
77
cleanup(void)78 void cleanup(void)
79 {
80 set_sys_tune("nr_hugepages", orig_hugepages, 0);
81 }
82
shm_test(int size)83 void shm_test(int size)
84 {
85 int shmid;
86 char *shmaddr;
87
88 shmid = shmget(IPC_PRIVATE, size, 0600 | IPC_CREAT | SHM_HUGETLB);
89 if (shmid < 0)
90 tst_brkm(TBROK | TERRNO, cleanup, "shmget failed");
91
92 shmaddr = shmat(shmid, 0, 0);
93 if (shmaddr == (char *)-1) {
94 shmctl(shmid, IPC_RMID, NULL);
95 tst_brkm(TFAIL | TERRNO, cleanup,
96 "Bug: shared memory attach failure.");
97 }
98
99 shmaddr[0] = 1;
100 tst_resm(TINFO, "allocated %d huge bytes", size);
101
102 if (shmdt((const void *)shmaddr) != 0) {
103 shmctl(shmid, IPC_RMID, NULL);
104 tst_brkm(TFAIL | TERRNO, cleanup, "Detach failure.");
105 }
106
107 shmctl(shmid, IPC_RMID, NULL);
108 }
109
main(int ac,char ** av)110 int main(int ac, char **av)
111 {
112 int lc;
113 unsigned int i;
114
115 tst_parse_opts(ac, av, NULL, NULL);
116
117 setup();
118
119 const int tst_sizes[] = {
120 N * hpage_size - page_size,
121 N * hpage_size - page_size - 1,
122 hpage_size,
123 hpage_size + 1
124 };
125
126 for (lc = 0; TEST_LOOPING(lc); lc++) {
127 tst_count = 0;
128
129 for (i = 0; i < ARRAY_SIZE(tst_sizes); ++i)
130 shm_test(tst_sizes[i]);
131
132 tst_resm(TPASS, "No regression found.");
133 }
134
135 cleanup();
136 tst_exit();
137 }
138