1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2018 FUJITSU LIMITED. All rights reserved.
4 * Author: Xiao Yang <[email protected]>
5 */
6 /*
7 * Description:
8 * Check the basic functionality of the mlock2(2) since kernel v2.6.9:
9 * 1) When we use mlock2() without MLOCK_ONFAULT to lock memory in the
10 * specified range that is multiples of page size or not, we can
11 * show correct size of locked memory by VmLck from /proc/PID/status
12 * and lock all pages including non-present.
13 * 2) When we use mlock2() with MLOCK_ONFAULT to lock memory in the
14 * specified range that is multiples of page size or not, we can
15 * show correct size of locked memory by VmLck from /proc/PID/status
16 * and just lock present pages.
17 */
18 #include <errno.h>
19 #include <unistd.h>
20 #include <string.h>
21 #include <stdlib.h>
22 #include <sys/mman.h>
23 #include <linux/mman.h>
24
25 #include "tst_test.h"
26 #include "lapi/syscalls.h"
27 #include "lapi/mlock2.h"
28 #include "pgsize_helpers.h"
29
30 #define PAGES 8
31 #define HPAGES (PAGES / 2)
32
33 static size_t pgsz;
34
35 static DECLARE_MINCORE_VECTOR(vec, PAGES+1);
36
37 static struct tcase {
38 size_t populate_pages;
39 size_t lock_pages;
40 ssize_t offset; /* Can be negative */
41 size_t exp_vmlcks;
42 size_t exp_present_pages;
43 int flag;
44 } tcases[] = {
45 /* lock single page, expect it to be locked and present */
46 {0, 1, 0, 1, 1, 0},
47
48 /* lock all pages, expect all to be locked and present */
49 {0, PAGES, 0, PAGES, PAGES, 0},
50
51 /* mlock2() locks 3 pages if the specified
52 * range is little more than 2 pages.
53 */
54 {0, 2, 1, 3, 3, 0},
55
56 /* mlock2() locks 2 pages if the specified
57 * range is little less than 2 pages.
58 */
59 {0, 2, -1, 2, 2, 0},
60
61 /* mlock2() with MLOCK_ONFAULT just lock present
62 * pages populated by data.
63 */
64 {0, 1, 0, 1, 0, MLOCK_ONFAULT},
65
66 /* fault-in half of pages, lock all with MLOCK_ONFAULT */
67 {HPAGES, PAGES, 0, PAGES, HPAGES, MLOCK_ONFAULT},
68
69 /* fault-in 1 page, lock half of pages */
70 {1, HPAGES, 1, HPAGES + 1, 1, MLOCK_ONFAULT},
71
72 /* fault-in half, lock little less than 2 pages */
73 {HPAGES, HPAGES, -1, HPAGES, HPAGES, MLOCK_ONFAULT},
74 };
75
check_locked_pages(char * addr,size_t len,size_t num_pgs)76 static size_t check_locked_pages(char *addr, size_t len, size_t num_pgs)
77 {
78 size_t n;
79 size_t act_pages = 0;
80
81 SAFE_MINCORE(addr, len, vec);
82
83 for (n = 0; n < nr_pgs_to_nr_kernel_pgs(num_pgs); n++) {
84 if (vec[n] & 1)
85 act_pages++;
86 }
87
88 return nr_kernel_pgs_to_nr_pgs(act_pages);
89 }
90
verify_mlock2(unsigned int n)91 static void verify_mlock2(unsigned int n)
92 {
93 struct tcase *tc = &tcases[n];
94 size_t bsize, asize, act_vmlcks, act_pgs;
95 char *addr;
96
97 addr = SAFE_MMAP(NULL, PAGES * pgsz, PROT_WRITE,
98 MAP_SHARED | MAP_ANONYMOUS, 0, 0);
99
100 if (tc->populate_pages)
101 memset(addr, 0, tc->populate_pages * pgsz);
102
103 SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &bsize);
104
105 TEST(tst_syscall(__NR_mlock2, addr, tc->lock_pages * pgsz + tc->offset,
106 tc->flag));
107 SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &asize);
108
109 if (TST_RET != 0) {
110 if (tc->flag && TST_ERR == EINVAL)
111 tst_res(TCONF, "mlock2() didn't support MLOCK_ONFAULT");
112 else
113 tst_res(TFAIL | TTERRNO, "mlock2() failed");
114 goto end2;
115 }
116
117 act_vmlcks = (asize - bsize) * 1024 / pgsz;
118 if (tc->exp_vmlcks != act_vmlcks) {
119 tst_res(TFAIL, "VmLck showed wrong %ld pages, expected %ld",
120 act_vmlcks, tc->exp_vmlcks);
121 goto end1;
122 }
123
124 act_pgs = check_locked_pages(addr, PAGES * pgsz, PAGES);
125 if (act_pgs != tc->exp_present_pages) {
126 tst_res(TFAIL, "mlock2(%d) locked %ld pages, expected %ld",
127 tc->flag, act_pgs, tc->exp_present_pages);
128 } else {
129 tst_res(TPASS, "mlock2(%d) succeeded in locking %ld pages",
130 tc->flag, tc->exp_present_pages);
131 }
132
133 end1:
134 SAFE_MUNLOCK(addr, tc->lock_pages * pgsz + tc->offset);
135 end2:
136 SAFE_MUNMAP(addr, PAGES * pgsz);
137 }
138
setup(void)139 static void setup(void)
140 {
141 pgsz = getpagesize();
142 MLOCK_PAGE_SIZE_EMULATION_OFFSET(tcases);
143 }
144
145 static struct tst_test test = {
146 .tcnt = ARRAY_SIZE(tcases),
147 .test = verify_mlock2,
148 .setup = setup,
149 .needs_root = 1,
150 };
151