1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2020 ARM Limited
3
4 #define _GNU_SOURCE
5
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <signal.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <ucontext.h>
13 #include <sys/mman.h>
14
15 #include "kselftest.h"
16 #include "mte_common_util.h"
17 #include "mte_def.h"
18
19 #define TEST_UNIT 10
20 #define PATH_KSM "/sys/kernel/mm/ksm/"
21 #define MAX_LOOP 4
22
23 static size_t page_sz;
24 static unsigned long ksm_sysfs[5];
25
26 static unsigned long read_sysfs(char *str)
27 {
28 FILE *f;
29 unsigned long val = 0;
30
31 f = fopen(str, "r");
32 if (!f) {
33 ksft_print_msg("ERR: missing %s\n", str);
34 return 0;
35 }
36 if (fscanf(f, "%lu", &val) != 1) {
37 ksft_print_msg("ERR: parsing %s\n", str);
38 val = 0;
39 }
40 fclose(f);
41 return val;
42 }
43
44 static void write_sysfs(char *str, unsigned long val)
45 {
46 FILE *f;
47
48 f = fopen(str, "w");
49 if (!f) {
50 ksft_print_msg("ERR: missing %s\n", str);
51 return;
52 }
53 fprintf(f, "%lu", val);
54 fclose(f);
55 }
56
57 static void mte_ksm_setup(void)
58 {
59 ksm_sysfs[0] = read_sysfs(PATH_KSM "merge_across_nodes");
60 write_sysfs(PATH_KSM "merge_across_nodes", 1);
61 ksm_sysfs[1] = read_sysfs(PATH_KSM "sleep_millisecs");
62 write_sysfs(PATH_KSM "sleep_millisecs", 0);
63 ksm_sysfs[2] = read_sysfs(PATH_KSM "run");
64 write_sysfs(PATH_KSM "run", 1);
65 ksm_sysfs[3] = read_sysfs(PATH_KSM "max_page_sharing");
66 write_sysfs(PATH_KSM "max_page_sharing", ksm_sysfs[3] + TEST_UNIT);
67 ksm_sysfs[4] = read_sysfs(PATH_KSM "pages_to_scan");
68 write_sysfs(PATH_KSM "pages_to_scan", ksm_sysfs[4] + TEST_UNIT);
69 }
70
71 static void mte_ksm_restore(void)
72 {
73 write_sysfs(PATH_KSM "merge_across_nodes", ksm_sysfs[0]);
74 write_sysfs(PATH_KSM "sleep_millisecs", ksm_sysfs[1]);
75 write_sysfs(PATH_KSM "run", ksm_sysfs[2]);
76 write_sysfs(PATH_KSM "max_page_sharing", ksm_sysfs[3]);
77 write_sysfs(PATH_KSM "pages_to_scan", ksm_sysfs[4]);
78 }
79
80 static void mte_ksm_scan(void)
81 {
82 int cur_count = read_sysfs(PATH_KSM "full_scans");
83 int scan_count = cur_count + 1;
84 int max_loop_count = MAX_LOOP;
85
86 while ((cur_count < scan_count) && max_loop_count) {
87 sleep(1);
88 cur_count = read_sysfs(PATH_KSM "full_scans");
89 max_loop_count--;
90 }
91 #ifdef DEBUG
92 ksft_print_msg("INFO: pages_shared=%lu pages_sharing=%lu\n",
93 read_sysfs(PATH_KSM "pages_shared"),
94 read_sysfs(PATH_KSM "pages_sharing"));
95 #endif
96 }
97
98 static int check_madvise_options(int mem_type, int mode, int mapping)
99 {
100 char *ptr;
101 int err, ret;
102
103 err = KSFT_FAIL;
104 if (access(PATH_KSM, F_OK) == -1) {
105 ksft_print_msg("ERR: Kernel KSM config not enabled\n");
106 return err;
107 }
108
109 mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
110 ptr = mte_allocate_memory(TEST_UNIT * page_sz, mem_type, mapping, true);
111 if (check_allocated_memory(ptr, TEST_UNIT * page_sz, mem_type, false) != KSFT_PASS)
112 return KSFT_FAIL;
113
114 /* Insert same data in all the pages */
115 memset(ptr, 'A', TEST_UNIT * page_sz);
116 ret = madvise(ptr, TEST_UNIT * page_sz, MADV_MERGEABLE);
117 if (ret) {
118 ksft_print_msg("ERR: madvise failed to set MADV_UNMERGEABLE\n");
119 goto madvise_err;
120 }
121 mte_ksm_scan();
122 /* Tagged pages should not merge */
123 if ((read_sysfs(PATH_KSM "pages_shared") < 1) ||
124 (read_sysfs(PATH_KSM "pages_sharing") < (TEST_UNIT - 1)))
125 err = KSFT_PASS;
126 madvise_err:
127 mte_free_memory(ptr, TEST_UNIT * page_sz, mem_type, true);
128 return err;
129 }
130
131 int main(int argc, char *argv[])
132 {
133 int err;
134
135 err = mte_default_setup();
136 if (err)
137 return err;
138 page_sz = getpagesize();
139 if (!page_sz) {
140 ksft_print_msg("ERR: Unable to get page size\n");
141 return KSFT_FAIL;
142 }
143 /* Register signal handlers */
144 mte_register_signal(SIGBUS, mte_default_handler);
145 mte_register_signal(SIGSEGV, mte_default_handler);
146
147 /* Set test plan */
148 ksft_set_plan(4);
149
150 /* Enable KSM */
151 mte_ksm_setup();
152
153 evaluate_test(check_madvise_options(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
154 "Check KSM mte page merge for private mapping, sync mode and mmap memory\n");
155 evaluate_test(check_madvise_options(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
156 "Check KSM mte page merge for private mapping, async mode and mmap memory\n");
157 evaluate_test(check_madvise_options(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
158 "Check KSM mte page merge for shared mapping, sync mode and mmap memory\n");
159 evaluate_test(check_madvise_options(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
160 "Check KSM mte page merge for shared mapping, async mode and mmap memory\n");
161
162 mte_ksm_restore();
163 mte_restore_setup();
164 ksft_print_cnts();
165 return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
166 }
167
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.