summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/mm/vm_util.c
blob: 3082b40492dd8181b75d182c87bde20779f526db (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include <fcntl.h>
#include <dirent.h>
#include <sys/ioctl.h>
#include <linux/userfaultfd.h>
#include <sys/syscall.h>
#include <unistd.h>
#include "../kselftest.h"
#include "vm_util.h"

#define PMD_SIZE_FILE_PATH "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size"
#define SMAP_FILE_PATH "/proc/self/smaps"
#define MAX_LINE_LENGTH 500

unsigned int __page_size;
unsigned int __page_shift;

uint64_t pagemap_get_entry(int fd, char *start)
{
	const unsigned long pfn = (unsigned long)start / getpagesize();
	uint64_t entry;
	int ret;

	ret = pread(fd, &entry, sizeof(entry), pfn * sizeof(entry));
	if (ret != sizeof(entry))
		ksft_exit_fail_msg("reading pagemap failed\n");
	return entry;
}

bool pagemap_is_softdirty(int fd, char *start)
{
	return pagemap_get_entry(fd, start) & PM_SOFT_DIRTY;
}

bool pagemap_is_swapped(int fd, char *start)
{
	return pagemap_get_entry(fd, start) & PM_SWAP;
}

bool pagemap_is_populated(int fd, char *start)
{
	return pagemap_get_entry(fd, start) & (PM_PRESENT | PM_SWAP);
}

unsigned long pagemap_get_pfn(int fd, char *start)
{
	uint64_t entry = pagemap_get_entry(fd, start);

	/* If present (63th bit), PFN is at bit 0 -- 54. */
	if (entry & PM_PRESENT)
		return entry & 0x007fffffffffffffull;
	return -1ul;
}

void clear_softdirty(void)
{
	int ret;
	const char *ctrl = "4";
	int fd = open("/proc/self/clear_refs", O_WRONLY);

	if (fd < 0)
		ksft_exit_fail_msg("opening clear_refs failed\n");
	ret = write(fd, ctrl, strlen(ctrl));
	close(fd);
	if (ret != strlen(ctrl))
		ksft_exit_fail_msg("writing clear_refs failed\n");
}

bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len)
{
	while (fgets(buf, len, fp)) {
		if (!strncmp(buf, pattern, strlen(pattern)))
			return true;
	}
	return false;
}

uint64_t read_pmd_pagesize(void)
{
	int fd;
	char buf[20];
	ssize_t num_read;

	fd = open(PMD_SIZE_FILE_PATH, O_RDONLY);
	if (fd == -1)
		return 0;

	num_read = read(fd, buf, 19);
	if (num_read < 1) {
		close(fd);
		return 0;
	}
	buf[num_read] = '\0';
	close(fd);

	return strtoul(buf, NULL, 10);
}

bool __check_huge(void *addr, char *pattern, int nr_hpages,
		  uint64_t hpage_size)
{
	uint64_t thp = -1;
	int ret;
	FILE *fp;
	char buffer[MAX_LINE_LENGTH];
	char addr_pattern[MAX_LINE_LENGTH];

	ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-",
		       (unsigned long) addr);
	if (ret >= MAX_LINE_LENGTH)
		ksft_exit_fail_msg("%s: Pattern is too long\n", __func__);

	fp = fopen(SMAP_FILE_PATH, "r");
	if (!fp)
		ksft_exit_fail_msg("%s: Failed to open file %s\n", __func__, SMAP_FILE_PATH);

	if (!check_for_pattern(fp, addr_pattern, buffer, sizeof(buffer)))
		goto err_out;

	/*
	 * Fetch the pattern in the same block and check the number of
	 * hugepages.
	 */
	if (!check_for_pattern(fp, pattern, buffer, sizeof(buffer)))
		goto err_out;

	snprintf(addr_pattern, MAX_LINE_LENGTH, "%s%%9ld kB", pattern);

	if (sscanf(buffer, addr_pattern, &thp) != 1)
		ksft_exit_fail_msg("Reading smap error\n");

err_out:
	fclose(fp);
	return thp == (nr_hpages * (hpage_size >> 10));
}

bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size)
{
	return __check_huge(addr, "AnonHugePages: ", nr_hpages, hpage_size);
}

bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size)
{
	return __check_huge(addr, "FilePmdMapped:", nr_hpages, hpage_size);
}

bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size)
{
	return __check_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size);
}

int64_t allocate_transhuge(void *ptr, int pagemap_fd)
{
	uint64_t ent[2];

	/* drop pmd */
	if (mmap(ptr, HPAGE_SIZE, PROT_READ | PROT_WRITE,
		 MAP_FIXED | MAP_ANONYMOUS |
		 MAP_NORESERVE | MAP_PRIVATE, -1, 0) != ptr)
		errx(2, "mmap transhuge");

	if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE))
		err(2, "MADV_HUGEPAGE");

	/* allocate transparent huge page */
	*(volatile void **)ptr = ptr;

	if (pread(pagemap_fd, ent, sizeof(ent),
		  (uintptr_t)ptr >> (pshift() - 3)) != sizeof(ent))
		err(2, "read pagemap");

	if (PAGEMAP_PRESENT(ent[0]) && PAGEMAP_PRESENT(ent[1]) &&
	    PAGEMAP_PFN(ent[0]) + 1 == PAGEMAP_PFN(ent[1]) &&
	    !(PAGEMAP_PFN(ent[0]) & ((1 << (HPAGE_SHIFT - pshift())) - 1)))
		return PAGEMAP_PFN(ent[0]);

	return -1;
}

unsigned long default_huge_page_size(void)
{
	unsigned long hps = 0;
	char *line = NULL;
	size_t linelen = 0;
	FILE *f = fopen("/proc/meminfo", "r");

	if (!f)
		return 0;
	while (getline(&line, &linelen, f) > 0) {
		if (sscanf(line, "Hugepagesize:       %lu kB", &hps) == 1) {
			hps <<= 10;
			break;
		}
	}

	free(line);
	fclose(f);
	return hps;
}

int detect_hugetlb_page_sizes(size_t sizes[], int max)
{
	DIR *dir = opendir("/sys/kernel/mm/hugepages/");
	int count = 0;

	if (!dir)
		return 0;

	while (count < max) {
		struct dirent *entry = readdir(dir);
		size_t kb;

		if (!entry)
			break;
		if (entry->d_type != DT_DIR)
			continue;
		if (sscanf(entry->d_name, "hugepages-%zukB", &kb) != 1)
			continue;
		sizes[count++] = kb * 1024;
		ksft_print_msg("[INFO] detected hugetlb page size: %zu KiB\n",
			       kb);
	}
	closedir(dir);
	return count;
}

/* If `ioctls' non-NULL, the allowed ioctls will be returned into the var */
int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len,
			      bool miss, bool wp, bool minor, uint64_t *ioctls)
{
	struct uffdio_register uffdio_register = { 0 };
	uint64_t mode = 0;
	int ret = 0;

	if (miss)
		mode |= UFFDIO_REGISTER_MODE_MISSING;
	if (wp)
		mode |= UFFDIO_REGISTER_MODE_WP;
	if (minor)
		mode |= UFFDIO_REGISTER_MODE_MINOR;

	uffdio_register.range.start = (unsigned long)addr;
	uffdio_register.range.len = len;
	uffdio_register.mode = mode;

	if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1)
		ret = -errno;
	else if (ioctls)
		*ioctls = uffdio_register.ioctls;

	return ret;
}

int uffd_register(int uffd, void *addr, uint64_t len,
		  bool miss, bool wp, bool minor)
{
	return uffd_register_with_ioctls(uffd, addr, len,
					 miss, wp, minor, NULL);
}

int uffd_unregister(int uffd, void *addr, uint64_t len)
{
	struct uffdio_range range = { .start = (uintptr_t)addr, .len = len };
	int ret = 0;

	if (ioctl(uffd, UFFDIO_UNREGISTER, &range) == -1)
		ret = -errno;

	return ret;
}

unsigned long get_free_hugepages(void)
{
	unsigned long fhp = 0;
	char *line = NULL;
	size_t linelen = 0;
	FILE *f = fopen("/proc/meminfo", "r");

	if (!f)
		return fhp;
	while (getline(&line, &linelen, f) > 0) {
		if (sscanf(line, "HugePages_Free:      %lu", &fhp) == 1)
			break;
	}

	free(line);
	fclose(f);
	return fhp;
}