1// SPDX-License-Identifier: GPL-2.0
  2#include <string.h>
  3#include <fcntl.h>
  4#include "../kselftest.h"
  5#include "vm_util.h"
  6
  7#define PMD_SIZE_FILE_PATH "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size"
  8#define SMAP_FILE_PATH "/proc/self/smaps"
  9#define MAX_LINE_LENGTH 500
 10
 11uint64_t pagemap_get_entry(int fd, char *start)
 12{
 13	const unsigned long pfn = (unsigned long)start / getpagesize();
 14	uint64_t entry;
 15	int ret;
 16
 17	ret = pread(fd, &entry, sizeof(entry), pfn * sizeof(entry));
 18	if (ret != sizeof(entry))
 19		ksft_exit_fail_msg("reading pagemap failed\n");
 20	return entry;
 21}
 22
 23bool pagemap_is_softdirty(int fd, char *start)
 24{
 25	uint64_t entry = pagemap_get_entry(fd, start);
 26
 27	// Check if dirty bit (55th bit) is set
 28	return entry & 0x0080000000000000ull;
 29}
 30
 31bool pagemap_is_swapped(int fd, char *start)
 32{
 33	uint64_t entry = pagemap_get_entry(fd, start);
 34
 35	return entry & 0x4000000000000000ull;
 36}
 37
 38bool pagemap_is_populated(int fd, char *start)
 39{
 40	uint64_t entry = pagemap_get_entry(fd, start);
 41
 42	/* Present or swapped. */
 43	return entry & 0xc000000000000000ull;
 44}
 45
 46unsigned long pagemap_get_pfn(int fd, char *start)
 47{
 48	uint64_t entry = pagemap_get_entry(fd, start);
 49
 50	/* If present (63th bit), PFN is at bit 0 -- 54. */
 51	if (entry & 0x8000000000000000ull)
 52		return entry & 0x007fffffffffffffull;
 53	return -1ul;
 54}
 55
 56void clear_softdirty(void)
 57{
 58	int ret;
 59	const char *ctrl = "4";
 60	int fd = open("/proc/self/clear_refs", O_WRONLY);
 61
 62	if (fd < 0)
 63		ksft_exit_fail_msg("opening clear_refs failed\n");
 64	ret = write(fd, ctrl, strlen(ctrl));
 65	close(fd);
 66	if (ret != strlen(ctrl))
 67		ksft_exit_fail_msg("writing clear_refs failed\n");
 68}
 69
 70bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len)
 71{
 72	while (fgets(buf, len, fp)) {
 73		if (!strncmp(buf, pattern, strlen(pattern)))
 74			return true;
 75	}
 76	return false;
 77}
 78
 79uint64_t read_pmd_pagesize(void)
 80{
 81	int fd;
 82	char buf[20];
 83	ssize_t num_read;
 84
 85	fd = open(PMD_SIZE_FILE_PATH, O_RDONLY);
 86	if (fd == -1)
 87		ksft_exit_fail_msg("Open hpage_pmd_size failed\n");
 88
 89	num_read = read(fd, buf, 19);
 90	if (num_read < 1) {
 91		close(fd);
 92		ksft_exit_fail_msg("Read hpage_pmd_size failed\n");
 93	}
 94	buf[num_read] = '\0';
 95	close(fd);
 96
 97	return strtoul(buf, NULL, 10);
 98}
 99
100bool __check_huge(void *addr, char *pattern, int nr_hpages,
101		  uint64_t hpage_size)
102{
103	uint64_t thp = -1;
104	int ret;
105	FILE *fp;
106	char buffer[MAX_LINE_LENGTH];
107	char addr_pattern[MAX_LINE_LENGTH];
108
109	ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-",
110		       (unsigned long) addr);
111	if (ret >= MAX_LINE_LENGTH)
112		ksft_exit_fail_msg("%s: Pattern is too long\n", __func__);
113
114	fp = fopen(SMAP_FILE_PATH, "r");
115	if (!fp)
116		ksft_exit_fail_msg("%s: Failed to open file %s\n", __func__, SMAP_FILE_PATH);
117
118	if (!check_for_pattern(fp, addr_pattern, buffer, sizeof(buffer)))
119		goto err_out;
120
121	/*
122	 * Fetch the pattern in the same block and check the number of
123	 * hugepages.
124	 */
125	if (!check_for_pattern(fp, pattern, buffer, sizeof(buffer)))
126		goto err_out;
127
128	snprintf(addr_pattern, MAX_LINE_LENGTH, "%s%%9ld kB", pattern);
129
130	if (sscanf(buffer, addr_pattern, &thp) != 1)
131		ksft_exit_fail_msg("Reading smap error\n");
132
133err_out:
134	fclose(fp);
135	return thp == (nr_hpages * (hpage_size >> 10));
136}
137
138bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size)
139{
140	return __check_huge(addr, "AnonHugePages: ", nr_hpages, hpage_size);
141}
142
143bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size)
144{
145	return __check_huge(addr, "FilePmdMapped:", nr_hpages, hpage_size);
146}
147
148bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size)
149{
150	return __check_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size);
151}