1 files changed, 364 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
new file mode 100644
index 000000000000..5a62530da3b5
--- /dev/null
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <string.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <sys/ioctl.h>
+#include <linux/userfaultfd.h>
+#include <linux/fs.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;
+}
+
+static uint64_t __pagemap_scan_get_categories(int fd, char *start, struct page_region *r)
+{
+	struct pm_scan_arg arg;
+
+	arg.start = (uintptr_t)start;
+	arg.end = (uintptr_t)(start + psize());
+	arg.vec = (uintptr_t)r;
+	arg.vec_len = 1;
+	arg.flags = 0;
+	arg.size = sizeof(struct pm_scan_arg);
+	arg.max_pages = 0;
+	arg.category_inverted = 0;
+	arg.category_mask = 0;
+	arg.category_anyof_mask = PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | PAGE_IS_FILE |
+				  PAGE_IS_PRESENT | PAGE_IS_SWAPPED | PAGE_IS_PFNZERO |
+				  PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY;
+	arg.return_mask = arg.category_anyof_mask;
+
+	return ioctl(fd, PAGEMAP_SCAN, &arg);
+}
+
+static uint64_t pagemap_scan_get_categories(int fd, char *start)
+{
+	struct page_region r;
+	long ret;
+
+	ret = __pagemap_scan_get_categories(fd, start, &r);
+	if (ret < 0)
+		ksft_exit_fail_msg("PAGEMAP_SCAN failed: %s\n", strerror(errno));
+	if (ret == 0)
+		return 0;
+	return r.categories;
+}
+
+/* `start` is any valid address. */
+static bool pagemap_scan_supported(int fd, char *start)
+{
+	static int supported = -1;
+	int ret;
+
+	if (supported != -1)
+		return supported;
+
+	/* Provide an invalid address in order to trigger EFAULT. */
+	ret = __pagemap_scan_get_categories(fd, start, (struct page_region *) ~0UL);
+	if (ret == 0)
+		ksft_exit_fail_msg("PAGEMAP_SCAN succeeded unexpectedly\n");
+
+	supported = errno == EFAULT;
+
+	return supported;
+}
+
+static bool page_entry_is(int fd, char *start, char *desc,
+			  uint64_t pagemap_flags, uint64_t pagescan_flags)
+{
+	bool m = pagemap_get_entry(fd, start) & pagemap_flags;
+
+	if (pagemap_scan_supported(fd, start)) {
+		bool s = pagemap_scan_get_categories(fd, start) & pagescan_flags;
+
+		if (m == s)
+			return m;
+
+		ksft_exit_fail_msg(
+			"read and ioctl return unmatched results for %s: %d %d", desc, m, s);
+	}
+	return m;
+}
+
+bool pagemap_is_softdirty(int fd, char *start)
+{
+	return page_entry_is(fd, start, "soft-dirty",
+				PM_SOFT_DIRTY, PAGE_IS_SOFT_DIRTY);
+}
+
+bool pagemap_is_swapped(int fd, char *start)
+{
+	return page_entry_is(fd, start, "swap", PM_SWAP, PAGE_IS_SWAPPED);
+}
+
+bool pagemap_is_populated(int fd, char *start)
+{
+	return page_entry_is(fd, start, "populated",
+				PM_PRESENT | PM_SWAP,
+				PAGE_IS_PRESENT | PAGE_IS_SWAPPED);
+}
+
+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)
+		ksft_exit_fail_msg("mmap transhuge\n");
+
+	if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE))
+		ksft_exit_fail_msg("MADV_HUGEPAGE\n");
+
+	/* allocate transparent huge page */
+	*(volatile void **)ptr = ptr;
+
+	if (pread(pagemap_fd, ent, sizeof(ent),
+		  (uintptr_t)ptr >> (pshift() - 3)) != sizeof(ent))
+		ksft_exit_fail_msg("read pagemap\n");
+
+	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;
+}