1 files changed, 725 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..d954bf91afd5
--- /dev/null
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -0,0 +1,725 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <inttypes.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 STATUS_FILE_PATH "/proc/self/status"
+#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 != (signed int)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);
+}
+
+unsigned long rss_anon(void)
+{
+	unsigned long rss_anon = 0;
+	FILE *fp;
+	char buffer[MAX_LINE_LENGTH];
+
+	fp = fopen(STATUS_FILE_PATH, "r");
+	if (!fp)
+		ksft_exit_fail_msg("%s: Failed to open file %s\n", __func__, STATUS_FILE_PATH);
+
+	if (!check_for_pattern(fp, "RssAnon:", buffer, sizeof(buffer)))
+		goto err_out;
+
+	if (sscanf(buffer, "RssAnon:%10lu kB", &rss_anon) != 1)
+		ksft_exit_fail_msg("Reading status error\n");
+
+err_out:
+	fclose(fp);
+	return rss_anon;
+}
+
+char *__get_smap_entry(void *addr, const char *pattern, char *buf, size_t len)
+{
+	int ret;
+	FILE *fp;
+	char *entry = NULL;
+	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, buf, len))
+		goto err_out;
+
+	/* Fetch the pattern in the same block */
+	if (!check_for_pattern(fp, pattern, buf, len))
+		goto err_out;
+
+	/* Trim trailing newline */
+	entry = strchr(buf, '\n');
+	if (entry)
+		*entry = '\0';
+
+	entry = buf + strlen(pattern);
+
+err_out:
+	fclose(fp);
+	return entry;
+}
+
+bool __check_huge(void *addr, char *pattern, int nr_hpages,
+		  uint64_t hpage_size)
+{
+	char buffer[MAX_LINE_LENGTH];
+	uint64_t thp = -1;
+	char *entry;
+
+	entry = __get_smap_entry(addr, pattern, buffer, sizeof(buffer));
+	if (!entry)
+		goto err_out;
+
+	if (sscanf(entry, "%9" SCNu64 " kB", &thp) != 1)
+		ksft_exit_fail_msg("Reading smap error\n");
+
+err_out:
+	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;
+}
+
+int pageflags_get(unsigned long pfn, int kpageflags_fd, uint64_t *flags)
+{
+	size_t count;
+
+	count = pread(kpageflags_fd, flags, sizeof(*flags),
+		      pfn * sizeof(*flags));
+
+	if (count != sizeof(*flags))
+		return -1;
+
+	return 0;
+}
+
+/* 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;
+}
+
+static bool check_vmflag(void *addr, const char *flag)
+{
+	char buffer[MAX_LINE_LENGTH];
+	const char *flags;
+	size_t flaglen;
+
+	flags = __get_smap_entry(addr, "VmFlags:", buffer, sizeof(buffer));
+	if (!flags)
+		ksft_exit_fail_msg("%s: No VmFlags for %p\n", __func__, addr);
+
+	while (true) {
+		flags += strspn(flags, " ");
+
+		flaglen = strcspn(flags, " ");
+		if (!flaglen)
+			return false;
+
+		if (flaglen == strlen(flag) && !memcmp(flags, flag, flaglen))
+			return true;
+
+		flags += flaglen;
+	}
+}
+
+bool check_vmflag_io(void *addr)
+{
+	return check_vmflag(addr, "io");
+}
+
+bool check_vmflag_pfnmap(void *addr)
+{
+	return check_vmflag(addr, "pf");
+}
+
+bool check_vmflag_guard(void *addr)
+{
+	return check_vmflag(addr, "gu");
+}
+
+bool softdirty_supported(void)
+{
+	char *addr;
+	bool supported = false;
+	const size_t pagesize = getpagesize();
+
+	/* New mappings are expected to be marked with VM_SOFTDIRTY (sd). */
+	addr = mmap(0, pagesize, PROT_READ | PROT_WRITE,
+		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (!addr)
+		ksft_exit_fail_msg("mmap failed\n");
+
+	supported = check_vmflag(addr, "sd");
+	munmap(addr, pagesize);
+	return supported;
+}
+
+/*
+ * Open an fd at /proc/$pid/maps and configure procmap_out ready for
+ * PROCMAP_QUERY query. Returns 0 on success, or an error code otherwise.
+ */
+int open_procmap(pid_t pid, struct procmap_fd *procmap_out)
+{
+	char path[256];
+	int ret = 0;
+
+	memset(procmap_out, '\0', sizeof(*procmap_out));
+	sprintf(path, "/proc/%d/maps", pid);
+	procmap_out->query.size = sizeof(procmap_out->query);
+	procmap_out->fd = open(path, O_RDONLY);
+	if (procmap_out->fd < 0)
+		ret = -errno;
+
+	return ret;
+}
+
+/* Perform PROCMAP_QUERY. Returns 0 on success, or an error code otherwise. */
+int query_procmap(struct procmap_fd *procmap)
+{
+	int ret = 0;
+
+	if (ioctl(procmap->fd, PROCMAP_QUERY, &procmap->query) == -1)
+		ret = -errno;
+
+	return ret;
+}
+
+/*
+ * Try to find the VMA at specified address, returns true if found, false if not
+ * found, and the test is failed if any other error occurs.
+ *
+ * On success, procmap->query is populated with the results.
+ */
+bool find_vma_procmap(struct procmap_fd *procmap, void *address)
+{
+	int err;
+
+	procmap->query.query_flags = 0;
+	procmap->query.query_addr = (unsigned long)address;
+	err = query_procmap(procmap);
+	if (!err)
+		return true;
+
+	if (err != -ENOENT)
+		ksft_exit_fail_msg("%s: Error %d on ioctl(PROCMAP_QUERY)\n",
+				   __func__, err);
+	return false;
+}
+
+/*
+ * Close fd used by PROCMAP_QUERY mechanism. Returns 0 on success, or an error
+ * code otherwise.
+ */
+int close_procmap(struct procmap_fd *procmap)
+{
+	return close(procmap->fd);
+}
+
+int write_sysfs(const char *file_path, unsigned long val)
+{
+	FILE *f = fopen(file_path, "w");
+
+	if (!f) {
+		fprintf(stderr, "f %s\n", file_path);
+		perror("fopen");
+		return 1;
+	}
+	if (fprintf(f, "%lu", val) < 0) {
+		perror("fprintf");
+		fclose(f);
+		return 1;
+	}
+	fclose(f);
+
+	return 0;
+}
+
+int read_sysfs(const char *file_path, unsigned long *val)
+{
+	FILE *f = fopen(file_path, "r");
+
+	if (!f) {
+		fprintf(stderr, "f %s\n", file_path);
+		perror("fopen");
+		return 1;
+	}
+	if (fscanf(f, "%lu", val) != 1) {
+		perror("fscanf");
+		fclose(f);
+		return 1;
+	}
+	fclose(f);
+
+	return 0;
+}
+
+void *sys_mremap(void *old_address, unsigned long old_size,
+		 unsigned long new_size, int flags, void *new_address)
+{
+	return (void *)syscall(__NR_mremap, (unsigned long)old_address,
+			       old_size, new_size, flags,
+			       (unsigned long)new_address);
+}
+
+bool detect_huge_zeropage(void)
+{
+	int fd = open("/sys/kernel/mm/transparent_hugepage/use_zero_page",
+		      O_RDONLY);
+	bool enabled = 0;
+	char buf[15];
+	int ret;
+
+	if (fd < 0)
+		return 0;
+
+	ret = pread(fd, buf, sizeof(buf), 0);
+	if (ret > 0 && ret < sizeof(buf)) {
+		buf[ret] = 0;
+
+		if (strtoul(buf, NULL, 10) == 1)
+			enabled = 1;
+	}
+
+	close(fd);
+	return enabled;
+}
+
+long ksm_get_self_zero_pages(void)
+{
+	int proc_self_ksm_stat_fd;
+	char buf[200];
+	char *substr_ksm_zero;
+	size_t value_pos;
+	ssize_t read_size;
+
+	proc_self_ksm_stat_fd = open("/proc/self/ksm_stat", O_RDONLY);
+	if (proc_self_ksm_stat_fd < 0)
+		return -errno;
+
+	read_size = pread(proc_self_ksm_stat_fd, buf, sizeof(buf) - 1, 0);
+	close(proc_self_ksm_stat_fd);
+	if (read_size < 0)
+		return -errno;
+
+	buf[read_size] = 0;
+
+	substr_ksm_zero = strstr(buf, "ksm_zero_pages");
+	if (!substr_ksm_zero)
+		return 0;
+
+	value_pos = strcspn(substr_ksm_zero, "0123456789");
+	return strtol(substr_ksm_zero + value_pos, NULL, 10);
+}
+
+long ksm_get_self_merging_pages(void)
+{
+	int proc_self_ksm_merging_pages_fd;
+	char buf[10];
+	ssize_t ret;
+
+	proc_self_ksm_merging_pages_fd = open("/proc/self/ksm_merging_pages",
+						O_RDONLY);
+	if (proc_self_ksm_merging_pages_fd < 0)
+		return -errno;
+
+	ret = pread(proc_self_ksm_merging_pages_fd, buf, sizeof(buf) - 1, 0);
+	close(proc_self_ksm_merging_pages_fd);
+	if (ret <= 0)
+		return -errno;
+	buf[ret] = 0;
+
+	return strtol(buf, NULL, 10);
+}
+
+long ksm_get_full_scans(void)
+{
+	int ksm_full_scans_fd;
+	char buf[10];
+	ssize_t ret;
+
+	ksm_full_scans_fd = open("/sys/kernel/mm/ksm/full_scans", O_RDONLY);
+	if (ksm_full_scans_fd < 0)
+		return -errno;
+
+	ret = pread(ksm_full_scans_fd, buf, sizeof(buf) - 1, 0);
+	close(ksm_full_scans_fd);
+	if (ret <= 0)
+		return -errno;
+	buf[ret] = 0;
+
+	return strtol(buf, NULL, 10);
+}
+
+int ksm_use_zero_pages(void)
+{
+	int ksm_use_zero_pages_fd;
+	ssize_t ret;
+
+	ksm_use_zero_pages_fd = open("/sys/kernel/mm/ksm/use_zero_pages", O_RDWR);
+	if (ksm_use_zero_pages_fd < 0)
+		return -errno;
+
+	ret = write(ksm_use_zero_pages_fd, "1", 1);
+	close(ksm_use_zero_pages_fd);
+	return ret == 1 ? 0 : -errno;
+}
+
+int ksm_start(void)
+{
+	int ksm_fd;
+	ssize_t ret;
+	long start_scans, end_scans;
+
+	ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR);
+	if (ksm_fd < 0)
+		return -errno;
+
+	/* Wait for two full scans such that any possible merging happened. */
+	start_scans = ksm_get_full_scans();
+	if (start_scans < 0) {
+		close(ksm_fd);
+		return start_scans;
+	}
+	ret = write(ksm_fd, "1", 1);
+	close(ksm_fd);
+	if (ret != 1)
+		return -errno;
+	do {
+		end_scans = ksm_get_full_scans();
+		if (end_scans < 0)
+			return end_scans;
+	} while (end_scans < start_scans + 2);
+
+	return 0;
+}
+
+int ksm_stop(void)
+{
+	int ksm_fd;
+	ssize_t ret;
+
+	ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR);
+	if (ksm_fd < 0)
+		return -errno;
+
+	ret = write(ksm_fd, "2", 1);
+	close(ksm_fd);
+	return ret == 1 ? 0 : -errno;
+}