--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MADV_POPULATE_READ and MADV_POPULATE_WRITE tests
+ *
+ * Copyright 2021, Red Hat, Inc.
+ *
+ * Author(s): David Hildenbrand <david@redhat.com>
+ */
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include "../kselftest.h"
+
+#if defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE)
+
+/*
+ * For now, we're using 2 MiB of private anonymous memory for all tests.
+ */
+#define SIZE (2 * 1024 * 1024)
+
+static size_t pagesize;
+
+static uint64_t pagemap_get_entry(int fd, char *start)
+{
+ const unsigned long pfn = (unsigned long)start / pagesize;
+ 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 bool pagemap_is_populated(int fd, char *start)
+{
+ uint64_t entry = pagemap_get_entry(fd, start);
+
+ /* Present or swapped. */
+ return entry & 0xc000000000000000ull;
+}
+
+static bool pagemap_is_softdirty(int fd, char *start)
+{
+ uint64_t entry = pagemap_get_entry(fd, start);
+
+ return entry & 0x0080000000000000ull;
+}
+
+static void sense_support(void)
+{
+ char *addr;
+ int ret;
+
+ addr = mmap(0, pagesize, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+ if (!addr)
+ ksft_exit_fail_msg("mmap failed\n");
+
+ ret = madvise(addr, pagesize, MADV_POPULATE_READ);
+ if (ret)
+ ksft_exit_skip("MADV_POPULATE_READ is not available\n");
+
+ ret = madvise(addr, pagesize, MADV_POPULATE_WRITE);
+ if (ret)
+ ksft_exit_skip("MADV_POPULATE_WRITE is not available\n");
+
+ munmap(addr, pagesize);
+}
+
+static void test_prot_read(void)
+{
+ char *addr;
+ int ret;
+
+ ksft_print_msg("[RUN] %s\n", __func__);
+
+ addr = mmap(0, SIZE, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+ if (addr == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed\n");
+
+ ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+ ksft_test_result(!ret, "MADV_POPULATE_READ with PROT_READ\n");
+
+ ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+ ksft_test_result(ret == -1 && errno == EINVAL,
+ "MADV_POPULATE_WRITE with PROT_READ\n");
+
+ munmap(addr, SIZE);
+}
+
+static void test_prot_write(void)
+{
+ char *addr;
+ int ret;
+
+ ksft_print_msg("[RUN] %s\n", __func__);
+
+ addr = mmap(0, SIZE, PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+ if (addr == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed\n");
+
+ ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+ ksft_test_result(ret == -1 && errno == EINVAL,
+ "MADV_POPULATE_READ with PROT_WRITE\n");
+
+ ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+ ksft_test_result(!ret, "MADV_POPULATE_WRITE with PROT_WRITE\n");
+
+ munmap(addr, SIZE);
+}
+
+static void test_holes(void)
+{
+ char *addr;
+ int ret;
+
+ ksft_print_msg("[RUN] %s\n", __func__);
+
+ addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+ if (addr == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed\n");
+ ret = munmap(addr + pagesize, pagesize);
+ if (ret)
+ ksft_exit_fail_msg("munmap failed\n");
+
+ /* Hole in the middle */
+ ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+ ksft_test_result(ret == -1 && errno == ENOMEM,
+ "MADV_POPULATE_READ with holes in the middle\n");
+ ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+ ksft_test_result(ret == -1 && errno == ENOMEM,
+ "MADV_POPULATE_WRITE with holes in the middle\n");
+
+ /* Hole at end */
+ ret = madvise(addr, 2 * pagesize, MADV_POPULATE_READ);
+ ksft_test_result(ret == -1 && errno == ENOMEM,
+ "MADV_POPULATE_READ with holes at the end\n");
+ ret = madvise(addr, 2 * pagesize, MADV_POPULATE_WRITE);
+ ksft_test_result(ret == -1 && errno == ENOMEM,
+ "MADV_POPULATE_WRITE with holes at the end\n");
+
+ /* Hole at beginning */
+ ret = madvise(addr + pagesize, pagesize, MADV_POPULATE_READ);
+ ksft_test_result(ret == -1 && errno == ENOMEM,
+ "MADV_POPULATE_READ with holes at the beginning\n");
+ ret = madvise(addr + pagesize, pagesize, MADV_POPULATE_WRITE);
+ ksft_test_result(ret == -1 && errno == ENOMEM,
+ "MADV_POPULATE_WRITE with holes at the beginning\n");
+
+ munmap(addr, SIZE);
+}
+
+static bool range_is_populated(char *start, ssize_t size)
+{
+ int fd = open("/proc/self/pagemap", O_RDONLY);
+ bool ret = true;
+
+ if (fd < 0)
+ ksft_exit_fail_msg("opening pagemap failed\n");
+ for (; size > 0 && ret; size -= pagesize, start += pagesize)
+ if (!pagemap_is_populated(fd, start))
+ ret = false;
+ close(fd);
+ return ret;
+}
+
+static bool range_is_not_populated(char *start, ssize_t size)
+{
+ int fd = open("/proc/self/pagemap", O_RDONLY);
+ bool ret = true;
+
+ if (fd < 0)
+ ksft_exit_fail_msg("opening pagemap failed\n");
+ for (; size > 0 && ret; size -= pagesize, start += pagesize)
+ if (pagemap_is_populated(fd, start))
+ ret = false;
+ close(fd);
+ return ret;
+}
+
+static void test_populate_read(void)
+{
+ char *addr;
+ int ret;
+
+ ksft_print_msg("[RUN] %s\n", __func__);
+
+ addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+ if (addr == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed\n");
+ ksft_test_result(range_is_not_populated(addr, SIZE),
+ "range initially not populated\n");
+
+ ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+ ksft_test_result(!ret, "MADV_POPULATE_READ\n");
+ ksft_test_result(range_is_populated(addr, SIZE),
+ "range is populated\n");
+
+ munmap(addr, SIZE);
+}
+
+static void test_populate_write(void)
+{
+ char *addr;
+ int ret;
+
+ ksft_print_msg("[RUN] %s\n", __func__);
+
+ addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+ if (addr == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed\n");
+ ksft_test_result(range_is_not_populated(addr, SIZE),
+ "range initially not populated\n");
+
+ ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+ ksft_test_result(!ret, "MADV_POPULATE_WRITE\n");
+ ksft_test_result(range_is_populated(addr, SIZE),
+ "range is populated\n");
+
+ munmap(addr, SIZE);
+}
+
+static bool range_is_softdirty(char *start, ssize_t size)
+{
+ int fd = open("/proc/self/pagemap", O_RDONLY);
+ bool ret = true;
+
+ if (fd < 0)
+ ksft_exit_fail_msg("opening pagemap failed\n");
+ for (; size > 0 && ret; size -= pagesize, start += pagesize)
+ if (!pagemap_is_softdirty(fd, start))
+ ret = false;
+ close(fd);
+ return ret;
+}
+
+static bool range_is_not_softdirty(char *start, ssize_t size)
+{
+ int fd = open("/proc/self/pagemap", O_RDONLY);
+ bool ret = true;
+
+ if (fd < 0)
+ ksft_exit_fail_msg("opening pagemap failed\n");
+ for (; size > 0 && ret; size -= pagesize, start += pagesize)
+ if (pagemap_is_softdirty(fd, start))
+ ret = false;
+ close(fd);
+ return ret;
+}
+
+static void clear_softdirty(void)
+{
+ int fd = open("/proc/self/clear_refs", O_WRONLY);
+ const char *ctrl = "4";
+ int ret;
+
+ if (fd < 0)
+ ksft_exit_fail_msg("opening clear_refs failed\n");
+ ret = write(fd, ctrl, strlen(ctrl));
+ if (ret != strlen(ctrl))
+ ksft_exit_fail_msg("writing clear_refs failed\n");
+ close(fd);
+}
+
+static void test_softdirty(void)
+{
+ char *addr;
+ int ret;
+
+ ksft_print_msg("[RUN] %s\n", __func__);
+
+ addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+ if (addr == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed\n");
+
+ /* Clear any softdirty bits. */
+ clear_softdirty();
+ ksft_test_result(range_is_not_softdirty(addr, SIZE),
+ "range is not softdirty\n");
+
+ /* Populating READ should set softdirty. */
+ ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+ ksft_test_result(!ret, "MADV_POPULATE_READ\n");
+ ksft_test_result(range_is_not_softdirty(addr, SIZE),
+ "range is not softdirty\n");
+
+ /* Populating WRITE should set softdirty. */
+ ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+ ksft_test_result(!ret, "MADV_POPULATE_WRITE\n");
+ ksft_test_result(range_is_softdirty(addr, SIZE),
+ "range is softdirty\n");
+
+ munmap(addr, SIZE);
+}
+
+int main(int argc, char **argv)
+{
+ int err;
+
+ pagesize = getpagesize();
+
+ ksft_print_header();
+ ksft_set_plan(21);
+
+ sense_support();
+ test_prot_read();
+ test_prot_write();
+ test_holes();
+ test_populate_read();
+ test_populate_write();
+ test_softdirty();
+
+ err = ksft_get_fail_cnt();
+ if (err)
+ ksft_exit_fail_msg("%d out of %d tests failed\n",
+ err, ksft_test_num());
+ return ksft_exit_pass();
+}
+
+#else /* defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE) */
+
+#warning "missing MADV_POPULATE_READ or MADV_POPULATE_WRITE definition"
+
+int main(int argc, char **argv)
+{
+ ksft_print_header();
+ ksft_exit_skip("MADV_POPULATE_READ or MADV_POPULATE_WRITE not defined\n");
+}
+
+#endif /* defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE) */
projects / linux-2.6-microblaze.git / commitdiff