214 lines · c
1// SPDX-License-Identifier: GPL-2.02#include <stdio.h>3#include <string.h>4#include <stdbool.h>5#include <fcntl.h>6#include <stdint.h>7#include <malloc.h>8#include <sys/mman.h>9#include "../kselftest.h"10#include "vm_util.h"11 12#define PAGEMAP_FILE_PATH "/proc/self/pagemap"13#define TEST_ITERATIONS 1000014 15static void test_simple(int pagemap_fd, int pagesize)16{17 int i;18 char *map;19 20 map = aligned_alloc(pagesize, pagesize);21 if (!map)22 ksft_exit_fail_msg("mmap failed\n");23 24 clear_softdirty();25 26 for (i = 0 ; i < TEST_ITERATIONS; i++) {27 if (pagemap_is_softdirty(pagemap_fd, map) == 1) {28 ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i);29 break;30 }31 32 clear_softdirty();33 // Write something to the page to get the dirty bit enabled on the page34 map[0]++;35 36 if (pagemap_is_softdirty(pagemap_fd, map) == 0) {37 ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i);38 break;39 }40 41 clear_softdirty();42 }43 free(map);44 45 ksft_test_result(i == TEST_ITERATIONS, "Test %s\n", __func__);46}47 48static void test_vma_reuse(int pagemap_fd, int pagesize)49{50 char *map, *map2;51 52 map = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0);53 if (map == MAP_FAILED)54 ksft_exit_fail_msg("mmap failed");55 56 // The kernel always marks new regions as soft dirty57 ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 1,58 "Test %s dirty bit of allocated page\n", __func__);59 60 clear_softdirty();61 munmap(map, pagesize);62 63 map2 = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0);64 if (map2 == MAP_FAILED)65 ksft_exit_fail_msg("mmap failed");66 67 // Dirty bit is set for new regions even if they are reused68 if (map == map2)69 ksft_test_result(pagemap_is_softdirty(pagemap_fd, map2) == 1,70 "Test %s dirty bit of reused address page\n", __func__);71 else72 ksft_test_result_skip("Test %s dirty bit of reused address page\n", __func__);73 74 munmap(map2, pagesize);75}76 77static void test_hugepage(int pagemap_fd, int pagesize)78{79 char *map;80 int i, ret;81 size_t hpage_len = read_pmd_pagesize();82 83 if (!hpage_len)84 ksft_exit_fail_msg("Reading PMD pagesize failed");85 86 map = memalign(hpage_len, hpage_len);87 if (!map)88 ksft_exit_fail_msg("memalign failed\n");89 90 ret = madvise(map, hpage_len, MADV_HUGEPAGE);91 if (ret)92 ksft_exit_fail_msg("madvise failed %d\n", ret);93 94 for (i = 0; i < hpage_len; i++)95 map[i] = (char)i;96 97 if (check_huge_anon(map, 1, hpage_len)) {98 ksft_test_result_pass("Test %s huge page allocation\n", __func__);99 100 clear_softdirty();101 for (i = 0 ; i < TEST_ITERATIONS ; i++) {102 if (pagemap_is_softdirty(pagemap_fd, map) == 1) {103 ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i);104 break;105 }106 107 clear_softdirty();108 // Write something to the page to get the dirty bit enabled on the page109 map[0]++;110 111 if (pagemap_is_softdirty(pagemap_fd, map) == 0) {112 ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i);113 break;114 }115 clear_softdirty();116 }117 118 ksft_test_result(i == TEST_ITERATIONS, "Test %s huge page dirty bit\n", __func__);119 } else {120 // hugepage allocation failed. skip these tests121 ksft_test_result_skip("Test %s huge page allocation\n", __func__);122 ksft_test_result_skip("Test %s huge page dirty bit\n", __func__);123 }124 free(map);125}126 127static void test_mprotect(int pagemap_fd, int pagesize, bool anon)128{129 const char *type[] = {"file", "anon"};130 const char *fname = "./soft-dirty-test-file";131 int test_fd;132 char *map;133 134 if (anon) {135 map = mmap(NULL, pagesize, PROT_READ|PROT_WRITE,136 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);137 if (!map)138 ksft_exit_fail_msg("anon mmap failed\n");139 } else {140 test_fd = open(fname, O_RDWR | O_CREAT, 0664);141 if (test_fd < 0) {142 ksft_test_result_skip("Test %s open() file failed\n", __func__);143 return;144 }145 unlink(fname);146 ftruncate(test_fd, pagesize);147 map = mmap(NULL, pagesize, PROT_READ|PROT_WRITE,148 MAP_SHARED, test_fd, 0);149 if (!map)150 ksft_exit_fail_msg("file mmap failed\n");151 }152 153 *map = 1;154 ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 1,155 "Test %s-%s dirty bit of new written page\n",156 __func__, type[anon]);157 clear_softdirty();158 ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 0,159 "Test %s-%s soft-dirty clear after clear_refs\n",160 __func__, type[anon]);161 mprotect(map, pagesize, PROT_READ);162 ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 0,163 "Test %s-%s soft-dirty clear after marking RO\n",164 __func__, type[anon]);165 mprotect(map, pagesize, PROT_READ|PROT_WRITE);166 ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 0,167 "Test %s-%s soft-dirty clear after marking RW\n",168 __func__, type[anon]);169 *map = 2;170 ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 1,171 "Test %s-%s soft-dirty after rewritten\n",172 __func__, type[anon]);173 174 munmap(map, pagesize);175 176 if (!anon)177 close(test_fd);178}179 180static void test_mprotect_anon(int pagemap_fd, int pagesize)181{182 test_mprotect(pagemap_fd, pagesize, true);183}184 185static void test_mprotect_file(int pagemap_fd, int pagesize)186{187 test_mprotect(pagemap_fd, pagesize, false);188}189 190int main(int argc, char **argv)191{192 int pagemap_fd;193 int pagesize;194 195 ksft_print_header();196 ksft_set_plan(15);197 198 pagemap_fd = open(PAGEMAP_FILE_PATH, O_RDONLY);199 if (pagemap_fd < 0)200 ksft_exit_fail_msg("Failed to open %s\n", PAGEMAP_FILE_PATH);201 202 pagesize = getpagesize();203 204 test_simple(pagemap_fd, pagesize);205 test_vma_reuse(pagemap_fd, pagesize);206 test_hugepage(pagemap_fd, pagesize);207 test_mprotect_anon(pagemap_fd, pagesize);208 test_mprotect_file(pagemap_fd, pagesize);209 210 close(pagemap_fd);211 212 ksft_finished();213}214