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Diffstat (limited to 'tools/testing/selftests/mm/soft-dirty.c')
-rw-r--r--tools/testing/selftests/mm/soft-dirty.c210
1 files changed, 210 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c
new file mode 100644
index 000000000000..21d8830c5f24
--- /dev/null
+++ b/tools/testing/selftests/mm/soft-dirty.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <malloc.h>
+#include <sys/mman.h>
+#include "../kselftest.h"
+#include "vm_util.h"
+
+#define PAGEMAP_FILE_PATH "/proc/self/pagemap"
+#define TEST_ITERATIONS 10000
+
+static void test_simple(int pagemap_fd, int pagesize)
+{
+ int i;
+ char *map;
+
+ map = aligned_alloc(pagesize, pagesize);
+ if (!map)
+ ksft_exit_fail_msg("mmap failed\n");
+
+ clear_softdirty();
+
+ for (i = 0 ; i < TEST_ITERATIONS; i++) {
+ if (pagemap_is_softdirty(pagemap_fd, map) == 1) {
+ ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i);
+ break;
+ }
+
+ clear_softdirty();
+ // Write something to the page to get the dirty bit enabled on the page
+ map[0]++;
+
+ if (pagemap_is_softdirty(pagemap_fd, map) == 0) {
+ ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i);
+ break;
+ }
+
+ clear_softdirty();
+ }
+ free(map);
+
+ ksft_test_result(i == TEST_ITERATIONS, "Test %s\n", __func__);
+}
+
+static void test_vma_reuse(int pagemap_fd, int pagesize)
+{
+ char *map, *map2;
+
+ map = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0);
+ if (map == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed");
+
+ // The kernel always marks new regions as soft dirty
+ ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 1,
+ "Test %s dirty bit of allocated page\n", __func__);
+
+ clear_softdirty();
+ munmap(map, pagesize);
+
+ map2 = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0);
+ if (map2 == MAP_FAILED)
+ ksft_exit_fail_msg("mmap failed");
+
+ // Dirty bit is set for new regions even if they are reused
+ if (map == map2)
+ ksft_test_result(pagemap_is_softdirty(pagemap_fd, map2) == 1,
+ "Test %s dirty bit of reused address page\n", __func__);
+ else
+ ksft_test_result_skip("Test %s dirty bit of reused address page\n", __func__);
+
+ munmap(map2, pagesize);
+}
+
+static void test_hugepage(int pagemap_fd, int pagesize)
+{
+ char *map;
+ int i, ret;
+ size_t hpage_len = read_pmd_pagesize();
+
+ map = memalign(hpage_len, hpage_len);
+ if (!map)
+ ksft_exit_fail_msg("memalign failed\n");
+
+ ret = madvise(map, hpage_len, MADV_HUGEPAGE);
+ if (ret)
+ ksft_exit_fail_msg("madvise failed %d\n", ret);
+
+ for (i = 0; i < hpage_len; i++)
+ map[i] = (char)i;
+
+ if (check_huge_anon(map, 1, hpage_len)) {
+ ksft_test_result_pass("Test %s huge page allocation\n", __func__);
+
+ clear_softdirty();
+ for (i = 0 ; i < TEST_ITERATIONS ; i++) {
+ if (pagemap_is_softdirty(pagemap_fd, map) == 1) {
+ ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i);
+ break;
+ }
+
+ clear_softdirty();
+ // Write something to the page to get the dirty bit enabled on the page
+ map[0]++;
+
+ if (pagemap_is_softdirty(pagemap_fd, map) == 0) {
+ ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i);
+ break;
+ }
+ clear_softdirty();
+ }
+
+ ksft_test_result(i == TEST_ITERATIONS, "Test %s huge page dirty bit\n", __func__);
+ } else {
+ // hugepage allocation failed. skip these tests
+ ksft_test_result_skip("Test %s huge page allocation\n", __func__);
+ ksft_test_result_skip("Test %s huge page dirty bit\n", __func__);
+ }
+ free(map);
+}
+
+static void test_mprotect(int pagemap_fd, int pagesize, bool anon)
+{
+ const char *type[] = {"file", "anon"};
+ const char *fname = "./soft-dirty-test-file";
+ int test_fd;
+ char *map;
+
+ if (anon) {
+ map = mmap(NULL, pagesize, PROT_READ|PROT_WRITE,
+ MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+ if (!map)
+ ksft_exit_fail_msg("anon mmap failed\n");
+ } else {
+ test_fd = open(fname, O_RDWR | O_CREAT);
+ if (test_fd < 0) {
+ ksft_test_result_skip("Test %s open() file failed\n", __func__);
+ return;
+ }
+ unlink(fname);
+ ftruncate(test_fd, pagesize);
+ map = mmap(NULL, pagesize, PROT_READ|PROT_WRITE,
+ MAP_SHARED, test_fd, 0);
+ if (!map)
+ ksft_exit_fail_msg("file mmap failed\n");
+ }
+
+ *map = 1;
+ ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 1,
+ "Test %s-%s dirty bit of new written page\n",
+ __func__, type[anon]);
+ clear_softdirty();
+ ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 0,
+ "Test %s-%s soft-dirty clear after clear_refs\n",
+ __func__, type[anon]);
+ mprotect(map, pagesize, PROT_READ);
+ ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 0,
+ "Test %s-%s soft-dirty clear after marking RO\n",
+ __func__, type[anon]);
+ mprotect(map, pagesize, PROT_READ|PROT_WRITE);
+ ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 0,
+ "Test %s-%s soft-dirty clear after marking RW\n",
+ __func__, type[anon]);
+ *map = 2;
+ ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 1,
+ "Test %s-%s soft-dirty after rewritten\n",
+ __func__, type[anon]);
+
+ munmap(map, pagesize);
+
+ if (!anon)
+ close(test_fd);
+}
+
+static void test_mprotect_anon(int pagemap_fd, int pagesize)
+{
+ test_mprotect(pagemap_fd, pagesize, true);
+}
+
+static void test_mprotect_file(int pagemap_fd, int pagesize)
+{
+ test_mprotect(pagemap_fd, pagesize, false);
+}
+
+int main(int argc, char **argv)
+{
+ int pagemap_fd;
+ int pagesize;
+
+ ksft_print_header();
+ ksft_set_plan(15);
+
+ pagemap_fd = open(PAGEMAP_FILE_PATH, O_RDONLY);
+ if (pagemap_fd < 0)
+ ksft_exit_fail_msg("Failed to open %s\n", PAGEMAP_FILE_PATH);
+
+ pagesize = getpagesize();
+
+ test_simple(pagemap_fd, pagesize);
+ test_vma_reuse(pagemap_fd, pagesize);
+ test_hugepage(pagemap_fd, pagesize);
+ test_mprotect_anon(pagemap_fd, pagesize);
+ test_mprotect_file(pagemap_fd, pagesize);
+
+ close(pagemap_fd);
+
+ return ksft_exit_pass();
+}