tools/testing/selftests/mm/madv_populate.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/mm/madv_populate.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/mm/madv_populate.c
Extension
.c
Size
7412 bytes
Lines
295
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// 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 <linux/mman.h>
#include <sys/mman.h>

#include "kselftest.h"
#include "vm_util.h"

/*
 * For now, we're using 2 MiB of private anonymous memory for all tests.
 */
#define SIZE (2 * 1024 * 1024)

static size_t pagesize;

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);

Annotation

Implementation Notes