Commit 47fba2b6 authored by Peter Xu's avatar Peter Xu Committed by Andrew Morton
Browse files

selftests/mm: smoke test UFFD_FEATURE_WP_UNPOPULATED 

Enable it by default on the stress test, and add some smoke tests for the
pte markers on anonymous.

Link: https://lkml.kernel.org/r/20230309223711.823547-3-peterx@redhat.com


Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Paul Gofman <pgofman@codeweavers.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 2bad466c

tools/testing/selftests/mm/userfaultfd.c

+43 −2
Original line number Diff line number Diff line
@@ -1444,6 +1444,43 @@ static int pagemap_test_fork(bool present) 
	return result;

}



static void userfaultfd_wp_unpopulated_test(int pagemap_fd)

{

	uint64_t value;



	/* Test applying pte marker to anon unpopulated */

	wp_range(uffd, (uint64_t)area_dst, page_size, true);

	value = pagemap_read_vaddr(pagemap_fd, area_dst);

	pagemap_check_wp(value, true);



	/* Test unprotect on anon pte marker */

	wp_range(uffd, (uint64_t)area_dst, page_size, false);

	value = pagemap_read_vaddr(pagemap_fd, area_dst);

	pagemap_check_wp(value, false);



	/* Test zap on anon marker */

	wp_range(uffd, (uint64_t)area_dst, page_size, true);

	if (madvise(area_dst, page_size, MADV_DONTNEED))

		err("madvise(MADV_DONTNEED) failed");

	value = pagemap_read_vaddr(pagemap_fd, area_dst);

	pagemap_check_wp(value, false);



	/* Test fault in after marker removed */

	*area_dst = 1;

	value = pagemap_read_vaddr(pagemap_fd, area_dst);

	pagemap_check_wp(value, false);

	/* Drop it to make pte none again */

	if (madvise(area_dst, page_size, MADV_DONTNEED))

		err("madvise(MADV_DONTNEED) failed");



	/* Test read-zero-page upon pte marker */

	wp_range(uffd, (uint64_t)area_dst, page_size, true);

	*(volatile char *)area_dst;

	/* Drop it to make pte none again */

	if (madvise(area_dst, page_size, MADV_DONTNEED))

		err("madvise(MADV_DONTNEED) failed");

}



static void userfaultfd_pagemap_test(unsigned int test_pgsize)

{

	struct uffdio_register uffdio_register;
@@ -1462,7 +1499,7 @@ static void userfaultfd_pagemap_test(unsigned int test_pgsize) 
	/* Flush so it doesn't flush twice in parent/child later */

	fflush(stdout);



	uffd_test_ctx_init(0);

	uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED);



	if (test_pgsize > page_size) {

		/* This is a thp test */
@@ -1482,6 +1519,10 @@ static void userfaultfd_pagemap_test(unsigned int test_pgsize) 


	pagemap_fd = pagemap_open();



	/* Smoke test WP_UNPOPULATED first when it's still empty */

	if (test_pgsize == page_size)

		userfaultfd_wp_unpopulated_test(pagemap_fd);



	/* Touch the page */

	*area_dst = 1;

	wp_range(uffd, (uint64_t)area_dst, test_pgsize, true);
@@ -1526,7 +1567,7 @@ static int userfaultfd_stress(void) 
	struct uffdio_register uffdio_register;

	struct uffd_stats uffd_stats[nr_cpus];



	uffd_test_ctx_init(0);

	uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED);



	if (posix_memalign(&area, page_size, page_size))

		err("out of memory");