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From:   Peter Xu <peterx@redhat.com>
To:     linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc:     Mike Kravetz <mike.kravetz@oracle.com>,
        Mike Rapoport <rppt@linux.vnet.ibm.com>,
        Andrea Arcangeli <aarcange@redhat.com>, peterx@redhat.com,
        Leonardo Bras Soares Passos <lsoaresp@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        David Hildenbrand <david@redhat.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Nadav Amit <nadav.amit@gmail.com>
Subject: [PATCH 25/29] selftests/mm: Move zeropage test into uffd unit tests
Date:   Thu, 30 Mar 2023 12:08:29 -0400
Message-Id: <20230330160829.3107591-1-peterx@redhat.com>
In-Reply-To: <20230330155707.3106228-1-peterx@redhat.com>
References: <20230330155707.3106228-1-peterx@redhat.com>
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Precedence: bulk

Simplifies it a bit along the way, e.g., drop the never used offset
field (which was always the 1st page so offset=0).

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 tools/testing/selftests/mm/uffd-stress.c     | 94 +-------------------
 tools/testing/selftests/mm/uffd-unit-tests.c | 94 ++++++++++++++++++++
 2 files changed, 95 insertions(+), 93 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index f3046ae13a90..a6f3609c1ad1 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -110,15 +110,6 @@ static inline uint64_t uffd_minor_feature(void)
 		return 0;
 }
 
-static int my_bcmp(char *str1, char *str2, size_t n)
-{
-	unsigned long i;
-	for (i = 0; i < n; i++)
-		if (str1[i] != str2[i])
-			return 1;
-	return 0;
-}
-
 static void *locking_thread(void *arg)
 {
 	unsigned long cpu = (unsigned long) arg;
@@ -274,89 +265,6 @@ static int stress(struct uffd_stats *uffd_stats)
 	return 0;
 }
 
-static void retry_uffdio_zeropage(int ufd,
-				  struct uffdio_zeropage *uffdio_zeropage,
-				  unsigned long offset)
-{
-	uffd_test_ops->alias_mapping(&uffdio_zeropage->range.start,
-				     uffdio_zeropage->range.len,
-				     offset);
-	if (ioctl(ufd, UFFDIO_ZEROPAGE, uffdio_zeropage)) {
-		if (uffdio_zeropage->zeropage != -EEXIST)
-			err("UFFDIO_ZEROPAGE error: %"PRId64,
-			    (int64_t)uffdio_zeropage->zeropage);
-	} else {
-		err("UFFDIO_ZEROPAGE error: %"PRId64,
-		    (int64_t)uffdio_zeropage->zeropage);
-	}
-}
-
-static int __uffdio_zeropage(int ufd, unsigned long offset)
-{
-	struct uffdio_zeropage uffdio_zeropage;
-	int ret;
-	bool has_zeropage = !(test_type == TEST_HUGETLB);
-	__s64 res;
-
-	if (offset >= nr_pages * page_size)
-		err("unexpected offset %lu", offset);
-	uffdio_zeropage.range.start = (unsigned long) area_dst + offset;
-	uffdio_zeropage.range.len = page_size;
-	uffdio_zeropage.mode = 0;
-	ret = ioctl(ufd, UFFDIO_ZEROPAGE, &uffdio_zeropage);
-	res = uffdio_zeropage.zeropage;
-	if (ret) {
-		/* real retval in ufdio_zeropage.zeropage */
-		if (has_zeropage)
-			err("UFFDIO_ZEROPAGE error: %"PRId64, (int64_t)res);
-		else if (res != -EINVAL)
-			err("UFFDIO_ZEROPAGE not -EINVAL");
-	} else if (has_zeropage) {
-		if (res != page_size) {
-			err("UFFDIO_ZEROPAGE unexpected size");
-		} else {
-			retry_uffdio_zeropage(ufd, &uffdio_zeropage,
-					      offset);
-			return 1;
-		}
-	} else
-		err("UFFDIO_ZEROPAGE succeeded");
-
-	return 0;
-}
-
-static int uffdio_zeropage(int ufd, unsigned long offset)
-{
-	return __uffdio_zeropage(ufd, offset);
-}
-
-/* exercise UFFDIO_ZEROPAGE */
-static int userfaultfd_zeropage_test(void)
-{
-	printf("testing UFFDIO_ZEROPAGE: ");
-	fflush(stdout);
-
-	uffd_test_ctx_init(0);
-
-	if (uffd_register(uffd, area_dst, nr_pages * page_size,
-			  true, test_uffdio_wp, false))
-		err("register failure");
-
-	if (area_dst_alias) {
-		/* Needed this to test zeropage-retry on shared memory */
-		if (uffd_register(uffd, area_dst_alias, nr_pages * page_size,
-				  true, test_uffdio_wp, false))
-			err("register failure");
-	}
-
-	if (uffdio_zeropage(uffd, 0))
-		if (my_bcmp(area_dst, zeropage, page_size))
-			err("zeropage is not zero");
-
-	printf("done.\n");
-	return 0;
-}
-
 static int userfaultfd_stress(void)
 {
 	void *area;
@@ -468,7 +376,7 @@ static int userfaultfd_stress(void)
 		uffd_stats_report(uffd_stats, nr_cpus);
 	}
 
-	return userfaultfd_zeropage_test();
+	return 0;
 }
 
 static void set_test_type(const char *type)
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index ebf45cb0eca8..376dfa320b6f 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -663,7 +663,101 @@ static void uffd_events_wp_test(void)
 	uffd_events_test_common(true);
 }
 
+static void retry_uffdio_zeropage(int ufd,
+				  struct uffdio_zeropage *uffdio_zeropage)
+{
+	uffd_test_ops->alias_mapping(&uffdio_zeropage->range.start,
+				     uffdio_zeropage->range.len,
+				     0);
+	if (ioctl(ufd, UFFDIO_ZEROPAGE, uffdio_zeropage)) {
+		if (uffdio_zeropage->zeropage != -EEXIST)
+			err("UFFDIO_ZEROPAGE error: %"PRId64,
+			    (int64_t)uffdio_zeropage->zeropage);
+	} else {
+		err("UFFDIO_ZEROPAGE error: %"PRId64,
+		    (int64_t)uffdio_zeropage->zeropage);
+	}
+}
+
+static bool do_uffdio_zeropage(int ufd, bool has_zeropage)
+{
+	struct uffdio_zeropage uffdio_zeropage = { 0 };
+	int ret;
+	__s64 res;
+
+	uffdio_zeropage.range.start = (unsigned long) area_dst;
+	uffdio_zeropage.range.len = page_size;
+	uffdio_zeropage.mode = 0;
+	ret = ioctl(ufd, UFFDIO_ZEROPAGE, &uffdio_zeropage);
+	res = uffdio_zeropage.zeropage;
+	if (ret) {
+		/* real retval in ufdio_zeropage.zeropage */
+		if (has_zeropage)
+			err("UFFDIO_ZEROPAGE error: %"PRId64, (int64_t)res);
+		else if (res != -EINVAL)
+			err("UFFDIO_ZEROPAGE not -EINVAL");
+	} else if (has_zeropage) {
+		if (res != page_size)
+			err("UFFDIO_ZEROPAGE unexpected size");
+		else
+			retry_uffdio_zeropage(ufd, &uffdio_zeropage);
+		return true;
+	} else
+		err("UFFDIO_ZEROPAGE succeeded");
+
+	return false;
+}
+
+/* exercise UFFDIO_ZEROPAGE */
+static void uffd_zeropage_test_common(bool has_zeropage)
+{
+	if (uffd_register(uffd, area_dst, page_size,
+			  true, false, false))
+		err("register");
+
+	if (area_dst_alias)
+		if (uffd_register(uffd, area_dst_alias, page_size,
+				  true, false, false))
+			err("register");
+
+	if (do_uffdio_zeropage(uffd, has_zeropage)) {
+		int i;
+
+		for (i = 0; i < page_size; i++)
+			if (area_dst[i] != 0)
+				err("data non-zero at offset %d\n", i);
+	}
+
+
+	if (uffd_unregister(uffd, area_dst, page_size * nr_pages))
+		err("unregister");
+
+	uffd_test_pass();
+}
+
+static void uffd_zeropage_test(void)
+{
+	uffd_zeropage_test_common(true);
+}
+
+static void uffd_zeropage_hugetlb_test(void)
+{
+	uffd_zeropage_test_common(false);
+}
+
 uffd_test_case_t uffd_tests[] = {
+	{
+		.name = "zeropage",
+		.uffd_fn = uffd_zeropage_test,
+		.mem_targets = MEM_ANON | MEM_SHMEM | MEM_SHMEM_PRIVATE,
+		.uffd_feature_required = 0,
+	},
+	{
+		.name = "zeropage-hugetlb",
+		.uffd_fn = uffd_zeropage_hugetlb_test,
+		.mem_targets = MEM_HUGETLB | MEM_HUGETLB_PRIVATE,
+		.uffd_feature_required = 0,
+	},
 	{
 		.name = "pagemap",
 		.uffd_fn = uffd_pagemap_test,
-- 
2.39.1