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From:   Peter Xu <peterx@redhat.com>
To:     linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc:     Andrew Morton <akpm@linux-foundation.org>, peterx@redhat.com,
        Axel Rasmussen <axelrasmussen@google.com>,
        Mike Kravetz <mike.kravetz@oracle.com>
Subject: [PATCH 1/4] selftests/vm: Use memfd for hugetlb tests
Date:   Tue,  4 Oct 2022 17:41:22 -0400
Message-Id: <20221004214125.120993-2-peterx@redhat.com>
In-Reply-To: <20221004214125.120993-1-peterx@redhat.com>
References: <20221004214125.120993-1-peterx@redhat.com>
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We already used memfd for shmem test, move it forward with hugetlb too so
that we don't need user to specify the hugetlb file path explicitly when
running hugetlb shared tests.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 tools/testing/selftests/vm/userfaultfd.c | 60 ++++++++----------------
 1 file changed, 20 insertions(+), 40 deletions(-)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 74babdbc02e5..c0c6853cdce5 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -93,10 +93,8 @@ static volatile bool test_uffdio_zeropage_eexist = true;
 static bool test_uffdio_wp = true;
 /* Whether to test uffd minor faults */
 static bool test_uffdio_minor = false;
-
 static bool map_shared;
-static int shm_fd;
-static int huge_fd;
+static int mem_fd;
 static unsigned long long *count_verify;
 static int uffd = -1;
 static int uffd_flags, finished, *pipefd;
@@ -260,35 +258,21 @@ static void hugetlb_release_pages(char *rel_area)
 
 static void hugetlb_allocate_area(void **alloc_area, bool is_src)
 {
+	off_t size = nr_pages * page_size;
+	off_t offset = is_src ? 0 : size;
 	void *area_alias = NULL;
 	char **alloc_area_alias;
 
-	if (!map_shared)
-		*alloc_area = mmap(NULL,
-			nr_pages * page_size,
-			PROT_READ | PROT_WRITE,
-			MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB |
-				(is_src ? 0 : MAP_NORESERVE),
-			-1,
-			0);
-	else
-		*alloc_area = mmap(NULL,
-			nr_pages * page_size,
-			PROT_READ | PROT_WRITE,
-			MAP_SHARED |
-				(is_src ? 0 : MAP_NORESERVE),
-			huge_fd,
-			is_src ? 0 : nr_pages * page_size);
+	*alloc_area = mmap(NULL, size, PROT_READ | PROT_WRITE,
+			   (map_shared ? MAP_SHARED : MAP_PRIVATE) |
+			   (is_src ? 0 : MAP_NORESERVE),
+			   mem_fd, offset);
 	if (*alloc_area == MAP_FAILED)
 		err("mmap of hugetlbfs file failed");
 
 	if (map_shared) {
-		area_alias = mmap(NULL,
-			nr_pages * page_size,
-			PROT_READ | PROT_WRITE,
-			MAP_SHARED,
-			huge_fd,
-			is_src ? 0 : nr_pages * page_size);
+		area_alias = mmap(NULL, size, PROT_READ | PROT_WRITE,
+				  MAP_SHARED, mem_fd, offset);
 		if (area_alias == MAP_FAILED)
 			err("mmap of hugetlb file alias failed");
 	}
@@ -334,14 +318,14 @@ static void shmem_allocate_area(void **alloc_area, bool is_src)
 	}
 
 	*alloc_area = mmap(p, bytes, PROT_READ | PROT_WRITE, MAP_SHARED,
-			   shm_fd, offset);
+			   mem_fd, offset);
 	if (*alloc_area == MAP_FAILED)
 		err("mmap of memfd failed");
 	if (test_collapse && *alloc_area != p)
 		err("mmap of memfd failed at %p", p);
 
 	area_alias = mmap(p_alias, bytes, PROT_READ | PROT_WRITE, MAP_SHARED,
-			  shm_fd, offset);
+			  mem_fd, offset);
 	if (area_alias == MAP_FAILED)
 		err("mmap of memfd alias failed");
 	if (test_collapse && area_alias != p_alias)
@@ -1821,21 +1805,17 @@ int main(int argc, char **argv)
 	}
 	nr_pages = nr_pages_per_cpu * nr_cpus;
 
-	if (test_type == TEST_HUGETLB && map_shared) {
-		if (argc < 5)
-			usage();
-		huge_fd = open(argv[4], O_CREAT | O_RDWR, 0755);
-		if (huge_fd < 0)
-			err("Open of %s failed", argv[4]);
-		if (ftruncate(huge_fd, 0))
-			err("ftruncate %s to size 0 failed", argv[4]);
-	} else if (test_type == TEST_SHMEM) {
-		shm_fd = memfd_create(argv[0], 0);
-		if (shm_fd < 0)
+	if (test_type == TEST_SHMEM || test_type == TEST_HUGETLB) {
+		unsigned int memfd_flags = 0;
+
+		if (test_type == TEST_HUGETLB)
+			memfd_flags = MFD_HUGETLB;
+		mem_fd = memfd_create(argv[0], memfd_flags);
+		if (mem_fd < 0)
 			err("memfd_create");
-		if (ftruncate(shm_fd, nr_pages * page_size * 2))
+		if (ftruncate(mem_fd, nr_pages * page_size * 2))
 			err("ftruncate");
-		if (fallocate(shm_fd,
+		if (fallocate(mem_fd,
 			      FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0,
 			      nr_pages * page_size * 2))
 			err("fallocate");
-- 
2.37.3