[PATCH 7/7] userfaultfd: shmem: add userfaultfd_shmem test

[Mike Rapoport]

The test verifies that anonymous shared mapping can be used with userfault
using the existing testing method.
The shared memory area is allocated using mmap(..., MAP_SHARED |
MAP_ANONYMOUS, ...) and released using madvise(MADV_REMOVE)

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
---
 tools/testing/selftests/vm/Makefile      |  3 +++
 tools/testing/selftests/vm/run_vmtests   | 11 ++++++++++
 tools/testing/selftests/vm/userfaultfd.c | 37 ++++++++++++++++++++++++++++++--
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index aaa4225..12ff211 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -11,6 +11,7 @@ BINARIES += thuge-gen
 BINARIES += transhuge-stress
 BINARIES += userfaultfd
 BINARIES += userfaultfd_hugetlb
+BINARIES += userfaultfd_shmem
 
 all: $(BINARIES)
 %: %.c
@@ -19,6 +20,8 @@ userfaultfd: userfaultfd.c ../../../../usr/include/linux/kernel.h
 	$(CC) $(CFLAGS) -O2 -o $@ $< -lpthread
 userfaultfd_hugetlb: userfaultfd.c ../../../../usr/include/linux/kernel.h
 	$(CC) $(CFLAGS) -DHUGETLB_TEST -O2 -o $@ $< -lpthread
+userfaultfd_shmem: userfaultfd.c ../../../../usr/include/linux/kernel.h
+	$(CC) $(CFLAGS) -DSHMEM_TEST -O2 -o $@ $< -lpthread
 
 ../../../../usr/include/linux/kernel.h:
 	make -C ../../../.. headers_install
diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests
index 14d697e..c92f6cf 100755
--- a/tools/testing/selftests/vm/run_vmtests
+++ b/tools/testing/selftests/vm/run_vmtests
@@ -116,6 +116,17 @@ else
 fi
 rm -f $mnt/ufd_test_file
 
+echo "----------------------------"
+echo "running userfaultfd_shmem"
+echo "----------------------------"
+./userfaultfd_shmem 128 32
+if [ $? -ne 0 ]; then
+	echo "[FAIL]"
+	exitcode=1
+else
+	echo "[PASS]"
+fi
+
 #cleanup
 umount $mnt
 rm -rf $mnt
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index d753a91..a5e5808 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -101,8 +101,9 @@ pthread_attr_t attr;
 				 ~(unsigned long)(sizeof(unsigned long long) \
 						  -  1)))
 
-#ifndef HUGETLB_TEST
+#if !defined(HUGETLB_TEST) && !defined(SHMEM_TEST)
 
+/* Anonymous memory */
 #define EXPECTED_IOCTLS		((1 << _UFFDIO_WAKE) | \
 				 (1 << _UFFDIO_COPY) | \
 				 (1 << _UFFDIO_ZEROPAGE))
@@ -127,10 +128,13 @@ static void allocate_area(void **alloc_area)
 	}
 }
 
-#else /* HUGETLB_TEST */
+#else /* HUGETLB_TEST or SHMEM_TEST */
 
 #define EXPECTED_IOCTLS		UFFD_API_RANGE_IOCTLS_BASIC
 
+#ifdef HUGETLB_TEST
+
+/* HugeTLB memory */
 static int release_pages(char *rel_area)
 {
 	int ret = 0;
@@ -162,8 +166,37 @@ static void allocate_area(void **alloc_area)
 		huge_fd_off0 = *alloc_area;
 }
 
+#elif defined(SHMEM_TEST)
+
+/* Shared memory */
+static int release_pages(char *rel_area)
+{
+	int ret = 0;
+
+	if (madvise(rel_area, nr_pages * page_size, MADV_REMOVE)) {
+		perror("madvise");
+		ret = 1;
+	}
+
+	return ret;
+}
+
+static void allocate_area(void **alloc_area)
+{
+	*alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
+			   MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+	if (*alloc_area == MAP_FAILED) {
+		fprintf(stderr, "shared memory mmap failed\n");
+		*alloc_area = NULL;
+	}
+}
+
+#else /* SHMEM_TEST */
+#error "Undefined test type"
 #endif /* HUGETLB_TEST */
 
+#endif /* !defined(HUGETLB_TEST) && !defined(SHMEM_TEST) */
+
 static int my_bcmp(char *str1, char *str2, size_t n)
 {
 	unsigned long i;
-- 
1.9.1