[RFC PATCH v2 2/6] KVM: selftests: Add negative test cases for punch hole for guest_memfd()

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Add test cases to check for punch hole of guest_memfd to reject unaligned
offset or size.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 .../testing/selftests/kvm/guest_memfd_test.c  | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index 75073645aaa1..d5b4bfcdc3fe 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -91,6 +91,37 @@ static void test_fallocate(int fd, size_t page_size, size_t total_size)
 	TEST_ASSERT(!ret, "fallocate to restore punched hole should succeed");
 }
 
+/* Negative tests */
+static void test_fallocate_fail(int fd, size_t page_size, size_t total_size)
+{
+	struct {
+		off_t offset;
+		off_t len;
+	} cases[] = {
+		{0, 1},
+		{0, page_size - 1},
+		{0, page_size + 1},
+
+		{1, 1},
+		{1, page_size - 1},
+		{1, page_size},
+		{1, page_size + 1},
+
+		{page_size, 1},
+		{page_size, page_size - 1},
+		{page_size, page_size + 1},
+	};
+	int ret;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(cases); i++) {
+		ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE,
+				cases[i].offset, cases[i].len);
+		TEST_ASSERT(ret == -1,
+			    "fallocate(PUNCH_HOLE) with unaligned offset and/or size should fail");
+	}
+}
+
 static void test_create_guest_memfd_invalid(struct kvm_vm *vm)
 {
 	uint64_t valid_flags = 0;
@@ -160,6 +191,7 @@ int main(int argc, char *argv[])
 	test_mmap(fd, page_size);
 	test_file_size(fd, page_size, total_size);
 	test_fallocate(fd, page_size, total_size);
+	test_fallocate_fail(fd, page_size, total_size);
 
 	close(fd);
 }
-- 
2.25.1