Extend kvm_syscalls.h to wrap fstat() to assert success. This will be used
in the next patch.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
 tools/testing/selftests/kvm/guest_memfd_test.c     | 15 +++++----------
 tools/testing/selftests/kvm/include/kvm_syscalls.h |  2 ++
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index ec7644aae999d..638906298ed73 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -270,10 +270,8 @@ static void test_mmap_not_supported(int fd, size_t total_size)
 static void test_file_size(int fd, size_t total_size)
 {
 	struct stat sb;
-	int ret;
 
-	ret = fstat(fd, &sb);
-	TEST_ASSERT(!ret, "fstat should succeed");
+	kvm_fstat(fd, &sb);
 	TEST_ASSERT_EQ(sb.st_size, total_size);
 	TEST_ASSERT_EQ(sb.st_blksize, page_size);
 }
@@ -361,25 +359,22 @@ static void test_create_guest_memfd_invalid_sizes(struct kvm_vm *vm,
 
 static void test_create_guest_memfd_multiple(struct kvm_vm *vm)
 {
-	int fd1, fd2, ret;
+	int fd1, fd2;
 	struct stat st1, st2;
 
 	fd1 = __vm_create_guest_memfd(vm, page_size, 0);
 	TEST_ASSERT(fd1 != -1, "memfd creation should succeed");
 
-	ret = fstat(fd1, &st1);
-	TEST_ASSERT(ret != -1, "memfd fstat should succeed");
+	kvm_fstat(fd1, &st1);
 	TEST_ASSERT(st1.st_size == page_size, "memfd st_size should match requested size");
 
 	fd2 = __vm_create_guest_memfd(vm, page_size * 2, 0);
 	TEST_ASSERT(fd2 != -1, "memfd creation should succeed");
 
-	ret = fstat(fd2, &st2);
-	TEST_ASSERT(ret != -1, "memfd fstat should succeed");
+	kvm_fstat(fd2, &st2);
 	TEST_ASSERT(st2.st_size == page_size * 2, "second memfd st_size should match requested size");
 
-	ret = fstat(fd1, &st1);
-	TEST_ASSERT(ret != -1, "memfd fstat should succeed");
+	kvm_fstat(fd1, &st1);
 	TEST_ASSERT(st1.st_size == page_size, "first memfd st_size should still match requested size");
 	TEST_ASSERT(st1.st_ino != st2.st_ino, "different memfd should have different inode numbers");
 
diff --git a/tools/testing/selftests/kvm/include/kvm_syscalls.h b/tools/testing/selftests/kvm/include/kvm_syscalls.h
index 843c9904c46f6..2266c06347f5d 100644
--- a/tools/testing/selftests/kvm/include/kvm_syscalls.h
+++ b/tools/testing/selftests/kvm/include/kvm_syscalls.h
@@ -2,6 +2,7 @@
 #ifndef SELFTEST_KVM_SYSCALLS_H
 #define SELFTEST_KVM_SYSCALLS_H
 
+#include <sys/stat.h>
 #include <sys/syscall.h>
 
 #define MAP_ARGS0(m,...)
@@ -78,5 +79,6 @@ __KVM_SYSCALL_DEFINE(close, 1, int, fd);
 __KVM_SYSCALL_DEFINE(fallocate, 4, int, fd, int, mode, loff_t, offset, loff_t, len);
 __KVM_SYSCALL_DEFINE(ftruncate, 2, unsigned int, fd, off_t, length);
 __KVM_SYSCALL_DEFINE(madvise, 3, void *, addr, size_t, length, int, advice);
+__KVM_SYSCALL_DEFINE(fstat, 2, int, fd, struct stat *, buf);
 
 #endif /* SELFTEST_KVM_SYSCALLS_H */

-- 
2.53.0.473.g4a7958ca14-goog