1 files changed, 38 insertions, 20 deletions

diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index d76ae98a34a2..c589a2d495a3 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -242,6 +242,40 @@ int seccomp(unsigned int op, unsigned int flags, void *args)
 #define SIBLING_EXIT_FAILURE	0xbadface
 #define SIBLING_EXIT_NEWPRIVS	0xbadfeed
 
+static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
+{
+#ifdef __NR_kcmp
+	errno = 0;
+	return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+
+/* Have TH_LOG report actual location filecmp() is used. */
+#define filecmp(pid1, pid2, fd1, fd2)	({		\
+	int _ret;					\
+							\
+	_ret = __filecmp(pid1, pid2, fd1, fd2);		\
+	if (_ret != 0) {				\
+		if (_ret < 0 && errno == ENOSYS) {	\
+			TH_LOG("kcmp() syscall missing (test is less accurate)");\
+			_ret = 0;			\
+		}					\
+	}						\
+	_ret; })
+
+TEST(kcmp)
+{
+	int ret;
+
+	ret = __filecmp(getpid(), getpid(), 1, 1);
+	EXPECT_EQ(ret, 0);
+	if (ret != 0 && errno == ENOSYS)
+		SKIP(return, "Kernel does not support kcmp() (missing CONFIG_CHECKPOINT_RESTORE?)");
+}
+
 TEST(mode_strict_support)
 {
 	long ret;
@@ -3601,16 +3635,6 @@ TEST(seccomp_get_notif_sizes)
 	EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
 }
 
-static int filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
-{
-#ifdef __NR_kcmp
-	return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
-#else
-	errno = ENOSYS;
-	return -1;
-#endif
-}
-
 TEST(user_notification_continue)
 {
 	pid_t pid;
@@ -3635,20 +3659,14 @@ TEST(user_notification_continue)
 		int dup_fd, pipe_fds[2];
 		pid_t self;
 
-		ret = pipe(pipe_fds);
-		if (ret < 0)
-			exit(1);
+		ASSERT_GE(pipe(pipe_fds), 0);
 
 		dup_fd = dup(pipe_fds[0]);
-		if (dup_fd < 0)
-			exit(1);
+		ASSERT_GE(dup_fd, 0);
+		EXPECT_NE(pipe_fds[0], dup_fd);
 
 		self = getpid();
-
-		ret = filecmp(self, self, pipe_fds[0], dup_fd);
-		if (ret)
-			exit(2);
-
+		ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0);
 		exit(0);
 	}