[PATCH for-next/seccomp v2 1/2] selftests/seccomp: Add SKIPs for failed unshare()

[Kees Cook]

Running the seccomp tests as a regular user shouldn't just fail tests
that require CAP_SYS_ADMIN (for getting a PID namespace). Instead,
detect those cases and SKIP them. Additionally, gracefully SKIP missing
CONFIG_USER_NS (and add to "config" since we'd prefer to actually test
this case).

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 tools/testing/selftests/seccomp/config        |  1 +
 tools/testing/selftests/seccomp/seccomp_bpf.c | 10 ++++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/seccomp/config b/tools/testing/selftests/seccomp/config
index db1e11b08c8a..64c19d8eba79 100644
--- a/tools/testing/selftests/seccomp/config
+++ b/tools/testing/selftests/seccomp/config
@@ -1,2 +1,3 @@
 CONFIG_SECCOMP=y
 CONFIG_SECCOMP_FILTER=y
+CONFIG_USER_NS=y
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index c0aa46ce14f6..14b038361549 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -3439,7 +3439,10 @@ TEST(user_notification_child_pid_ns)
 	struct seccomp_notif req = {};
 	struct seccomp_notif_resp resp = {};
 
-	ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0);
+	ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) {
+		if (errno == EINVAL)
+			SKIP(return, "kernel missing CLONE_NEWUSER support");
+	};
 
 	listener = user_trap_syscall(__NR_getppid,
 				     SECCOMP_FILTER_FLAG_NEW_LISTENER);
@@ -3504,7 +3507,10 @@ TEST(user_notification_sibling_pid_ns)
 	}
 
 	/* Create the sibling ns, and sibling in it. */
-	ASSERT_EQ(unshare(CLONE_NEWPID), 0);
+	ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
+		if (errno == EPERM)
+			SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
+	}
 	ASSERT_EQ(errno, 0);
 
 	pid2 = fork();
-- 
2.25.1