selftests/seccomp: Remove SIGSTOP si_pid check

Commit f149b3155744 ("signal: Never allocate siginfo for SIGKILL or SIGSTOP")
means that the seccomp selftest cannot check si_pid under SIGSTOP anymore.
Since it's believed[1] there are no other userspace things depending on the
old behavior, this removes the behavioral check in the selftest, since it's
more a "extra" sanity check (which turns out, maybe, not to have been
useful to test).

[1] https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com

Reported-by: Tycho Andersen <tycho@tycho.ws>
Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index e1473234968de7d0166d7f4446b5f6c796d5204e..c9a2abf8be1b38d0ea3d0ee14019b6078ca95af2 100644 (file)
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -2731,9 +2731,14 @@ TEST(syscall_restart)
        ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
        ASSERT_EQ(true, WIFSTOPPED(status));
        ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
-       /* Verify signal delivery came from parent now. */
        ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
-       EXPECT_EQ(getpid(), info.si_pid);
+       /*
+        * There is no siginfo on SIGSTOP any more, so we can't verify
+        * signal delivery came from parent now (getpid() == info.si_pid).
+        * https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
+        * At least verify the SIGSTOP via PTRACE_GETSIGINFO.
+        */
+       EXPECT_EQ(SIGSTOP, info.si_signo);
 
        /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
        ASSERT_EQ(0, kill(child_pid, SIGCONT));