Revert "seccomp: add a selftest for get_metadata"

This reverts commit e65cd9a2.

Tommi T. Rrantala notes:

	PTRACE_SECCOMP_GET_METADATA was only added in 4.16
	(26500475)

	And it's also breaking seccomp_bpf.c compilation for me:

	seccomp_bpf.c: In function ‘get_metadata’:
	seccomp_bpf.c:2878:26: error: storage size of ‘md’ isn’t known
	  struct seccomp_metadata md;
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/testing/selftests/seccomp/seccomp_bpf.c

@@ -145,15 +145,6 @@ struct seccomp_data {
 #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
 #endif
 
-#ifndef PTRACE_SECCOMP_GET_METADATA
-#define PTRACE_SECCOMP_GET_METADATA	0x420d
-
-struct seccomp_metadata {
-	__u64 filter_off;       /* Input: which filter */
-	__u64 flags;             /* Output: filter's flags */
-};
-#endif
-
 #ifndef seccomp
 int seccomp(unsigned int op, unsigned int flags, void *args)
 {
@@ -2870,58 +2861,6 @@ TEST(get_action_avail)
 	EXPECT_EQ(errno, EOPNOTSUPP);
 }
 
-TEST(get_metadata)
-{
-	pid_t pid;
-	int pipefd[2];
-	char buf;
-	struct seccomp_metadata md;
-
-	ASSERT_EQ(0, pipe(pipefd));
-
-	pid = fork();
-	ASSERT_GE(pid, 0);
-	if (pid == 0) {
-		struct sock_filter filter[] = {
-			BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
-		};
-		struct sock_fprog prog = {
-			.len = (unsigned short)ARRAY_SIZE(filter),
-			.filter = filter,
-		};
-
-		/* one with log, one without */
-		ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
-				     SECCOMP_FILTER_FLAG_LOG, &prog));
-		ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
-
-		ASSERT_EQ(0, close(pipefd[0]));
-		ASSERT_EQ(1, write(pipefd[1], "1", 1));
-		ASSERT_EQ(0, close(pipefd[1]));
-
-		while (1)
-			sleep(100);
-	}
-
-	ASSERT_EQ(0, close(pipefd[1]));
-	ASSERT_EQ(1, read(pipefd[0], &buf, 1));
-
-	ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
-	ASSERT_EQ(pid, waitpid(pid, NULL, 0));
-
-	md.filter_off = 0;
-	ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
-	EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
-	EXPECT_EQ(md.filter_off, 0);
-
-	md.filter_off = 1;
-	ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
-	EXPECT_EQ(md.flags, 0);
-	EXPECT_EQ(md.filter_off, 1);
-
-	ASSERT_EQ(0, kill(pid, SIGKILL));
-}
-
 /*
  * TODO:
  * - add microbenchmarks