[MIPS] Add seccomp bpf support

sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <errno.h>
 #include <pthread.h>
 #include <sched.h>
 #include <signal.h>
 #include <sys/prctl.h>
 #include <sys/ptrace.h>
 #include <sys/syscall.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/utsname.h>
 #include <unistd.h>
+#include <sys/socket.h>
 
 #if defined(ANDROID)
 // Work-around for buggy headers in Android's NDK
 #define __user
 #endif
 #include <linux/futex.h>
 
 #include <ostream>
 
 #include "base/bind.h"
@@ skipping 629 matching lines @@
 
 BPF_TEST_C(SandboxBPF, SigBus, RedirectAllSyscallsPolicy) {
   // We use the SIGBUS bit in the signal mask as a thread-local boolean
   // value in the implementation of UnsafeTrap(). This is obviously a bit
   // of a hack that could conceivably interfere with code that uses SIGBUS
   // in more traditional ways. This test verifies that basic functionality
   // of SIGBUS is not impacted, but it is certainly possibly to construe
   // more complex uses of signals where our use of the SIGBUS mask is not
   // 100% transparent. This is expected behavior.
   int fds[2];
-  BPF_ASSERT(pipe(fds) == 0);
+  BPF_ASSERT(socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0);
   bus_handler_fd_ = fds[1];
   struct sigaction sa = {};
   sa.sa_sigaction = SigBusHandler;
   sa.sa_flags = SA_SIGINFO;
   BPF_ASSERT(sigaction(SIGBUS, &sa, NULL) == 0);
   raise(SIGBUS);
   char c = '\000';
   BPF_ASSERT(read(fds[0], &c, 1) == 1);
   BPF_ASSERT(close(fds[0]) == 0);
   BPF_ASSERT(close(fds[1]) == 0);
@@ skipping 1307 matching lines @@
   if (SandboxBPF::SupportsSeccompSandbox(-1) !=
       sandbox::SandboxBPF::STATUS_AVAILABLE) {
     return;
   }
 
 #if defined(__arm__)
   printf("This test is currently disabled on ARM due to a kernel bug.");
   return;
 #endif
 
+#if defined(__mips__)
+  // TODO: Figure out how to support specificity of handling indirect syscalls
+  //        in this test and enable it.
+  printf("This test is currently disabled on MIPS.");
+  return;
+#endif
+
   pid_t pid = fork();
   BPF_ASSERT_NE(-1, pid);
   if (pid == 0) {
     pid_t my_pid = getpid();
     BPF_ASSERT_NE(-1, ptrace(PTRACE_TRACEME, -1, NULL, NULL));
     BPF_ASSERT_EQ(0, raise(SIGSTOP));
     SandboxBPF sandbox;
     sandbox.SetSandboxPolicy(new TraceAllPolicy);
     BPF_ASSERT(sandbox.StartSandbox(SandboxBPF::PROCESS_SINGLE_THREADED));
 
@@ skipping 143 matching lines @@
                          kLargeOffset));
   BPF_ASSERT_EQ(0, memcmp(kTestString, read_test_string, sizeof(kTestString)));
   BPF_ASSERT(pread_64_was_forwarded);
 }
 
 #endif  // !defined(OS_ANDROID)
 
 }  // namespace
 
 }  // namespace sandbox