[MIPS] Add seccomp bpf support

sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc

Index: sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
diff --git a/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc b/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
index 95fcbc6b5eb800906fe6e2ef319066825b48b5b5..65ec4ce5a602ee1f034300a31435d58751f92c04 100644
--- a/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
+++ b/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
@@ -13,6 +13,7 @@
 #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
@@ -662,7 +663,7 @@ BPF_TEST_C(SandboxBPF, SigBus, RedirectAllSyscallsPolicy) {
   // 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);

[mdempsky, 2014/07/14 18:10:51]

Why switch from a pipe to a socket pair?

[nedeljko, 2014/07/15 15:22:15]

In short, there is a problem in using pipe() here on Mips because of they way it
is implemented on Mips.

Please see comments from Patch Set 2 for more detailed explanation.

   bus_handler_fd_ = fds[1];
   struct sigaction sa = {};
   sa.sa_sigaction = SigBusHandler;
@@ -1990,6 +1991,13 @@ SANDBOX_TEST(SandboxBPF, DISABLE_ON_TSAN(SeccompRetTrace)) {
   return;
 #endif
 
+#if defined(__mips__)
+  // TODO: Figure out how to support specificity of handeling indirect syscalls

[mdempsky, 2014/07/14 18:10:51]

Typo: handling

[nedeljko, 2014/07/15 15:22:15]

Done.

+  //        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) {