Add basic ARM support to the seccomp-bpf sandbox.

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 b8ae3b72407fc94883b22cf06043d23f16415bd9..699855f9ab361e91b178b5f677f8fe48f68c8034 100644
--- a/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
+++ b/sandbox/linux/seccomp-bpf/sandbox_bpf_unittest.cc
@@ -13,6 +13,9 @@ using namespace playground2;
 namespace {
 
 const int kExpectedReturnValue = 42;
+#if defined(__arm__)
+const int kArmPublicSysnoCeiling = __NR_SYSCALL_BASE + 1024;
+#endif
 
 TEST(SandboxBpf, CallSupports) {
   // We check that we don't crash, but it's ok if the kernel doesn't
@@ -234,6 +237,13 @@ Sandbox::ErrorCode SyntheticPolicy(int sysno) {
     // FIXME: we should really not have to do that in a trivial policy.
     return ENOSYS;
   }
+
+  // TODO(jorgelo): remove this restriction once crbug.com/141694 is fixed.
+#if defined(__arm__)
+  if (sysno > kArmPublicSysnoCeiling)
+    return ENOSYS;
+#endif
+
   if (sysno == __NR_exit_group) {
     // exit_group() is special, we really need it to work.
     return Sandbox::SB_ALLOWED;
@@ -249,8 +259,16 @@ void SyntheticProcess(void) {
       static_cast<int>(MAX_SYSCALL)) {
     ExitGroup(1);
   }
+
+  // TODO(jorgelo): remove this limit once crbug.com/141694 is fixed.
+#if defined(__arm__)
+  int sysno_ceiling = kArmPublicSysnoCeiling;

[jln (very slow on Chromium), 2012/08/09 22:41:23]

These should be const.

[Jorge Lucangeli Obes, 2012/08/09 22:58:26]

Done.

+#else
+  int sysno_ceiling = static_cast<int>(MAX_SYSCALL);
+#endif
+
   for (int syscall_number =  static_cast<int>(MIN_SYSCALL);
-           syscall_number <= static_cast<int>(MAX_SYSCALL);
+           syscall_number <= sysno_ceiling;
          ++syscall_number) {
     if (syscall_number == __NR_exit_group) {
       // exit_group() is special