Linux Sandbox: whitelist arm64 syscalls

components/nacl/loader/sandbox_linux/nacl_bpf_sandbox_linux.cc

Index: components/nacl/loader/sandbox_linux/nacl_bpf_sandbox_linux.cc
diff --git a/components/nacl/loader/sandbox_linux/nacl_bpf_sandbox_linux.cc b/components/nacl/loader/sandbox_linux/nacl_bpf_sandbox_linux.cc
index 66a606ad30ab2078074830584bd45ea832c36242..3e8830464ea7ccda1c239c4e83d039b9584dc918 100644
--- a/components/nacl/loader/sandbox_linux/nacl_bpf_sandbox_linux.cc
+++ b/components/nacl/loader/sandbox_linux/nacl_bpf_sandbox_linux.cc
@@ -106,7 +106,8 @@ ResultExpr NaClBPFSandboxPolicy::EvaluateSyscall(int sysno) const {
     // NaCl uses custom signal stacks.
     case __NR_sigaltstack:
     // Below is fairly similar to the policy for a Chromium renderer.
-#if defined(__i386__) || defined(__x86_64__) || defined(__mips__)
+#if defined(__i386__) || defined(__x86_64__) || defined(__mips__) || \
+    defined(__aarch64__)

[Mark Seaborn, 2016/02/26 20:25:30]

This implies that we support running this NaCl code on ARM64, which isn't the
case, so it's a bit misleading to add this.  I assume you just added this for
consistency with the other files?

     case __NR_getrlimit:
 #endif
 #if defined(__i386__) || defined(__arm__)