[Android] Allow __NR_sysinfo and __NR_clock_getres under seccomp.

content/common/sandbox_linux/android/sandbox_bpf_base_policy_android.cc

 // Copyright 2014 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 "content/common/sandbox_linux/android/sandbox_bpf_base_policy_android.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/net.h>
 #include <sys/socket.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 
 #include "build/build_config.h"
 #include "sandbox/linux/bpf_dsl/bpf_dsl.h"
+#include "sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.h"
 
 using sandbox::bpf_dsl::AllOf;
 using sandbox::bpf_dsl::Allow;
 using sandbox::bpf_dsl::AnyOf;
 using sandbox::bpf_dsl::Arg;
 using sandbox::bpf_dsl::BoolExpr;
 using sandbox::bpf_dsl::If;
 using sandbox::bpf_dsl::Error;
 using sandbox::bpf_dsl::ResultExpr;
 
@@ skipping 70 matching lines @@
     case __NR_sched_getscheduler:
     case __NR_sched_setscheduler:
     case __NR_setpriority:
     case __NR_set_tid_address:
     case __NR_sigaltstack:
 #if defined(__i386__) || defined(__arm__)
     case __NR_ugetrlimit:
 #else
     case __NR_getrlimit:
 #endif
+    case __NR_sysinfo:  // https://crbug.com/655277
     case __NR_uname:
 
     // Permit socket operations so that renderers can connect to logd and
     // debuggerd. The arguments to socket() are further restricted below.
     // Note that on i386, both of these calls map to __NR_socketcall, which
     // is demultiplexed below.
 #if defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) || \
       defined(__mips__)
     case __NR_getsockopt:
     case __NR_connect:
     case __NR_socket:
 #endif
 
     // Ptrace is allowed so the Breakpad Microdumper can fork in a renderer
     // and then ptrace the parent.
     case __NR_ptrace:
       override_and_allow = true;

[rickyz (no longer on Chrome), 2016/10/12 22:24:50]

This doesn't have anything to do with your change, but out of curiosity, why the
override_and_allow variable instead of just returning Allow()?

[Robert Sesek, 2016/10/12 23:24:01]

I don't know why. It goes back to the initial version of the policy. I can clean
that up in a later CL.

       break;
   }
 
   // https://crbug.com/644759
   if (sysno == __NR_rt_tgsigqueueinfo) {
     const Arg<pid_t> tgid(0);
     return If(tgid == pid_, Allow())
            .Else(Error(EPERM));
   }
 
+  // https://crbug.com/655299
+  if (sysno == __NR_clock_getres) {
+    return sandbox::RestrictClockID();
+  }
+
 #if defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) || \
       defined(__mips__)
   if (sysno == __NR_socket) {
     const Arg<int> domain(0);
     const Arg<int> type(1);
     const Arg<int> protocol(2);
     return If(RestrictSocketArguments(domain, type, protocol), Allow())
            .Else(Error(EPERM));
   }
 #elif defined(__i386__)
@@ skipping 11 matching lines @@
   }
 #endif
 
   if (override_and_allow)
     return Allow();
 
   return SandboxBPFBasePolicy::EvaluateSyscall(sysno);
 }
 
 }  // namespace content