SECCOMP-BPF: Added support for greylisting of system calls.

sandbox/linux/seccomp-bpf/errorcode.h

 // 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.
 
 #ifndef SANDBOX_LINUX_SECCOMP_BPF_ERRORCODE_H__
 #define SANDBOX_LINUX_SECCOMP_BPF_ERRORCODE_H__
 
 namespace playground2 {
 
 struct arch_seccomp_data;
@@ skipping 76 matching lines @@
   friend class Sandbox;
   friend class Verifier;
 
   enum ErrorType {
     ET_INVALID, ET_SIMPLE, ET_TRAP, ET_COND,
   };
 
   // If we are wrapping a callback, we must assign a unique id. This id is
   // how the kernel tells us which one of our different SECCOMP_RET_TRAP
   // cases has been triggered.
-  ErrorCode(TrapFnc fnc, const void *aux, uint16_t id);
+  ErrorCode(TrapFnc fnc, const void *aux, bool safe, uint16_t id);
 
   // Some system calls require inspection of arguments. This constructor
   // allows us to specify additional constraints.
   ErrorCode(int argno, ArgType width, Operation op, uint64_t value,
             const ErrorCode *passed, const ErrorCode *failed);
 
   ErrorType error_type_;
 
   union {
     // Fields needed for SECCOMP_RET_TRAP callbacks
     struct {
       TrapFnc fnc_;              // Callback function and arg, if trap was
       void    *aux_;             //   triggered by the kernel's BPF filter.
+      bool    safe_;             // Keep sandbox active while calling fnc_()
     };
 
     // Fields needed when inspecting additional arguments.
     struct {
       uint64_t  value_;          // Value that we are comparing with.
       int       argno_;          // Syscall arg number that we are inspecting.
       ArgType   width_;          // Whether we are looking at a 32/64bit value.
       Operation op_;             // Comparison operation.
       const ErrorCode *passed_;  // Value to be returned if comparison passed,
       const ErrorCode *failed_;  //   or if it failed.
     };
   };
 
   // 32bit field used for all possible types of ErrorCode values. This is
   // the value that uniquely identifies any ErrorCode and it (typically) can
   // be emitted directly into a BPF filter program.
   uint32_t err_;
 
 };
 
 }  // namespace
 
 #endif  // SANDBOX_LINUX_SECCOMP_BPF_ERRORCODE_H__