Linux Sandbox: Add support for SECCOMP_RET_TRACE.

sandbox/linux/seccomp-bpf/codegen.cc

 // 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.
 
 #include <stdio.h>
 
 #include "base/logging.h"
 #include "sandbox/linux/seccomp-bpf/codegen.h"
 
 namespace {
@@ skipping 88 matching lines @@
               (int)iter->k,
               ip + iter->jt + 1, ip + iter->jf + 1);
         }
         break;
       case BPF_RET:
         fprintf(stderr, "RET 0x%x  // ", iter->k);
         if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_TRAP) {
           fprintf(stderr, "Trap #%d\n", iter->k & SECCOMP_RET_DATA);
         } else if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_ERRNO) {
           fprintf(stderr, "errno = %d\n", iter->k & SECCOMP_RET_DATA);
+        } else if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_TRACE) {
+          fprintf(stderr, "Trace #%d\n", iter->k & SECCOMP_RET_DATA);
         } else if (iter->k == SECCOMP_RET_ALLOW) {
           fprintf(stderr, "Allowed\n");
         } else {
           fprintf(stderr, "???\n");
         }
         break;
       case BPF_ALU:
         fprintf(stderr, BPF_OP(iter->code) == BPF_NEG
             ? "A := -A\n" : "A := A %s 0x%x\n",
             BPF_OP(iter->code) == BPF_ADD ? "+"  :
@@ skipping 640 matching lines @@
       CutGraphIntoBasicBlocks(instructions, branch_targets, &all_blocks);
   MergeTails(&all_blocks);
   BasicBlocks basic_blocks;
   TopoSortBasicBlocks(first_block, all_blocks, &basic_blocks);
   ComputeRelativeJumps(&basic_blocks, all_blocks);
   ConcatenateBasicBlocks(basic_blocks, program);
   return;
 }
 
 }  // namespace sandbox