bpf gpu policy: Change GPU bpf policy to support DRI3

content/common/sandbox_linux/bpf_gpu_policy_linux.cc

 // Copyright (c) 2013 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/bpf_gpu_policy_linux.h"
 
 #include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/socket.h>
@@ skipping 116 matching lines @@
   ~GpuBrokerProcessPolicy() override {}
 
   ResultExpr EvaluateSyscall(int system_call_number) const override;
 
  private:
   GpuBrokerProcessPolicy() {}
   DISALLOW_COPY_AND_ASSIGN(GpuBrokerProcessPolicy);
 };
 
 // x86_64/i386 or desktop ARM.
-// A GPU broker policy is the same as a GPU policy with open and
-// openat allowed.
+// A GPU broker policy is the same as a GPU policy with access, open,
+// openat and in the non-Chrome OS case unlink allowed.
 ResultExpr GpuBrokerProcessPolicy::EvaluateSyscall(int sysno) const {
   switch (sysno) {
     case __NR_access:
     case __NR_open:
     case __NR_openat:
+#if !defined(OS_CHROMEOS)
+    // The broker process needs to able to unlink the temporary
+    // files that it may create. This is used by DRI3.
+    case __NR_unlink:
+#endif
       return Allow();
     default:
       return GpuProcessPolicy::EvaluateSyscall(sysno);
   }
 }
 
 void UpdateProcessTypeToGpuBroker() {
   base::CommandLine::StringVector exec =
       base::CommandLine::ForCurrentProcess()->GetArgs();
   base::CommandLine::Reset();
@@ skipping 23 matching lines @@
 
 GpuProcessPolicy::GpuProcessPolicy(bool allow_mincore)
     : broker_process_(NULL), allow_mincore_(allow_mincore) {
 }
 
 GpuProcessPolicy::~GpuProcessPolicy() {}
 
 // Main policy for x86_64/i386. Extended by CrosArmGpuProcessPolicy.
 ResultExpr GpuProcessPolicy::EvaluateSyscall(int sysno) const {
   switch (sysno) {
+#if !defined(OS_CHROMEOS)
+    case __NR_ftruncate:
+#endif
     case __NR_ioctl:
       return Allow();
     case __NR_mincore:
       if (allow_mincore_) {
         return Allow();
       } else {
         return SandboxBPFBasePolicy::EvaluateSyscall(sysno);
       }
 #if defined(__i386__) || defined(__x86_64__) || defined(__mips__)
     // The Nvidia driver uses flags not in the baseline policy
@@ skipping 57 matching lines @@
   }
 
   return true;
 }
 
 void GpuProcessPolicy::InitGpuBrokerProcess(
     sandbox::bpf_dsl::Policy* (*broker_sandboxer_allocator)(void),
     const std::vector<BrokerFilePermission>& permissions_extra) {
   static const char kDriRcPath[] = "/etc/drirc";
   static const char kDriCard0Path[] = "/dev/dri/card0";
+  static const char kDevShm[] = "/dev/shm/";
 
   CHECK(broker_process_ == NULL);
 
   // All GPU process policies need these files brokered out.
   std::vector<BrokerFilePermission> permissions;
   permissions.push_back(BrokerFilePermission::ReadWrite(kDriCard0Path));
   permissions.push_back(BrokerFilePermission::ReadOnly(kDriRcPath));
+  if (!IsChromeOS()) {
+    permissions.push_back(
+        BrokerFilePermission::ReadWriteCreateUnlinkRecursive(kDevShm));
+  }
 
   // Add eventual extra files from permissions_extra.
   for (const auto& perm : permissions_extra) {
     permissions.push_back(perm);
   }
 
   broker_process_ = new BrokerProcess(GetFSDeniedErrno(), permissions);
   // The initialization callback will perform generic initialization and then
   // call broker_sandboxer_callback.
   CHECK(broker_process_->Init(base::Bind(&UpdateProcessTypeAndEnableSandbox,
                                          broker_sandboxer_allocator)));
 }
 
 }  // namespace content