Linux Sandbox: split the GPU policies to their own file.

content/common/sandbox_linux/bpf_cros_arm_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_cros_arm_gpu_policy_linux.h"
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h"
+#include "content/common/sandbox_linux/sandbox_seccomp_bpf_linux.h"
+#include "sandbox/linux/seccomp-bpf-helpers/syscall_sets.h"
+#include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
+#include "sandbox/linux/services/linux_syscalls.h"
+
+using sandbox::ErrorCode;
+using sandbox::SandboxBPF;
+using sandbox::SyscallSets;
+
+namespace content {
+
+namespace {
+
+inline bool IsChromeOS() {
+#if defined(OS_CHROMEOS)
+  return true;
+#else
+  return false;
+#endif
+}
+
+inline bool IsArchitectureArm() {
+#if defined(__arm__)
+  return true;
+#else
+  return false;
+#endif
+}
+
+void AddArmMaliGpuWhitelist(std::vector<std::string>* read_whitelist,
+                            std::vector<std::string>* write_whitelist) {
+  // Device file needed by the ARM GPU userspace.
+  static const char kMali0Path[] = "/dev/mali0";
+
+  // Devices needed for video decode acceleration on ARM.
+  static const char kDevMfcDecPath[] = "/dev/mfc-dec";
+  static const char kDevGsc1Path[] = "/dev/gsc1";
+
+  // Devices needed for video encode acceleration on ARM.
+  static const char kDevMfcEncPath[] = "/dev/mfc-enc";
+
+  read_whitelist->push_back(kMali0Path);
+  read_whitelist->push_back(kDevMfcDecPath);
+  read_whitelist->push_back(kDevGsc1Path);
+  read_whitelist->push_back(kDevMfcEncPath);
+
+  write_whitelist->push_back(kMali0Path);
+  write_whitelist->push_back(kDevMfcDecPath);
+  write_whitelist->push_back(kDevGsc1Path);
+  write_whitelist->push_back(kDevMfcEncPath);
+}
+
+void AddArmTegraGpuWhitelist(std::vector<std::string>* read_whitelist,
+                             std::vector<std::string>* write_whitelist) {
+  // Device files needed by the Tegra GPU userspace.
+  static const char kDevNvhostCtrlPath[] = "/dev/nvhost-ctrl";
+  static const char kDevNvhostGr2dPath[] = "/dev/nvhost-gr2d";
+  static const char kDevNvhostGr3dPath[] = "/dev/nvhost-gr3d";
+  static const char kDevNvhostIspPath[] = "/dev/nvhost-isp";
+  static const char kDevNvhostViPath[] = "/dev/nvhost-vi";
+  static const char kDevNvmapPath[] = "/dev/nvmap";
+  static const char kDevTegraSemaPath[] = "/dev/tegra_sema";
+
+  read_whitelist->push_back(kDevNvhostCtrlPath);
+  read_whitelist->push_back(kDevNvhostGr2dPath);
+  read_whitelist->push_back(kDevNvhostGr3dPath);
+  read_whitelist->push_back(kDevNvhostIspPath);
+  read_whitelist->push_back(kDevNvhostViPath);
+  read_whitelist->push_back(kDevNvmapPath);
+  read_whitelist->push_back(kDevTegraSemaPath);
+
+  write_whitelist->push_back(kDevNvhostCtrlPath);
+  write_whitelist->push_back(kDevNvhostGr2dPath);
+  write_whitelist->push_back(kDevNvhostGr3dPath);
+  write_whitelist->push_back(kDevNvhostIspPath);
+  write_whitelist->push_back(kDevNvhostViPath);
+  write_whitelist->push_back(kDevNvmapPath);
+  write_whitelist->push_back(kDevTegraSemaPath);
+}
+
+void AddArmGpuWhitelist(std::vector<std::string>* read_whitelist,
+                        std::vector<std::string>* write_whitelist) {
+  // On ARM we're enabling the sandbox before the X connection is made,
+  // so we need to allow access to |.Xauthority|.
+  static const char kXAuthorityPath[] = "/home/chronos/.Xauthority";
+  static const char kLdSoCache[] = "/etc/ld.so.cache";
+
+  // Files needed by the ARM GPU userspace.
+  static const char kLibGlesPath[] = "/usr/lib/libGLESv2.so.2";
+  static const char kLibEglPath[] = "/usr/lib/libEGL.so.1";
+
+  read_whitelist->push_back(kXAuthorityPath);
+  read_whitelist->push_back(kLdSoCache);
+  read_whitelist->push_back(kLibGlesPath);
+  read_whitelist->push_back(kLibEglPath);
+
+  AddArmMaliGpuWhitelist(read_whitelist, write_whitelist);
+  AddArmTegraGpuWhitelist(read_whitelist, write_whitelist);
+}
+
+class CrosArmGpuBrokerProcessPolicy : public CrosArmGpuProcessPolicy {
+ public:
+  CrosArmGpuBrokerProcessPolicy() : CrosArmGpuProcessPolicy(false) {}
+  virtual ~CrosArmGpuBrokerProcessPolicy() {}
+
+  virtual ErrorCode EvaluateSyscall(SandboxBPF* sandbox_compiler,
+                                    int system_call_number) const OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CrosArmGpuBrokerProcessPolicy);
+};
+
+// A GPU broker policy is the same as a GPU policy with open and
+// openat allowed.
+ErrorCode CrosArmGpuBrokerProcessPolicy::EvaluateSyscall(SandboxBPF* sandbox,
+    int sysno) const {
+  switch (sysno) {
+    case __NR_access:
+    case __NR_open:
+    case __NR_openat:
+      return ErrorCode(ErrorCode::ERR_ALLOWED);
+    default:
+      return CrosArmGpuProcessPolicy::EvaluateSyscall(sandbox, sysno);
+  }
+}
+
+bool EnableArmGpuBrokerPolicyCallback() {
+  return SandboxSeccompBPF::StartSandboxWithExternalPolicy(
+      scoped_ptr<sandbox::SandboxBPFPolicy>(new CrosArmGpuBrokerProcessPolicy));
+}
+
+}  // namespace
+
+CrosArmGpuProcessPolicy::CrosArmGpuProcessPolicy(bool allow_shmat)
+    : allow_shmat_(allow_shmat) {}
+
+CrosArmGpuProcessPolicy::~CrosArmGpuProcessPolicy() {}
+
+ErrorCode CrosArmGpuProcessPolicy::EvaluateSyscall(SandboxBPF* sandbox,
+                                                   int sysno) const {
+#if defined(__arm__)
+  if (allow_shmat_ && sysno == __NR_shmat)
+    return ErrorCode(ErrorCode::ERR_ALLOWED);
+#endif  // defined(__arm__)
+
+  switch (sysno) {
+#if defined(__arm__)
+    // ARM GPU sandbox is started earlier so we need to allow networking
+    // in the sandbox.
+    case __NR_connect:
+    case __NR_getpeername:
+    case __NR_getsockname:
+    case __NR_sysinfo:
+    case __NR_uname:
+      return ErrorCode(ErrorCode::ERR_ALLOWED);
+    // Allow only AF_UNIX for |domain|.
+    case __NR_socket:
+    case __NR_socketpair:
+      return sandbox->Cond(0, ErrorCode::TP_32BIT,
+                           ErrorCode::OP_EQUAL, AF_UNIX,
+                           ErrorCode(ErrorCode::ERR_ALLOWED),
+                           ErrorCode(EPERM));
+#endif  // defined(__arm__)
+    default:
+      if (SyscallSets::IsAdvancedScheduler(sysno))
+        return ErrorCode(ErrorCode::ERR_ALLOWED);
+
+      // Default to the generic GPU policy.
+      return GpuProcessPolicy::EvaluateSyscall(sandbox, sysno);
+  }
+}
+
+bool CrosArmGpuProcessPolicy::PreSandboxHook() {
+  DCHECK(IsChromeOS() && IsArchitectureArm());
+  // Create a new broker process.
+  DCHECK(!broker_process());
+
+  std::vector<std::string> read_whitelist_extra;
+  std::vector<std::string> write_whitelist_extra;
+  // Add ARM-specific files to whitelist in the broker.
+
+  AddArmGpuWhitelist(&read_whitelist_extra, &write_whitelist_extra);
+  InitGpuBrokerProcess(EnableArmGpuBrokerPolicyCallback,
+                       read_whitelist_extra,
+                       write_whitelist_extra);
+
+  const int dlopen_flag = RTLD_NOW | RTLD_GLOBAL | RTLD_NODELETE;
+
+  // Preload the Mali library.
+  dlopen("/usr/lib/libmali.so", dlopen_flag);

[Mark Seaborn, 2013/12/13 01:08:47]

You should probably be checking for errors here, if only to warn

[jln (very slow on Chromium), 2013/12/13 01:31:31]

Agreed. This is old code that I'm moving. I mentioned that to jorgelo@. It's
even worse than it seems, because this will run even on non Mali machines and
thus is expected to fail.

+
+  // Preload the Tegra libraries.
+  dlopen("/usr/lib/libnvrm.so", dlopen_flag);
+  dlopen("/usr/lib/libnvrm_graphics.so", dlopen_flag);
+  dlopen("/usr/lib/libnvos.so", dlopen_flag);
+  dlopen("/usr/lib/libnvddk_2d.so", dlopen_flag);
+  dlopen("/usr/lib/libardrv_dynamic.so", dlopen_flag);
+  dlopen("/usr/lib/libnvwsi.so", dlopen_flag);
+  dlopen("/usr/lib/libnvglsi.so", dlopen_flag);
+  dlopen("/usr/lib/libcgdrv.so", dlopen_flag);
+
+  return true;
+}
+
+}  // namespace content