ozone gbm: whitelist 3 DRM ioctl code for native GpuMemoryBuffer.

content/common/sandbox_linux/bpf_renderer_policy_linux.cc

 // Copyright 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_renderer_policy_linux.h"
 
 #include <errno.h>
+#include <sys/ioctl.h>
 
 #include "base/basictypes.h"
 #include "build/build_config.h"
 #include "content/common/sandbox_linux/sandbox_linux.h"
 #include "sandbox/linux/bpf_dsl/bpf_dsl.h"
+#include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.h"
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_sets.h"
 #include "sandbox/linux/system_headers/linux_syscalls.h"
 
+#if defined(USE_VGEM_MAP)
+#include <libdrm/vgem_drm.h>
+#endif
+
 using sandbox::SyscallSets;
 using sandbox::bpf_dsl::Allow;
+using sandbox::bpf_dsl::Arg;
 using sandbox::bpf_dsl::Error;
 using sandbox::bpf_dsl::ResultExpr;
 
 namespace content {
 
+namespace {
+
+ResultExpr RestrictIoctl() {
+#if defined(USE_VGEM_MAP)
+  // The type of DRM_IOCTL_XXX macro is long unsigned int.

[mdempsky, 2015/09/02 22:19:38]

For simplicity, I would suggest writing this as just:

    const Arg<unsigned long> request(1);
    return Switch(request)
        .CASES((static_cast<unsigned long>(TCGETS), FIONREAD), Allow())
#if defined(USE_VGEM_MAP)
        .CASES((DRM_IOCTL_GEM_CLOSE, ...), Allow())
#endif
        .Default(sandbox::CrashSIGSYSIoctl());

There's no need to vary the Arg type parameter based on USE_VGEM_MAP.

(The static_cast is annoying, but unavoidable until we're allowed to use
<initializer_list>. :-/)

[dshwang, 2015/09/03 08:38:04]

Thx for taking your time. Done.

+  auto reference_type = DRM_IOCTL_GEM_CLOSE;
+#else
+  auto reference_type = TCGETS;
+#endif
+  const Arg<decltype(reference_type)> request(1);
+  return Switch(request)
+      .SANDBOX_BPF_DSL_CASES(
+          (static_cast<decltype(reference_type)>(TCGETS), FIONREAD), Allow())
+#if defined(USE_VGEM_MAP)
+      .SANDBOX_BPF_DSL_CASES((DRM_IOCTL_GEM_CLOSE, DRM_IOCTL_VGEM_MODE_MAP_DUMB,
+                              DRM_IOCTL_PRIME_FD_TO_HANDLE),
+                             Allow())
+#endif
+      .Default(sandbox::CrashSIGSYSIoctl());
+}
+
+}  // namespace
+
 RendererProcessPolicy::RendererProcessPolicy() {}
 RendererProcessPolicy::~RendererProcessPolicy() {}
 
 ResultExpr RendererProcessPolicy::EvaluateSyscall(int sysno) const {
   switch (sysno) {
     // The baseline policy allows __NR_clock_gettime. Allow
     // clock_getres() for V8. crbug.com/329053.
     case __NR_clock_getres:
       return sandbox::RestrictClockID();
     case __NR_ioctl:
-      return sandbox::RestrictIoctl();
+      return RestrictIoctl();
     // Allow the system calls below.
     case __NR_fdatasync:
     case __NR_fsync:
 #if defined(__i386__) || defined(__x86_64__) || defined(__mips__)
     case __NR_getrlimit:
 #endif
 #if defined(__i386__) || defined(__arm__)
     case __NR_ugetrlimit:
 #endif
     case __NR_mremap:  // See crbug.com/149834.
@@ skipping 12 matching lines @@
       return sandbox::RestrictSchedTarget(GetPolicyPid(), sysno);
     case __NR_prlimit64:
       return Error(EPERM);  // See crbug.com/160157.
     default:
       // Default on the content baseline policy.
       return SandboxBPFBasePolicy::EvaluateSyscall(sysno);
   }
 }
 
 }  // namespace content