Make chrome_elf use thunks instead of function pointers.

1. Add functionality to ServiceResolverThunk to copy a thunk without patching.
2. Move chrome_elf thunk-handling code to a common location.
3. Use a thunk instead of a f'n ptr for redirects.

BUG=334379

Review URL: https://codereview.chromium.org/183833004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255151 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 229 insertions, 133 deletions

diff --git a/chrome_elf/blacklist/blacklist.cc b/chrome_elf/blacklist/blacklist.cc
index 23a06b4..19c7641 100644
--- a/chrome_elf/blacklist/blacklist.cc
+++ b/chrome_elf/blacklist/blacklist.cc
@@ -11,9 +11,9 @@
 #include "chrome_elf/blacklist/blacklist_interceptions.h"
 #include "chrome_elf/chrome_elf_constants.h"
 #include "chrome_elf/chrome_elf_util.h"
+#include "chrome_elf/thunk_getter.h"
 #include "sandbox/win/src/interception_internal.h"
 #include "sandbox/win/src/internal_types.h"
-#include "sandbox/win/src/sandbox_utils.h"
 #include "sandbox/win/src/service_resolver.h"
 
 // http://blogs.msdn.com/oldnewthing/archive/2004/10/25/247180.aspx
@@ -42,109 +42,10 @@ __declspec(allocate(".crthunk")) sandbox::ThunkData g_thunk_storage;
 
 namespace {
 
-enum Version {
-  VERSION_PRE_XP_SP2 = 0,  // Not supported.
-  VERSION_XP_SP2,
-  VERSION_SERVER_2003, // Also includes XP Pro x64 and Server 2003 R2.
-  VERSION_VISTA,       // Also includes Windows Server 2008.
-  VERSION_WIN7,        // Also includes Windows Server 2008 R2.
-  VERSION_WIN8,        // Also includes Windows Server 2012.
-  VERSION_WIN8_1,
-  VERSION_WIN_LAST,    // Indicates error condition.
-};
-
-// Whether a process is running under WOW64 (the wrapper that allows 32-bit
-// processes to run on 64-bit versions of Windows).  This will return
-// WOW64_DISABLED for both "32-bit Chrome on 32-bit Windows" and "64-bit
-// Chrome on 64-bit Windows".  WOW64_UNKNOWN means "an error occurred", e.g.
-// the process does not have sufficient access rights to determine this.
-enum WOW64Status {
-  WOW64_DISABLED,
-  WOW64_ENABLED,
-  WOW64_UNKNOWN,
-};
-
 // Record if the blacklist was successfully initialized so processes can easily
 // determine if the blacklist is enabled for them.
 bool g_blacklist_initialized = false;
 
-WOW64Status GetWOW64StatusForCurrentProcess() {
-  typedef BOOL (WINAPI* IsWow64ProcessFunc)(HANDLE, PBOOL);
-  IsWow64ProcessFunc is_wow64_process = reinterpret_cast<IsWow64ProcessFunc>(
-      GetProcAddress(GetModuleHandle(L"kernel32.dll"), "IsWow64Process"));
-  if (!is_wow64_process)
-    return WOW64_DISABLED;
-  BOOL is_wow64 = FALSE;
-  if (!(*is_wow64_process)(GetCurrentProcess(), &is_wow64))
-    return WOW64_UNKNOWN;
-  return is_wow64 ? WOW64_ENABLED : WOW64_DISABLED;
-}
-
-class OSInfo {
- public:
-  struct VersionNumber {
-    int major;
-    int minor;
-    int build;
-  };
-
-  struct ServicePack {
-    int major;
-    int minor;
-  };
-
-  OSInfo() {
-    OSVERSIONINFOEX version_info = { sizeof(version_info) };
-    GetVersionEx(reinterpret_cast<OSVERSIONINFO*>(&version_info));
-    version_number_.major = version_info.dwMajorVersion;
-    version_number_.minor = version_info.dwMinorVersion;
-    version_number_.build = version_info.dwBuildNumber;
-    if ((version_number_.major == 5) && (version_number_.minor > 0)) {
-      // Treat XP Pro x64, Home Server, and Server 2003 R2 as Server 2003.
-      version_ = (version_number_.minor == 1) ? VERSION_XP_SP2 :
-                                                VERSION_SERVER_2003;
-      if (version_ == VERSION_XP_SP2 && version_info.wServicePackMajor < 2)
-        version_ = VERSION_PRE_XP_SP2;
-    } else if (version_number_.major == 6) {
-      switch (version_number_.minor) {
-        case 0:
-          // Treat Windows Server 2008 the same as Windows Vista.
-          version_ = VERSION_VISTA;
-          break;
-        case 1:
-          // Treat Windows Server 2008 R2 the same as Windows 7.
-          version_ = VERSION_WIN7;
-          break;
-        case 2:
-          // Treat Windows Server 2012 the same as Windows 8.
-          version_ = VERSION_WIN8;
-          break;
-        default:
-          version_ = VERSION_WIN8_1;
-          break;
-      }
-    } else if (version_number_.major > 6) {
-      version_ = VERSION_WIN_LAST;
-    } else {
-      version_ = VERSION_PRE_XP_SP2;
-    }
-
-    service_pack_.major = version_info.wServicePackMajor;
-    service_pack_.minor = version_info.wServicePackMinor;
-  }
-
-  Version version() const { return version_; }
-  VersionNumber version_number() const { return version_number_; }
-  ServicePack service_pack() const { return service_pack_; }
-
- private:
-  Version version_;
-  VersionNumber version_number_;
-  ServicePack service_pack_;
-
-  DISALLOW_COPY_AND_ASSIGN(OSInfo);
-};
-
 // Record that the thunk setup completed succesfully and close the registry
 // key handle since it is no longer needed.
 void RecordSuccessfulThunkSetup(HKEY* key) {
@@ -343,17 +244,16 @@ bool Initialize(bool force) {
   if (!force && !LeaveSetupBeacon())
     return false;
 
-  // Don't try blacklisting on unsupported OS versions.
-  OSInfo os_info;
-  if (os_info.version() <= VERSION_PRE_XP_SP2)
-    return false;
-
-  // Pseudo-handle, no need to close.
-  HANDLE current_process = ::GetCurrentProcess();
-
   // Tells the resolver to patch already patched functions.
   const bool kRelaxed = true;
 
+  // Create a thunk via the appropriate ServiceResolver instance.
+  sandbox::ServiceResolverThunk* thunk = GetThunk(kRelaxed);
+
+  // Don't try blacklisting on unsupported OS versions.
+  if (!thunk)
+    return false;
+
   // Record that we are starting the thunk setup code.
   HKEY key = NULL;
   DWORD disposition = 0;
@@ -378,26 +278,6 @@ bool Initialize(bool force) {
     key = NULL;
   }
 
-  // Create a thunk via the appropriate ServiceResolver instance.
-  sandbox::ServiceResolverThunk* thunk = NULL;
-#if defined(_WIN64)
-  // Because Windows 8 and 8.1 have different stubs in 64-bit,
-  // ServiceResolverThunk can handle all the formats in 64-bit (instead only
-  // handling 1 like it does in 32-bit versions).
-  thunk = new sandbox::ServiceResolverThunk(current_process, kRelaxed);
-#else
-  if (GetWOW64StatusForCurrentProcess() == WOW64_ENABLED) {
-    if (os_info.version() >= VERSION_WIN8)
-      thunk = new sandbox::Wow64W8ResolverThunk(current_process, kRelaxed);
-    else
-      thunk = new sandbox::Wow64ResolverThunk(current_process, kRelaxed);
-  } else if (os_info.version() >= VERSION_WIN8) {
-    thunk = new sandbox::Win8ResolverThunk(current_process, kRelaxed);
-  } else {
-    thunk = new sandbox::ServiceResolverThunk(current_process, kRelaxed);
-  }
-#endif
-
   // Record that we have initialized the blacklist.
   g_blacklist_initialized = true;
 
diff --git a/chrome_elf/chrome_elf.gyp b/chrome_elf/chrome_elf.gyp
index 1534dbf..775f48d 100644
--- a/chrome_elf/chrome_elf.gyp
+++ b/chrome_elf/chrome_elf.gyp
@@ -97,6 +97,8 @@
       ],
       'dependencies': [
         'chrome_elf_common',
+        '../base/base.gyp:base_static',
+        '../sandbox/sandbox.gyp:sandbox',
       ],
     },
     {
@@ -123,6 +125,8 @@
         'chrome_elf_types.h',
         'chrome_elf_util.cc',
         'chrome_elf_util.h',
+        'thunk_getter.cc',
+        'thunk_getter.h',
       ],
     },
     {
diff --git a/chrome_elf/create_file/chrome_create_file_unittest.cc b/chrome_elf/create_file/chrome_create_file_unittest.cc
index e25b159..e958aa9 100644
--- a/chrome_elf/create_file/chrome_create_file_unittest.cc
+++ b/chrome_elf/create_file/chrome_create_file_unittest.cc
@@ -377,9 +377,7 @@ TEST_F(ChromeCreateFileTest, BypassTest) {
 }
 
 TEST_F(ChromeCreateFileTest, NtCreateFileAddressCheck) {
-  HMODULE ntdll_handle = ::GetModuleHandle(L"ntdll.dll");
-  EXPECT_EQ(::GetProcAddress(ntdll_handle, "NtCreateFile"),
-            g_ntdll_lookup["NtCreateFile"]);
+  EXPECT_EQ(&g_nt_thunk_storage, g_ntdll_lookup["NtCreateFile"]);
 }
 
 TEST_F(ChromeCreateFileTest, ReadWriteFromNtDll) {
diff --git a/chrome_elf/ntdll_cache.cc b/chrome_elf/ntdll_cache.cc
index e550442..73b0e11 100644
--- a/chrome_elf/ntdll_cache.cc
+++ b/chrome_elf/ntdll_cache.cc
@@ -2,15 +2,26 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "chrome_elf/ntdll_cache.h"
+
 #include <stdint.h>
 #include <windows.h>
 
-#include "chrome_elf/ntdll_cache.h"
+#include "base/basictypes.h"
+#include "chrome_elf/thunk_getter.h"
+#include "sandbox/win/src/interception_internal.h"
+#include "sandbox/win/src/internal_types.h"
+#include "sandbox/win/src/service_resolver.h"
+
+// Allocate storage for thunks in a page of this module to save on doing
+// an extra allocation at run time.
+#pragma section(".crthunk", read, execute)
+__declspec(allocate(".crthunk")) sandbox::ThunkData g_nt_thunk_storage;
 
 FunctionLookupTable g_ntdll_lookup;
 
 void InitCache() {
-  HMODULE ntdll_handle = ::GetModuleHandle(L"ntdll.dll");
+  HMODULE ntdll_handle = ::GetModuleHandle(sandbox::kNtdllName);
 
   // To find the Export Address Table address, we start from the DOS header.
   // The module handle is actually the address of the header.
@@ -48,4 +59,43 @@ void InitCache() {
     FARPROC func_addr = reinterpret_cast<FARPROC>(func + base_addr);
     g_ntdll_lookup[std::string(name)] = func_addr;
   }
+
+  const bool kRelaxed = true;
+
+  // Create a thunk via the appropriate ServiceResolver instance.
+  sandbox::ServiceResolverThunk* thunk = GetThunk(kRelaxed);
+
+  if (thunk) {
+    BYTE* thunk_storage = reinterpret_cast<BYTE*>(&g_nt_thunk_storage);
+
+    // Mark the thunk storage as readable and writeable, since we
+    // ready to write to it.
+    DWORD old_protect = 0;
+    if (!::VirtualProtect(&g_nt_thunk_storage,
+                          sizeof(g_nt_thunk_storage),
+                          PAGE_EXECUTE_READWRITE,
+                          &old_protect)) {
+      return;
+    }
+
+    size_t storage_used = 0;
+    NTSTATUS ret = thunk->CopyThunk(::GetModuleHandle(sandbox::kNtdllName),
+                                    "NtCreateFile",
+                                    thunk_storage,
+                                    sizeof(sandbox::ThunkData),
+                                    &storage_used);
+    delete thunk;
+
+    // Ensure that the pointer to the old function can't be changed.
+    ::VirtualProtect(&g_nt_thunk_storage,
+                     sizeof(g_nt_thunk_storage),
+                     PAGE_EXECUTE_READ,
+                     &old_protect);
+
+    if (NT_SUCCESS(ret)) {
+      // Add an entry in the lookup table for the thunk.
+      g_ntdll_lookup["NtCreateFile"] =
+          reinterpret_cast<FARPROC>(&g_nt_thunk_storage);
+    }
+  }
 }
diff --git a/chrome_elf/ntdll_cache.h b/chrome_elf/ntdll_cache.h
index 4608cf19..5e4fb2b 100644
--- a/chrome_elf/ntdll_cache.h
+++ b/chrome_elf/ntdll_cache.h
@@ -7,9 +7,15 @@
 
 #include "chrome_elf/chrome_elf_types.h"
 
+namespace sandbox {
+struct ThunkData;
+}
+
 // Caches the addresses of all functions exported by ntdll in  |g_ntdll_lookup|.
 void InitCache();
 
 extern FunctionLookupTable g_ntdll_lookup;
 
+extern sandbox::ThunkData g_nt_thunk_storage;
+
 #endif  // CHROME_ELF_NTDLL_CACHE_H_
diff --git a/chrome_elf/thunk_getter.cc b/chrome_elf/thunk_getter.cc
new file mode 100644
index 0000000..8421e5e
--- /dev/null
+++ b/chrome_elf/thunk_getter.cc
@@ -0,0 +1,142 @@
+// Copyright 2014 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 <stdint.h>
+#include <windows.h>
+
+#include "base/basictypes.h"
+#include "sandbox/win/src/interception_internal.h"
+#include "sandbox/win/src/internal_types.h"
+#include "sandbox/win/src/sandbox_utils.h"
+#include "sandbox/win/src/service_resolver.h"
+
+namespace {
+enum Version {
+  VERSION_PRE_XP_SP2 = 0,  // Not supported.
+  VERSION_XP_SP2,
+  VERSION_SERVER_2003,  // Also includes XP Pro x64 and Server 2003 R2.
+  VERSION_VISTA,        // Also includes Windows Server 2008.
+  VERSION_WIN7,         // Also includes Windows Server 2008 R2.
+  VERSION_WIN8,         // Also includes Windows Server 2012.
+  VERSION_WIN8_1,
+  VERSION_WIN_LAST,  // Indicates error condition.
+};
+
+// Whether a process is running under WOW64 (the wrapper that allows 32-bit
+// processes to run on 64-bit versions of Windows).  This will return
+// WOW64_DISABLED for both "32-bit Chrome on 32-bit Windows" and "64-bit
+// Chrome on 64-bit Windows".  WOW64_UNKNOWN means "an error occurred", e.g.
+// the process does not have sufficient access rights to determine this.
+enum WOW64Status { WOW64_DISABLED, WOW64_ENABLED, WOW64_UNKNOWN, };
+
+WOW64Status GetWOW64StatusForCurrentProcess() {
+  typedef BOOL(WINAPI * IsWow64ProcessFunc)(HANDLE, PBOOL);
+  IsWow64ProcessFunc is_wow64_process = reinterpret_cast<IsWow64ProcessFunc>(
+      GetProcAddress(GetModuleHandle(L"kernel32.dll"), "IsWow64Process"));
+  if (!is_wow64_process)
+    return WOW64_DISABLED;
+  BOOL is_wow64 = FALSE;
+  if (!is_wow64_process(GetCurrentProcess(), &is_wow64))
+    return WOW64_UNKNOWN;
+  return is_wow64 ? WOW64_ENABLED : WOW64_DISABLED;
+}
+
+class OSInfo {
+ public:
+  struct VersionNumber {
+    int major;
+    int minor;
+    int build;
+  };
+
+  struct ServicePack {
+    int major;
+    int minor;
+  };
+
+  OSInfo() {
+    OSVERSIONINFOEX version_info = {sizeof(version_info)};
+    GetVersionEx(reinterpret_cast<OSVERSIONINFO*>(&version_info));
+    version_number_.major = version_info.dwMajorVersion;
+    version_number_.minor = version_info.dwMinorVersion;
+    version_number_.build = version_info.dwBuildNumber;
+    if ((version_number_.major == 5) && (version_number_.minor > 0)) {
+      // Treat XP Pro x64, Home Server, and Server 2003 R2 as Server 2003.
+      version_ =
+          (version_number_.minor == 1) ? VERSION_XP_SP2 : VERSION_SERVER_2003;
+      if (version_ == VERSION_XP_SP2 && version_info.wServicePackMajor < 2)
+        version_ = VERSION_PRE_XP_SP2;
+    } else if (version_number_.major == 6) {
+      switch (version_number_.minor) {
+        case 0:
+          // Treat Windows Server 2008 the same as Windows Vista.
+          version_ = VERSION_VISTA;
+          break;
+        case 1:
+          // Treat Windows Server 2008 R2 the same as Windows 7.
+          version_ = VERSION_WIN7;
+          break;
+        case 2:
+          // Treat Windows Server 2012 the same as Windows 8.
+          version_ = VERSION_WIN8;
+          break;
+        default:
+          version_ = VERSION_WIN8_1;
+          break;
+      }
+    } else if (version_number_.major > 6) {
+      version_ = VERSION_WIN_LAST;
+    } else {
+      version_ = VERSION_PRE_XP_SP2;
+    }
+
+    service_pack_.major = version_info.wServicePackMajor;
+    service_pack_.minor = version_info.wServicePackMinor;
+  }
+
+  Version version() const { return version_; }
+  VersionNumber version_number() const { return version_number_; }
+  ServicePack service_pack() const { return service_pack_; }
+
+ private:
+  Version version_;
+  VersionNumber version_number_;
+  ServicePack service_pack_;
+
+  DISALLOW_COPY_AND_ASSIGN(OSInfo);
+};
+
+}  // namespace
+
+sandbox::ServiceResolverThunk* GetThunk(bool relaxed) {
+  // Create a thunk via the appropriate ServiceResolver instance.
+  sandbox::ServiceResolverThunk* thunk = NULL;
+
+  // No thunks for unsupported OS versions.
+  OSInfo os_info;
+  if (os_info.version() <= VERSION_PRE_XP_SP2)
+    return thunk;
+
+  // Pseudo-handle, no need to close.
+  HANDLE current_process = ::GetCurrentProcess();
+
+#if defined(_WIN64)
+  // ServiceResolverThunk can handle all the formats in 64-bit (instead only
+  // handling one like it does in 32-bit versions).
+  thunk = new sandbox::ServiceResolverThunk(current_process, relaxed);
+#else
+  if (GetWOW64StatusForCurrentProcess() == WOW64_ENABLED) {
+    if (os_info.version() >= VERSION_WIN8)
+      thunk = new sandbox::Wow64W8ResolverThunk(current_process, relaxed);
+    else
+      thunk = new sandbox::Wow64ResolverThunk(current_process, relaxed);
+  } else if (os_info.version() >= VERSION_WIN8) {
+    thunk = new sandbox::Win8ResolverThunk(current_process, relaxed);
+  } else {
+    thunk = new sandbox::ServiceResolverThunk(current_process, relaxed);
+  }
+#endif
+
+  return thunk;
+}
diff --git a/chrome_elf/thunk_getter.h b/chrome_elf/thunk_getter.h
new file mode 100644
index 0000000..5bc20fe
--- /dev/null
+++ b/chrome_elf/thunk_getter.h
@@ -0,0 +1,16 @@
+// Copyright 2014 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 CHROME_ELF_THUNK_GETTER_H_
+#define CHROME_ELF_THUNK_GETTER_H_
+
+namespace sandbox {
+class ServiceResolverThunk;
+}
+
+// Creates a |ServiceResolverThunk| based on the OS version. Ownership of the
+// resulting thunk is passed to the caller.
+sandbox::ServiceResolverThunk* GetThunk(bool relaxed);
+
+#endif  // CHROME_ELF_THUNK_GETTER_H_