[Issue jenkinsci#29] - Native code should be tolerant against the mis…

…sing IsWow64Process API method
oleg-nenashev · Apr 20, 2017 · 7542b57 · 7542b57
1 parent 442988f
commit 7542b57
Show file tree

Hide file tree

Showing 3 changed files with 35 additions and 15 deletions.
diff --git a/native/envvar-cmdline.cpp b/native/envvar-cmdline.cpp
@@ -169,17 +169,20 @@ jstring getCmdLineAndEnvVars(
 	// There is a risk that somebody starts the 32bit DLL in x64 process, but within WinP JAR it must not happen.
 	// TODO: Consider adding defensive logic just in case
 	BOOL procIsWow64 = FALSE;
-	if (!IsWow64Process(hProcess, &procIsWow64))
+	if (fnIsWow64Process != NULL)
 	{
-		reportError(pEnv, "Failed to determine if the process is a 32bit or 64bit executable");
-		return NULL;
-	}
-
-	if (!procIsWow64) {
-		// We are trying to query a 64-bit process from a 32-bit DLL
-		sprintf_s<ERRMSG_SIZE>(errorBuffer, "Process with pid=%d is not a 32bit process (or it is not running). Cannot query it from a 32bit library", pid);
-		reportErrorWithCode(pEnv, 2, errorBuffer);
-		return NULL;
+		if (!fnIsWow64Process(hProcess, &procIsWow64))
+		{
+			reportError(pEnv, "Failed to determine if the process is a 32bit or 64bit executable");
+			return NULL;
+		}
+
+		if (!procIsWow64) {
+			// We are trying to query a 64-bit process from a 32-bit DLL
+			sprintf_s<ERRMSG_SIZE>(errorBuffer, "Process with pid=%d is not a 32bit process (or it is not running). Cannot query it from a 32bit library", pid);
+			reportErrorWithCode(pEnv, 2, errorBuffer);
+			return NULL;
+		}
 	}
 
 #endif
@@ -194,7 +197,17 @@ jstring getCmdLineAndEnvVars(
 	// from there to PEB
 	PEB ProcPEB;
 	if(!ReadProcessMemory(hProcess, ProcInfo.PebBaseAddress, &ProcPEB, sizeof(ProcPEB), &sRead)) {
-		reportError(pEnv, "Failed to read PEB");
+#ifndef _WIN64
+		if (fnIsWow64Process == NULL) {
+			// We are unable to determine it, no API call available
+			reportError(pEnv, "Failed to read PEB. Probably the process is 64bit, which cannot be read from the 32bit WinP DLL");
+		}
+		else {
+#endif
+			reportError(pEnv, "Failed to read PEB");
+#ifndef _WIN64
+		}
+#endif
 		return NULL;
 	}
 

diff --git a/native/runtime.cpp b/native/runtime.cpp
@@ -1,7 +1,12 @@
 #include "stdafx.h"
+#include "winp.h"
+
+LPFN_ISWOW64PROCESS fnIsWow64Process;
 
 extern "C"
 BOOL WINAPI _DllMainCRTStartup(HANDLE  hDllHandle, DWORD   dwReason, LPVOID  lpreserved) {
+	fnIsWow64Process = (LPFN_ISWOW64PROCESS)GetProcAddress(
+		GetModuleHandle(TEXT("kernel32")), "IsWow64Process");
 	return TRUE;
 }
 

diff --git a/native/winp.h b/native/winp.h
@@ -9,12 +9,14 @@ void error(JNIEnv* env, const char* file, int line, const char* msg);
 //
 // Kernel32.dll
 //
+
 BOOL WINAPI KillProcessEx(IN DWORD dwProcessId, IN BOOL bTree);
+
 // https://msdn.microsoft.com/en-us/library/ms684139.aspx
-extern "C" BOOL WINAPI IsWow64Process(HANDLE, PBOOL);
-// https://msdn.microsoft.com/en-us/library/ms683189(VS.85).aspx
-//BOOL WINAPI GetExitCodeProcess(HANDLE, LPDWORD);
-//VOID WINAPI SetLastError(DWORD);
+typedef BOOL(WINAPI *LPFN_ISWOW64PROCESS) (HANDLE, PBOOL);
+// Reference to the IsWow64Process method.
+// It is being handled via the reference, because the method is not available for the non-desktop-app mode (e.g. Windows service or AppVeyor build)
+extern LPFN_ISWOW64PROCESS fnIsWow64Process;
 
 //
 // NTDLL functions