Use GetFinalPathNameByHandle for Process.open_files

Fixes #1967

psutil/_psutil_common.c

@@ -270,10 +270,6 @@ psutil_loadlibs() {
         "ntdll.dll", "NtSetInformationProcess");
     if (! NtSetInformationProcess)
         return 1;
-    NtQueryObject = psutil_GetProcAddressFromLib(
-        "ntdll.dll", "NtQueryObject");
-    if (! NtQueryObject)
-        return 1;
     RtlIpv4AddressToStringA = psutil_GetProcAddressFromLib(
         "ntdll.dll", "RtlIpv4AddressToStringA");
     if (! RtlIpv4AddressToStringA)

psutil/_psutil_windows.c

@@ -9,7 +9,6 @@
  * other modules:
  * - NtQuerySystemInformation
  * - NtQueryInformationProcess
- * - NtQueryObject
  * - NtSuspendProcess
  * - NtResumeProcess
  */

psutil/arch/windows/ntextapi.h

@@ -660,15 +660,6 @@ ULONGLONG (CALLBACK *_GetTickCount64) (
 
 #define GetTickCount64 _GetTickCount64
 
-NTSTATUS (NTAPI *_NtQueryObject) (
-    HANDLE Handle,
-    OBJECT_INFORMATION_CLASS ObjectInformationClass,
-    PVOID ObjectInformation,
-    ULONG ObjectInformationLength,
-    PULONG ReturnLength);
-
-#define NtQueryObject _NtQueryObject
-
 NTSTATUS (WINAPI *_RtlGetVersion) (
     PRTL_OSVERSIONINFOW lpVersionInformation
 );

psutil/arch/windows/process_handles.c

@@ -6,12 +6,6 @@
 
 /*
  * This module retrieves handles opened by a process.
- * We use NtQuerySystemInformation to enumerate them and NtQueryObject
- * to obtain the corresponding file name.
- * Since NtQueryObject hangs for certain handle types we call it in a
- * separate thread which gets killed if it doesn't complete within 100ms.
- * This is a limitation of the Windows API and ProcessHacker uses the
- * same trick: https://github.com/giampaolo/psutil/pull/597
  *
  * CREDITS: original implementation was written by Jeff Tang.
  * It was then rewritten by Giampaolo Rodola many years later.
@@ -23,12 +17,7 @@
 #include <Python.h>
 
 #include "../../_psutil_common.h"
-#include "process_utils.h"
-
-
-#define THREAD_TIMEOUT 100  // ms
-// Global object shared between the 2 threads.
-PUNICODE_STRING globalFileName = NULL;
+#include "process_info.h"
 
 
 static int
@@ -81,151 +70,32 @@ psutil_enum_handles(PSYSTEM_HANDLE_INFORMATION_EX *handles) {
 }
 
 
-static int
-psutil_get_filename(LPVOID lpvParam) {
-    HANDLE hFile = *((HANDLE*)lpvParam);
-    NTSTATUS status;
-    ULONG bufferSize;
-    ULONG attempts = 8;
-
-    bufferSize = 0x200;
-    globalFileName = MALLOC_ZERO(bufferSize);
-    if (globalFileName == NULL) {
-        PyErr_NoMemory();
-        goto error;
-    }
-
-
-    // Note: also this is supposed to hang, hence why we do it in here.
-    if (GetFileType(hFile) != FILE_TYPE_DISK) {
-        SetLastError(0);
-        globalFileName->Length = 0;
-        return 0;
-    }
-
-    // A loop is needed because the I/O subsystem likes to give us the
-    // wrong return lengths...
-    do {
-        status = NtQueryObject(
-            hFile,
-            ObjectNameInformation,
-            globalFileName,
-            bufferSize,
-            &bufferSize
-            );
-        if (status == STATUS_BUFFER_OVERFLOW ||
-                status == STATUS_INFO_LENGTH_MISMATCH ||
-                status == STATUS_BUFFER_TOO_SMALL)
-        {
-            FREE(globalFileName);
-            globalFileName = MALLOC_ZERO(bufferSize);
-            if (globalFileName == NULL) {
-                PyErr_NoMemory();
-                goto error;
-            }
-        }
-        else {
-            break;
-        }
-    } while (--attempts);
-
-    if (! NT_SUCCESS(status)) {
-        psutil_SetFromNTStatusErr(status, "NtQuerySystemInformation");
-        FREE(globalFileName);
-        globalFileName = NULL;
-        return 1;
-    }
-
-    return 0;
-
-error:
-    if (globalFileName != NULL) {
-        FREE(globalFileName);
-        globalFileName = NULL;
-    }
-    return 1;
-}
-
-
-static DWORD
-psutil_threaded_get_filename(HANDLE hFile) {
-    DWORD dwWait;
-    HANDLE hThread;
-    DWORD threadRetValue;
-
-    hThread = CreateThread(
-        NULL, 0, (LPTHREAD_START_ROUTINE)psutil_get_filename, &hFile, 0, NULL);
-    if (hThread == NULL) {
-        PyErr_SetFromOSErrnoWithSyscall("CreateThread");
-        return 1;
-    }
-
-    // Wait for the worker thread to finish.
-    dwWait = WaitForSingleObject(hThread, THREAD_TIMEOUT);
-
-    // If the thread hangs, kill it and cleanup.
-    if (dwWait == WAIT_TIMEOUT) {
-        psutil_debug(
-            "get handle name thread timed out after %i ms", THREAD_TIMEOUT);
-        if (TerminateThread(hThread, 0) == 0) {
-            PyErr_SetFromOSErrnoWithSyscall("TerminateThread");
-            CloseHandle(hThread);
-            return 1;
-        }
-        CloseHandle(hThread);
-        return 0;
-    }
-
-    if (dwWait == WAIT_FAILED) {
-        psutil_debug("WaitForSingleObject -> WAIT_FAILED");
-        if (TerminateThread(hThread, 0) == 0) {
-            PyErr_SetFromOSErrnoWithSyscall(
-                "WaitForSingleObject -> WAIT_FAILED -> TerminateThread");
-            CloseHandle(hThread);
-            return 1;
-        }
-        PyErr_SetFromOSErrnoWithSyscall("WaitForSingleObject");
-        CloseHandle(hThread);
-        return 1;
-    }
-
-    if (GetExitCodeThread(hThread, &threadRetValue) == 0) {
-        if (TerminateThread(hThread, 0) == 0) {
-            PyErr_SetFromOSErrnoWithSyscall(
-                "GetExitCodeThread (failed) -> TerminateThread");
-            CloseHandle(hThread);
-            return 1;
-        }
-
-        CloseHandle(hThread);
-        PyErr_SetFromOSErrnoWithSyscall("GetExitCodeThread");
-        return 1;
-    }
-    CloseHandle(hThread);
-    return threadRetValue;
-}
-
-
 PyObject *
 psutil_get_open_files(DWORD dwPid, HANDLE hProcess) {
+    static ULONG                        fileNameBufferSize = (
+                                            sizeof(WCHAR) * (_MAX_PATH + 1));
     PSYSTEM_HANDLE_INFORMATION_EX       handlesList = NULL;
     PSYSTEM_HANDLE_TABLE_ENTRY_INFO_EX  hHandle = NULL;
     HANDLE                              hFile = NULL;
     ULONG                               i = 0;
     BOOLEAN                             errorOccurred = FALSE;
     PyObject*                           py_path = NULL;
-    PyObject*                           py_retlist = PyList_New(0);;
+    PyObject*                           py_retlist = PyList_New(0);
+    WCHAR*                              lpFileName = NULL;
+    ULONG                               status = 0;
 
     if (!py_retlist)
         return NULL;
 
-    // Due to the use of global variables, ensure only 1 call
-    // to psutil_get_open_files() is running.
-    EnterCriticalSection(&PSUTIL_CRITICAL_SECTION);
-
     if (psutil_enum_handles(&handlesList) != 0)
         goto error;
 
+    lpFileName = MALLOC_ZERO(fileNameBufferSize);
+    if (!lpFileName) {
+        PyErr_NoMemory();
+        goto error;
+    }
+
     for (i = 0; i < handlesList->NumberOfHandles; i++) {
         hHandle = &handlesList->Handles[i];
         if ((ULONG_PTR)hHandle->UniqueProcessId != dwPid)
@@ -243,25 +113,37 @@ psutil_get_open_files(DWORD dwPid, HANDLE hProcess) {
             continue;
         }
 
-        // This will set *globalFileName* global variable.
-        if (psutil_threaded_get_filename(hFile) != 0)
-            goto error;
+        if (GetFileType(hFile) != FILE_TYPE_DISK) {
+            goto cleanup_continue;
+        }
 
-        if ((globalFileName != NULL) && (globalFileName->Length > 0)) {
-            py_path = PyUnicode_FromWideChar(globalFileName->Buffer,
-                                             wcslen(globalFileName->Buffer));
-            if (! py_path)
-                goto error;
-            if (PyList_Append(py_retlist, py_path))
-                goto error;
-            Py_CLEAR(py_path);  // also sets to NULL
+        // Get the filename
+        if (! GetFinalPathNameByHandleW(
+                hFile,
+                lpFileName,
+                fileNameBufferSize,
+                VOLUME_NAME_NT))
+        {
+            status = GetLastError();
+            // Ignore some normal errors
+            if (status == ERROR_INVALID_FUNCTION) {
+                SetLastError(0);
+                goto cleanup_continue;
+            }
+            psutil_convert_winerr(status, "GetFinalPathNameByHandle");
+            goto error;
         }
 
+        py_path = PyUnicode_FromWideChar(lpFileName,
+                                         wcslen(lpFileName));
+        if (! py_path)
+            goto error;
+        if (PyList_Append(py_retlist, py_path))
+            goto error;
+        Py_CLEAR(py_path);  // also sets to NULL
+
         // Loop cleanup section.
-        if (globalFileName != NULL) {
-            FREE(globalFileName);
-            globalFileName = NULL;
-        }
+cleanup_continue:
         CloseHandle(hFile);
         hFile = NULL;
     }
@@ -276,16 +158,13 @@ psutil_get_open_files(DWORD dwPid, HANDLE hProcess) {
 exit:
     if (hFile != NULL)
         CloseHandle(hFile);
-    if (globalFileName != NULL) {
-        FREE(globalFileName);
-        globalFileName = NULL;
-    }
     if (py_path != NULL)
         Py_DECREF(py_path);
     if (handlesList != NULL)
         FREE(handlesList);
+    if (lpFileName != NULL)
+        FREE(lpFileName);
 
-    LeaveCriticalSection(&PSUTIL_CRITICAL_SECTION);
     if (errorOccurred == TRUE)
         return NULL;
     return py_retlist;

psutil/arch/windows/process_info.c

@@ -50,7 +50,7 @@ enum psutil_process_data_kind {
 };
 
 
-static void
+void
 psutil_convert_winerr(ULONG err, char* syscall) {
     char fullmsg[8192];
 

psutil/arch/windows/process_info.h

@@ -15,6 +15,7 @@
 
 int psutil_get_proc_info(DWORD pid, PSYSTEM_PROCESS_INFORMATION *retProcess,
                          PVOID *retBuffer);
+void psutil_convert_winerr(ULONG err, char* syscall);
 PyObject* psutil_get_cmdline(DWORD pid, int use_peb);
 PyObject* psutil_get_cwd(DWORD pid);
 PyObject* psutil_get_environ(DWORD pid);