Don't leave Windows 2000 behind.

* Makefile.in (ps.exe): Revert previous change.
	* ps.cc: Include psapi.h again.
	(main): In CW_GETPINFO_FULL case.  Evaluate minimal process access mask
	required per OS and use that in OpenProcess call.  Use
	GetModuleFileNameExW on Windows 2000 or if fetching the drive mapping
	failed.  Handle empty process name.

winsup/utils/ChangeLog

@@ -1,3 +1,12 @@
+2011-12-22  Corinna Vinschen  <corinna@vinschen.de>
+
+	* Makefile.in (ps.exe): Revert previous change.
+	* ps.cc: Include psapi.h again.
+	(main): In CW_GETPINFO_FULL case.  Evaluate minimal process access mask
+	required per OS and use that in OpenProcess call.  Use
+	GetModuleFileNameExW on Windows 2000 or if fetching the drive mapping
+	failed.  Handle empty process name.
+
 2011-12-22  Corinna Vinschen  <corinna@vinschen.de>
 
 	* Makefile.in (ps.exe): Drop -lpsapi from ALL_LDFLAGS.

winsup/utils/Makefile.in

@@ -77,7 +77,7 @@ mount.exe: path-mount.o
 cygcheck.exe: MINGW_LDFLAGS += -lntdll
 cygpath.exe: ALL_LDFLAGS += -lcygwin -luserenv -lntdll
 cygpath.exe: CXXFLAGS += -fno-threadsafe-statics
-ps.exe: ALL_LDFLAGS += -lcygwin -lntdll
+ps.exe: ALL_LDFLAGS += -lcygwin -lpsapi -lntdll
 strace.exe: MINGW_LDFLAGS += -lntdll
 
 ldd.exe: ALL_LDFLAGS += -lpsapi

winsup/utils/ps.cc

@@ -22,6 +22,7 @@ details. */
 #include <limits.h>
 #include <sys/cygwin.h>
 #include <cygwin/version.h>
+#include <psapi.h>
 #include <ddk/ntapi.h>
 #include <ddk/winddk.h>
 #include "loadlib.h"
@@ -150,6 +151,7 @@ main (int argc, char *argv[])
   external_pinfo *p;
   int aflag, lflag, fflag, sflag, uid, proc_id;
   bool found_proc_id = true;
+  DWORD proc_access = PROCESS_QUERY_LIMITED_INFORMATION;
   cygwin_getinfo_types query = CW_GETPINFO;
   const char *dtitle = "    PID  TTY        STIME COMMAND\n";
   const char *dfmt   = "%7d%4s%10s %s\n";
@@ -250,12 +252,33 @@ main (int argc, char *argv[])
 	      AdjustTokenPrivileges (tok, FALSE, &priv, 0, NULL, NULL);
 	    }
 	}
-      /* Fetch an opaque drive mapping object from the Cygwin DLL.
+
-	 This is used to map NT device paths to Win32 paths. */
+      /* Check process query capabilities. */
+      OSVERSIONINFO version;
+      version.dwOSVersionInfoSize = sizeof version;
+      GetVersionEx (&version);
+      if (version.dwMajorVersion <= 5)	/* pre-Vista */
+	{
+	  proc_access = PROCESS_QUERY_INFORMATION;
+	  if (version.dwMinorVersion < 1)	/* Windows 2000 */
+	    proc_access |= PROCESS_VM_READ;
+	  else
+	    {
+	    }
+	}
+
+      /* Except on Windows 2000, fetch an opaque drive mapping object from the
+	 Cygwin DLL.  This is used to map NT device paths to Win32 paths. */
+      if (!(proc_access & PROCESS_VM_READ))
+	{
 	  drive_map = (void *) cygwin_internal (CW_ALLOC_DRIVE_MAP);
 	  /* Check old Cygwin version. */
 	  if (drive_map == (void *) -1)
 	    drive_map = NULL;
+	  /* Allow fallback to GetModuleFileNameEx for post-W2K. */
+	  if (!drive_map)
+	    proc_access = PROCESS_QUERY_INFORMATION | PROCESS_VM_READ;
+	}
     }
 
   for (int pid = 0;
@@ -298,16 +321,20 @@ main (int argc, char *argv[])
 	  if (p->process_state & PID_EXITED || (p->exitcode & ~0xffff))
 	    strcat (pname, " <defunct>");
 	}
-      else if (query == CW_GETPINFO_FULL && drive_map)
+      else if (query == CW_GETPINFO_FULL)
 	{
 	  HANDLE h;
 	  NTSTATUS status;
 	  wchar_t *win32path = NULL;
 
-	  h = OpenProcess (PROCESS_QUERY_INFORMATION | PROCESS_VM_READ,
+	  h = OpenProcess (proc_access, FALSE, p->dwProcessId);
-			   FALSE, p->dwProcessId);
 	  if (!h)
 	    continue;
+	  /* We use NtQueryInformationProcess in the first place, because
+	     GetModuleFileNameEx does not work on 64 bit systems when trying
+	     to fetch module names of 64 bit processes. */
+	  if (!(proc_access & PROCESS_VM_READ))	/* Windows 2000 */
+	    {
 	      status = NtQueryInformationProcess (h, ProcessImageFileName, uni,
 						  sizeof unicode_buf, NULL);
 	      if (NT_SUCCESS (status))
@@ -316,11 +343,25 @@ main (int argc, char *argv[])
 		     Call CW_MAP_DRIVE_MAP to convert the path to an ordinary
 		     Win32 path.  The returned pointer is a pointer into the
 		     incoming buffer given as third argument.  It's expected
-		 to be big enough, which we made sure by defining unicode_buf
+		     to be big enough, which we made sure by defining
-		 to have enough space for a maximum sized UNICODE_STRING. */
+		     unicode_buf to have enough space for a maximum sized
+		     UNICODE_STRING. */
+		  if (uni->Length == 0)	/* System process */
+		    win32path = L"System";
+		  else
+		    {
 		      uni->Buffer[uni->Length / sizeof (WCHAR)] = L'\0';
 		      win32path = (wchar_t *) cygwin_internal (CW_MAP_DRIVE_MAP,
-						       drive_map, uni->Buffer);
+							       drive_map,
+							       uni->Buffer);
+		    }
+		}
+	    }
+	  else
+	    {
+	      if (GetModuleFileNameExW (h, NULL, (PWCHAR) unicode_buf,
+					NT_MAX_PATH))
+		win32path = (wchar_t *) unicode_buf;
 	    }
 	  if (win32path)
 	    wcstombs (pname, win32path, sizeof pname);