Several fixes to MakeProcInstance.
diff --git a/loader/task.c b/loader/task.c
index 8c38da3..396e6b7 100644
--- a/loader/task.c
+++ b/loader/task.c
@@ -930,17 +930,44 @@
BYTE *thunk,*lfunc;
SEGPTR thunkaddr;
- if (!func) {
- ERR("Ouch ! MakeProcInstance called with func == NULL !\n");
- return (FARPROC16)0; /* Windows seems to do the same */
+ TRACE("(%08lx, %04x);", (DWORD)func, hInstance);
+
+ if (!HIWORD(func)) {
+ /* Win95 actually protects via SEH, but this is better for debugging */
+ ERR("Ouch ! Called with invalid func 0x%08lx !\n", (DWORD)func);
+ return (FARPROC16)0;
}
- if ( GetTaskDS16() !=hInstance )
+
+ if (hInstance)
{
- ERR("Problem with hInstance? Got %04x, using %04x instead\n",
- hInstance,GetTaskDS16());
- hInstance = GetTaskDS16();
+ if ( (!(hInstance & 4)) ||
+ ((hInstance != 0xffff) && IS_SELECTOR_FREE(hInstance|7)) )
+ {
+ ERR("Invalid hInstance (%04x) passed to MakeProcInstance !\n",
+ hInstance);
+ return 0;
+ }
}
- if (!hInstance) hInstance = CURRENT_DS;
+
+ if ( (CURRENT_DS != hInstance)
+ && (hInstance != 0)
+ && (hInstance != 0xffff) )
+ {
+ /* calling MPI with a foreign DSEG is invalid ! */
+ ERR("Problem with hInstance? Got %04x, using %04x instead\n",
+ hInstance,CURRENT_DS);
+ }
+
+ /* Always use the DSEG that MPI was entered with.
+ * We used to set hInstance to GetTaskDS16(), but this should be wrong
+ * as CURRENT_DS provides the DSEG value we need.
+ * ("calling" DS, *not* "task" DS !) */
+ hInstance = CURRENT_DS;
+
+ /* no thunking for DLLs */
+ if (NE_GetPtr(FarGetOwner16(hInstance))->flags & NE_FFLAGS_LIBMODULE)
+ return func;
+
thunkaddr = TASK_AllocThunk( GetCurrentTask() );
if (!thunkaddr) return (FARPROC16)0;
thunk = PTR_SEG_TO_LIN( thunkaddr );
@@ -948,12 +975,10 @@
TRACE("(%08lx,%04x): got thunk %08lx\n",
(DWORD)func, hInstance, (DWORD)thunkaddr );
- if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) ||
- ((lfunc[0]==0x1e) && (lfunc[1]==0x58))
+ if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) || /* movw %ds, %ax */
+ ((lfunc[0]==0x1e) && (lfunc[1]==0x58)) /* pushw %ds, popw %ax */
) {
- FIXME("thunk would be useless for %p, overwriting with nop;nop;\n", func );
- lfunc[0]=0x90; /* nop */
- lfunc[1]=0x90; /* nop */
+ FIXME("This was the (in)famous \"thunk useless\" warning. We thought we have to overwrite with nop;nop;, but this isn't true.\n");
}
*thunk++ = 0xb8; /* movw instance, %ax */
@@ -962,6 +987,7 @@
*thunk++ = 0xea; /* ljmp func */
*(DWORD *)thunk = (DWORD)func;
return (FARPROC16)thunkaddr;
+ /* CX reg indicates if thunkaddr != NULL, implement if needed */
}
