/* * Routines for dynamically building calls to Wine from * protected mode applications. * * Copyright 2002 Jukka Heinonen * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA */ #include "dosexe.h" #include "wine/winbase16.h" #include "wine/debug.h" WINE_DEFAULT_DEBUG_CHANNEL(int); /* * Magic DWORD used to check stack integrity. */ #define RELAY_MAGIC 0xabcdef00 /* * Memory block for temporary 16-bit stacks used with relay calls. */ typedef struct { DWORD inuse; /* non-zero if stack block is in use */ DWORD eip; /* saved ip */ DWORD seg_cs; /* saved cs */ DWORD esp; /* saved sp */ DWORD seg_ss; /* saved ss */ DWORD stack_bottom; /* guard dword */ BYTE stack[256-7*4]; /* 16-bit stack */ DWORD stack_top; /* guard dword */ } RELAY_Stack16; /********************************************************************** * RELAY_GetPointer * * Get pointer to stack block when given esp pointing to 16-bit stack * inside relay data segment. */ static RELAY_Stack16 *RELAY_GetPointer( DWORD offset ) { offset = offset / sizeof(RELAY_Stack16) * sizeof(RELAY_Stack16); return MapSL(MAKESEGPTR(DOSVM_dpmi_segments->relay_data_sel, offset)); } /********************************************************************** * RELAY_MakeShortContext * * Allocate separate 16-bit stack, make stack pointer point to this * stack and make code pointer point to stub that restores everything. * So, after this routine, SS and CS are guaranteed to be 16-bit. * * Note: This might be called from signal handler, so the stack * allocation algorithm must be signal safe. */ static void RELAY_MakeShortContext( CONTEXT86 *context ) { DWORD offset = offsetof(RELAY_Stack16, stack_top); RELAY_Stack16 *stack = RELAY_GetPointer( 0 ); while (stack->inuse && offset < DOSVM_RELAY_DATA_SIZE) { stack++; offset += sizeof(RELAY_Stack16); } if (offset >= DOSVM_RELAY_DATA_SIZE) ERR( "Too many nested interrupts!\n" ); stack->inuse = 1; stack->eip = context->Eip; stack->seg_cs = context->SegCs; stack->esp = context->Esp; stack->seg_ss = context->SegSs; stack->stack_bottom = RELAY_MAGIC; stack->stack_top = RELAY_MAGIC; context->SegSs = DOSVM_dpmi_segments->relay_data_sel; context->Esp = offset; context->SegCs = DOSVM_dpmi_segments->relay_code_sel; context->Eip = 3; } /********************************************************************** * RELAY_RelayStub * * This stub is called by __wine_call_from_16_regs in order to marshall * relay parameters. */ static void __stdcall RELAY_RelayStub( DOSRELAY proc, unsigned char *args, void *ctx86 ) { if (proc) { CONTEXT86 *context = (CONTEXT86*)ctx86; RELAY_Stack16 *stack = RELAY_GetPointer( context->Esp ); DWORD old_seg_cs = context->SegCs; DWORD old_eip = context->Eip; DWORD old_seg_ss = context->SegSs; DWORD old_esp = context->Esp; context->SegCs = stack->seg_cs; context->Eip = stack->eip; context->SegSs = stack->seg_ss; context->Esp = stack->esp; proc( context, *(LPVOID *)args ); stack->seg_cs = context->SegCs; stack->eip = context->Eip; stack->seg_ss = context->SegSs; stack->esp = context->Esp; context->SegCs = old_seg_cs; context->Eip = old_eip; context->SegSs = old_seg_ss; context->Esp = old_esp; } } /********************************************************************** * DOSVM_RelayHandler * * Restore saved code and stack pointers and release stack block. */ void DOSVM_RelayHandler( CONTEXT86 *context ) { RELAY_Stack16 *stack = RELAY_GetPointer( context->Esp ); context->SegSs = stack->seg_ss; context->Esp = stack->esp; context->SegCs = stack->seg_cs; context->Eip = stack->eip; if (!stack->inuse || stack->stack_bottom != RELAY_MAGIC || stack->stack_top != RELAY_MAGIC) ERR( "Stack corrupted!\n" ); stack->inuse = 0; } /********************************************************************** * DOSVM_BuildCallFrame * * Modifies the context so that return to context calls DOSRELAY and * only after return from DOSRELAY the original context will be returned to. */ void DOSVM_BuildCallFrame( CONTEXT86 *context, DOSRELAY relay, LPVOID data ) { static void (*__wine_call_from_16_regs_ptr)(); WORD code_sel = DOSVM_dpmi_segments->relay_code_sel; /* * Allocate separate stack for relay call. */ RELAY_MakeShortContext( context ); /* * Build call frame. */ PUSH_WORD16( context, HIWORD(data) ); /* argument.hiword */ PUSH_WORD16( context, LOWORD(data) ); /* argument.loword */ PUSH_WORD16( context, context->SegCs ); /* STACK16FRAME.cs */ PUSH_WORD16( context, LOWORD(context->Eip) ); /* STACK16FRAME.ip */ PUSH_WORD16( context, LOWORD(context->Ebp) ); /* STACK16FRAME.bp */ PUSH_WORD16( context, HIWORD(relay) ); /* STACK16FRAME.entry_point.hiword */ PUSH_WORD16( context, LOWORD(relay) ); /* STACK16FRAME.entry_point.loword */ PUSH_WORD16( context, 0 ); /* STACK16FRAME.entry_ip */ PUSH_WORD16( context, HIWORD(RELAY_RelayStub) ); /* STACK16FRAME.relay.hiword */ PUSH_WORD16( context, LOWORD(RELAY_RelayStub) ); /* STACK16FRAME.relay.loword */ PUSH_WORD16( context, 0 ); /* STACK16FRAME.module_cs.hiword */ PUSH_WORD16( context, code_sel ); /* STACK16FRAME.module_cs.loword */ PUSH_WORD16( context, 0 ); /* STACK16FRAME.callfrom_ip.hiword */ PUSH_WORD16( context, 0 ); /* STACK16FRAME.callfrom_ip.loword */ /* * Adjust code pointer. */ if (!__wine_call_from_16_regs_ptr) __wine_call_from_16_regs_ptr = (void *)GetProcAddress(GetModuleHandleA("kernel32.dll"), "__wine_call_from_16_regs" ); context->SegCs = wine_get_cs(); context->Eip = (DWORD)__wine_call_from_16_regs_ptr; }