src/video/Xext/Xxf86dga/XF86DGA2.c
author Ryan C. Gordon <icculus@icculus.org>
Sat, 19 Nov 2005 18:57:00 +0000
changeset 1176 dd2a8deeb26d
parent 1168 045f186426e1
child 1226 d05306f0dc21
permissions -rw-r--r--
Date: Mon, 17 Oct 2005 20:09:03 -0400 From: Mark Schreiber <mark7@alumni.cmu.edu> To: ryan@clutteredmind.org Subject: [PATCH]SDL mprotect() crash fix (I'm going to throw this patch your way at the suggestion of #SDL -- for some reason, I had some difficulty sending it to the main list last time, and I go bonkers subscribing to send each email or patch...) Currently, when I run SDL applications as non-root using SDL_VIDEODRIVER=dga, the fbdev fallback mprotect()s read/write the proper size of mmapped /dev/fb0 (7.5MB), but on framebuffer release mprotect()s read-only the range by the entire size of my video memory (128MB), which causes a segfault: #0 0x002a9a27 in ?? () from /lib/libc.so.6 #1 0x04a63eb6 in SDL_XDGAUnmapFramebuffer (screen=3D0) at XF86DGA2.c:978 #2 0x04a63efc in SDL_XDGACloseFramebuffer (dpy=3D0x9d3f008, screen=3D0) at XF86DGA2.c:268 #3 0x04a68b57 in DGA_Available () at SDL_dgavideo.c:98 #4 0x04a53677 in SDL_VideoInit (driver_name=3D0xbfb0bfc7 "dga", flags=3D0) at SDL_video.c:180 #5 0x04a2613f in SDL_InitSubSystem (flags=3D32) at SDL.c:74 #6 0x04a2617c in SDL_Init (flags=3D32) at SDL.c:166 #7 0x08049722 in main (argc=3D1, argv=3D0x0) at testwin.c:32 This is SDL 1.2.8 on Fedora Core 4, radeon driver for a Radeon 9250, xorg-x11-6.8.2-37. I've attached a one-line patch against SDL CVS that updates the size of the framebuffer at framebuffer map time so that the mprotect() on unmap will be the same size. I'm not sure if this is the best approach (i.e. one might want to retain the original value), but it does make my SDL applications work without segfaulting. -- Best of luck, Mark Schreiber

/* $XFree86: xc/lib/Xxf86dga/XF86DGA2.c,v 1.18 2001/08/17 13:27:51 dawes Exp $ */
/*

Copyright (c) 1995  Jon Tombs
Copyright (c) 1995,1996  The XFree86 Project, Inc

*/

/* THIS IS NOT AN X CONSORTIUM STANDARD */

#ifdef __EMX__ /* needed here to override certain constants in X headers */
#define INCL_DOS
#define INCL_DOSIOCTL
#include <os2.h>
#endif

#define NEED_EVENTS
#define NEED_REPLIES
#include <X11/Xlibint.h>
#include "xf86dga.h"
#include "xf86dgastr.h"
#include <X11/extensions/Xext.h>
#include "extutil.h"
#include <stdio.h>

#if defined(ENABLE_FBCON)  /* Needed for framebuffer console support */
#include <sys/ioctl.h>
#include <linux/fb.h>
#endif

#include "../../x11/SDL_x11dyn.h"

/* Workaround code in headers... */
#define _XFlush p_XFlush
#define _XFlushGCCache p_XFlushGCCache
#define _XReply p_XReply
#define _XSend p_XSend

/* If you change this, change the Bases[] array below as well */
#define MAX_HEADS 16

char *SDL_NAME(xdga_extension_name) = XF86DGANAME;

static XExtensionInfo _xdga_info_data;
static XExtensionInfo *xdga_info = &_xdga_info_data;

 
Bool SDL_NAME(XDGAMapFramebuffer)(int, char *, unsigned char*, CARD32, CARD32, CARD32);
void SDL_NAME(XDGAUnmapFramebuffer)(int);
unsigned char* SDL_NAME(XDGAGetMappedMemory)(int);

#define XDGACheckExtension(dpy,i,val) \
  XextCheckExtension (dpy, i, SDL_NAME(xdga_extension_name), val)

/*****************************************************************************
 *                                                                           *
 *			   private utility routines                          *
 *                                                                           *
 *****************************************************************************/

static int xdga_close_display(Display *dpy, XExtCodes *codes);
static Bool xdga_wire_to_event(Display *dpy, XEvent *event, xEvent *wire_ev);
static Status xdga_event_to_wire(Display *dpy, XEvent *event, xEvent *wire_ev);

static XExtensionHooks xdga_extension_hooks = {
    NULL,				/* create_gc */
    NULL,				/* copy_gc */
    NULL,				/* flush_gc */
    NULL,				/* free_gc */
    NULL,				/* create_font */
    NULL,				/* free_font */
    xdga_close_display,			/* close_display */
    xdga_wire_to_event,			/* wire_to_event */
    xdga_event_to_wire,			/* event_to_wire */
    NULL,				/* error */
    NULL,				/* error_string */
};

static XEXT_GENERATE_CLOSE_DISPLAY (xdga_close_display, xdga_info)


XEXT_GENERATE_FIND_DISPLAY (SDL_NAME(xdga_find_display), xdga_info, 
				   "XFree86-DGA", 
				   &xdga_extension_hooks, 
				   0, NULL)


static Status
xdga_event_to_wire(
  Display *dpy,
  XEvent *event,
  xEvent *wire_ev
){
    return True;
}

static Bool
xdga_wire_to_event(
  Display *dpy,
  XEvent *event,
  xEvent *wire_ev
){
  dgaEvent *wire = (dgaEvent *) wire_ev;
  SDL_NAME(XDGAButtonEvent) *bevent;
  SDL_NAME(XDGAKeyEvent) *kevent;
  SDL_NAME(XDGAMotionEvent) *mevent;
  XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);

  XDGACheckExtension (dpy, info, False);

  switch((wire->u.u.type & 0x7f) - info->codes->first_event) {
  case MotionNotify:
	mevent = (SDL_NAME(XDGAMotionEvent)*)event;
	mevent->type = wire->u.u.type & 0x7F;
	mevent->serial = p_XSetLastRequestRead(dpy, (xGenericReply *)wire);
	mevent->display = dpy;
	mevent->screen = wire->u.event.screen;
	mevent->time = wire->u.event.time;
	mevent->state = wire->u.event.state;
	mevent->dx = wire->u.event.dx;
	mevent->dy = wire->u.event.dy;
	return True;
  case ButtonPress:
  case ButtonRelease:
	bevent = (SDL_NAME(XDGAButtonEvent)*)event;
	bevent->type = wire->u.u.type & 0x7F;
	bevent->serial = p_XSetLastRequestRead(dpy, (xGenericReply *)wire);
	bevent->display = dpy;
	bevent->screen = wire->u.event.screen;
	bevent->time = wire->u.event.time;
	bevent->state = wire->u.event.state;
	bevent->button = wire->u.u.detail;
	return True;
  case KeyPress:
  case KeyRelease:
	kevent = (SDL_NAME(XDGAKeyEvent)*)event;
	kevent->type = wire->u.u.type & 0x7F;
	kevent->serial = p_XSetLastRequestRead(dpy, (xGenericReply *)wire);
	kevent->display = dpy;
	kevent->screen = wire->u.event.screen;
	kevent->time = wire->u.event.time;
	kevent->state = wire->u.event.state;
	kevent->keycode = wire->u.u.detail;
	return True;
  }

  return False;
}


Bool SDL_NAME(XDGAQueryExtension) (
    Display *dpy,
    int *event_basep,
    int *error_basep
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);

    if (XextHasExtension(info)) {
	*event_basep = info->codes->first_event;
	*error_basep = info->codes->first_error;
	return True;
    } else {
	return False;
    }
}


Bool SDL_NAME(XDGAQueryVersion)(
    Display *dpy,
    int *majorVersion, 
    int *minorVersion
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGAQueryVersionReply rep;
    xXDGAQueryVersionReq *req;

    XDGACheckExtension (dpy, info, False);

    LockDisplay(dpy);
    GetReq(XDGAQueryVersion, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGAQueryVersion;
    if (!p_XReply(dpy, (xReply *)&rep, 0, xFalse)) {
	UnlockDisplay(dpy);
	SyncHandle();
	return False;
    }
    *majorVersion = rep.majorVersion;
    *minorVersion = rep.minorVersion;
    UnlockDisplay(dpy);
    SyncHandle();
    if (*majorVersion >= 2)
    {
	int i, j;

	for (i = 0, j = info->codes->first_event;
	     i < XF86DGANumberEvents;
	     i++, j++) 
	{
	    pXESetWireToEvent(dpy, j, xdga_wire_to_event);
	    pXESetEventToWire(dpy, j, xdga_event_to_wire);
	}
	SDL_NAME(XDGASetClientVersion)(dpy);
    }
    return True;
}

Bool SDL_NAME(XDGASetClientVersion)(
    Display	*dpy
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGASetClientVersionReq *req;

    XDGACheckExtension (dpy, info, False);

    LockDisplay(dpy);
    GetReq(XDGASetClientVersion, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGASetClientVersion;
    req->major = XDGA_MAJOR_VERSION;
    req->minor = XDGA_MINOR_VERSION;
    UnlockDisplay(dpy);
    SyncHandle();
    return True;
}

Bool SDL_NAME(XDGAOpenFramebuffer)(
    Display	*dpy,
    int 	screen
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGAOpenFramebufferReply rep;
    xXDGAOpenFramebufferReq *req;
    char *deviceName = NULL;
    Bool ret;

    XDGACheckExtension (dpy, info, False);

    LockDisplay(dpy);
    GetReq(XDGAOpenFramebuffer, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGAOpenFramebuffer;
    req->screen = screen;
    if (!p_XReply(dpy, (xReply *)&rep, 0, xFalse)) {
	UnlockDisplay(dpy);
	SyncHandle();
	return False;
    }

    if(rep.length) {
	deviceName = Xmalloc(rep.length << 2);
	p_XRead(dpy, deviceName, rep.length << 2);
    }

    ret = SDL_NAME(XDGAMapFramebuffer)(screen, deviceName,
				(unsigned char*)(long)rep.mem1, 
				rep.size, rep.offset, rep.extra);

    if(deviceName)
	Xfree(deviceName);	

    UnlockDisplay(dpy);
    SyncHandle();
    return ret;
}

void SDL_NAME(XDGACloseFramebuffer)(
    Display	*dpy,
    int		screen
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGACloseFramebufferReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    SDL_NAME(XDGAUnmapFramebuffer)(screen);

    LockDisplay(dpy);
    GetReq(XDGACloseFramebuffer, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGACloseFramebuffer;
    req->screen = screen;
    UnlockDisplay(dpy);
    SyncHandle();
}



SDL_NAME(XDGAMode)* SDL_NAME(XDGAQueryModes)(
    Display *dpy,
    int screen,
    int *num
){
    XExtDisplayInfo *dinfo = SDL_NAME(xdga_find_display) (dpy);
    xXDGAQueryModesReply rep;
    xXDGAQueryModesReq *req;
    SDL_NAME(XDGAMode) *modes = NULL;

    *num = 0;

    XDGACheckExtension (dpy, dinfo, NULL);

    LockDisplay(dpy);
    GetReq(XDGAQueryModes, req);
    req->reqType = dinfo->codes->major_opcode;
    req->dgaReqType = X_XDGAQueryModes;
    req->screen = screen;

    if (p_XReply(dpy, (xReply *)&rep, 0, xFalse)) {
	if(rep.length) {
	   xXDGAModeInfo info;
	   int i, size;
	   char *offset;

	   size = rep.length << 2;
	   size -= rep.number * sz_xXDGAModeInfo; /* find text size */
	   modes = (SDL_NAME(XDGAMode)*)Xmalloc((rep.number * sizeof(SDL_NAME(XDGAMode))) + size);
	   offset = (char*)(&modes[rep.number]); /* start of text */


	   if(modes) {	
	      for(i = 0; i < rep.number; i++) {
		p_XRead(dpy, (char*)(&info), sz_xXDGAModeInfo);

		modes[i].num = info.num;
		modes[i].verticalRefresh = 
			(float)info.vsync_num / (float)info.vsync_den;
		modes[i].flags = info.flags;
		modes[i].imageWidth = info.image_width;
		modes[i].imageHeight = info.image_height;
		modes[i].pixmapWidth = info.pixmap_width;
		modes[i].pixmapHeight = info.pixmap_height;
		modes[i].bytesPerScanline = info.bytes_per_scanline;
		modes[i].byteOrder = info.byte_order;
		modes[i].depth = info.depth;
		modes[i].bitsPerPixel = info.bpp;
		modes[i].redMask = info.red_mask;
		modes[i].greenMask = info.green_mask;
		modes[i].blueMask = info.blue_mask;
		modes[i].visualClass = info.visual_class;
		modes[i].viewportWidth = info.viewport_width;
		modes[i].viewportHeight = info.viewport_height;
		modes[i].xViewportStep = info.viewport_xstep;
		modes[i].yViewportStep = info.viewport_ystep;
		modes[i].maxViewportX = info.viewport_xmax;
		modes[i].maxViewportY = info.viewport_ymax;
		modes[i].viewportFlags = info.viewport_flags;
		modes[i].reserved1 = info.reserved1;
		modes[i].reserved2 = info.reserved2;	

		p_XRead(dpy, offset, info.name_size);
		modes[i].name = offset;
		offset += info.name_size;
	      }
	      *num = rep.number;
	   } else
		p_XEatData(dpy, rep.length << 2);
	}
    }

    UnlockDisplay(dpy);
    SyncHandle();

    return modes;
}


SDL_NAME(XDGADevice) * 
SDL_NAME(XDGASetMode)(
    Display	*dpy,
    int		screen,
    int		mode
){
    XExtDisplayInfo *dinfo = SDL_NAME(xdga_find_display) (dpy);
    xXDGASetModeReply rep;
    xXDGASetModeReq *req;
    SDL_NAME(XDGADevice) *dev = NULL;
    Pixmap pid;

    XDGACheckExtension (dpy, dinfo, NULL);

    LockDisplay(dpy);
    GetReq(XDGASetMode, req);
    req->reqType = dinfo->codes->major_opcode;
    req->dgaReqType = X_XDGASetMode;
    req->screen = screen;
    req->mode = mode;
    req->pid = pid = XAllocID(dpy);
    
    if (p_XReply(dpy, (xReply *)&rep, 0, xFalse)) {
	if(rep.length) {
	   xXDGAModeInfo info;
	   int size;

	   size = rep.length << 2;
	   size -= sz_xXDGAModeInfo; /* get text size */

	   dev = (SDL_NAME(XDGADevice)*)Xmalloc(sizeof(SDL_NAME(XDGADevice)) + size);
	    
	   if(dev) {
		p_XRead(dpy, (char*)(&info), sz_xXDGAModeInfo);

		dev->mode.num = info.num;
		dev->mode.verticalRefresh = 
				(float)info.vsync_num / (float)info.vsync_den;
		dev->mode.flags = info.flags;
		dev->mode.imageWidth = info.image_width;
		dev->mode.imageHeight = info.image_height;
		dev->mode.pixmapWidth = info.pixmap_width;
		dev->mode.pixmapHeight = info.pixmap_height;
		dev->mode.bytesPerScanline = info.bytes_per_scanline;
		dev->mode.byteOrder = info.byte_order;
		dev->mode.depth = info.depth;
		dev->mode.bitsPerPixel = info.bpp;
		dev->mode.redMask = info.red_mask;
		dev->mode.greenMask = info.green_mask;
		dev->mode.blueMask = info.blue_mask;
		dev->mode.visualClass = info.visual_class;
		dev->mode.viewportWidth = info.viewport_width;
		dev->mode.viewportHeight = info.viewport_height;
		dev->mode.xViewportStep = info.viewport_xstep;
		dev->mode.yViewportStep = info.viewport_ystep;
		dev->mode.maxViewportX = info.viewport_xmax;
		dev->mode.maxViewportY = info.viewport_ymax;
		dev->mode.viewportFlags = info.viewport_flags;
		dev->mode.reserved1 = info.reserved1;
		dev->mode.reserved2 = info.reserved2;

		dev->mode.name = (char*)(&dev[1]);	
		p_XRead(dpy, dev->mode.name, info.name_size);

		dev->pixmap = (rep.flags & XDGAPixmap) ? pid : 0;
		dev->data = SDL_NAME(XDGAGetMappedMemory)(screen);

		if(dev->data)
		    dev->data += rep.offset;
	   } 
	   /* not sure what to do if the allocation fails */
	}
    }

    UnlockDisplay(dpy);
    SyncHandle();

    return dev;
}


void SDL_NAME(XDGASetViewport)(
    Display	*dpy,
    int		screen,
    int		x,
    int		y,
    int		flags
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGASetViewportReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGASetViewport, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGASetViewport;
    req->screen = screen;
    req->x = x;
    req->y = y;
    req->flags = flags;
    UnlockDisplay(dpy);
    SyncHandle();
}


void SDL_NAME(XDGAInstallColormap)(
    Display	*dpy,
    int		screen,
    Colormap	cmap
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGAInstallColormapReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGAInstallColormap, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGAInstallColormap;
    req->screen = screen;
    req->cmap = cmap;
    UnlockDisplay(dpy);
    SyncHandle();
}

void SDL_NAME(XDGASelectInput)(
    Display	*dpy,
    int		screen,
    long	mask
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGASelectInputReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGASelectInput, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGASelectInput;
    req->screen = screen;
    req->mask = mask;
    UnlockDisplay(dpy);
    SyncHandle();
}

void SDL_NAME(XDGAFillRectangle)(
    Display	*dpy,
    int		screen,
    int		x,
    int		y,
    unsigned int	width,
    unsigned int	height,
    unsigned long	color
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGAFillRectangleReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGAFillRectangle, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGAFillRectangle;
    req->screen = screen;
    req->x = x;
    req->y = y;
    req->width = width;
    req->height = height;
    req->color = color;
    UnlockDisplay(dpy);
    SyncHandle();
}

void SDL_NAME(XDGACopyArea)(
    Display	*dpy,
    int		screen,
    int		srcx,
    int		srcy,
    unsigned int	width,
    unsigned int	height,
    int		dstx,
    int		dsty
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGACopyAreaReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGACopyArea, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGACopyArea;
    req->screen = screen;
    req->srcx = srcx;
    req->srcy = srcy;
    req->width = width;
    req->height = height;
    req->dstx = dstx;
    req->dsty = dsty;
    UnlockDisplay(dpy);
    SyncHandle();
}

void SDL_NAME(XDGACopyTransparentArea)(
    Display	*dpy,
    int		screen,
    int		srcx,
    int		srcy,
    unsigned int	width,
    unsigned int	height,
    int		dstx,
    int		dsty,
    unsigned long key
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGACopyTransparentAreaReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGACopyTransparentArea, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGACopyTransparentArea;
    req->screen = screen;
    req->srcx = srcx;
    req->srcy = srcy;
    req->width = width;
    req->height = height;
    req->dstx = dstx;
    req->dsty = dsty;
    req->key = key;
    UnlockDisplay(dpy);
    SyncHandle();
}


int SDL_NAME(XDGAGetViewportStatus)(
    Display *dpy,
    int screen 
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGAGetViewportStatusReply rep;
    xXDGAGetViewportStatusReq *req;
    int status = 0;

    XDGACheckExtension (dpy, info, 0);

    LockDisplay(dpy);
    GetReq(XDGAGetViewportStatus, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGAGetViewportStatus;
    req->screen = screen;
    if (!p_XReply(dpy, (xReply *)&rep, 0, xFalse))
	status = rep.status;
    UnlockDisplay(dpy);
    SyncHandle();
    return status;
}

void SDL_NAME(XDGASync)(
    Display *dpy,
    int screen 
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGASyncReply rep;
    xXDGASyncReq *req;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGASync, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGASync;
    req->screen = screen;
    p_XReply(dpy, (xReply *)&rep, 0, xFalse);
    UnlockDisplay(dpy);
    SyncHandle();
}


void SDL_NAME(XDGAChangePixmapMode)(
    Display *dpy,
    int screen,
    int *x,
    int *y,
    int mode 
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGAChangePixmapModeReq *req;
    xXDGAChangePixmapModeReply rep;

    XextSimpleCheckExtension (dpy, info, SDL_NAME(xdga_extension_name));

    LockDisplay(dpy);
    GetReq(XDGAChangePixmapMode, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGAChangePixmapMode;
    req->screen = screen;
    req->x = *x;
    req->y = *y;
    req->flags = mode;
    p_XReply(dpy, (xReply *)&rep, 0, xFalse);
    *x = rep.x;
    *y = rep.y;
    UnlockDisplay(dpy);
    SyncHandle();
}

Colormap SDL_NAME(XDGACreateColormap)(
    Display *dpy,
    int screen,
    SDL_NAME(XDGADevice) *dev,
    int	alloc
){
    XExtDisplayInfo *info = SDL_NAME(xdga_find_display) (dpy);
    xXDGACreateColormapReq *req;
    Colormap cid;

    XDGACheckExtension (dpy, info, -1);

    LockDisplay(dpy);
    GetReq(XDGACreateColormap, req);
    req->reqType = info->codes->major_opcode;
    req->dgaReqType = X_XDGACreateColormap;
    req->screen = screen;
    req->mode = dev->mode.num;
    req->alloc = alloc;
    cid = req->id = XAllocID(dpy);
    UnlockDisplay(dpy);
    SyncHandle();

    return cid;
}


void SDL_NAME(XDGAKeyEventToXKeyEvent)(
    SDL_NAME(XDGAKeyEvent)* dk, 
    XKeyEvent* xk
){
    xk->type = dk->type;
    xk->serial = dk->serial;
    xk->send_event = False;
    xk->display = dk->display;
    xk->window = RootWindow(dk->display, dk->screen);
    xk->root = xk->window;
    xk->subwindow = None;
    xk->time = dk->time;
    xk->x = xk->y = xk->x_root = xk->y_root = 0;
    xk->state = dk->state;
    xk->keycode = dk->keycode;
    xk->same_screen = True;
}

#include <X11/Xmd.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#if defined(ISC) 
# define HAS_SVR3_MMAP
# include <sys/types.h>
# include <errno.h>

# include <sys/at_ansi.h>
# include <sys/kd.h>

# include <sys/sysmacros.h>
# include <sys/immu.h>
# include <sys/region.h>

# include <sys/mmap.h>
#else
# if !defined(Lynx)
#  if !defined(__EMX__)
#   include <sys/mman.h>
#  endif
# else
#  include <sys/types.h>
#  include <errno.h>
#  include <smem.h>
# endif
#endif
#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>

#if defined(SVR4) && !defined(sun) && !defined(SCO325)
#define DEV_MEM "/dev/pmem"
#elif defined(SVR4) && defined(sun)
#define DEV_MEM "/dev/xsvc"
#else
#define DEV_MEM "/dev/mem"
#endif



typedef struct _DGAMapRec{
  unsigned char *physical;
  unsigned char *virtual;
  CARD32 size;
  int fd;
  int screen;
  struct _DGAMapRec *next;
} DGAMapRec, *DGAMapPtr;

static Bool
DGAMapPhysical(int, char*, unsigned char*, CARD32, CARD32, CARD32, DGAMapPtr); 
static void DGAUnmapPhysical(DGAMapPtr);

static DGAMapPtr _Maps = NULL;


unsigned char*
SDL_NAME(XDGAGetMappedMemory)(int screen)
{
    DGAMapPtr pMap = _Maps;
    unsigned char *pntr = NULL;

    while(pMap != NULL) {
	if(pMap->screen == screen) {
	    pntr = pMap->virtual;
	    break;
	}
	pMap = pMap->next;
    }

    return pntr;
}

Bool
SDL_NAME(XDGAMapFramebuffer)(
   int screen,
   char *name,			/* optional device name */
   unsigned char* base,		/* physical memory */
   CARD32 size,			/* size */
   CARD32 offset,		/* optional offset */
   CARD32 extra			/* optional extra data */
){
   DGAMapPtr pMap = _Maps;
   Bool result;
   
   /* is it already mapped ? */
   while(pMap != NULL) {
     if(pMap->screen == screen)
	return True;
     pMap = pMap->next;
   }

   if(extra & XDGANeedRoot) {
    /* we should probably check if we have root permissions and
       return False here */

   }

   pMap = (DGAMapPtr)Xmalloc(sizeof(DGAMapRec));

   result = DGAMapPhysical(screen, name, base, size, offset, extra, pMap);

   if(result) {
      pMap->next = _Maps;
      _Maps = pMap;
   } else 
      Xfree(pMap);
   
   return result;
}

void
SDL_NAME(XDGAUnmapFramebuffer)(int screen)
{
   DGAMapPtr pMap = _Maps;
   DGAMapPtr pPrev = NULL;

   /* is it already mapped */
    while(pMap != NULL) {
	if(pMap->screen == screen)
	    break;
	pPrev = pMap;
	pMap = pMap->next;
    }

    if(!pMap)
	return;

    DGAUnmapPhysical(pMap);

    if(!pPrev)
	_Maps = pMap->next;
    else
	pPrev->next = pMap->next;

    Xfree(pMap);
}


static Bool
DGAMapPhysical(
   int screen,
   char *name,			/* optional device name */
   unsigned char* base,		/* physical memory */
   CARD32 size,			/* size */
   CARD32 offset,		/* optional offset */
   CARD32 extra,		/* optional extra data */
   DGAMapPtr pMap
) {
#if defined(ISC) && defined(HAS_SVR3_MMAP)
    struct kd_memloc mloc;
#elif defined(__EMX__)
    APIRET rc;
    ULONG action;
    HFILE hfd;
#endif
  
    base += offset;

    pMap->screen = screen;
    pMap->physical = base;
    pMap->size = size;

#if defined(ISC) && defined(HAS_SVR3_MMAP)
    if ((pMap->fd = open("/dev/mmap", O_RDWR)) < 0)
	return False;
    mloc.vaddr = (char *)0;
    mloc.physaddr = (char *)base;
    mloc.length = size;
    mloc.ioflg=1;

    if ((pMap->virtual = (void *)ioctl(pMap->fd, MAP, &mloc)) == (void *)-1)
	return False;
#elif defined (__EMX__)
    /*
     * Dragon warning here! /dev/pmap$ is never closed, except on progam exit.
     * Consecutive calling of this routine will make PMAP$ driver run out
     * of memory handles. Some umap/close mechanism should be provided
     */

    rc = DosOpen("/dev/pmap$", &hfd, &action, 0, FILE_NORMAL, FILE_OPEN,
		 OPEN_ACCESS_READWRITE | OPEN_SHARE_DENYNONE, (PEAOP2)NULL);
    if (rc != 0)
	return False;
    {
	struct map_ioctl {
		union {
			ULONG phys;
			void* user;
		} a;
		ULONG size;
	} pmap,dmap;
	ULONG plen,dlen;
#define XFREE86_PMAP	0x76
#define PMAP_MAP	0x44

	pmap.a.phys = base;
	pmap.size = size;
	rc = DosDevIOCtl(hfd, XFREE86_PMAP, PMAP_MAP,
			 (PULONG)&pmap, sizeof(pmap), &plen,
			 (PULONG)&dmap, sizeof(dmap), &dlen);
	if (rc == 0) {
		pMap->virtual = dmap.a.user;
	}
   }
   if (rc != 0)
	return False;
#elif defined (Lynx)
    pMap->virtual = smem_create("XF86DGA", (char*)base, size, SM_READ|SM_WRITE);
#else
#ifndef MAP_FILE
#define MAP_FILE 0
#endif
    if (!name)
	    name = DEV_MEM;
    if ((pMap->fd = open(name, O_RDWR)) < 0)
#if defined(ENABLE_FBCON)
    { /* /dev/fb0 fallback added by Sam Lantinga <hercules@lokigames.com> */
        /* Try to fall back to /dev/fb on Linux - FIXME: verify the device */
        struct fb_fix_screeninfo finfo;

        if ((pMap->fd = open("/dev/fb0", O_RDWR)) < 0) {
            return False;
        }
        /* The useable framebuffer console memory may not be the whole
           framebuffer that X has access to. :-(
         */
        if ( ioctl(pMap->fd, FBIOGET_FSCREENINFO, &finfo) < 0 ) {
            close(pMap->fd);
            return False;
        }
        /* Warning: On PPC, the size and virtual need to be offset by:
           (((long)finfo.smem_start) -
           (((long)finfo.smem_start)&~(PAGE_SIZE-1)))
         */
        base = 0;
        size = pMap->size = finfo.smem_len;
    }
#else
	return False;
#endif
    pMap->virtual = mmap(NULL, size, PROT_READ | PROT_WRITE, 
			MAP_FILE | MAP_SHARED, pMap->fd, (off_t)base);
    if (pMap->virtual == (void *)-1)
	return False;
#endif

#if !defined(ISC) && !defined(HAS_SVR3_MMAP) && !defined(Lynx) \
	&& !defined(__EMX__)
    mprotect(pMap->virtual, size, PROT_READ | PROT_WRITE);
#endif

    return True;
}



static void
DGAUnmapPhysical(DGAMapPtr pMap)
{
#if !defined(ISC) && !defined(HAS_SVR3_MMAP) && !defined(Lynx) \
	&& !defined(__EMX__)
    mprotect(pMap->virtual,pMap->size, PROT_READ);
#elif defined(Lynx)
	/* XXX this doesn't allow enable after disable */
    smem_create(NULL, pMap->virtual, pMap->size, SM_DETACH);
    smem_remove("XF86DGA");
#endif


   /* We need to unmap and close too !!!!!!!!!!*/
}