view src/video/fbcon/SDL_fbmatrox.c @ 1176:dd2a8deeb26d

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
author Ryan C. Gordon <icculus@icculus.org>
date Sat, 19 Nov 2005 18:57:00 +0000
parents b8d311d90021
children c9b51268668f
line wrap: on
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/*
	SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 Sam Lantinga

	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Library General Public
	License as published by the Free Software Foundation; either
	version 2 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
	Library General Public License for more details.

	You should have received a copy of the GNU Library General Public
	License along with this library; if not, write to the Free
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

	Sam Lantinga
	slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

#include "SDL_types.h"
#include "SDL_video.h"
#include "SDL_blit.h"
#include "SDL_fbmatrox.h"
#include "matrox_mmio.h"


/* Wait for vertical retrace - taken from the XFree86 Matrox driver */
static void WaitVBL(_THIS)
{
	int count;

	/* find start of retrace */
	mga_waitidle();
	while (  (mga_in8(0x1FDA) & 0x08) )
		;
	while ( !(mga_in8(0x1FDA) & 0x08) )
		; 
	/* wait until we're past the start */
	count = mga_in32(0x1E20) + 2;
	while ( mga_in32(0x1E20) < count )
		;
}
static void WaitIdle(_THIS)
{
	mga_waitidle();
}

/* Sets video mem colorkey and accelerated blit function */
static int SetHWColorKey(_THIS, SDL_Surface *surface, Uint32 key)
{
	return(0);
}

/* Sets per surface hardware alpha value */
#if 0
static int SetHWAlpha(_THIS, SDL_Surface *surface, Uint8 value)
{
	return(0);
}
#endif

static int FillHWRect(_THIS, SDL_Surface *dst, SDL_Rect *rect, Uint32 color)
{
	int dstX, dstY;
	Uint32 fxbndry;
	Uint32 ydstlen;
	Uint32 fillop;

	/* Don't blit to the display surface when switched away */
	if ( dst == this->screen ) {
		SDL_mutexP(hw_lock);
	}

	switch (dst->format->BytesPerPixel) {
	    case 1:
		color |= (color<<8);
	    case 2:
		color |= (color<<16);
		break;
	}

	/* Set up the X/Y base coordinates */
	FB_dst_to_xy(this, dst, &dstX, &dstY);

	/* Adjust for the current rectangle */
	dstX += rect->x;
	dstY += rect->y;

	/* Set up the X boundaries */
	fxbndry = (dstX | ((dstX+rect->w) << 16));

	/* Set up the Y boundaries */
	ydstlen = (rect->h | (dstY << 16));

	/* Set up for color fill operation */
	fillop = MGADWG_TRAP | MGADWG_SOLID |
	         MGADWG_ARZERO | MGADWG_SGNZERO | MGADWG_SHIFTZERO;

	/* Execute the operations! */
	mga_wait(5);
	mga_out32(MGAREG_DWGCTL, fillop | MGADWG_REPLACE);
	mga_out32(MGAREG_FCOL, color);
	mga_out32(MGAREG_FXBNDRY, fxbndry);
	mga_out32(MGAREG_YDSTLEN + MGAREG_EXEC, ydstlen);

	FB_AddBusySurface(dst);

	if ( dst == this->screen ) {
		SDL_mutexV(hw_lock);
	}
	return(0);
}

static int HWAccelBlit(SDL_Surface *src, SDL_Rect *srcrect,
                       SDL_Surface *dst, SDL_Rect *dstrect)
{
	SDL_VideoDevice *this = current_video;
	int pitch, w, h;
	int srcX, srcY;
	int dstX, dstY;
	Uint32 sign;
	Uint32 start, stop;
	int skip;
	Uint32 blitop;

	/* FIXME: For now, only blit to display surface */
	if ( dst->pitch != SDL_VideoSurface->pitch ) {
		return(src->map->sw_blit(src, srcrect, dst, dstrect));
	}

	/* Don't blit to the display surface when switched away */
	if ( dst == this->screen ) {
		SDL_mutexP(hw_lock);
	}

	/* Calculate source and destination base coordinates (in pixels) */
	w = dstrect->w;
	h = dstrect->h;
	FB_dst_to_xy(this, src, &srcX, &srcY);
	FB_dst_to_xy(this, dst, &dstX, &dstY);

	/* Adjust for the current blit rectangles */
	srcX += srcrect->x;
	srcY += srcrect->y;
	dstX += dstrect->x;
	dstY += dstrect->y;
	pitch = dst->pitch/dst->format->BytesPerPixel;

	/* Set up the blit direction (sign) flags */
	sign = 0;
	if ( srcX < dstX ) {
		sign |= 1;
	}
	if ( srcY < dstY ) {
		sign |= 4;
		srcY += (h - 1);
		dstY += (h - 1);
	}

	/* Set up the blit source row start, end, and skip (in pixels) */
	stop = start = (srcY * pitch) + srcX;
	if ( srcX < dstX ) {
		start += (w - 1);
	} else {
		stop  += (w - 1);
	}
	if ( srcY < dstY ) {
		skip = -pitch;
	} else {
		skip = pitch;
	}

	/* Set up the blit operation */
	if ( (src->flags & SDL_SRCCOLORKEY) == SDL_SRCCOLORKEY ) {
		Uint32 colorkey;

		blitop = MGADWG_BFCOL | MGADWG_BITBLT |
		         MGADWG_SHIFTZERO | MGADWG_RSTR | (0x0C << 16) |
		         MGADWG_TRANSC;

		colorkey = src->format->colorkey;
		switch (dst->format->BytesPerPixel) {
		    case 1:
			colorkey |= (colorkey<<8);
		    case 2:
			colorkey |= (colorkey<<16);
			break;
		}
		mga_wait(2);
		mga_out32(MGAREG_FCOL, colorkey);
		mga_out32(MGAREG_BCOL, 0xFFFFFFFF);
	} else {
		blitop = MGADWG_BFCOL | MGADWG_BITBLT |
		         MGADWG_SHIFTZERO | MGADWG_RSTR | (0x0C << 16);
	}
	mga_wait(7);
	mga_out32(MGAREG_SGN, sign);
	mga_out32(MGAREG_AR3, start);
	mga_out32(MGAREG_AR0, stop);
	mga_out32(MGAREG_AR5, skip);
	mga_out32(MGAREG_FXBNDRY, (dstX | ((dstX + w-1) << 16)));
	mga_out32(MGAREG_YDSTLEN, (dstY << 16) | h);
	mga_out32(MGAREG_DWGCTL + MGAREG_EXEC, blitop);

	FB_AddBusySurface(src);
	FB_AddBusySurface(dst);

	if ( dst == this->screen ) {
		SDL_mutexV(hw_lock);
	}
	return(0);
}

static int CheckHWBlit(_THIS, SDL_Surface *src, SDL_Surface *dst)
{
	int accelerated;

	/* Set initial acceleration on */
	src->flags |= SDL_HWACCEL;

	/* Set the surface attributes */
	if ( (src->flags & SDL_SRCALPHA) == SDL_SRCALPHA ) {
		if ( ! this->info.blit_hw_A ) {
			src->flags &= ~SDL_HWACCEL;
		}
	}
	if ( (src->flags & SDL_SRCCOLORKEY) == SDL_SRCCOLORKEY ) {
		if ( ! this->info.blit_hw_CC ) {
			src->flags &= ~SDL_HWACCEL;
		}
	}

	/* Check to see if final surface blit is accelerated */
	accelerated = !!(src->flags & SDL_HWACCEL);
	if ( accelerated ) {
		src->map->hw_blit = HWAccelBlit;
	}
	return(accelerated);
}

void FB_MatroxAccel(_THIS, __u32 card)
{
	/* We have hardware accelerated surface functions */
	this->CheckHWBlit = CheckHWBlit;
	wait_vbl = WaitVBL;
	wait_idle = WaitIdle;

	/* The Matrox has an accelerated color fill */
	this->info.blit_fill = 1;
	this->FillHWRect = FillHWRect;

	/* The Matrox has accelerated normal and colorkey blits. */
	this->info.blit_hw = 1;
	/* The Millenium I appears to do the colorkey test a word
	   at a time, and the transparency is intverted. (?)
	 */
	if ( card != FB_ACCEL_MATROX_MGA2064W ) {
		this->info.blit_hw_CC = 1;
		this->SetHWColorKey = SetHWColorKey;
	}

#if 0 /* Not yet implemented? */
	/* The Matrox G200/G400 has an accelerated alpha blit */
	if ( (card == FB_ACCEL_MATROX_MGAG200)
	  || (card == FB_ACCEL_MATROX_MGAG400)
	) {
		this->info.blit_hw_A = 1;
		this->SetHWAlpha = SetHWAlpha;
	}
#endif
}