view src/video/xbios/SDL_xbios.h @ 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 fba6b67b4d60
children c9b51268668f
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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

#ifndef _SDL_xbios_h
#define _SDL_xbios_h

#include "SDL_types.h"
#include "SDL_sysvideo.h"

/* Hidden "this" pointer for the video functions */
#define _THIS	SDL_VideoDevice *this

/* TT video modes:	2
   Falcon RVB:		16 (could be *2 by adding PAL/NTSC modes)
   Falcon VGA:		6
   ST low:		1
*/
#define SDL_NUMMODES 16

typedef struct
{
	Uint16 number;		/* Video mode number */
	Uint16 width;		/* Size */	
	Uint16 height;
	Uint16 depth;		/* bits per plane */
	SDL_bool doubleline;	/* Double the lines ? */
} xbiosmode_t;

/* Private display data */
#define NUM_MODELISTS	2		/* 8 and 16 bits-per-pixel */

struct SDL_PrivateVideoData {
	long cookie_vdo;
	int old_video_mode;				/* Old video mode before entering SDL */
	void *old_video_base;			/* Old pointer to screen buffer */
	void *old_palette;				/* Old palette */
	Uint32 old_num_colors;			/* Nb of colors in saved palette */
	int num_modes;					/* Number of xbios video modes */
	xbiosmode_t	*mode_list;			/* List of xbios video modes */

	void *screens[2];		/* Pointers to aligned screen buffer */
	void *screensmem[2];	/* Pointers to screen buffer */
	void *shadowscreen;		/* Shadow screen for c2p conversion */
	int doubleline;			/* Double line mode ? */
	int frame_number;		/* Number of frame for double buffer */
	int pitch;				/* Destination line width for C2P */
	int width, height;		/* Screen size for centered C2P */

	SDL_bool centscreen;	/* Centscreen extension present ? */

	SDL_Rect *SDL_modelist[NUM_MODELISTS][SDL_NUMMODES+1];
	xbiosmode_t *videomodes[NUM_MODELISTS][SDL_NUMMODES+1];
};

/* _VDO cookie values */
enum {
	VDO_ST=0,
	VDO_STE,
	VDO_TT,
	VDO_F30
};

/* Monitor types */
enum {
	MONITOR_MONO=0,
	MONITOR_TV,
	MONITOR_VGA,
	MONITOR_RGB
};

/* EgetShift masks */
#define ES_BANK		0x000f
#define ES_MODE		0x0700
#define ES_GRAY		0x1000
#define ES_SMEAR	0x8000

/* TT shifter modes */
#define ST_LOW	0x0000
#define ST_MED	0x0100
#define ST_HIGH	0x0200
#define TT_LOW	0x0700
#define TT_MED	0x0300
#define TT_HIGH	0x0600

/* Hidden structure -> variables names */
#define SDL_modelist		(this->hidden->SDL_modelist)
#define XBIOS_mutex		    (this->hidden->mutex)
#define XBIOS_cvdo		    (this->hidden->cookie_vdo)
#define XBIOS_oldpalette	(this->hidden->old_palette)
#define XBIOS_oldnumcol		(this->hidden->old_num_colors)
#define XBIOS_oldvbase		(this->hidden->old_video_base)
#define XBIOS_oldvmode		(this->hidden->old_video_mode)
#define XBIOS_nummodes		(this->hidden->num_modes)
#define XBIOS_modelist		(this->hidden->mode_list)
#define XBIOS_screens		(this->hidden->screens)
#define XBIOS_screensmem	(this->hidden->screensmem)
#define XBIOS_shadowscreen	(this->hidden->shadowscreen)
#define XBIOS_videomodes	(this->hidden->videomodes)
#define XBIOS_doubleline	(this->hidden->doubleline)
#define XBIOS_fbnum			(this->hidden->frame_number)
#define XBIOS_pitch			(this->hidden->pitch)
#define XBIOS_width			(this->hidden->width)
#define XBIOS_height		(this->hidden->height)
#define XBIOS_centscreen	(this->hidden->centscreen)

/*--- Functions prototypes ---*/

void SDL_XBIOS_AddMode(_THIS, Uint16 modecode, Uint16 width, Uint16 height,
	Uint16 depth, SDL_bool flags);

#endif /* _SDL_xbios_h */