view src/video/ataricommon/SDL_xbiosinterrupt.S @ 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 0fb50bfaea7f
children c9b51268668f
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  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

/*
 *	XBIOS mouse & joystick vectors
 *
 *	Patrice Mandin
 */

	.text

	.globl	_SDL_AtariXbios_Install
	.globl	_SDL_AtariXbios_Restore
	.globl	_SDL_AtariXbios_MouseVector
	.globl	_SDL_AtariXbios_JoystickVector

	.globl	_SDL_AtariXbios_mouseb
	.globl	_SDL_AtariXbios_mousex
	.globl	_SDL_AtariXbios_mousey
	.globl	_SDL_AtariXbios_joystick

/*--- Vector installer ---*/

_SDL_AtariXbios_Install:
	movel	sp@(4),a0

	/* Stop interrupts */

	movew	#0x2700,sr

	/* Save old mouse vector, set our routine */

	clrl	oldmousevector
	movel	sp@(8),d0
	beqs	no_new_mouse_vector
	movel	a0@(16),oldmousevector
	movel	d0,a0@(16)
no_new_mouse_vector:

	/* Save old joystick vector, set our routine */

	clrl	oldjoystickvector
	movel	sp@(12),d0
	beqs	no_new_joystick_vector
	movel	a0@(24),oldjoystickvector
	movel	d0,a0@(24)
no_new_joystick_vector:

	/* Restart interrupts */

	movew	#0x2300,sr

	rts

/*--- Vector restorer ---*/

_SDL_AtariXbios_Restore:
	movel	sp@(4),a0

	/* Stop interrupts */

	movew	#0x2700,sr

	/* Restore mouse vector */

	movel	oldmousevector,d0
	beqs	no_restore_mouse
	movel	d0,a0@(16)
no_restore_mouse:

	/* Restore joystick vector */

	movel	oldjoystickvector,d0
	beqs	no_restore_joystick
	movel	d0,a0@(24)
no_restore_joystick:

	/* Restart interrupts */

	movew	#0x2300,sr

	rts

/*--- Our mouse vector ---*/

	.text
	.even
	.ascii "XBRA"
	.ascii "LSDL"
	.comm	oldmousevector,4*1
_SDL_AtariXbios_MouseVector:
	movel	d0,sp@-

	/* Mouse buttons */
	moveb	(a0),d0
	andw	#3,d0
	movew	d0,_SDL_AtariXbios_mouseb

	/* X movement */
	moveb	a0@(1),d0
	extw	d0
	addw	d0,_SDL_AtariXbios_mousex

	/* Y movement */
	moveb	a0@(2),d0
	extw	d0
	addw	d0,_SDL_AtariXbios_mousey

	/* Jump through old vector */
	movel	sp@+,d0

	movel	oldmousevector,sp@-
	rts

	.data
	.even
	.comm	_SDL_AtariXbios_mousex,2*1
	.even
	.comm	_SDL_AtariXbios_mousey,2*1
	.even
	.comm	_SDL_AtariXbios_mouseb,2*1

/*--- Our joystick vector ---*/

	.text
	.even
	.ascii "XBRA"
	.ascii "LSDL"
	.comm	oldjoystickvector,4*1
_SDL_AtariXbios_JoystickVector:
	movel	d0,sp@-

	/* New joystick state */
	moveb	a0@(2),d0
	andw	#0x8f,d0
	movew	d0,_SDL_AtariXbios_joystick

	/* Jump through old vector */
	movel	sp@+,d0

	movel	oldjoystickvector,sp@-
	rts

	.data
	.even
	.comm	_SDL_AtariXbios_joystick,2*1