view src/cdrom/SDL_syscdrom.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 b8d311d90021
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

/* This is the system specific header for the SDL CD-ROM API */

/* Structure of CD audio control functions */
extern struct CDcaps {
	/* Get the name of the specified drive */
	const char *(*Name)(int drive);

	/* Open the specified drive, returning a drive id, or -1 on error */
	int (*Open)(int drive);

	/* Get table-of-contents (number of tracks + track info) for disk.
	   The TOC information should be stored in the cdrom structure.
	   This function should return 0 on success, or -1 on error.
	 */
	int (*GetTOC)(SDL_CD *cdrom);

	/* Return the current status and play position, in frames, of the
	   drive.  'position' may be NULL, and if so, should be ignored.
	 */
	CDstatus (*Status)(SDL_CD *cdrom, int *position);

	/* Play from frame 'start' to 'start+len' */
	int (*Play)(SDL_CD *cdrom, int start, int len); 

	/* Pause play */
	int (*Pause)(SDL_CD *cdrom);

	/* Resume play */
	int (*Resume)(SDL_CD *cdrom);

	/* Stop play */
	int (*Stop)(SDL_CD *cdrom);

	/* Eject the current disk */
	int (*Eject)(SDL_CD *cdrom);

	/* Close the specified drive */
	void (*Close)(SDL_CD *cdrom);
} SDL_CDcaps;

/* The number of available CD-ROM drives on the system */
extern int SDL_numcds;

/* Function to scan the system for CD-ROM drives and fill SDL_CDcaps.
 * This function should set SDL_numcds to the number of available CD
 * drives.  Drive 0 should be the system default CD-ROM.
 * It should return 0, or -1 on an unrecoverable fatal error.
*/
extern int  SDL_SYS_CDInit(void);

/* Function to perform any system-specific CD-ROM related cleanup */
extern void SDL_SYS_CDQuit(void);