view src/video/wincommon/SDL_lowvideo.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 31fa08b36380
children 86d0d01290ea
line wrap: on
line source

/*
    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_lowvideo_h
#define _SDL_lowvideo_h

#include <windows.h>

#include "SDL_sysvideo.h"

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

#define WINDIB_FULLSCREEN()						\
(									\
	SDL_VideoSurface &&						\
	((SDL_VideoSurface->flags & SDL_FULLSCREEN) == SDL_FULLSCREEN) && \
	(((SDL_VideoSurface->flags & SDL_OPENGL   ) == SDL_OPENGL    ) || \
	 (strcmp(this->name, "windib") == 0))				\
)
#define DDRAW_FULLSCREEN() 						\
(									\
	SDL_VideoSurface &&						\
	((SDL_VideoSurface->flags & SDL_FULLSCREEN) == SDL_FULLSCREEN) && \
	((SDL_VideoSurface->flags & SDL_OPENGL    ) != SDL_OPENGL    ) && \
	(strcmp(this->name, "directx") == 0)				\
)

#define DINPUT_FULLSCREEN()	DDRAW_FULLSCREEN()

/* The main window -- and a function to set it for the audio */
#ifdef _WIN32_WCE
extern LPWSTR SDL_Appname;
#else
extern LPSTR SDL_Appname;
#endif
extern HINSTANCE SDL_Instance;
extern HWND SDL_Window;
extern const char *SDL_windowid;

/* Variables and functions exported to other parts of the native video
   subsystem (SDL_sysevents.c)
*/
/* Called by windows message loop when system palette is available */
extern void (*WIN_RealizePalette)(_THIS);

/* Called by windows message loop when the system palette changes */
extern void (*WIN_PaletteChanged)(_THIS, HWND window);

/* Called by windows message loop when a portion of the screen needs update */
extern void (*WIN_WinPAINT)(_THIS, HDC hdc);

/* Called by windows message loop when the message isn't handled */
extern LONG (*HandleMessage)(_THIS, HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

/* The window cursor (from SDL_sysmouse.c) */
extern HCURSOR SDL_hcursor;

/* The bounds of the window in screen coordinates */
extern RECT SDL_bounds;

/* The position of the window in windowed mode */
extern int SDL_windowX;
extern int SDL_windowY;

/* Flag -- SDL is performing a resize, rather than the user */
extern int SDL_resizing;

/* Flag -- the mouse is in relative motion mode */
extern int mouse_relative;

/* The GDI fullscreen mode currently active */
#ifndef NO_CHANGEDISPLAYSETTINGS
extern DEVMODE SDL_fullscreen_mode;
#endif

/* The system gamma ramp for GDI modes */
extern WORD *gamma_saved;

/* This is really from SDL_dx5audio.c */
extern void DX5_SoundFocus(HWND window);

/* DJM: This is really from SDL_sysevents.c, we need it in
   GDL_CreateWindow as well */
LONG CALLBACK WinMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

#endif /* SDL_lowvideo_h */