Mercurial > sdl-ios-xcode
view src/video/xbios/SDL_xbios_blowup.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 | c6ed27c7d47d |
| children | d910939febfa |
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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 */ /* Blowup extension definitions Patrice Mandin */ #ifndef _SDL_xbios_blowup_h #define _SDL_xbios_blowup_h #include "SDL_xbios.h" /*--- Types ---*/ typedef struct { /* 64 bytes */ unsigned short enabled; /* Extended mode enabled ? 0=yes, <>0=no */ unsigned short dummy10[6]; unsigned short registers_0E; /* value for register 0xffff820e */ unsigned short registers_10; /* value for register 0xffff8210 */ unsigned short dummy11[23]; /* 64 bytes */ unsigned short width; /* width-1 */ unsigned short height; /* height-1 */ unsigned short dummy20; unsigned long screensize; /* screensize in bytes */ unsigned short dummy21[8]; unsigned short virtual; /* Virtual screen ? */ unsigned short virwidth; /* Virtual screen width */ unsigned short virheight; /* Virtual screen height */ unsigned short dummy22; unsigned short monitor; /* Monitor defined for this mode */ unsigned short extension; /* Extended mode defined ? 0=yes, 1=no */ unsigned short dummy23[13]; /* 64 bytes */ unsigned short dummy30; unsigned short registers_82[6]; /* values for registers 0xffff8282-8c */ unsigned short dummy31[9]; unsigned short dummy32; unsigned short registers_A2[6]; /* values for registers 0xffff82a2-ac */ unsigned short dummy33[9]; /* 64 bytes */ unsigned short registers_C0; /* value for register 0xffff82c0 */ unsigned short registers_C2; /* value for register 0xffff82c2 */ unsigned short dummy40[30]; } __attribute__((packed)) blow_mode_t; typedef struct { blow_mode_t blowup_modes[10]; unsigned char num_mode[6]; unsigned long dummy; unsigned short montype; } __attribute__((packed)) blow_cookie_t; /*--- Functions prototypes ---*/ void SDL_XBIOS_BlowupInit(_THIS, blow_cookie_t *cookie_blow); #endif /* _SDL_xbios_blowup_h */