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view README.PicoGUI @ 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 | 706de3956894 |
| children |
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======================== Using SDL with PicoGUI ======================== - Originally contributed by Micah Dowty <micahjd@users.sourceforge.net> PicoGUI is a scalable GUI system with a unique architecture, primarily focused on scalability to various embedded systems. You can find more information including a FAQ at http://picogui.org To use the patch: 1. When compiling, add the "--enable-video-picogui" switch to ./configure 2. When running your program, ensure that the picogui driver for SDL is in use by setting the SDL_VIDEODRIVER environment variable to "picogui". 3. The program must also be linked to the C client library for PicoGUI (libpgui.so). If the program is being compiled with a patched SDL installed this should be done automatically. If you want to use an existing binary with PicoGUI, you can set the LD_PRELOAD environment variable to the path of your libpgui.so file. Capabilities: So far only basic functionality is provided on true color (linear16/24/32) devices. Accessing a memory mapped bitmap, updating the display, and handling mouse/keyboard input. This functionality has been tested with several applications, including mplayer, Xine, sldroids, and Abuse. TODO list: - YUV overlays will be helpful for watching video on set top boxes or other embedded devices that have some graphics acceleration hardware - Account for rotated bitmap storage in pgserver - Support for hiding or changing the cursor - The display should be centered when the SDL application is smaller than the PicoGUI panel - Fullscreen or any other special modes - Support for indexed and grayscale modes - Probably much more... --- The End ---