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

This is the porting of 1.2.0 version of SDL (the latest stable one)
to AmigaOS/68k.

All the bugs known of the past version have been corrected. And I've
added all the new SDL features.

This version of SDL needs Cybergraphx V3 (r69+) or CyberGraphX V4
and AHI v3+. Probably it works also with P96 or CGXAga, but it's 
untested.

This version is available as linked library for SAS/C and GCC, only 68k this 
time, a powerup (ppcemu compatible) and a morphos version will be ready quite 
soon (i hope).

Implemented:

- 8/16/24/32bit video modes, both fullscreen and windowed.
- Hardware surfaces.
- CGX blitting acceleration.
- CGX colorkey blitting acceleration.
- AHI audio (8/16 bit, with any audio format), always uses unit 0 for now.
- Thread support (maybe not 100% compatible with other implementations)
- Semaphores 
- Window resizing and backdrop windows (NEW)
- Joystick/Joypad support.

To do:

- CDRom audio playing support
- OpenGL (A guy was working on it but I've lost his tracks :( )

The SAS/C library is distributed with debug info attached, to strip debug info 
simply add STRIPDEBUG argument to the linker.

NOTE: SDL includes debug output using kprintf, to disable it add to your 
project a function like this:

void kprintf(char *a,...)
{
}

Otherwise you can redirect the debug to a console window with sushi, sashimi or
similar tools (the default output is the internal serial port). 

For info, support, bugfix and other feel free to mail me:

Gabriele Greco (gabriele.greco@aruba.it)

You can find also a small SDL Amiga page at:
http://ggreco.interfree.it/sdl.html