view src/video/aalib/SDL_aavideo.c @ 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
line wrap: on
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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

/* AAlib based SDL video driver implementation.
*/

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>


#include "SDL.h"
#include "SDL_error.h"
#include "SDL_video.h"
#include "SDL_mouse.h"
#include "SDL_sysvideo.h"
#include "SDL_pixels_c.h"
#include "SDL_events_c.h"

#include "SDL_aavideo.h"
#include "SDL_aaevents_c.h"
#include "SDL_aamouse_c.h"

#include <aalib.h>

/* Initialization/Query functions */
static int AA_VideoInit(_THIS, SDL_PixelFormat *vformat);
static SDL_Rect **AA_ListModes(_THIS, SDL_PixelFormat *format, Uint32 flags);
static SDL_Surface *AA_SetVideoMode(_THIS, SDL_Surface *current, int width, int height, int bpp, Uint32 flags);
static int AA_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color *colors);
static void AA_VideoQuit(_THIS);

/* Hardware surface functions */
static int AA_AllocHWSurface(_THIS, SDL_Surface *surface);
static int AA_LockHWSurface(_THIS, SDL_Surface *surface);
static int AA_FlipHWSurface(_THIS, SDL_Surface *surface);
static void AA_UnlockHWSurface(_THIS, SDL_Surface *surface);
static void AA_FreeHWSurface(_THIS, SDL_Surface *surface);

/* Cache the VideoDevice struct */
static struct SDL_VideoDevice *local_this;

/* AAlib driver bootstrap functions */

static int AA_Available(void)
{
	return 1; /* Always available ! */
}

static void AA_DeleteDevice(SDL_VideoDevice *device)
{
	free(device->hidden);
	free(device);
}

static SDL_VideoDevice *AA_CreateDevice(int devindex)
{
	SDL_VideoDevice *device;

	/* Initialize all variables that we clean on shutdown */
	device = (SDL_VideoDevice *)malloc(sizeof(SDL_VideoDevice));
	if ( device ) {
		memset(device, 0, (sizeof *device));
		device->hidden = (struct SDL_PrivateVideoData *)
				malloc((sizeof *device->hidden));
	}
	if ( (device == NULL) || (device->hidden == NULL) ) {
		SDL_OutOfMemory();
		if ( device ) {
			free(device);
		}
		return(0);
	}
	memset(device->hidden, 0, (sizeof *device->hidden));

	/* Set the function pointers */
	device->VideoInit = AA_VideoInit;
	device->ListModes = AA_ListModes;
	device->SetVideoMode = AA_SetVideoMode;
	device->CreateYUVOverlay = NULL;
	device->SetColors = AA_SetColors;
	device->UpdateRects = NULL;
	device->VideoQuit = AA_VideoQuit;
	device->AllocHWSurface = AA_AllocHWSurface;
	device->CheckHWBlit = NULL;
	device->FillHWRect = NULL;
	device->SetHWColorKey = NULL;
	device->SetHWAlpha = NULL;
	device->LockHWSurface = AA_LockHWSurface;
	device->UnlockHWSurface = AA_UnlockHWSurface;
	device->FlipHWSurface = NULL;
	device->FreeHWSurface = AA_FreeHWSurface;
	device->SetCaption = NULL;
	device->SetIcon = NULL;
	device->IconifyWindow = NULL;
	device->GrabInput = NULL;
	device->GetWMInfo = NULL;
	device->InitOSKeymap = AA_InitOSKeymap;
	device->PumpEvents = AA_PumpEvents;

	device->free = AA_DeleteDevice;

	return device;
}

VideoBootStrap AALIB_bootstrap = {
	"aalib", "ASCII Art Library",
	AA_Available, AA_CreateDevice
};

static void AA_ResizeHandler(aa_context *);

int AA_VideoInit(_THIS, SDL_PixelFormat *vformat)
{
	int keyboard;
	int i;

	/* Initialize all variables that we clean on shutdown */
	for ( i=0; i<SDL_NUMMODES; ++i ) {
		SDL_modelist[i] = malloc(sizeof(SDL_Rect));
		SDL_modelist[i]->x = SDL_modelist[i]->y = 0;
	}
	/* Modes sorted largest to smallest */
	SDL_modelist[0]->w = 1024; SDL_modelist[0]->h = 768;
	SDL_modelist[1]->w = 800; SDL_modelist[1]->h = 600;
	SDL_modelist[2]->w = 640; SDL_modelist[2]->h = 480;
	SDL_modelist[3]->w = 320; SDL_modelist[3]->h = 400;
	SDL_modelist[4]->w = 320; SDL_modelist[4]->h = 240;
	SDL_modelist[5]->w = 320; SDL_modelist[5]->h = 200;
	SDL_modelist[6] = NULL;

	/* Initialize the library */

	AA_mutex = SDL_CreateMutex();

	aa_parseoptions (NULL, NULL, NULL, NULL);

	AA_context = aa_autoinit(&aa_defparams);
	if ( ! AA_context ) {
		SDL_SetError("Unable to initialize AAlib");
		return(-1);
	}

	/* Enable mouse and keyboard support */

	if ( ! aa_autoinitkbd (AA_context, AA_SENDRELEASE) ) {
		SDL_SetError("Unable to initialize AAlib keyboard");
		return(-1);
	}
	if ( ! aa_autoinitmouse (AA_context, AA_SENDRELEASE) ) {
		fprintf(stderr,"Warning: Unable to initialize AAlib mouse");
	}
	AA_rparams = aa_getrenderparams();

	local_this = this;

	aa_resizehandler(AA_context, AA_ResizeHandler);

	fprintf(stderr,"Using AAlib driver: %s (%s)\n", AA_context->driver->name, AA_context->driver->shortname);

	AA_in_x11 = (strcmp(AA_context->driver->shortname,"X11") == 0);
	/* Determine the screen depth (use default 8-bit depth) */
	vformat->BitsPerPixel = 8;
	vformat->BytesPerPixel = 1;

	/* We're done! */
	return(0);
}

SDL_Rect **AA_ListModes(_THIS, SDL_PixelFormat *format, Uint32 flags)
{
     if(format->BitsPerPixel != 8)
 		return NULL;

	 if ( flags & SDL_FULLSCREEN ) {
		 return SDL_modelist;
	 } else {
		 return (SDL_Rect **) -1;
	 }
}

/* From aavga.c
   AAlib does not give us the choice of the actual resolution, thus we have to simulate additional
   resolution by scaling down manually each frame
*/
static void fastscale (register char *b1, register char *b2, int x1, int x2, int y1, int y2)
{
	register int ex, spx = 0, ddx, ddx1;
	int ddy1, ddy, spy = 0, ey;
	int x;
	char *bb1 = b1;
	if (!x1 || !x2 || !y1 || !y2)
		return;
	ddx = x1 + x1;
	ddx1 = x2 + x2;
	if (ddx1 < ddx)
		spx = ddx / ddx1, ddx %= ddx1;
	ddy = y1 + y1;
	ddy1 = y2 + y2;
	if (ddy1 < ddy)
		spy = (ddy / ddy1) * x1, ddy %= ddy1;
	ey = -ddy1;
	for (; y2; y2--) {
		ex = -ddx1;
		for (x = x2; x; x--) {
			*b2 = *b1;
			b2++;
			b1 += spx;
			ex += ddx;
			if (ex > 0) {
				b1++;
				ex -= ddx1;
			}
		}
		bb1 += spy;
		ey += ddy;
		if (ey > 0) {
			bb1 += x1;
			ey -= ddy1;
		}
		b1 = bb1;
	}
}

/* Various screen update functions available */
static void AA_DirectUpdate(_THIS, int numrects, SDL_Rect *rects);

SDL_Surface *AA_SetVideoMode(_THIS, SDL_Surface *current,
				int width, int height, int bpp, Uint32 flags)
{
	int mode;

	if ( AA_buffer ) {
		free( AA_buffer );
	}

	AA_buffer = malloc(width * height);
	if ( ! AA_buffer ) {
		SDL_SetError("Couldn't allocate buffer for requested mode");
		return(NULL);
	}

/* 	printf("Setting mode %dx%d\n", width, height); */

	memset(aa_image(AA_context), 0, aa_imgwidth(AA_context) * aa_imgheight(AA_context));
	memset(AA_buffer, 0, width * height);

	/* Allocate the new pixel format for the screen */
	if ( ! SDL_ReallocFormat(current, 8, 0, 0, 0, 0) ) {
		return(NULL);
	}

	/* Set up the new mode framebuffer */
	current->flags = SDL_FULLSCREEN;
	AA_w = current->w = width;
	AA_h = current->h = height;
	current->pitch = current->w;
	current->pixels = AA_buffer;

	AA_x_ratio = ((double)aa_imgwidth(AA_context)) / ((double)width);
	AA_y_ratio = ((double)aa_imgheight(AA_context)) / ((double)height);

	/* Set the blit function */
	this->UpdateRects = AA_DirectUpdate;

	/* We're done */
	return(current);
}

static void AA_ResizeHandler(aa_context *context)
{
	aa_resize(context);
	local_this->hidden->x_ratio = ((double)aa_imgwidth(context)) / ((double)local_this->screen->w);
	local_this->hidden->y_ratio = ((double)aa_imgheight(context)) / ((double)local_this->screen->h);

	fastscale (local_this->hidden->buffer, aa_image(context), local_this->hidden->w, aa_imgwidth (context), local_this->hidden->h, aa_imgheight (context));
	aa_renderpalette(context, local_this->hidden->palette, local_this->hidden->rparams, 0, 0, aa_scrwidth(context), aa_scrheight(context));
	aa_flush(context);
}

/* We don't actually allow hardware surfaces other than the main one */
static int AA_AllocHWSurface(_THIS, SDL_Surface *surface)
{
	return(-1);
}
static void AA_FreeHWSurface(_THIS, SDL_Surface *surface)
{
	return;
}

/* We need to wait for vertical retrace on page flipped displays */
static int AA_LockHWSurface(_THIS, SDL_Surface *surface)
{
	/* TODO ? */
	return(0);
}
static void AA_UnlockHWSurface(_THIS, SDL_Surface *surface)
{
	return;
}

/* FIXME: How is this done with AAlib? */
static int AA_FlipHWSurface(_THIS, SDL_Surface *surface)
{
	SDL_mutexP(AA_mutex);
	aa_flush(AA_context);
	SDL_mutexV(AA_mutex);
	return(0);
}

static void AA_DirectUpdate(_THIS, int numrects, SDL_Rect *rects)
{
	int i;
	SDL_Rect *rect;

	fastscale (AA_buffer, aa_image(AA_context), AA_w, aa_imgwidth (AA_context), AA_h, aa_imgheight (AA_context));
#if 1
	aa_renderpalette(AA_context, AA_palette, AA_rparams, 0, 0, aa_scrwidth(AA_context), aa_scrheight(AA_context));
#else
	/* Render only the rectangles in the list */
	printf("Update rects : ");
	for ( i=0; i < numrects; ++i ) {
		rect = &rects[i];
		printf("(%d,%d-%d,%d)", rect->x, rect->y, rect->w, rect->h);
		aa_renderpalette(AA_context, AA_palette, AA_rparams, rect->x * AA_x_ratio, rect->y * AA_y_ratio, rect->w * AA_x_ratio, rect->h * AA_y_ratio);
	}
	printf("\n");
#endif
	SDL_mutexP(AA_mutex);
	aa_flush(AA_context);
	SDL_mutexV(AA_mutex);
	return;
}

int AA_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color *colors)
{
	int i;

	for ( i=0; i < ncolors; i++ ) {
	        aa_setpalette(AA_palette, firstcolor + i,
			      colors[i].r>>2,
			      colors[i].g>>2,
			      colors[i].b>>2);
	}
	return(1);
}

/* Note:  If we are terminated, this could be called in the middle of
   another SDL video routine -- notably UpdateRects.
*/
void AA_VideoQuit(_THIS)
{
	int i;

	aa_uninitkbd(AA_context);
	aa_uninitmouse(AA_context);

	/* Free video mode lists */
	for ( i=0; i<SDL_NUMMODES; ++i ) {
		if ( SDL_modelist[i] != NULL ) {
			free(SDL_modelist[i]);
			SDL_modelist[i] = NULL;
		}
	}
	
	aa_close(AA_context);

	SDL_DestroyMutex(AA_mutex);

	this->screen->pixels = NULL;	
}