view src/video/vgl/SDL_vglvideo.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 e8157fcb3114
children c9b51268668f
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000  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

/* libvga based SDL video driver implementation.
*/

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

#include <sys/fbio.h>
#include <sys/consio.h>
#include <sys/kbio.h>
#include <vgl.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_vglvideo.h"
#include "SDL_vglevents_c.h"
#include "SDL_vglmouse_c.h"


/* Initialization/Query functions */
static int VGL_VideoInit(_THIS, SDL_PixelFormat *vformat);
static SDL_Rect **VGL_ListModes(_THIS, SDL_PixelFormat *format, Uint32 flags);
static SDL_Surface *VGL_SetVideoMode(_THIS, SDL_Surface *current, int width, int height, int bpp, Uint32 flags);
static int VGL_SetColors(_THIS, int firstcolor, int ncolors,
			  SDL_Color *colors);
static void VGL_VideoQuit(_THIS);

/* Hardware surface functions */
static int VGL_AllocHWSurface(_THIS, SDL_Surface *surface);
static int VGL_LockHWSurface(_THIS, SDL_Surface *surface);
static int VGL_FlipHWSurface(_THIS, SDL_Surface *surface);
static void VGL_UnlockHWSurface(_THIS, SDL_Surface *surface);
static void VGL_FreeHWSurface(_THIS, SDL_Surface *surface);

/* Misc function */
static VGLMode ** VGLListModes(int depth, int mem_model);
static void VGLWaitRetrace(void);

/* VGL driver bootstrap functions */

static int VGL_Available(void)
{
	/*
	 * Check to see if we are root and stdin is a
	 * virtual console. Also try to ensure that
	 * modes other than 320x200 are available
	 */
	int console, hires_available, i;
	VGLMode **modes;

	console = STDIN_FILENO;
	if ( console >= 0 ) {
		struct stat sb;
		struct vt_mode dummy;

		if ( (fstat(console, &sb) < 0) ||
		     (ioctl(console, VT_GETMODE, &dummy) < 0) ) {
			console = -1;
		}
	}
	if (geteuid() != 0 && console == -1)
		return 0;

	modes = VGLListModes(8, V_INFO_MM_DIRECT | V_INFO_MM_PACKED);
	hires_available = 0;
	for (i = 0; modes[i] != NULL; i++) {
		if ((modes[i]->ModeInfo.Xsize > 320) &&
		    (modes[i]->ModeInfo.Ysize > 200) &&
		    ((modes[i]->ModeInfo.Type == VIDBUF8) ||
		     (modes[i]->ModeInfo.Type == VIDBUF16) ||
		     (modes[i]->ModeInfo.Type == VIDBUF32))) {
			hires_available = 1;
			break;
		}
	}
	return hires_available;
}

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

static SDL_VideoDevice *VGL_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 = VGL_VideoInit;
	device->ListModes = VGL_ListModes;
	device->SetVideoMode = VGL_SetVideoMode;
	device->SetColors = VGL_SetColors;
	device->UpdateRects = NULL;
	device->VideoQuit = VGL_VideoQuit;
	device->AllocHWSurface = VGL_AllocHWSurface;
	device->CheckHWBlit = NULL;
	device->FillHWRect = NULL;
	device->SetHWColorKey = NULL;
	device->SetHWAlpha = NULL;
	device->LockHWSurface = VGL_LockHWSurface;
	device->UnlockHWSurface = VGL_UnlockHWSurface;
	device->FlipHWSurface = VGL_FlipHWSurface;
	device->FreeHWSurface = VGL_FreeHWSurface;
	device->SetIcon = NULL;
	device->SetCaption = NULL;
	device->GetWMInfo = NULL;
	device->FreeWMCursor = VGL_FreeWMCursor;
	device->CreateWMCursor = VGL_CreateWMCursor;
	device->ShowWMCursor = VGL_ShowWMCursor;
	device->WarpWMCursor = VGL_WarpWMCursor;
	device->InitOSKeymap = VGL_InitOSKeymap;
	device->PumpEvents = VGL_PumpEvents;

	device->free = VGL_DeleteDevice;

	return device;
}

VideoBootStrap VGL_bootstrap = {
	"vgl", "FreeBSD libVGL",
	VGL_Available, VGL_CreateDevice
};

static int VGL_AddMode(_THIS, VGLMode *inmode)
{
	SDL_Rect *mode;

	int i, index;
	int next_mode;

	/* Check to see if we already have this mode */
	if (inmode->Depth < 8) {  /* Not supported */
		return 0;
	}
	index = ((inmode->Depth + 7) / 8) - 1;
	for (i=0; i<SDL_nummodes[index]; ++i) {
		mode = SDL_modelist[index][i];
		if ((mode->w == inmode->ModeInfo.Xsize) &&
		    (mode->h == inmode->ModeInfo.Ysize))
			return 0;
	}

	/* Set up the new video mode rectangle */
	mode = (SDL_Rect *)malloc(sizeof *mode);
	if (mode == NULL) {
		SDL_OutOfMemory();
		return -1;
	}
	mode->x = 0;
	mode->y = 0;
	mode->w = inmode->ModeInfo.Xsize;
	mode->h = inmode->ModeInfo.Ysize;

	/* Allocate the new list of modes, and fill in the new mode */
	next_mode = SDL_nummodes[index];
	SDL_modelist[index] = (SDL_Rect **)
		realloc(SDL_modelist[index], (1+next_mode+1)*sizeof(SDL_Rect *));
	if (SDL_modelist[index] == NULL) {
		SDL_OutOfMemory();
		SDL_nummodes[index] = 0;
		free(mode);
		return -1;
	}
	SDL_modelist[index][next_mode] = mode;
	SDL_modelist[index][next_mode+1] = NULL;
	SDL_nummodes[index]++;

	return 0;
}

static void VGL_UpdateVideoInfo(_THIS)
{
	this->info.wm_available = 0;
	this->info.hw_available = 1;
	this->info.video_mem = 0;
	if (VGLCurMode == NULL) {
		return;
	}
	if (VGLCurMode->ModeInfo.PixelBytes > 0) {
		this->info.video_mem = VGLCurMode->ModeInfo.PixelBytes *
				       VGLCurMode->ModeInfo.Xsize *
				       VGLCurMode->ModeInfo.Ysize;
	}
}

int VGL_VideoInit(_THIS, SDL_PixelFormat *vformat)
{
	int i;
	int total_modes;
	VGLMode **modes;

	/* Initialize all variables that we clean on shutdown */
	for ( i=0; i<NUM_MODELISTS; ++i ) {
		SDL_nummodes[i] = 0;
		SDL_modelist[i] = NULL;
	}

	/* Enable mouse and keyboard support */
	if (getenv("SDL_NO_RAWKBD") == NULL) {
		if (VGLKeyboardInit(VGL_CODEKEYS) != 0) {
			SDL_SetError("Unable to initialize keyboard");
			return -1;
		}
	} else {
		warnx("Requiest to put keyboard into a raw mode ignored");
	}
	if (VGL_initkeymaps(STDIN_FILENO) != 0) {
		SDL_SetError("Unable to initialize keymap");
		return -1;
	}
	if (VGL_initmouse(STDIN_FILENO) != 0) {
		SDL_SetError("Unable to initialize mouse");
		return -1;
	}

	/* Determine the screen depth */
	if (VGLCurMode != NULL)
		vformat->BitsPerPixel = VGLCurMode->Depth;
	else
		vformat->BitsPerPixel = 16;	/* Good default */

	/* Query for the list of available video modes */
	total_modes = 0;
	modes = VGLListModes(-1, V_INFO_MM_DIRECT | V_INFO_MM_PACKED);
	for (i = 0; modes[i] != NULL; i++) {
		if ((modes[i]->ModeInfo.Type == VIDBUF8) ||
		    (modes[i]->ModeInfo.Type == VIDBUF16) ||
		    (modes[i]->ModeInfo.Type == VIDBUF32)) {
			VGL_AddMode(this, modes[i]);
			total_modes++;
		}
	}
	if (total_modes == 0) {
		SDL_SetError("No linear video modes available");
		return -1;
	}

	/* Fill in our hardware acceleration capabilities */
	VGL_UpdateVideoInfo(this);

	/* Create the hardware surface lock mutex */
	hw_lock = SDL_CreateMutex();
	if (hw_lock == NULL) {
		SDL_SetError("Unable to create lock mutex");
		VGL_VideoQuit(this);
		return -1;
	}

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

SDL_Rect **VGL_ListModes(_THIS, SDL_PixelFormat *format, Uint32 flags)
{
	return SDL_modelist[((format->BitsPerPixel+7)/8)-1];
}

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

SDL_Surface *VGL_SetVideoMode(_THIS, SDL_Surface *current,
			      int width, int height, int bpp, Uint32 flags)
{
	int mode_found;
	int i;
	VGLMode **modes;

	modes = VGLListModes(bpp, V_INFO_MM_DIRECT | V_INFO_MM_PACKED);
	mode_found = 0;
	for (i = 0; modes[i] != NULL; i++) {
		if ((modes[i]->ModeInfo.Xsize == width) &&
		    (modes[i]->ModeInfo.Ysize == height) &&
		    ((modes[i]->ModeInfo.Type == VIDBUF8) ||
		     (modes[i]->ModeInfo.Type == VIDBUF16) ||
		     (modes[i]->ModeInfo.Type == VIDBUF32))) {
			mode_found = 1;
			break;
		}
	}
	if (mode_found == 0) {
		SDL_SetError("No matching video mode found");
		return NULL;
	}

	/* Shutdown previous videomode (if any) */
	if (VGLCurMode != NULL)
		VGLEnd();

	/* Try to set the requested linear video mode */
	if (VGLInit(modes[i]->ModeId) != 0) {
		SDL_SetError("Unable to switch to requested mode");
		return NULL;
	}

	VGLCurMode = realloc(VGLCurMode, sizeof(VGLMode));
	VGLCurMode->ModeInfo = *VGLDisplay;
	VGLCurMode->Depth = modes[i]->Depth;
	VGLCurMode->ModeId = modes[i]->ModeId;
	VGLCurMode->Rmask = modes[i]->Rmask;
	VGLCurMode->Gmask = modes[i]->Gmask;
	VGLCurMode->Bmask = modes[i]->Bmask;

	/* Workaround a bug in libvgl */
	if (VGLCurMode->ModeInfo.PixelBytes == 0)
		(VGLCurMode->ModeInfo.PixelBytes = 1);

	current->w = VGLCurMode->ModeInfo.Xsize;
	current->h = VGLCurMode->ModeInfo.Ysize;
	current->pixels = VGLCurMode->ModeInfo.Bitmap;
	current->pitch = VGLCurMode->ModeInfo.Xsize *
			 VGLCurMode->ModeInfo.PixelBytes;
	current->flags = (SDL_FULLSCREEN | SDL_HWSURFACE);

	/* Check if we are in a pseudo-color mode */
	if (VGLCurMode->ModeInfo.Type == VIDBUF8)
		current->flags |= SDL_HWPALETTE;

	/* Check if we can do doublebuffering */
	if (flags & SDL_DOUBLEBUF) {
		if (VGLCurMode->ModeInfo.Xsize * 2 <=
		    VGLCurMode->ModeInfo.VYsize) {
			current->flags |= SDL_DOUBLEBUF;
			flip_page = 0;
			flip_address[0] = (byte *)current->pixels;
			flip_address[1] = (byte *)current->pixels +
					  current->h * current->pitch;
			VGL_FlipHWSurface(this, current);
		}
	}

	if (! SDL_ReallocFormat(current, modes[i]->Depth, VGLCurMode->Rmask,
				VGLCurMode->Gmask, VGLCurMode->Bmask, 0)) {
		return NULL;
	}

	/* Update hardware acceleration info */
	VGL_UpdateVideoInfo(this);

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

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

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

/* We need to wait for vertical retrace on page flipped displays */
static int VGL_LockHWSurface(_THIS, SDL_Surface *surface)
{
	if (surface == SDL_VideoSurface) {
		SDL_mutexP(hw_lock);
	}
	return 0;
}
static void VGL_UnlockHWSurface(_THIS, SDL_Surface *surface)
{
	if (surface == SDL_VideoSurface) {
		SDL_mutexV(hw_lock);
	}
}

static int VGL_FlipHWSurface(_THIS, SDL_Surface *surface)
{
//	VGLWaitRetrace();
	if (VGLPanScreen(VGLDisplay, 0, flip_page * surface->h) < 0) {
		SDL_SetError("VGLPanSreen() failed");
                return -1;
        }

	flip_page = !flip_page;
	surface->pixels = flip_address[flip_page];

	return 0;
}

static void VGL_DirectUpdate(_THIS, int numrects, SDL_Rect *rects)
{
	return;
}

static void VGL_BankedUpdate(_THIS, int numrects, SDL_Rect *rects)
{
	return;
}

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

	for(i = 0; i < ncolors; i++) {
	        VGLSetPaletteIndex(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 VGL_VideoQuit(_THIS)
{
	int i, j;

	/* Return the keyboard to the normal state */
	VGLKeyboardEnd();

	/* Reset the console video mode if we actually initialised one */
	if (VGLCurMode != NULL) {
		VGLEnd();
		free(VGLCurMode);
		VGLCurMode = NULL;
	}

	/* Clear the lock mutex */
	if (hw_lock != NULL) {
		SDL_DestroyMutex(hw_lock);
		hw_lock = NULL;
	}

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

	if ( this->screen && (this->screen->flags & SDL_HWSURFACE) ) {
	/* Direct screen access, not a memory buffer */
		this->screen->pixels = NULL;
	}
}

#define VGL_RED_INDEX	0
#define VGL_GREEN_INDEX	1
#define VGL_BLUE_INDEX	2

static VGLMode **
VGLListModes(int depth, int mem_model)
{
  static VGLMode **modes = NULL;

  VGLBitmap *vminfop;
  VGLMode **modesp, *modescp;
  video_info_t minfo;
  int adptype, i, modenum;

  if (modes == NULL) {
    modes = malloc(sizeof(VGLMode *) * M_VESA_MODE_MAX);
    bzero(modes, sizeof(VGLMode *) * M_VESA_MODE_MAX);
  }
  modesp = modes;

  for (modenum = 0; modenum < M_VESA_MODE_MAX; modenum++) {
    minfo.vi_mode = modenum;
    if (ioctl(0, CONS_MODEINFO, &minfo) || ioctl(0, CONS_CURRENT, &adptype))
      continue;
    if (minfo.vi_mode != modenum)
      continue;
    if ((minfo.vi_flags & V_INFO_GRAPHICS) == 0)
      continue;
    if ((mem_model != -1) && ((minfo.vi_mem_model & mem_model) == 0))
      continue;
    if ((depth > 1) && (minfo.vi_depth != depth))
      continue;

    /* reallocf can fail */
    if ((*modesp = reallocf(*modesp, sizeof(VGLMode))) == NULL)
      return NULL;
    modescp = *modesp;

    vminfop = &(modescp->ModeInfo);
    bzero(vminfop, sizeof(VGLBitmap));

    vminfop->Type = NOBUF;

    vminfop->PixelBytes = 1;	/* Good default value */
    switch (minfo.vi_mem_model) {
    case V_INFO_MM_PLANAR:
      /* we can handle EGA/VGA planar modes only */
      if (!(minfo.vi_depth != 4 || minfo.vi_planes != 4
	    || (adptype != KD_EGA && adptype != KD_VGA)))
	vminfop->Type = VIDBUF4;
      break;
    case V_INFO_MM_PACKED:
      /* we can do only 256 color packed modes */
      if (minfo.vi_depth == 8)
	vminfop->Type = VIDBUF8;
      break;
    case V_INFO_MM_VGAX:
      vminfop->Type = VIDBUF8X;
      break;
#if defined(__FreeBSD_version) && __FreeBSD_version >= 500000
    case V_INFO_MM_DIRECT:
      vminfop->PixelBytes = minfo.vi_pixel_size;
      switch (vminfop->PixelBytes) {
      case 2:
	vminfop->Type = VIDBUF16;
	break;
#if notyet
      case 3:
	vminfop->Type = VIDBUF24;
	break;
#endif
      case 4:
	vminfop->Type = VIDBUF32;
	break;
      default:
	break;
      }
#endif
    default:
      break;
    }
    if (vminfop->Type == NOBUF)
      continue;

    switch (vminfop->Type) {
    case VIDBUF16:
    case VIDBUF32:
      modescp->Rmask = ((1 << minfo.vi_pixel_fsizes[VGL_RED_INDEX]) - 1) <<
		       minfo.vi_pixel_fields[VGL_RED_INDEX];
      modescp->Gmask = ((1 << minfo.vi_pixel_fsizes[VGL_GREEN_INDEX]) - 1) <<
		       minfo.vi_pixel_fields[VGL_GREEN_INDEX];
      modescp->Bmask = ((1 << minfo.vi_pixel_fsizes[VGL_BLUE_INDEX]) - 1) <<
		       minfo.vi_pixel_fields[VGL_BLUE_INDEX];
      break;

    default:
      break;
    }

    vminfop->Xsize = minfo.vi_width;
    vminfop->Ysize = minfo.vi_height;
    modescp->Depth = minfo.vi_depth;

    /* XXX */
    if (minfo.vi_mode >= M_VESA_BASE)
      modescp->ModeId = _IO('V', minfo.vi_mode - M_VESA_BASE);
    else
      modescp->ModeId = _IO('S', minfo.vi_mode);

    /* Sort list */
    for (i = 0; modes + i < modesp ; i++) {
      if (modes[i]->ModeInfo.Xsize * modes[i]->ModeInfo.Ysize >
	  vminfop->Xsize * modes[i]->ModeInfo.Ysize)
	continue;
      if ((modes[i]->ModeInfo.Xsize * modes[i]->ModeInfo.Ysize ==
	   vminfop->Xsize * vminfop->Ysize) &&
	  (modes[i]->Depth >= modescp->Depth))
	continue;
      *modesp = modes[i];
      modes[i] = modescp;
      modescp = *modesp;
      vminfop = &(modescp->ModeInfo);
    }

    modesp++;
  }

  if (*modesp != NULL) {
    free(*modesp);
    *modesp = NULL;
  }

  return modes;
}

static void
VGLWaitRetrace(void)
{
  while (!(inb(0x3DA) & 8));
  while (inb(0x3DA) & 8);
}