view src/joystick/bsd/SDL_sysjoystick.c @ 4158:96ce26f24b01 SDL-1.2

Date: Sun, 7 Sep 2008 15:17:00 +0200 From: c2woody@gmx.net Subject: [SDL] SDL 1.2 doube free/pointer zeroing missing Hello, this is about a crash/debug breakage for the current SDL 1.2 source tree (today's svn checkout, same problem in 1.2.13 and before as far as relevant). In some places memory is free()d but the associated pointer is not zeroed, leading to for example double free()s. For me this happened because SDL_StopEventThread() was executed twice (during restart of the subsystems), once for the close down in SDL_VideoQuit() and once at the startup, right at the beginning of SDL_StartEventLoop(). Thus the code SDL_DestroyMutex(SDL_EventQ.lock); (see SDL_events.c) was called twice and executed the SDL_free(mutex); twice as well, leading to a crash (msvc 64bit for which it was noticed). I've tried to check all other occurrences of SDL_free and similar code in msvc, see the attached patch (udiff against revision 4082). Non-windows only codepaths have neither been checked nor touched. Comments/ideas welcome. Attached patch: NULLifies some pointers after they have been free()d.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 12 Nov 2008 17:23:40 +0000
parents c5a6dcdaef04
children a1b03ba2fcd0
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#ifdef SDL_JOYSTICK_USBHID

/*
 * Joystick driver for the uhid(4) interface found in OpenBSD,
 * NetBSD and FreeBSD.
 *
 * Maintainer: <vedge at csoft.org>
 */

#include <sys/param.h>

#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#if defined(HAVE_USB_H)
#include <usb.h>
#endif
#ifdef __DragonFly__
#include <bus/usb/usb.h>
#include <bus/usb/usbhid.h>
#else
#include <dev/usb/usb.h>
#include <dev/usb/usbhid.h>
#endif

#if defined(HAVE_USBHID_H)
#include <usbhid.h>
#elif defined(HAVE_LIBUSB_H)
#include <libusb.h>
#elif defined(HAVE_LIBUSBHID_H)
#include <libusbhid.h>
#endif

#ifdef __FREEBSD__
#ifndef __DragonFly__
#include <osreldate.h>
#endif
#include <sys/joystick.h>
#endif

#if SDL_JOYSTICK_USBHID_MACHINE_JOYSTICK_H
#include <machine/joystick.h>
#endif

#include "SDL_joystick.h"
#include "../SDL_sysjoystick.h"
#include "../SDL_joystick_c.h"

#define MAX_UHID_JOYS	4
#define MAX_JOY_JOYS	2
#define MAX_JOYS	(MAX_UHID_JOYS + MAX_JOY_JOYS)

struct report {
	struct	usb_ctl_report *buf;	/* Buffer */
	size_t	size;			/* Buffer size */
	int	rid;			/* Report ID */
	enum {
		SREPORT_UNINIT,
		SREPORT_CLEAN,
		SREPORT_DIRTY
	} status;
};

static struct {
	int	uhid_report;
	hid_kind_t kind;
	const	char *name;
} const repinfo[] = {
	{ UHID_INPUT_REPORT,	hid_input,	"input" },
	{ UHID_OUTPUT_REPORT,	hid_output,	"output" },
	{ UHID_FEATURE_REPORT,	hid_feature,	"feature" }
};

enum {
	REPORT_INPUT = 0,
	REPORT_OUTPUT = 1,
	REPORT_FEATURE = 2
};

enum {
	JOYAXE_X,
	JOYAXE_Y,
	JOYAXE_Z,
	JOYAXE_SLIDER,
	JOYAXE_WHEEL,
	JOYAXE_RX,
	JOYAXE_RY,
	JOYAXE_RZ,
	JOYAXE_count
};

struct joystick_hwdata {
	int	fd;
	char	*path;
	enum {
		BSDJOY_UHID,	/* uhid(4) */
		BSDJOY_JOY	/* joy(4) */
	} type;
	struct	report_desc *repdesc;
	struct	report inreport;
	int	axis_map[JOYAXE_count];	/* map present JOYAXE_* to 0,1,..*/
	int	x;
	int	y;
	int	xmin;
	int	ymin;
	int	xmax;
	int	ymax;
};

static char *joynames[MAX_JOYS];
static char *joydevnames[MAX_JOYS];

static int	report_alloc(struct report *, struct report_desc *, int);
static void	report_free(struct report *);

#ifdef USBHID_UCR_DATA
#define REP_BUF_DATA(rep) ((rep)->buf->ucr_data)
#else
#define REP_BUF_DATA(rep) ((rep)->buf->data)
#endif

int
SDL_SYS_JoystickInit(void)
{
	char s[16];
	int i, fd;

	SDL_numjoysticks = 0;

	SDL_memset(joynames, 0, sizeof(joynames));
	SDL_memset(joydevnames, 0, sizeof(joydevnames));

	for (i = 0; i < MAX_UHID_JOYS; i++) {
		SDL_Joystick nj;

		SDL_snprintf(s, SDL_arraysize(s), "/dev/uhid%d", i);

		nj.index = SDL_numjoysticks;
		joynames[nj.index] = strdup(s);

		if (SDL_SYS_JoystickOpen(&nj) == 0) {
			SDL_SYS_JoystickClose(&nj);
			SDL_numjoysticks++;
		} else {
			SDL_free(joynames[nj.index]);
			joynames[nj.index] = NULL;
		}
	}
	for (i = 0; i < MAX_JOY_JOYS; i++) {
		SDL_snprintf(s, SDL_arraysize(s), "/dev/joy%d", i);
		fd = open(s, O_RDONLY);
		if (fd != -1) {
			joynames[SDL_numjoysticks++] = strdup(s);
			close(fd);
		}
	}

	/* Read the default USB HID usage table. */
	hid_init(NULL);

	return (SDL_numjoysticks);
}

const char *
SDL_SYS_JoystickName(int index)
{
	if (joydevnames[index] != NULL) {
		return (joydevnames[index]);
	}
	return (joynames[index]);
}

static int
usage_to_joyaxe(unsigned usage)
{
    int joyaxe;
    switch (usage) {
    case HUG_X:
	joyaxe = JOYAXE_X; break;
    case HUG_Y:
	joyaxe = JOYAXE_Y; break;
    case HUG_Z:
	joyaxe = JOYAXE_Z; break;
    case HUG_SLIDER:
	joyaxe = JOYAXE_SLIDER; break;
    case HUG_WHEEL:
	joyaxe = JOYAXE_WHEEL; break;
    case HUG_RX:
	joyaxe = JOYAXE_RX; break;
    case HUG_RY:
	joyaxe = JOYAXE_RY; break;
    case HUG_RZ:
	joyaxe = JOYAXE_RZ; break;
    default:
	joyaxe = -1;
    }
    return joyaxe;    
}

static unsigned
hatval_to_sdl(Sint32 hatval)
{
    static const unsigned hat_dir_map[8] = {
	SDL_HAT_UP, SDL_HAT_RIGHTUP, SDL_HAT_RIGHT, SDL_HAT_RIGHTDOWN, 
	SDL_HAT_DOWN, SDL_HAT_LEFTDOWN, SDL_HAT_LEFT, SDL_HAT_LEFTUP
    };
    unsigned result;
    if ((hatval & 7) == hatval) 
	result = hat_dir_map[hatval];
    else 
	result = SDL_HAT_CENTERED;
    return result;
}


int
SDL_SYS_JoystickOpen(SDL_Joystick *joy)
{
	char *path = joynames[joy->index];
	struct joystick_hwdata *hw;
	struct hid_item hitem;
	struct hid_data *hdata;
	struct report *rep;
	int fd;
	int i;

	fd = open(path, O_RDONLY);
	if (fd == -1) {
		SDL_SetError("%s: %s", path, strerror(errno));
		return (-1);
	}

	hw = (struct joystick_hwdata *)SDL_malloc(sizeof(struct joystick_hwdata));
	if (hw == NULL) {
		SDL_OutOfMemory();
		close(fd);
		return (-1);
	}
	joy->hwdata = hw;
	hw->fd = fd;
	hw->path = strdup(path);
	hw->x = 0;
	hw->y = 0;
	hw->xmin = 0xffff;
	hw->ymin = 0xffff;
	hw->xmax = 0;
	hw->ymax = 0;
	if (! SDL_strncmp(path, "/dev/joy", 8)) {
		hw->type = BSDJOY_JOY;
		joy->naxes = 2;
		joy->nbuttons = 2;
		joy->nhats = 0;
		joy->nballs = 0;
		joydevnames[joy->index] = strdup("Gameport joystick");
		goto usbend;
	} else {
		hw->type = BSDJOY_UHID;
	}

	{
	    int ax;
	    for (ax = 0; ax < JOYAXE_count; ax++)
		hw->axis_map[ax] = -1;
	}
	hw->repdesc = hid_get_report_desc(fd);
	if (hw->repdesc == NULL) {
		SDL_SetError("%s: USB_GET_REPORT_DESC: %s", hw->path,
		    strerror(errno));
		goto usberr;
	}

	rep = &hw->inreport;
	if (ioctl(fd, USB_GET_REPORT_ID, &rep->rid) < 0) {
		rep->rid = -1; /* XXX */
	}
	if (report_alloc(rep, hw->repdesc, REPORT_INPUT) < 0) {
		goto usberr;
	}
	if (rep->size <= 0) {
		SDL_SetError("%s: Input report descriptor has invalid length",
		    hw->path);
		goto usberr;
	}

#if defined(USBHID_NEW) || (defined(__FREEBSD__) && __FreeBSD_version >= 500111)
	hdata = hid_start_parse(hw->repdesc, 1 << hid_input, rep->rid);
#else
	hdata = hid_start_parse(hw->repdesc, 1 << hid_input);
#endif
	if (hdata == NULL) {
		SDL_SetError("%s: Cannot start HID parser", hw->path);
		goto usberr;
	}
	joy->naxes = 0;
	joy->nbuttons = 0;
	joy->nhats = 0;
	joy->nballs = 0;
	for (i=0; i<JOYAXE_count; i++)
		hw->axis_map[i] = -1;

	while (hid_get_item(hdata, &hitem) > 0) {
		char *sp;
		const char *s;

		switch (hitem.kind) {
		case hid_collection:
			switch (HID_PAGE(hitem.usage)) {
			case HUP_GENERIC_DESKTOP:
				switch (HID_USAGE(hitem.usage)) {
				case HUG_JOYSTICK:
				case HUG_GAME_PAD:
					s = hid_usage_in_page(hitem.usage);
					sp = SDL_malloc(SDL_strlen(s) + 5);
					SDL_snprintf(sp, SDL_strlen(s) + 5, "%s (%d)", s,
					    joy->index);
					joydevnames[joy->index] = sp;
				}
			}
			break;
		case hid_input:
			switch (HID_PAGE(hitem.usage)) {
			case HUP_GENERIC_DESKTOP: {
			    unsigned usage = HID_USAGE(hitem.usage);
			    int joyaxe = usage_to_joyaxe(usage);
			    if (joyaxe >= 0) {
				hw->axis_map[joyaxe] = 1;
			    } else if (usage == HUG_HAT_SWITCH) {
				joy->nhats++;
			    }
			    break;
			}
			case HUP_BUTTON:
				joy->nbuttons++;
				break;
			default:
				break;
			}
			break;
		default:
			break;
		}
	}
	hid_end_parse(hdata);
	for (i=0; i<JOYAXE_count; i++)
		if (hw->axis_map[i] > 0)
			hw->axis_map[i] = joy->naxes++;

usbend:
	/* The poll blocks the event thread. */
	fcntl(fd, F_SETFL, O_NONBLOCK);

	return (0);
usberr:
	close(hw->fd);
	SDL_free(hw->path);
	SDL_free(hw);
	return (-1);
}

void
SDL_SYS_JoystickUpdate(SDL_Joystick *joy)
{
	struct hid_item hitem;
	struct hid_data *hdata;
	struct report *rep;
	int nbutton, naxe = -1;
	Sint32 v;

#if defined(__FREEBSD__) || SDL_JOYSTICK_USBHID_MACHINE_JOYSTICK_H
	struct joystick gameport;
 
	if (joy->hwdata->type == BSDJOY_JOY) {
		if (read(joy->hwdata->fd, &gameport, sizeof gameport) != sizeof gameport)
			return;
		if (abs(joy->hwdata->x - gameport.x) > 8) {
			joy->hwdata->x = gameport.x;
			if (joy->hwdata->x < joy->hwdata->xmin) {
				joy->hwdata->xmin = joy->hwdata->x;
			}
			if (joy->hwdata->x > joy->hwdata->xmax) {
				joy->hwdata->xmax = joy->hwdata->x;
			}
			if (joy->hwdata->xmin == joy->hwdata->xmax) {
				joy->hwdata->xmin--;
				joy->hwdata->xmax++;
			}
			v = (Sint32)joy->hwdata->x;
			v -= (joy->hwdata->xmax + joy->hwdata->xmin + 1)/2;
			v *= 32768/((joy->hwdata->xmax - joy->hwdata->xmin + 1)/2);
			SDL_PrivateJoystickAxis(joy, 0, v);
		}
		if (abs(joy->hwdata->y - gameport.y) > 8) {
			joy->hwdata->y = gameport.y;
			if (joy->hwdata->y < joy->hwdata->ymin) {
				joy->hwdata->ymin = joy->hwdata->y;
			}
			if (joy->hwdata->y > joy->hwdata->ymax) {
				joy->hwdata->ymax = joy->hwdata->y;
			}
			if (joy->hwdata->ymin == joy->hwdata->ymax) {
				joy->hwdata->ymin--;
				joy->hwdata->ymax++;
			}
			v = (Sint32)joy->hwdata->y;
			v -= (joy->hwdata->ymax + joy->hwdata->ymin + 1)/2;
			v *= 32768/((joy->hwdata->ymax - joy->hwdata->ymin + 1)/2);
			SDL_PrivateJoystickAxis(joy, 1, v);
		}
		if (gameport.b1 != joy->buttons[0]) {
			SDL_PrivateJoystickButton(joy, 0, gameport.b1);
		}
		if (gameport.b2 != joy->buttons[1]) {
			SDL_PrivateJoystickButton(joy, 1, gameport.b2);
		}
		return;
	}
#endif /* defined(__FREEBSD__) || SDL_JOYSTICK_USBHID_MACHINE_JOYSTICK_H */
	
	rep = &joy->hwdata->inreport;

	if (read(joy->hwdata->fd, REP_BUF_DATA(rep), rep->size) != rep->size) {
		return;
	}
#if defined(USBHID_NEW) || (defined(__FREEBSD__) && __FreeBSD_version >= 500111)
	hdata = hid_start_parse(joy->hwdata->repdesc, 1 << hid_input, rep->rid);
#else
	hdata = hid_start_parse(joy->hwdata->repdesc, 1 << hid_input);
#endif
	if (hdata == NULL) {
		fprintf(stderr, "%s: Cannot start HID parser\n",
		    joy->hwdata->path);
		return;
	}

	for (nbutton = 0; hid_get_item(hdata, &hitem) > 0;) {
		switch (hitem.kind) {
		case hid_input:
			switch (HID_PAGE(hitem.usage)) {
			case HUP_GENERIC_DESKTOP: {
			    unsigned usage = HID_USAGE(hitem.usage);
			    int joyaxe = usage_to_joyaxe(usage);
			    if (joyaxe >= 0) {
				naxe = joy->hwdata->axis_map[joyaxe];
				/* scaleaxe */
				v = (Sint32)hid_get_data(REP_BUF_DATA(rep),
							 &hitem);
				v -= (hitem.logical_maximum + hitem.logical_minimum + 1)/2;
				v *= 32768/((hitem.logical_maximum - hitem.logical_minimum + 1)/2);
				if (v != joy->axes[naxe]) {
				    SDL_PrivateJoystickAxis(joy, naxe, v);
				}
			    } else if (usage == HUG_HAT_SWITCH) {
				v = (Sint32)hid_get_data(REP_BUF_DATA(rep),
							 &hitem);
				SDL_PrivateJoystickHat(joy, 0,
					hatval_to_sdl(v)-hitem.logical_minimum);
			    }
			    break;
			}
			case HUP_BUTTON:
				v = (Sint32)hid_get_data(REP_BUF_DATA(rep),
				    &hitem);
				if (joy->buttons[nbutton] != v) {
					SDL_PrivateJoystickButton(joy,
					    nbutton, v);
				}
				nbutton++;
				break;
			default:
				continue;
			}
			break;
		default:
			break;
		}
	}
	hid_end_parse(hdata);

	return;
}

/* Function to close a joystick after use */
void
SDL_SYS_JoystickClose(SDL_Joystick *joy)
{
	if (SDL_strncmp(joy->hwdata->path, "/dev/joy", 8))	{
		report_free(&joy->hwdata->inreport);
		hid_dispose_report_desc(joy->hwdata->repdesc);
	}
	close(joy->hwdata->fd);
	SDL_free(joy->hwdata->path);
	SDL_free(joy->hwdata);

	return;
}

void
SDL_SYS_JoystickQuit(void)
{
	int i;

	for (i = 0; i < MAX_JOYS; i++) {
		if (joynames[i] != NULL)
			SDL_free(joynames[i]);
		if (joydevnames[i] != NULL)
			SDL_free(joydevnames[i]);
	}

	return;
}

static int
report_alloc(struct report *r, struct report_desc *rd, int repind)
{
	int len;

#ifdef __DragonFly__
	len = hid_report_size(rd, r->rid, repinfo[repind].kind);
#elif __FREEBSD__
# if (__FreeBSD_version >= 460000)
#  if (__FreeBSD_version <= 500111)
	len = hid_report_size(rd, r->rid, repinfo[repind].kind);
#  else
	len = hid_report_size(rd, repinfo[repind].kind, r->rid);
#  endif
# else
	len = hid_report_size(rd, repinfo[repind].kind, &r->rid);
# endif
#else
# ifdef USBHID_NEW
	len = hid_report_size(rd, repinfo[repind].kind, r->rid);
# else
	len = hid_report_size(rd, repinfo[repind].kind, &r->rid);
# endif
#endif

	if (len < 0) {
		SDL_SetError("Negative HID report size");
		return (-1);
	}
	r->size = len;

	if (r->size > 0) {
		r->buf = SDL_malloc(sizeof(*r->buf) - sizeof(REP_BUF_DATA(r)) +
		    r->size);
		if (r->buf == NULL) {
			SDL_OutOfMemory();
			return (-1);
		}
	} else {
		r->buf = NULL;
	}

	r->status = SREPORT_CLEAN;
	return (0);
}

static void
report_free(struct report *r)
{
	if (r->buf != NULL) {
		SDL_free(r->buf);
	}
	r->status = SREPORT_UNINIT;
}

#endif /* SDL_JOYSTICK_USBHID */