void gdImageFilledArc (gdImagePtr im, int cx, int cy, int w, int h, int s, int e, int color, int style)
{
	gdPoint pts[3];
	int i;
	int lx = 0, ly = 0;
	int fx = 0, fy = 0;

    if ((s % 360)  == (e % 360)) {
		s = 0; e = 360;
	} else {
		if (s > 360) {
			s = s % 360;
		}

		if (e > 360) {
			e = e % 360;
		}

		while (s < 0) {
			s += 360;
		}

		while (e < s) {
			e += 360;
		}
		if (s == e) {
			s = 0; e = 360;
		}
	}

	for (i = s; i <= e; i++) {
		int x, y;
		x = ((long) gdCosT[i % 360] * (long) w / (2 * 1024)) + cx;
		y = ((long) gdSinT[i % 360] * (long) h / (2 * 1024)) + cy;
		if (i != s) {
			if (!(style & gdChord)) {
				if (style & gdNoFill) {
					gdImageLine(im, lx, ly, x, y, color);
				} else {
					/* This is expensive! */
					pts[0].x = lx;
					pts[0].y = ly;
					pts[1].x = x;
					pts[1].y = y;
					pts[2].x = cx;
					pts[2].y = cy;
					gdImageFilledPolygon(im, pts, 3, color);
				}
			}
		} else {
			fx = x;
			fy = y;
		}
		lx = x;
		ly = y;
	}
	if (style & gdChord) {
		if (style & gdNoFill) {
			if (style & gdEdged) {
				gdImageLine(im, cx, cy, lx, ly, color);
				gdImageLine(im, cx, cy, fx, fy, color);
			}
			gdImageLine(im, fx, fy, lx, ly, color);
		} else {
			pts[0].x = fx;
			pts[0].y = fy;
			pts[1].x = lx;
			pts[1].y = ly;
			pts[2].x = cx;
			pts[2].y = cy;
			gdImageFilledPolygon(im, pts, 3, color);
		}
	} else {
		if (style & gdNoFill) {
			if (style & gdEdged) {
				gdImageLine(im, cx, cy, lx, ly, color);
				gdImageLine(im, cx, cy, fx, fy, color);
			}
		}
	}
}


static HWBType * RGB_to_HWB (RGBType RGB, HWBType * HWB)
{
	/*
	 * RGB are each on [0, 1]. W and B are returned on [0, 1] and H is
	 * returned on [0, 6]. Exception: H is returned UNDEFINED if W == 1 - B.
	 */

	float R = RGB.R, G = RGB.G, B = RGB.B, w, v, b, f;
	int i;

	w = MIN3 (R, G, B);
	v = MAX3 (R, G, B);
	b = 1 - v;
	if (v == w) {
		RETURN_HWB(HWB_UNDEFINED, w, b);
	}
	f = (R == w) ? G - B : ((G == w) ? B - R : R - G);
	i = (R == w) ? 3 : ((G == w) ? 5 : 1);

	RETURN_HWB(i - f / (v - w), w, b);
}

iFixed bug #72446 - Integer Overflow in gdImagePaletteToTrueColor() resulting in heap overflow


void gdImageArc (gdImagePtr im, int cx, int cy, int w, int h, int s, int e, int color)
{
	if ((s % 360) == (e % 360)) {
		gdImageEllipse(im, cx, cy, w, h, color);
	} else {
		gdImageFilledArc(im, cx, cy, w, h, s, e, color, gdNoFill);
	}
}


void gdImageChar (gdImagePtr im, gdFontPtr f, int x, int y, int c, int color)
{
	int cx, cy;
	int px, py;
	int fline;
	cx = 0;
	cy = 0;
#ifdef CHARSET_EBCDIC
	c = ASC (c);
#endif /*CHARSET_EBCDIC */
	if ((c < f->offset) || (c >= (f->offset + f->nchars))) {
		return;
	}
	fline = (c - f->offset) * f->h * f->w;
	for (py = y; (py < (y + f->h)); py++) {
		for (px = x; (px < (x + f->w)); px++) {
			if (f->data[fline + cy * f->w + cx]) {
				gdImageSetPixel(im, px, py, color);
			}
			cx++;
		}
		cx = 0;
		cy++;
	}
}


long lsqrt (long n)
{
 	long result = (long) sqrt ((double) n);
	return result;
}


int gdImageColorClosestHWB (gdImagePtr im, int r, int g, int b)
{
	int i;
	/* long rd, gd, bd; */
	int ct = (-1);
	int first = 1;
	float mindist = 0;
	if (im->trueColor) {
		return gdTrueColor(r, g, b);
	}
	for (i = 0; i < im->colorsTotal; i++) {
		float dist;
		if (im->open[i]) {
			continue;
		}
		dist = HWB_Diff(im->red[i], im->green[i], im->blue[i], r, g, b);
		if (first || (dist < mindist)) {
			mindist = dist;
			ct = i;
			first = 0;
		}
	}
	return ct;
}


int gdImageCompare (gdImagePtr im1, gdImagePtr im2)
{
	int x, y;
	int p1, p2;
	int cmpStatus = 0;
	int sx, sy;

	if (im1->interlace != im2->interlace) {
		cmpStatus |= GD_CMP_INTERLACE;
	}

	if (im1->transparent != im2->transparent) {
		cmpStatus |= GD_CMP_TRANSPARENT;
	}

	if (im1->trueColor != im2->trueColor) {
		cmpStatus |= GD_CMP_TRUECOLOR;
	}

	sx = im1->sx;
	if (im1->sx != im2->sx) {
		cmpStatus |= GD_CMP_SIZE_X + GD_CMP_IMAGE;
		if (im2->sx < im1->sx) {
			sx = im2->sx;
		}
	}

	sy = im1->sy;
	if (im1->sy != im2->sy) {
		cmpStatus |= GD_CMP_SIZE_Y + GD_CMP_IMAGE;
		if (im2->sy < im1->sy) {
			sy = im2->sy;
		}
	}

	if (im1->colorsTotal != im2->colorsTotal) {
		cmpStatus |= GD_CMP_NUM_COLORS;
	}

	for (y = 0; y < sy; y++) {
		for (x = 0; x < sx; x++) {
			p1 = im1->trueColor ? gdImageTrueColorPixel(im1, x, y) : gdImagePalettePixel(im1, x, y);
			p2 = im2->trueColor ? gdImageTrueColorPixel(im2, x, y) : gdImagePalettePixel(im2, x, y);

			if (gdImageRed(im1, p1) != gdImageRed(im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
			if (gdImageGreen(im1, p1) != gdImageGreen(im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
			if (gdImageBlue(im1, p1) != gdImageBlue(im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
#if 0
			/* Soon we'll add alpha channel to palettes */
			if (gdImageAlpha(im1, p1) != gdImageAlpha(im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
#endif
		}
		if (cmpStatus & GD_CMP_COLOR) {
			break;
		}
	}

	return cmpStatus;
}


static void gdImageVLine(gdImagePtr im, int x, int y1, int y2, int col)
{
	if (im->thick > 1) {
		int thickhalf = im->thick >> 1;
		gdImageFilledRectangle(im, x - thickhalf, y1, x + im->thick - thickhalf - 1, y2, col);
	} else {
		if (y2 < y1) {
			int t = y1;
			y1 = y2;
			y2 = t;
		}

		for (;y1 <= y2; y1++) {
			gdImageSetPixel(im, x, y1, col);
		}
	}
	return;
}


void gdImageSetBrush (gdImagePtr im, gdImagePtr brush)
{
	int i;
	im->brush = brush;
	if (!im->trueColor && !im->brush->trueColor) {
		for (i = 0; i < gdImageColorsTotal(brush); i++) {
			int index;
			index = gdImageColorResolveAlpha(im, gdImageRed(brush, i), gdImageGreen(brush, i), gdImageBlue(brush, i), gdImageAlpha(brush, i));
			im->brushColorMap[i] = index;
		}
	}
}


void gdImageAABlend (gdImagePtr im)
{
	float p_alpha, old_alpha;
	int color = im->AA_color, color_red, color_green, color_blue;
	int old_color, old_red, old_green, old_blue;
	int p_color, p_red, p_green, p_blue;
	int px, py;

	color_red = gdImageRed(im, color);
	color_green = gdImageGreen(im, color);
	color_blue = gdImageBlue(im, color);

	/* Impose the anti-aliased drawing on the image. */
	for (py = 0; py < im->sy; py++) {
		for (px = 0; px < im->sx; px++) {
			if (im->AA_opacity[py][px] != 0) {
				old_color = gdImageGetPixel(im, px, py);

				if ((old_color != color) && ((old_color != im->AA_dont_blend) || (im->AA_opacity[py][px] == 255))) {
					/* Only blend with different colors that aren't the dont_blend color. */
					p_alpha = (float) (im->AA_opacity[py][px]) / 255.0;
					old_alpha = 1.0 - p_alpha;

					if (p_alpha >= 1.0) {
						p_color = color;
					} else {
						old_red = gdImageRed(im, old_color);
						old_green = gdImageGreen(im, old_color);
						old_blue = gdImageBlue(im, old_color);

						p_red = (int) (((float) color_red * p_alpha) + ((float) old_red * old_alpha));
						p_green = (int) (((float) color_green * p_alpha) + ((float) old_green * old_alpha));
						p_blue = (int) (((float) color_blue * p_alpha) + ((float) old_blue * old_alpha));
						p_color = gdImageColorResolve(im, p_red, p_green, p_blue);
					}
					gdImageSetPixel(im, px, py, p_color);
				}
			}
		}
		/* Clear the AA_opacity array behind us. */
		memset(im->AA_opacity[py], 0, im->sx);
	}
}


void gdImageCopyResized (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX, int srcY, int dstW, int dstH, int srcW, int srcH)
{
	int c;
	int x, y;
	int tox, toy;
	int ydest;
	int i;
	int colorMap[gdMaxColors];
	/* Stretch vectors */
	int *stx, *sty;

	if (overflow2(sizeof(int), srcW)) {
		return;
	}
	if (overflow2(sizeof(int), srcH)) {
		return;
	}

	stx = (int *) gdMalloc (sizeof (int) * srcW);
	sty = (int *) gdMalloc (sizeof (int) * srcH);

	/* Fixed by Mao Morimoto 2.0.16 */
	for (i = 0; (i < srcW); i++) {
		stx[i] = dstW * (i+1) / srcW - dstW * i / srcW ;
	}
	for (i = 0; (i < srcH); i++) {
		sty[i] = dstH * (i+1) / srcH - dstH * i / srcH ;
	}
	for (i = 0; (i < gdMaxColors); i++) {
		colorMap[i] = (-1);
	}
	toy = dstY;
	for (y = srcY; (y < (srcY + srcH)); y++) {
		for (ydest = 0; (ydest < sty[y - srcY]); ydest++) {
			tox = dstX;
			for (x = srcX; (x < (srcX + srcW)); x++) {
				int nc = 0;
				int mapTo;
				if (!stx[x - srcX]) {
					continue;
				}
				if (dst->trueColor) {
					/* 2.0.9: Thorben Kundinger: Maybe the source image is not a truecolor image */
					if (!src->trueColor) {
					  	int tmp = gdImageGetPixel (src, x, y);
		  				mapTo = gdImageGetTrueColorPixel (src, x, y);
					  	if (gdImageGetTransparent (src) == tmp) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
					  		continue;
					  	}
					} else {
						/* TK: old code follows */
					  	mapTo = gdImageGetTrueColorPixel (src, x, y);
						/* Added 7/24/95: support transparent copies */
						if (gdImageGetTransparent (src) == mapTo) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
							continue;
						}
					}
				} else {
					c = gdImageGetPixel (src, x, y);
					/* Added 7/24/95: support transparent copies */
					if (gdImageGetTransparent (src) == c) {
					      tox += stx[x - srcX];
					      continue;
					}
					if (src->trueColor) {
					      /* Remap to the palette available in the destination image. This is slow and works badly. */
					      mapTo = gdImageColorResolveAlpha(dst, gdTrueColorGetRed(c),
					      					    gdTrueColorGetGreen(c),
					      					    gdTrueColorGetBlue(c),
					      					    gdTrueColorGetAlpha (c));
					} else {
						/* Have we established a mapping for this color? */
						if (colorMap[c] == (-1)) {
							/* If it's the same image, mapping is trivial */
							if (dst == src) {
								nc = c;
							} else {
								/* Find or create the best match */
								/* 2.0.5: can't use gdTrueColorGetRed, etc with palette */
								nc = gdImageColorResolveAlpha(dst, gdImageRed(src, c),
												   gdImageGreen(src, c),
												   gdImageBlue(src, c),
												   gdImageAlpha(src, c));
							}
							colorMap[c] = nc;
						}
						mapTo = colorMap[c];
					}
				}
				for (i = 0; (i < stx[x - srcX]); i++) {
					gdImageSetPixel (dst, tox, toy, mapTo);
					tox++;
				}
			}
			toy++;
		}
	}
	gdFree (stx);
	gdFree (sty);
}


void gdImageColorDeallocate (gdImagePtr im, int color)
{
	if (im->trueColor) {
		return;
	}
	/* Mark it open. */
	im->open[color] = 1;
}


void gdImageSetPixel (gdImagePtr im, int x, int y, int color)
{
	int p;
	switch (color) {
		case gdStyled:
			if (!im->style) {
				/* Refuse to draw if no style is set. */
				return;
			} else {
				p = im->style[im->stylePos++];
			}
			if (p != gdTransparent) {
				gdImageSetPixel(im, x, y, p);
			}
			im->stylePos = im->stylePos % im->styleLength;
			break;
		case gdStyledBrushed:
			if (!im->style) {
				/* Refuse to draw if no style is set. */
				return;
			}
			p = im->style[im->stylePos++];
			if (p != gdTransparent && p != 0) {
				gdImageSetPixel(im, x, y, gdBrushed);
			}
			im->stylePos = im->stylePos % im->styleLength;
			break;
		case gdBrushed:
			gdImageBrushApply(im, x, y);
			break;
		case gdTiled:
			gdImageTileApply(im, x, y);
			break;
		case gdAntiAliased:
			gdImageAntiAliasedApply(im, x, y);
			break;
		default:
			if (gdImageBoundsSafe(im, x, y)) {
				if (im->trueColor) {
					switch (im->alphaBlendingFlag) {
						default:
						case gdEffectReplace:
							im->tpixels[y][x] = color;
							break;
						case gdEffectAlphaBlend:
							im->tpixels[y][x] = gdAlphaBlend(im->tpixels[y][x], color);
							break;
						case gdEffectNormal:
							im->tpixels[y][x] = gdAlphaBlend(im->tpixels[y][x], color);
							break;
						case gdEffectOverlay :
							im->tpixels[y][x] = gdLayerOverlay(im->tpixels[y][x], color);
							break;
					}
				} else {
					im->pixels[y][x] = color;
				}
			}
			break;
	}
}


void gdImageSetAntiAliasedDontBlend (gdImagePtr im, int c, int dont_blend)
{
	im->AA = 1;
	im->AA_color = c;
	im->AA_dont_blend = dont_blend;
}


void gdImageInterlace (gdImagePtr im, int interlaceArg)
{
	im->interlace = interlaceArg;
}


int gdImageColorClosestAlpha (gdImagePtr im, int r, int g, int b, int a)
{
	int i;
	long rd, gd, bd, ad;
	int ct = (-1);
	int first = 1;
	long mindist = 0;

	if (im->trueColor) {
		return gdTrueColorAlpha(r, g, b, a);
	}
	for (i = 0; i < im->colorsTotal; i++) {
		long dist;
		if (im->open[i]) {
			continue;
		}
		rd = im->red[i] - r;
		gd = im->green[i] - g;
		bd = im->blue[i] - b;
		/* gd 2.02: whoops, was - b (thanks to David Marwood) */
		ad = im->alpha[i] - a;
		dist = rd * rd + gd * gd + bd * bd + ad * ad;
		if (first || (dist < mindist)) {
			mindist = dist;
			ct = i;
			first = 0;
		}
	}
	return ct;
}


static int gdImageTileGet (gdImagePtr im, int x, int y)
{
	int srcx, srcy;
	int tileColor,p;
	if (!im->tile) {
		return -1;
	}
	srcx = x % gdImageSX(im->tile);
	srcy = y % gdImageSY(im->tile);
	p = gdImageGetPixel(im->tile, srcx, srcy);

	if (im->trueColor) {
		if (im->tile->trueColor) {
			tileColor = p;
		} else {
			tileColor = gdTrueColorAlpha( gdImageRed(im->tile,p), gdImageGreen(im->tile,p), gdImageBlue (im->tile,p), gdImageAlpha (im->tile,p));
		}
	} else {
		if (im->tile->trueColor) {
			tileColor = gdImageColorResolveAlpha(im, gdTrueColorGetRed (p), gdTrueColorGetGreen (p), gdTrueColorGetBlue (p), gdTrueColorGetAlpha (p));
		} else {
			tileColor = p;
			tileColor = gdImageColorResolveAlpha(im, gdImageRed (im->tile,p), gdImageGreen (im->tile,p), gdImageBlue (im->tile,p), gdImageAlpha (im->tile,p));
		}
	}
	return tileColor;
}


void gdImageSetStyle (gdImagePtr im, int *style, int noOfPixels)
{
	if (im->style) {
		gdFree(im->style);
	}
	im->style = (int *) gdMalloc(sizeof(int) * noOfPixels);
	memcpy(im->style, style, sizeof(int) * noOfPixels);
	im->styleLength = noOfPixels;
	im->stylePos = 0;
}


int gdImageColorResolveAlpha (gdImagePtr im, int r, int g, int b, int a)
{
  int c;
  int ct = -1;
  int op = -1;
  long rd, gd, bd, ad, dist;
  long mindist = 4 * 255 * 255;	/* init to max poss dist */
  if (im->trueColor)
    {
      return gdTrueColorAlpha (r, g, b, a);
    }

  for (c = 0; c < im->colorsTotal; c++)
    {
      if (im->open[c])
	{
	  op = c;		/* Save open slot */
	  continue;		/* Color not in use */
	}
      if (c == im->transparent)
        {
          /* don't ever resolve to the color that has
           * been designated as the transparent color */
          continue;
	}
      rd = (long) (im->red[c] - r);
      gd = (long) (im->green[c] - g);
      bd = (long) (im->blue[c] - b);
      ad = (long) (im->alpha[c] - a);
      dist = rd * rd + gd * gd + bd * bd + ad * ad;
      if (dist < mindist)
	{
	  if (dist == 0)
	    {
	      return c;		/* Return exact match color */
	    }
	  mindist = dist;
	  ct = c;
	}
    }
  /* no exact match.  We now know closest, but first try to allocate exact */
  if (op == -1)
    {
      op = im->colorsTotal;
      if (op == gdMaxColors)
	{			/* No room for more colors */
	  return ct;		/* Return closest available color */
	}
      im->colorsTotal++;
    }
  im->red[op] = r;
  im->green[op] = g;
  im->blue[op] = b;
  im->alpha[op] = a;
  im->open[op] = 0;
  return op;			/* Return newly allocated color */
}


static void gdImageAntiAliasedApply (gdImagePtr im, int px, int py)
{
	float p_dist, p_alpha;
	unsigned char opacity;

	/*
	 * Find the perpendicular distance from point C (px, py) to the line
	 * segment AB that is being drawn.  (Adapted from an algorithm from the
	 * comp.graphics.algorithms FAQ.)
	 */

	int LAC_2, LBC_2;

	int Ax_Cx = im->AAL_x1 - px;
	int Ay_Cy = im->AAL_y1 - py;

	int Bx_Cx = im->AAL_x2 - px;
	int By_Cy = im->AAL_y2 - py;

	/* 2.0.13: bounds check! AA_opacity is just as capable of
	 * overflowing as the main pixel array. Arne Jorgensen.
	 * 2.0.14: typo fixed. 2.0.15: moved down below declarations
	 * to satisfy non-C++ compilers.
	 */
	if (!gdImageBoundsSafe(im, px, py)) {
		return;
	}

	/* Get the squares of the lengths of the segemnts AC and BC. */
	LAC_2 = (Ax_Cx * Ax_Cx) + (Ay_Cy * Ay_Cy);
	LBC_2 = (Bx_Cx * Bx_Cx) + (By_Cy * By_Cy);

	if (((im->AAL_LAB_2 + LAC_2) >= LBC_2) && ((im->AAL_LAB_2 + LBC_2) >= LAC_2)) {
		/* The two angles are acute.  The point lies inside the portion of the
		 * plane spanned by the line segment.
		 */
		p_dist = fabs ((float) ((Ay_Cy * im->AAL_Bx_Ax) - (Ax_Cx * im->AAL_By_Ay)) / im->AAL_LAB);
	} else {
		/* The point is past an end of the line segment.  It's length from the
		 * segment is the shorter of the lengths from the endpoints, but call
		 * the distance -1, so as not to compute the alpha nor draw the pixel.
		 */
		p_dist = -1;
	}

	if ((p_dist >= 0) && (p_dist <= (float) (im->thick))) {
		p_alpha = pow (1.0 - (p_dist / 1.5), 2);

		if (p_alpha > 0) {
			if (p_alpha >= 1) {
				opacity = 255;
			} else {
				opacity = (unsigned char) (p_alpha * 255.0);
			}
			if (!im->AA_polygon || (im->AA_opacity[py][px] < opacity)) {
				im->AA_opacity[py][px] = opacity;
			}
		}
	}
}


void gdImageStringUp (gdImagePtr im, gdFontPtr f, int x, int y, unsigned char *s, int color)
{
	int i;
	int l;
	l = strlen ((char *) s);
	for (i = 0; (i < l); i++) {
		gdImageCharUp(im, f, x, y, s[i], color);
		y -= f->w;
	}
}


void gdImageAntialias (gdImagePtr im, int antialias)
{
	if (im->trueColor){
		im->antialias = antialias;
	}
}


void gdImageLine (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int dx, dy, incr1, incr2, d, x, y, xend, yend, xdirflag, ydirflag;
	int wid;
	int w, wstart;
	int thick = im->thick;

	if (color == gdAntiAliased) {
		/*
		   gdAntiAliased passed as color: use the much faster, much cheaper
		   and equally attractive gdImageAALine implementation. That
		   clips too, so don't clip twice.
		   */
		gdImageAALine(im, x1, y1, x2, y2, im->AA_color);
		return;
	}

	/* 2.0.10: Nick Atty: clip to edges of drawing rectangle, return if no points need to be drawn */
	if (!clip_1d(&x1,&y1,&x2,&y2,gdImageSX(im)) || !clip_1d(&y1,&x1,&y2,&x2,gdImageSY(im))) {
		return;
	}

	dx = abs (x2 - x1);
	dy = abs (y2 - y1);

	if (dx == 0) {
		gdImageVLine(im, x1, y1, y2, color);
		return;
	} else if (dy == 0) {
		gdImageHLine(im, y1, x1, x2, color);
		return;
	}

	if (dy <= dx) {
		/* More-or-less horizontal. use wid for vertical stroke */
		/* Doug Claar: watch out for NaN in atan2 (2.0.5) */
		if ((dx == 0) && (dy == 0)) {
			wid = 1;
		} else {
			/* 2.0.12: Michael Schwartz: divide rather than multiply;
TBB: but watch out for /0! */
			double ac = cos (atan2 (dy, dx));
			if (ac != 0) {
				wid = thick / ac;
			} else {
				wid = 1;
			}
			if (wid == 0) {
				wid = 1;
			}
		}
		d = 2 * dy - dx;
		incr1 = 2 * dy;
		incr2 = 2 * (dy - dx);
		if (x1 > x2) {
			x = x2;
			y = y2;
			ydirflag = (-1);
			xend = x1;
		} else {
			x = x1;
			y = y1;
			ydirflag = 1;
			xend = x2;
		}

		/* Set up line thickness */
		wstart = y - wid / 2;
		for (w = wstart; w < wstart + wid; w++) {
			gdImageSetPixel(im, x, w, color);
		}

		if (((y2 - y1) * ydirflag) > 0) {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y++;
					d += incr2;
				}
				wstart = y - wid / 2;
				for (w = wstart; w < wstart + wid; w++) {
					gdImageSetPixel (im, x, w, color);
				}
			}
		} else {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y--;
					d += incr2;
				}
				wstart = y - wid / 2;
				for (w = wstart; w < wstart + wid; w++) {
					gdImageSetPixel (im, x, w, color);
				}
			}
		}
	} else {
		/* More-or-less vertical. use wid for horizontal stroke */
		/* 2.0.12: Michael Schwartz: divide rather than multiply;
		   TBB: but watch out for /0! */
		double as = sin (atan2 (dy, dx));
		if (as != 0) {
			wid = thick / as;
		} else {
			wid = 1;
		}
		if (wid == 0) {
			wid = 1;
		}

		d = 2 * dx - dy;
		incr1 = 2 * dx;
		incr2 = 2 * (dx - dy);
		if (y1 > y2) {
			y = y2;
			x = x2;
			yend = y1;
			xdirflag = (-1);
		} else {
			y = y1;
			x = x1;
			yend = y2;
			xdirflag = 1;
		}

		/* Set up line thickness */
		wstart = x - wid / 2;
		for (w = wstart; w < wstart + wid; w++) {
			gdImageSetPixel (im, w, y, color);
		}

		if (((x2 - x1) * xdirflag) > 0) {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x++;
					d += incr2;
				}
				wstart = x - wid / 2;
				for (w = wstart; w < wstart + wid; w++) {
					gdImageSetPixel (im, w, y, color);
				}
			}
		} else {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x--;
					d += incr2;
				}
				wstart = x - wid / 2;
				for (w = wstart; w < wstart + wid; w++) {
					gdImageSetPixel (im, w, y, color);
				}
			}
		}
	}
}


int gdImageGetTrueColorPixel (gdImagePtr im, int x, int y)
{
	int p = gdImageGetPixel(im, x, y);

	if (!im->trueColor)  {
		return gdTrueColorAlpha(im->red[p], im->green[p], im->blue[p], (im->transparent == p) ? gdAlphaTransparent : im->alpha[p]);
	} else {
		return p;
	}
}


void gdImagePaletteCopy (gdImagePtr to, gdImagePtr from)
{
	int i;
	int x, y, p;
	int xlate[256];
	if (to->trueColor || from->trueColor) {
		return;
	}

	for (i = 0; i < 256; i++) {
		xlate[i] = -1;
	}

	for (y = 0; y < to->sy; y++) {
		for (x = 0; x < to->sx; x++) {
			p = gdImageGetPixel(to, x, y);
			if (xlate[p] == -1) {
				/* This ought to use HWB, but we don't have an alpha-aware version of that yet. */
				xlate[p] = gdImageColorClosestAlpha (from, to->red[p], to->green[p], to->blue[p], to->alpha[p]);
			}
			gdImageSetPixel(to, x, y, xlate[p]);
		}
	}

	for (i = 0; i < from->colorsTotal; i++) {
		to->red[i] = from->red[i];
		to->blue[i] = from->blue[i];
		to->green[i] = from->green[i];
		to->alpha[i] = from->alpha[i];
		to->open[i] = 0;
	}

	for (i = from->colorsTotal; i < to->colorsTotal; i++) {
		to->open[i] = 1;
	}

	to->colorsTotal = from->colorsTotal;
}


int gdImagePaletteToTrueColor(gdImagePtr src)
{
	unsigned int y;
	unsigned int yy;

	if (src == NULL) {
		return 0;
	}

	if (src->trueColor == 1) {
		return 1;
	} else {
		unsigned int x;
		const unsigned int sy = gdImageSY(src);
		const unsigned int sx = gdImageSX(src);

		src->tpixels = (int **) gdMalloc(sizeof(int *) * sy);
		if (src->tpixels == NULL) {
			return 0;
		}

		for (y = 0; y < sy; y++) {
			const unsigned char *src_row = src->pixels[y];
			int * dst_row;

			/* no need to calloc it, we overwrite all pxl anyway */
			src->tpixels[y] = (int *) gdMalloc(sx * sizeof(int));
			if (src->tpixels[y] == NULL) {
				goto clean_on_error;
			}

			dst_row = src->tpixels[y];
			for (x = 0; x < sx; x++) {
				const unsigned char c = *(src_row + x);
				if (c == src->transparent) {
					*(dst_row + x) = gdTrueColorAlpha(0, 0, 0, 127);
				} else {
					*(dst_row + x) = gdTrueColorAlpha(src->red[c], src->green[c], src->blue[c], src->alpha[c]);
				}
			}
		}
	}

	/* free old palette buffer (y is sy) */
	for (yy = 0; yy < y; yy++) {
		gdFree(src->pixels[yy]);
	}
	gdFree(src->pixels);
	src->trueColor = 1;
	src->pixels = NULL;
	src->alphaBlendingFlag = 0;
	src->saveAlphaFlag = 1;

	if (src->transparent >= 0) {
		const unsigned char c = src->transparent;
		src->transparent =  gdTrueColorAlpha(src->red[c], src->green[c], src->blue[c], src->alpha[c]);
	}

	return 1;

clean_on_error:
	if (y > 0) {

		for (yy = y; yy >= yy - 1; y--) {
			gdFree(src->tpixels[y]);
		}
		gdFree(src->tpixels);
	}
	return 0;
}


void gdImageAlphaBlending (gdImagePtr im, int alphaBlendingArg)
{
	im->alphaBlendingFlag = alphaBlendingArg;
}


void gdImageCopyMerge (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX, int srcY, int w, int h, int pct)
{
	int c, dc;
	int x, y;
	int tox, toy;
	int ncR, ncG, ncB;
	toy = dstY;

	for (y = srcY; y < (srcY + h); y++) {
		tox = dstX;
		for (x = srcX; x < (srcX + w); x++) {
			int nc;
			c = gdImageGetPixel(src, x, y);
			/* Added 7/24/95: support transparent copies */
			if (gdImageGetTransparent(src) == c) {
				tox++;
				continue;
			}
			/* If it's the same image, mapping is trivial */
			if (dst == src) {
				nc = c;
			} else {
				dc = gdImageGetPixel(dst, tox, toy);

 				ncR = (int)(gdImageRed (src, c) * (pct / 100.0) + gdImageRed (dst, dc) * ((100 - pct) / 100.0));
 				ncG = (int)(gdImageGreen (src, c) * (pct / 100.0) + gdImageGreen (dst, dc) * ((100 - pct) / 100.0));
 				ncB = (int)(gdImageBlue (src, c) * (pct / 100.0) + gdImageBlue (dst, dc) * ((100 - pct) / 100.0));

				/* Find a reasonable color */
				nc = gdImageColorResolve (dst, ncR, ncG, ncB);
			}
			gdImageSetPixel (dst, tox, toy, nc);
			tox++;
		}
		toy++;
	}
}


static int gdLayerOverlay (int dst, int src)
{
	int a1, a2;
	a1 = gdAlphaMax - gdTrueColorGetAlpha(dst);
	a2 = gdAlphaMax - gdTrueColorGetAlpha(src);
	return ( ((gdAlphaMax - a1*a2/gdAlphaMax) << 24) +
		(gdAlphaOverlayColor( gdTrueColorGetRed(src), gdTrueColorGetRed(dst), gdRedMax ) << 16) +
		(gdAlphaOverlayColor( gdTrueColorGetGreen(src), gdTrueColorGetGreen(dst), gdGreenMax ) << 8) +
		(gdAlphaOverlayColor( gdTrueColorGetBlue(src), gdTrueColorGetBlue(dst), gdBlueMax ))
		);
}


static void _gdImageFillTiled(gdImagePtr im, int x, int y, int nc)
{
	int i, l, x1, x2, dy;
	int oc;   /* old pixel value */
	int wx2,wy2;
	/* stack of filled segments */
	struct seg *stack;
	struct seg *sp;
	char **pts;

	if (!im->tile) {
		return;
	}

	wx2=im->sx;wy2=im->sy;

	nc =  gdImageTileGet(im,x,y);

	pts = (char **) ecalloc(im->sy + 1, sizeof(char *));
	for (i = 0; i < im->sy + 1; i++) {
		pts[i] = (char *) ecalloc(im->sx + 1, sizeof(char));
	}

	stack = (struct seg *)safe_emalloc(sizeof(struct seg), ((int)(im->sy*im->sx)/4), 1);
	sp = stack;

	oc = gdImageGetPixel(im, x, y);

	/* required! */
	FILL_PUSH(y,x,x,1);
	/* seed segment (popped 1st) */
 	FILL_PUSH(y+1, x, x, -1);
	while (sp>stack) {
		FILL_POP(y, x1, x2, dy);
		for (x=x1; x>=0 && (!pts[y][x] && gdImageGetPixel(im,x,y)==oc); x--) {
			nc = gdImageTileGet(im,x,y);
			pts[y][x] = 1;
			gdImageSetPixel(im,x, y, nc);
		}
		if (x>=x1) {
			goto skip;
		}
		l = x+1;

		/* leak on left? */
		if (l<x1) {
			FILL_PUSH(y, l, x1-1, -dy);
		}
		x = x1+1;
		do {
			for(; x<wx2 && (!pts[y][x] && gdImageGetPixel(im,x, y)==oc); x++) {
				nc = gdImageTileGet(im,x,y);
				pts[y][x] = 1;
				gdImageSetPixel(im, x, y, nc);
			}
			FILL_PUSH(y, l, x-1, dy);
			/* leak on right? */
			if (x>x2+1) {
				FILL_PUSH(y, x2+1, x-1, -dy);
			}
skip:		for(x++; x<=x2 && (pts[y][x] || gdImageGetPixel(im,x, y)!=oc); x++);
			l = x;
		} while (x<=x2);
	}

	for(i = 0; i < im->sy + 1; i++) {
		efree(pts[i]);
	}

	efree(pts);
	efree(stack);
}


void gdImageSetTile (gdImagePtr im, gdImagePtr tile)
{
	int i;
	im->tile = tile;
	if (!im->trueColor && !im->tile->trueColor) {
		for (i = 0; i < gdImageColorsTotal(tile); i++) {
			int index;
			index = gdImageColorResolveAlpha(im, gdImageRed(tile, i), gdImageGreen(tile, i), gdImageBlue(tile, i), gdImageAlpha(tile, i));
			im->tileColorMap[i] = index;
		}
	}
}


void gdImageDashedLine (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int dx, dy, incr1, incr2, d, x, y, xend, yend, xdirflag, ydirflag;
	int dashStep = 0;
	int on = 1;
	int wid;
	int vert;
	int thick = im->thick;

	dx = abs(x2 - x1);
	dy = abs(y2 - y1);
	if (dy <= dx) {
		/* More-or-less horizontal. use wid for vertical stroke */
		/* 2.0.12: Michael Schwartz: divide rather than multiply;
		TBB: but watch out for /0! */
		double as = sin(atan2(dy, dx));
		if (as != 0) {
			wid = thick / as;
		} else {
			wid = 1;
		}
		wid = (int)(thick * sin(atan2(dy, dx)));
		vert = 1;

		d = 2 * dy - dx;
		incr1 = 2 * dy;
		incr2 = 2 * (dy - dx);
		if (x1 > x2) {
			x = x2;
			y = y2;
			ydirflag = (-1);
			xend = x1;
		} else {
			x = x1;
			y = y1;
			ydirflag = 1;
			xend = x2;
		}
		dashedSet(im, x, y, color, &on, &dashStep, wid, vert);
		if (((y2 - y1) * ydirflag) > 0) {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y++;
					d += incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep, wid, vert);
			}
		} else {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y--;
					d += incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep, wid, vert);
			}
		}
	} else {
		/* 2.0.12: Michael Schwartz: divide rather than multiply;
		TBB: but watch out for /0! */
		double as = sin (atan2 (dy, dx));
		if (as != 0) {
			wid = thick / as;
		} else {
			wid = 1;
		}
		vert = 0;

		d = 2 * dx - dy;
		incr1 = 2 * dx;
		incr2 = 2 * (dx - dy);
		if (y1 > y2) {
			y = y2;
			x = x2;
			yend = y1;
			xdirflag = (-1);
		} else {
			y = y1;
			x = x1;
			yend = y2;
			xdirflag = 1;
		}
		dashedSet(im, x, y, color, &on, &dashStep, wid, vert);
		if (((x2 - x1) * xdirflag) > 0) {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x++;
					d += incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep, wid, vert);
			}
		} else {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x--;
					d += incr2;
				}
				dashedSet(im, x, y, color, &on, &dashStep, wid, vert);
			}
		}
	}
}


void gdImageRectangle (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int x1h = x1, x1v = x1, y1h = y1, y1v = y1, x2h = x2, x2v = x2, y2h = y2, y2v = y2;
	int thick = im->thick;
	int t;

	if (x1 == x2 && y1 == y2 && thick == 1) {
		gdImageSetPixel(im, x1, y1, color);
		return;
	}

	if (y2 < y1) {
		t=y1;
		y1 = y2;
		y2 = t;

		t = x1;
		x1 = x2;
		x2 = t;
	}

	x1h = x1; x1v = x1; y1h = y1; y1v = y1; x2h = x2; x2v = x2; y2h = y2; y2v = y2;
	if (thick > 1) {
		int cx, cy, x1ul, y1ul, x2lr, y2lr;
		int half = thick >> 1;

		x1ul = x1 - half;
		y1ul = y1 - half;

		x2lr = x2 + half;
		y2lr = y2 + half;

		cy = y1ul + thick;
		while (cy-- > y1ul) {
			cx = x1ul - 1;
			while (cx++ < x2lr) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		cy = y2lr - thick;
		while (cy++ < y2lr) {
			cx = x1ul - 1;
			while (cx++ < x2lr) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		cy = y1ul + thick - 1;
		while (cy++ < y2lr -thick) {
			cx = x1ul - 1;
			while (cx++ < x1ul + thick) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		cy = y1ul + thick - 1;
		while (cy++ < y2lr -thick) {
			cx = x2lr - thick - 1;
			while (cx++ < x2lr) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		return;
	} else {
		y1v = y1h + 1;
		y2v = y2h - 1;
		gdImageLine(im, x1h, y1h, x2h, y1h, color);
		gdImageLine(im, x1h, y2h, x2h, y2h, color);
		gdImageLine(im, x1v, y1v, x1v, y2v, color);
		gdImageLine(im, x2v, y1v, x2v, y2v, color);
	}
}


static int clip_1d(int *x0, int *y0, int *x1, int *y1, int maxdim) {
	double m;      /* gradient of line */

	if (*x0 < 0) {  /* start of line is left of window */
		if(*x1 < 0) { /* as is the end, so the line never cuts the window */
			return 0;
		}
		m = (*y1 - *y0)/(double)(*x1 - *x0); /* calculate the slope of the line */
		/* adjust x0 to be on the left boundary (ie to be zero), and y0 to match */
		*y0 -= (int)(m * *x0);
		*x0 = 0;
		/* now, perhaps, adjust the far end of the line as well */
		if (*x1 > maxdim) {
			*y1 += (int)(m * (maxdim - *x1));
			*x1 = maxdim;
		}
		return 1;
	}
	if (*x0 > maxdim) { /* start of line is right of window - complement of above */
		if (*x1 > maxdim) { /* as is the end, so the line misses the window */
			return 0;
		}
		m = (*y1 - *y0)/(double)(*x1 - *x0);  /* calculate the slope of the line */
		*y0 += (int)(m * (maxdim - *x0)); /* adjust so point is on the right boundary */
		*x0 = maxdim;
		/* now, perhaps, adjust the end of the line */
		if (*x1 < 0) {
			*y1 -= (int)(m * *x1);
			*x1 = 0;
		}
		return 1;
	}
	/* the final case - the start of the line is inside the window */
	if (*x1 > maxdim) { /* other end is outside to the right */
		m = (*y1 - *y0)/(double)(*x1 - *x0);  /* calculate the slope of the line */
		*y1 += (int)(m * (maxdim - *x1));
		*x1 = maxdim;
		return 1;
	}
	if (*x1 < 0) { /* other end is outside to the left */
		m = (*y1 - *y0)/(double)(*x1 - *x0);  /* calculate the slope of the line */
		*y1 -= (int)(m * *x1);
		*x1 = 0;
		return 1;
	}
	/* only get here if both points are inside the window */
	return 1;
}


void gdImageSetAntiAliased (gdImagePtr im, int c)
{
	im->AA = 1;
	im->AA_color = c;
	im->AA_dont_blend = -1;
}


int gdImageColorClosest (gdImagePtr im, int r, int g, int b)
{
	return gdImageColorClosestAlpha (im, r, g, b, gdAlphaOpaque);
}


void gdImageSetThickness (gdImagePtr im, int thickness)
{
	im->thick = thickness;
}


void gdImagePolygon (gdImagePtr im, gdPointPtr p, int n, int c)
{
	int i;
	int lx, ly;
	typedef void (*image_line)(gdImagePtr im, int x1, int y1, int x2, int y2, int color);
	image_line draw_line;

	if (n <= 0) {
		return;
	}

	/* Let it be known that we are drawing a polygon so that the opacity
	 * mask doesn't get cleared after each line.
	 */
	if (c == gdAntiAliased) {
		im->AA_polygon = 1;
	}

	if ( im->antialias) {
		draw_line = gdImageAALine;
	} else {
		draw_line = gdImageLine;
	}
	lx = p->x;
	ly = p->y;
	draw_line(im, lx, ly, p[n - 1].x, p[n - 1].y, c);
	for (i = 1; i < n; i++) {
		p++;
		draw_line(im, lx, ly, p->x, p->y, c);
		lx = p->x;
		ly = p->y;
	}

	if (c == gdAntiAliased) {
		im->AA_polygon = 0;
		gdImageAABlend(im);
	}
}


static void gdImageBrushApply (gdImagePtr im, int x, int y)
{
	int lx, ly;
	int hy, hx;
	int x1, y1, x2, y2;
	int srcx, srcy;

	if (!im->brush) {
		return;
	}

	hy = gdImageSY(im->brush) / 2;
	y1 = y - hy;
	y2 = y1 + gdImageSY(im->brush);
	hx = gdImageSX(im->brush) / 2;
	x1 = x - hx;
	x2 = x1 + gdImageSX(im->brush);
	srcy = 0;

	if (im->trueColor) {
		if (im->brush->trueColor) {
			for (ly = y1; ly < y2; ly++) {
				srcx = 0;
				for (lx = x1; (lx < x2); lx++) {
					int p;
					p = gdImageGetTrueColorPixel(im->brush, srcx, srcy);
					/* 2.0.9, Thomas Winzig: apply simple full transparency */
					if (p != gdImageGetTransparent(im->brush)) {
						gdImageSetPixel(im, lx, ly, p);
					}
					srcx++;
				}
				srcy++;
			}
		} else {
			/* 2.0.12: Brush palette, image truecolor (thanks to Thorben Kundinger for pointing out the issue) */
			for (ly = y1; ly < y2; ly++) {
				srcx = 0;
				for (lx = x1; lx < x2; lx++) {
					int p, tc;
					p = gdImageGetPixel(im->brush, srcx, srcy);
					tc = gdImageGetTrueColorPixel(im->brush, srcx, srcy);
					/* 2.0.9, Thomas Winzig: apply simple full transparency */
					if (p != gdImageGetTransparent(im->brush)) {
						gdImageSetPixel(im, lx, ly, tc);
					}
					srcx++;
				}
				srcy++;
			}
		}
	} else {
		for (ly = y1; ly < y2; ly++) {
			srcx = 0;
			for (lx = x1; lx < x2; lx++) {
				int p;
				p = gdImageGetPixel(im->brush, srcx, srcy);
				/* Allow for non-square brushes! */
				if (p != gdImageGetTransparent(im->brush)) {
					/* Truecolor brush. Very slow on a palette destination. */
					if (im->brush->trueColor) {
						gdImageSetPixel(im, lx, ly, gdImageColorResolveAlpha(im, gdTrueColorGetRed(p),
													 gdTrueColorGetGreen(p),
													 gdTrueColorGetBlue(p),
													 gdTrueColorGetAlpha(p)));
					} else {
						gdImageSetPixel(im, lx, ly, im->brushColorMap[p]);
					}
				}
				srcx++;
			}
			srcy++;
		}
	}
}


void php_gd_error(const char *format, ...)
{
	va_list args;

	TSRMLS_FETCH();

	va_start(args, format);
	php_verror(NULL, "", E_WARNING, format, args TSRMLS_CC);
	va_end(args);
}


int gdImageColorAllocateAlpha (gdImagePtr im, int r, int g, int b, int a)
{
	int i;
	int ct = (-1);
	if (im->trueColor) {
		return gdTrueColorAlpha(r, g, b, a);
	}
	for (i = 0; i < im->colorsTotal; i++) {
		if (im->open[i]) {
			ct = i;
			break;
		}
	}
	if (ct == (-1)) {
		ct = im->colorsTotal;
		if (ct == gdMaxColors) {
			return -1;
		}
		im->colorsTotal++;
	}
	im->red[ct] = r;
	im->green[ct] = g;
	im->blue[ct] = b;
	im->alpha[ct] = a;
	im->open[ct] = 0;

	return ct;
}


gdImagePtr gdImageCreate (int sx, int sy)
{
	int i;
	gdImagePtr im;

	if (overflow2(sx, sy)) {
		return NULL;
	}

	if (overflow2(sizeof(unsigned char *), sy)) {
		return NULL;
	}

	if (overflow2(sizeof(unsigned char *), sx)) {
		return NULL;
	}

	im = (gdImage *) gdCalloc(1, sizeof(gdImage));

	/* Row-major ever since gd 1.3 */
	im->pixels = (unsigned char **) gdMalloc(sizeof(unsigned char *) * sy);
	im->AA_opacity = (unsigned char **) gdMalloc(sizeof(unsigned char *) * sy);
	im->polyInts = 0;
	im->polyAllocated = 0;
	im->brush = 0;
	im->tile = 0;
	im->style = 0;
	for (i = 0; i < sy; i++) {
		/* Row-major ever since gd 1.3 */
		im->pixels[i] = (unsigned char *) gdCalloc(sx, sizeof(unsigned char));
		im->AA_opacity[i] = (unsigned char *) gdCalloc(sx, sizeof(unsigned char));
	}
	im->sx = sx;
	im->sy = sy;
	im->colorsTotal = 0;
	im->transparent = (-1);
	im->interlace = 0;
	im->thick = 1;
	im->AA = 0;
	im->AA_polygon = 0;
	for (i = 0; i < gdMaxColors; i++) {
		im->open[i] = 1;
		im->red[i] = 0;
		im->green[i] = 0;
		im->blue[i] = 0;
	}
	im->trueColor = 0;
	im->tpixels = 0;
	im->cx1 = 0;
	im->cy1 = 0;
	im->cx2 = im->sx - 1;
	im->cy2 = im->sy - 1;
	im->interpolation = NULL;
	im->interpolation_id = GD_BILINEAR_FIXED;
	return im;
}


void gdImageFill(gdImagePtr im, int x, int y, int nc)
{
	int l, x1, x2, dy;
	int oc;   /* old pixel value */
	int wx2,wy2;

	int alphablending_bak;

	/* stack of filled segments */
	/* struct seg stack[FILL_MAX],*sp = stack;; */
	struct seg *stack = NULL;
	struct seg *sp;

	if (!im->trueColor && nc > (im->colorsTotal -1)) {
		return;
	}

	alphablending_bak = im->alphaBlendingFlag;
	im->alphaBlendingFlag = 0;

	if (nc==gdTiled){
		_gdImageFillTiled(im,x,y,nc);
		im->alphaBlendingFlag = alphablending_bak;
		return;
	}

	wx2=im->sx;wy2=im->sy;
	oc = gdImageGetPixel(im, x, y);
	if (oc==nc || x<0 || x>wx2 || y<0 || y>wy2) {
		im->alphaBlendingFlag = alphablending_bak;
		return;
	}

	/* Do not use the 4 neighbors implementation with
	 * small images
	 */
	if (im->sx < 4) {
		int ix = x, iy = y, c;
		do {
			do {
				c = gdImageGetPixel(im, ix, iy);
				if (c != oc) {
					goto done;
				}
				gdImageSetPixel(im, ix, iy, nc);
			} while(ix++ < (im->sx -1));
			ix = x;
		} while(iy++ < (im->sy -1));
		goto done;
	}

	stack = (struct seg *)safe_emalloc(sizeof(struct seg), ((int)(im->sy*im->sx)/4), 1);
	sp = stack;

	/* required! */
	FILL_PUSH(y,x,x,1);
	/* seed segment (popped 1st) */
 	FILL_PUSH(y+1, x, x, -1);
	while (sp>stack) {
		FILL_POP(y, x1, x2, dy);

		for (x=x1; x>=0 && gdImageGetPixel(im,x, y)==oc; x--) {
			gdImageSetPixel(im,x, y, nc);
		}
		if (x>=x1) {
			goto skip;
		}
		l = x+1;

                /* leak on left? */
		if (l<x1) {
			FILL_PUSH(y, l, x1-1, -dy);
		}
		x = x1+1;
		do {
			for (; x<=wx2 && gdImageGetPixel(im,x, y)==oc; x++) {
				gdImageSetPixel(im, x, y, nc);
			}
			FILL_PUSH(y, l, x-1, dy);
			/* leak on right? */
			if (x>x2+1) {
				FILL_PUSH(y, x2+1, x-1, -dy);
			}
skip:			for (x++; x<=x2 && (gdImageGetPixel(im, x, y)!=oc); x++);

			l = x;
		} while (x<=x2);
	}

	efree(stack);

done:
	im->alphaBlendingFlag = alphablending_bak;
}


void php_gd_error_ex(int type, const char *format, ...)
{
	va_list args;

	TSRMLS_FETCH();

	va_start(args, format);
	php_verror(NULL, "", type, format, args TSRMLS_CC);
	va_end(args);
}


gdAlphaBlendOld (int dst, int src)
{
	/* 2.0.12: TBB: alpha in the destination should be a
	 * component of the result. Thanks to Frank Warmerdam for
	 * pointing out the issue.
	 */
	return ((((gdTrueColorGetAlpha (src) *
	     gdTrueColorGetAlpha (dst)) / gdAlphaMax) << 24) +
	  ((((gdAlphaTransparent - gdTrueColorGetAlpha (src)) *
	     gdTrueColorGetRed (src) / gdAlphaMax) +
	    (gdTrueColorGetAlpha (src) *
	     gdTrueColorGetRed (dst)) / gdAlphaMax) << 16) +
	  ((((gdAlphaTransparent - gdTrueColorGetAlpha (src)) *
	     gdTrueColorGetGreen (src) / gdAlphaMax) +
	    (gdTrueColorGetAlpha (src) *
	     gdTrueColorGetGreen (dst)) / gdAlphaMax) << 8) +
	  (((gdAlphaTransparent - gdTrueColorGetAlpha (src)) *
	    gdTrueColorGetBlue (src) / gdAlphaMax) +
	   (gdTrueColorGetAlpha (src) *
	    gdTrueColorGetBlue (dst)) / gdAlphaMax));
}


int gdImageColorAllocate (gdImagePtr im, int r, int g, int b)
{
	return gdImageColorAllocateAlpha (im, r, g, b, gdAlphaOpaque);
}


int gdImageColorExact (gdImagePtr im, int r, int g, int b)
{
	return gdImageColorExactAlpha (im, r, g, b, gdAlphaOpaque);
}


void gdImageString16 (gdImagePtr im, gdFontPtr f, int x, int y, unsigned short *s, int color)
{
	int i;
	int l;
	l = strlen16(s);
	for (i = 0; (i < l); i++) {
		gdImageChar(im, f, x, y, s[i], color);
		x += f->w;
	}
}


void gdImageGetClip (gdImagePtr im, int *x1P, int *y1P, int *x2P, int *y2P)
{
	*x1P = im->cx1;
	*y1P = im->cy1;
	*x2P = im->cx2;
	*y2P = im->cy2;
}


void gdImageDestroy (gdImagePtr im)
{
	int i;
	if (im->pixels) {
		for (i = 0; i < im->sy; i++) {
			gdFree(im->pixels[i]);
		}
		gdFree(im->pixels);
	}
	if (im->tpixels) {
		for (i = 0; i < im->sy; i++) {
			gdFree(im->tpixels[i]);
		}
		gdFree(im->tpixels);
	}
	if (im->AA_opacity) {
		for (i = 0; i < im->sy; i++) {
			gdFree(im->AA_opacity[i]);
		}
		gdFree(im->AA_opacity);
	}
	if (im->polyInts) {
		gdFree(im->polyInts);
	}
	if (im->style) {
		gdFree(im->style);
	}
	gdFree(im);
}


static void gdImageHLine(gdImagePtr im, int y, int x1, int x2, int col)
{
	if (im->thick > 1) {
		int thickhalf = im->thick >> 1;
		gdImageFilledRectangle(im, x1, y - thickhalf, x2, y + im->thick - thickhalf - 1, col);
	} else {
		if (x2 < x1) {
			int t = x2;
			x2 = x1;
			x1 = t;
		}

		for (;x1 <= x2; x1++) {
			gdImageSetPixel(im, x1, y, col);
		}
	}
	return;
}


int gdCompareInt (const void *a, const void *b)
{
	return (*(const int *) a) - (*(const int *) b);
}


void gdImageCopy (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX, int srcY, int w, int h)
{
	int c;
	int x, y;
	int tox, toy;
	int i;
	int colorMap[gdMaxColors];

	if (dst->trueColor) {
		/* 2.0: much easier when the destination is truecolor. */
		/* 2.0.10: needs a transparent-index check that is still valid if
		 * the source is not truecolor. Thanks to Frank Warmerdam.
		 */

		if (src->trueColor) {
			for (y = 0; (y < h); y++) {
				for (x = 0; (x < w); x++) {
					int c = gdImageGetTrueColorPixel (src, srcX + x, srcY + y);
					gdImageSetPixel (dst, dstX + x, dstY + y, c);
				}
			}
		} else {
			/* source is palette based */
			for (y = 0; (y < h); y++) {
				for (x = 0; (x < w); x++) {
					int c = gdImageGetPixel (src, srcX + x, srcY + y);
					if (c != src->transparent) {
						gdImageSetPixel(dst, dstX + x, dstY + y, gdTrueColorAlpha(src->red[c], src->green[c], src->blue[c], src->alpha[c]));
					}
				}
			}
		}
		return;
	}

	/* Destination is palette based */
	if (src->trueColor) { /* But source is truecolor (Ouch!) */
		toy = dstY;
		for (y = srcY; (y < (srcY + h)); y++) {
			tox = dstX;
			for (x = srcX; x < (srcX + w); x++) {
				int nc;
				c = gdImageGetPixel (src, x, y);

				/* Get best match possible. */
				nc = gdImageColorResolveAlpha(dst, gdTrueColorGetRed(c), gdTrueColorGetGreen(c), gdTrueColorGetBlue(c), gdTrueColorGetAlpha(c));

				gdImageSetPixel(dst, tox, toy, nc);
				tox++;
			}
			toy++;
		}
		return;
	}

	/* Palette based to palette based */
	for (i = 0; i < gdMaxColors; i++) {
		colorMap[i] = (-1);
	}
	toy = dstY;
	for (y = srcY; y < (srcY + h); y++) {
		tox = dstX;
		for (x = srcX; x < (srcX + w); x++) {
			int nc;
			int mapTo;
			c = gdImageGetPixel (src, x, y);
			/* Added 7/24/95: support transparent copies */
			if (gdImageGetTransparent (src) == c) {
				tox++;
				continue;
			}
			/* Have we established a mapping for this color? */
			if (src->trueColor) {
				/* 2.05: remap to the palette available in the destination image. This is slow and
				 * works badly, but it beats crashing! Thanks to Padhrig McCarthy.
				 */
				mapTo = gdImageColorResolveAlpha (dst, gdTrueColorGetRed (c), gdTrueColorGetGreen (c), gdTrueColorGetBlue (c), gdTrueColorGetAlpha (c));
			} else if (colorMap[c] == (-1)) {
				/* If it's the same image, mapping is trivial */
				if (dst == src) {
					nc = c;
				} else {
					/* Get best match possible. This function never returns error. */
					nc = gdImageColorResolveAlpha (dst, src->red[c], src->green[c], src->blue[c], src->alpha[c]);
				}
				colorMap[c] = nc;
				mapTo = colorMap[c];
			} else {
				mapTo = colorMap[c];
			}
			gdImageSetPixel (dst, tox, toy, mapTo);
			tox++;
		}
		toy++;
	}
}


void gdImageFilledRectangle (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int x, y;

	if (x1 == x2 && y1 == y2) {
		gdImageSetPixel(im, x1, y1, color);
		return;
	}

	if (x1 > x2) {
		x = x1;
		x1 = x2;
		x2 = x;
	}

	if (y1 > y2) {
		y = y1;
		y1 = y2;
		y2 = y;
	}

	if (x1 < 0) {
		x1 = 0;
	}

	if (x2 >= gdImageSX(im)) {
		x2 = gdImageSX(im) - 1;
	}

	if (y1 < 0) {
		y1 = 0;
	}

	if (y2 >= gdImageSY(im)) {
		y2 = gdImageSY(im) - 1;
	}

	for (y = y1; (y <= y2); y++) {
		for (x = x1; (x <= x2); x++) {
			gdImageSetPixel (im, x, y, color);
		}
	}
}


static int gdAlphaOverlayColor (int src, int dst, int max )
{
	/* this function implements the algorithm
	 *
	 * for dst[rgb] < 0.5,
	 *   c[rgb] = 2.src[rgb].dst[rgb]
	 * and for dst[rgb] > 0.5,
	 *   c[rgb] = -2.src[rgb].dst[rgb] + 2.dst[rgb] + 2.src[rgb] - 1
	 *
	 */

	dst = dst << 1;
	if( dst > max ) {
		/* in the "light" zone */
		return dst + (src << 1) - (dst * src / max) - max;
	} else {
		/* in the "dark" zone */
		return dst * src / max;
	}
}


int gdImageGetPixel (gdImagePtr im, int x, int y)
{
	if (gdImageBoundsSafe(im, x, y)) {
		if (im->trueColor) {
			return im->tpixels[y][x];
		} else {
			return im->pixels[y][x];
		}
	} else {
		return 0;
	}
}


static float HWB_Diff (int r1, int g1, int b1, int r2, int g2, int b2)
{
	RGBType RGB1, RGB2;
	HWBType HWB1, HWB2;
	float diff;

	SETUP_RGB(RGB1, r1, g1, b1);
	SETUP_RGB(RGB2, r2, g2, b2);

	RGB_to_HWB(RGB1, &HWB1);
	RGB_to_HWB(RGB2, &HWB2);

	/*
	 * I made this bit up; it seems to produce OK results, and it is certainly
	 * more visually correct than the current RGB metric. (PJW)
	 */

	if ((HWB1.H == HWB_UNDEFINED) || (HWB2.H == HWB_UNDEFINED)) {
		diff = 0.0f;	/* Undefined hues always match... */
	} else {
		diff = fabsf(HWB1.H - HWB2.H);
		if (diff > 3.0f) {
			diff = 6.0f - diff;	/* Remember, it's a colour circle */
		}
	}

	diff = diff * diff + (HWB1.W - HWB2.W) * (HWB1.W - HWB2.W) + (HWB1.B - HWB2.B) * (HWB1.B - HWB2.B);

	return diff;
}


int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
		    const char *name, unsigned int flags,
		    struct path *path)
{
	struct path root = {.mnt = mnt, .dentry = dentry};
	/* the first argument of filename_lookup() is ignored with root */
	return filename_lookup(AT_FDCWD, getname_kernel(name),
			       flags , path, &root);
}

do_last(): fetch directory ->i_mode and ->i_uid before it's too late

may_create_in_sticky() call is done when we already have dropped the
reference to dir.

Fixes: 30aba6656f61e (namei: allow restricted O_CREAT of FIFOs and regular files)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>


int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	int error = may_create(dir, dentry);
	unsigned max_links = dir->i_sb->s_max_links;

	if (error)
		return error;

	if (!dir->i_op->mkdir)
		return -EPERM;

	mode &= (S_IRWXUGO|S_ISVTX);
	error = security_inode_mkdir(dir, dentry, mode);
	if (error)
		return error;

	if (max_links && dir->i_nlink >= max_links)
		return -EMLINK;

	error = dir->i_op->mkdir(dir, dentry, mode);
	if (!error)
		fsnotify_mkdir(dir, dentry);
	return error;
}


static int lookup_one_len_common(const char *name, struct dentry *base,
				 int len, struct qstr *this)
{
	this->name = name;
	this->len = len;
	this->hash = full_name_hash(base, name, len);
	if (!len)
		return -EACCES;

	if (unlikely(name[0] == '.')) {
		if (len < 2 || (len == 2 && name[1] == '.'))
			return -EACCES;
	}

	while (len--) {
		unsigned int c = *(const unsigned char *)name++;
		if (c == '/' || c == '\0')
			return -EACCES;
	}
	/*
	 * See if the low-level filesystem might want
	 * to use its own hash..
	 */
	if (base->d_flags & DCACHE_OP_HASH) {
		int err = base->d_op->d_hash(base, this);
		if (err < 0)
			return err;
	}

	return inode_permission(base->d_inode, MAY_EXEC);
}


int page_symlink(struct inode *inode, const char *symname, int len)
{
	return __page_symlink(inode, symname, len,
			!mapping_gfp_constraint(inode->i_mapping, __GFP_FS));
}


SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, dev)
{
	return do_mknodat(AT_FDCWD, filename, mode, dev);
}


SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
{
	return do_rmdir(AT_FDCWD, pathname);
}


static int walk_component(struct nameidata *nd, int flags)
{
	struct path path;
	struct inode *inode;
	unsigned seq;
	int err;
	/*
	 * "." and ".." are special - ".." especially so because it has
	 * to be able to know about the current root directory and
	 * parent relationships.
	 */
	if (unlikely(nd->last_type != LAST_NORM)) {
		err = handle_dots(nd, nd->last_type);
		if (!(flags & WALK_MORE) && nd->depth)
			put_link(nd);
		return err;
	}
	err = lookup_fast(nd, &path, &inode, &seq);
	if (unlikely(err <= 0)) {
		if (err < 0)
			return err;
		path.dentry = lookup_slow(&nd->last, nd->path.dentry,
					  nd->flags);
		if (IS_ERR(path.dentry))
			return PTR_ERR(path.dentry);

		path.mnt = nd->path.mnt;
		err = follow_managed(&path, nd);
		if (unlikely(err < 0))
			return err;

		seq = 0;	/* we are already out of RCU mode */
		inode = d_backing_inode(path.dentry);
	}

	return step_into(nd, &path, flags, inode, seq);
}


static struct dentry *lookup_slow(const struct qstr *name,
				  struct dentry *dir,
				  unsigned int flags)
{
	struct inode *inode = dir->d_inode;
	struct dentry *res;
	inode_lock_shared(inode);
	res = __lookup_slow(name, dir, flags);
	inode_unlock_shared(inode);
	return res;
}


static inline int do_inode_permission(struct inode *inode, int mask)
{
	if (unlikely(!(inode->i_opflags & IOP_FASTPERM))) {
		if (likely(inode->i_op->permission))
			return inode->i_op->permission(inode, mask);

		/* This gets set once for the inode lifetime */
		spin_lock(&inode->i_lock);
		inode->i_opflags |= IOP_FASTPERM;
		spin_unlock(&inode->i_lock);
	}
	return generic_permission(inode, mask);
}


struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag)
{
	struct dentry *child = NULL;
	struct inode *dir = dentry->d_inode;
	struct inode *inode;
	int error;

	/* we want directory to be writable */
	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
	if (error)
		goto out_err;
	error = -EOPNOTSUPP;
	if (!dir->i_op->tmpfile)
		goto out_err;
	error = -ENOMEM;
	child = d_alloc(dentry, &slash_name);
	if (unlikely(!child))
		goto out_err;
	error = dir->i_op->tmpfile(dir, child, mode);
	if (error)
		goto out_err;
	error = -ENOENT;
	inode = child->d_inode;
	if (unlikely(!inode))
		goto out_err;
	if (!(open_flag & O_EXCL)) {
		spin_lock(&inode->i_lock);
		inode->i_state |= I_LINKABLE;
		spin_unlock(&inode->i_lock);
	}
	ima_post_create_tmpfile(inode);
	return child;

out_err:
	dput(child);
	return ERR_PTR(error);
}


SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname)
{
	return do_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
}


bool may_open_dev(const struct path *path)
{
	return !(path->mnt->mnt_flags & MNT_NODEV) &&
		!(path->mnt->mnt_sb->s_iflags & SB_I_NODEV);
}


struct dentry *try_lookup_one_len(const char *name, struct dentry *base, int len)
{
	struct qstr this;
	int err;

	WARN_ON_ONCE(!inode_is_locked(base->d_inode));

	err = lookup_one_len_common(name, base, len, &this);
	if (err)
		return ERR_PTR(err);

	return lookup_dcache(&this, base, 0);
}


long do_mknodat(int dfd, const char __user *filename, umode_t mode,
		unsigned int dev)
{
	struct dentry *dentry;
	struct path path;
	int error;
	unsigned int lookup_flags = 0;

	error = may_mknod(mode);
	if (error)
		return error;
retry:
	dentry = user_path_create(dfd, filename, &path, lookup_flags);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);

	if (!IS_POSIXACL(path.dentry->d_inode))
		mode &= ~current_umask();
	error = security_path_mknod(&path, dentry, mode, dev);
	if (error)
		goto out;
	switch (mode & S_IFMT) {
		case 0: case S_IFREG:
			error = vfs_create(path.dentry->d_inode,dentry,mode,true);
			if (!error)
				ima_post_path_mknod(dentry);
			break;
		case S_IFCHR: case S_IFBLK:
			error = vfs_mknod(path.dentry->d_inode,dentry,mode,
					new_decode_dev(dev));
			break;
		case S_IFIFO: case S_IFSOCK:
			error = vfs_mknod(path.dentry->d_inode,dentry,mode,0);
			break;
	}
out:
	done_path_create(&path, dentry);
	if (retry_estale(error, lookup_flags)) {
		lookup_flags |= LOOKUP_REVAL;
		goto retry;
	}
	return error;
}


int readlink_copy(char __user *buffer, int buflen, const char *link)
{
	int len = PTR_ERR(link);
	if (IS_ERR(link))
		goto out;

	len = strlen(link);
	if (len > (unsigned) buflen)
		len = buflen;
	if (copy_to_user(buffer, link, len))
		len = -EFAULT;
out:
	return len;
}


static int do_o_path(struct nameidata *nd, unsigned flags, struct file *file)
{
	struct path path;
	int error = path_lookupat(nd, flags, &path);
	if (!error) {
		audit_inode(nd->name, path.dentry, 0);
		error = vfs_open(&path, file);
		path_put(&path);
	}
	return error;
}


static int do_last(struct nameidata *nd,
		   struct file *file, const struct open_flags *op)
{
	struct dentry *dir = nd->path.dentry;
	kuid_t dir_uid = dir->d_inode->i_uid;
	umode_t dir_mode = dir->d_inode->i_mode;
	int open_flag = op->open_flag;
	bool will_truncate = (open_flag & O_TRUNC) != 0;
	bool got_write = false;
	int acc_mode = op->acc_mode;
	unsigned seq;
	struct inode *inode;
	struct path path;
	int error;

	nd->flags &= ~LOOKUP_PARENT;
	nd->flags |= op->intent;

	if (nd->last_type != LAST_NORM) {
		error = handle_dots(nd, nd->last_type);
		if (unlikely(error))
			return error;
		goto finish_open;
	}

	if (!(open_flag & O_CREAT)) {
		if (nd->last.name[nd->last.len])
			nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
		/* we _can_ be in RCU mode here */
		error = lookup_fast(nd, &path, &inode, &seq);
		if (likely(error > 0))
			goto finish_lookup;

		if (error < 0)
			return error;

		BUG_ON(nd->inode != dir->d_inode);
		BUG_ON(nd->flags & LOOKUP_RCU);
	} else {
		/* create side of things */
		/*
		 * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED
		 * has been cleared when we got to the last component we are
		 * about to look up
		 */
		error = complete_walk(nd);
		if (error)
			return error;

		audit_inode(nd->name, dir, AUDIT_INODE_PARENT);
		/* trailing slashes? */
		if (unlikely(nd->last.name[nd->last.len]))
			return -EISDIR;
	}

	if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
		error = mnt_want_write(nd->path.mnt);
		if (!error)
			got_write = true;
		/*
		 * do _not_ fail yet - we might not need that or fail with
		 * a different error; let lookup_open() decide; we'll be
		 * dropping this one anyway.
		 */
	}
	if (open_flag & O_CREAT)
		inode_lock(dir->d_inode);
	else
		inode_lock_shared(dir->d_inode);
	error = lookup_open(nd, &path, file, op, got_write);
	if (open_flag & O_CREAT)
		inode_unlock(dir->d_inode);
	else
		inode_unlock_shared(dir->d_inode);

	if (error)
		goto out;

	if (file->f_mode & FMODE_OPENED) {
		if ((file->f_mode & FMODE_CREATED) ||
		    !S_ISREG(file_inode(file)->i_mode))
			will_truncate = false;

		audit_inode(nd->name, file->f_path.dentry, 0);
		goto opened;
	}

	if (file->f_mode & FMODE_CREATED) {
		/* Don't check for write permission, don't truncate */
		open_flag &= ~O_TRUNC;
		will_truncate = false;
		acc_mode = 0;
		path_to_nameidata(&path, nd);
		goto finish_open_created;
	}

	/*
	 * If atomic_open() acquired write access it is dropped now due to
	 * possible mount and symlink following (this might be optimized away if
	 * necessary...)
	 */
	if (got_write) {
		mnt_drop_write(nd->path.mnt);
		got_write = false;
	}

	error = follow_managed(&path, nd);
	if (unlikely(error < 0))
		return error;

	/*
	 * create/update audit record if it already exists.
	 */
	audit_inode(nd->name, path.dentry, 0);

	if (unlikely((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))) {
		path_to_nameidata(&path, nd);
		return -EEXIST;
	}

	seq = 0;	/* out of RCU mode, so the value doesn't matter */
	inode = d_backing_inode(path.dentry);
finish_lookup:
	error = step_into(nd, &path, 0, inode, seq);
	if (unlikely(error))
		return error;
finish_open:
	/* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */
	error = complete_walk(nd);
	if (error)
		return error;
	audit_inode(nd->name, nd->path.dentry, 0);
	if (open_flag & O_CREAT) {
		error = -EISDIR;
		if (d_is_dir(nd->path.dentry))
			goto out;
		error = may_create_in_sticky(dir_mode, dir_uid,
					     d_backing_inode(nd->path.dentry));
		if (unlikely(error))
			goto out;
	}
	error = -ENOTDIR;
	if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.dentry))
		goto out;
	if (!d_is_reg(nd->path.dentry))
		will_truncate = false;

	if (will_truncate) {
		error = mnt_want_write(nd->path.mnt);
		if (error)
			goto out;
		got_write = true;
	}
finish_open_created:
	error = may_open(&nd->path, acc_mode, open_flag);
	if (error)
		goto out;
	BUG_ON(file->f_mode & FMODE_OPENED); /* once it's opened, it's opened */
	error = vfs_open(&nd->path, file);
	if (error)
		goto out;
opened:
	error = ima_file_check(file, op->acc_mode);
	if (!error && will_truncate)
		error = handle_truncate(file);
out:
	if (unlikely(error > 0)) {
		WARN_ON(1);
		error = -EINVAL;
	}
	if (got_write)
		mnt_drop_write(nd->path.mnt);
	return error;
}


struct dentry *lookup_positive_unlocked(const char *name,
				       struct dentry *base, int len)
{
	struct dentry *ret = lookup_one_len_unlocked(name, base, len);
	if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
		dput(ret);
		ret = ERR_PTR(-ENOENT);
	}
	return ret;
}


struct dentry *kern_path_create(int dfd, const char *pathname,
				struct path *path, unsigned int lookup_flags)
{
	return filename_create(dfd, getname_kernel(pathname),
				path, lookup_flags);
}


static struct dentry *lookup_dcache(const struct qstr *name,
				    struct dentry *dir,
				    unsigned int flags)
{
	struct dentry *dentry = d_lookup(dir, name);
	if (dentry) {
		int error = d_revalidate(dentry, flags);
		if (unlikely(error <= 0)) {
			if (!error)
				d_invalidate(dentry);
			dput(dentry);
			return ERR_PTR(error);
		}
	}
	return dentry;
}


static int do_renameat2(int olddfd, const char __user *oldname, int newdfd,
			const char __user *newname, unsigned int flags)
{
	struct dentry *old_dentry, *new_dentry;
	struct dentry *trap;
	struct path old_path, new_path;
	struct qstr old_last, new_last;
	int old_type, new_type;
	struct inode *delegated_inode = NULL;
	struct filename *from;
	struct filename *to;
	unsigned int lookup_flags = 0, target_flags = LOOKUP_RENAME_TARGET;
	bool should_retry = false;
	int error;

	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
		return -EINVAL;

	if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) &&
	    (flags & RENAME_EXCHANGE))
		return -EINVAL;

	if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD))
		return -EPERM;

	if (flags & RENAME_EXCHANGE)
		target_flags = 0;

retry:
	from = filename_parentat(olddfd, getname(oldname), lookup_flags,
				&old_path, &old_last, &old_type);
	if (IS_ERR(from)) {
		error = PTR_ERR(from);
		goto exit;
	}

	to = filename_parentat(newdfd, getname(newname), lookup_flags,
				&new_path, &new_last, &new_type);
	if (IS_ERR(to)) {
		error = PTR_ERR(to);
		goto exit1;
	}

	error = -EXDEV;
	if (old_path.mnt != new_path.mnt)
		goto exit2;

	error = -EBUSY;
	if (old_type != LAST_NORM)
		goto exit2;

	if (flags & RENAME_NOREPLACE)
		error = -EEXIST;
	if (new_type != LAST_NORM)
		goto exit2;

	error = mnt_want_write(old_path.mnt);
	if (error)
		goto exit2;

retry_deleg:
	trap = lock_rename(new_path.dentry, old_path.dentry);

	old_dentry = __lookup_hash(&old_last, old_path.dentry, lookup_flags);
	error = PTR_ERR(old_dentry);
	if (IS_ERR(old_dentry))
		goto exit3;
	/* source must exist */
	error = -ENOENT;
	if (d_is_negative(old_dentry))
		goto exit4;
	new_dentry = __lookup_hash(&new_last, new_path.dentry, lookup_flags | target_flags);
	error = PTR_ERR(new_dentry);
	if (IS_ERR(new_dentry))
		goto exit4;
	error = -EEXIST;
	if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry))
		goto exit5;
	if (flags & RENAME_EXCHANGE) {
		error = -ENOENT;
		if (d_is_negative(new_dentry))
			goto exit5;

		if (!d_is_dir(new_dentry)) {
			error = -ENOTDIR;
			if (new_last.name[new_last.len])
				goto exit5;
		}
	}
	/* unless the source is a directory trailing slashes give -ENOTDIR */
	if (!d_is_dir(old_dentry)) {
		error = -ENOTDIR;
		if (old_last.name[old_last.len])
			goto exit5;
		if (!(flags & RENAME_EXCHANGE) && new_last.name[new_last.len])
			goto exit5;
	}
	/* source should not be ancestor of target */
	error = -EINVAL;
	if (old_dentry == trap)
		goto exit5;
	/* target should not be an ancestor of source */
	if (!(flags & RENAME_EXCHANGE))
		error = -ENOTEMPTY;
	if (new_dentry == trap)
		goto exit5;

	error = security_path_rename(&old_path, old_dentry,
				     &new_path, new_dentry, flags);
	if (error)
		goto exit5;
	error = vfs_rename(old_path.dentry->d_inode, old_dentry,
			   new_path.dentry->d_inode, new_dentry,
			   &delegated_inode, flags);
exit5:
	dput(new_dentry);
exit4:
	dput(old_dentry);
exit3:
	unlock_rename(new_path.dentry, old_path.dentry);
	if (delegated_inode) {
		error = break_deleg_wait(&delegated_inode);
		if (!error)
			goto retry_deleg;
	}
	mnt_drop_write(old_path.mnt);
exit2:
	if (retry_estale(error, lookup_flags))
		should_retry = true;
	path_put(&new_path);
	putname(to);
exit1:
	path_put(&old_path);
	putname(from);
	if (should_retry) {
		should_retry = false;
		lookup_flags |= LOOKUP_REVAL;
		goto retry;
	}
exit:
	return error;
}


static inline int may_lookup(struct nameidata *nd)
{
	if (nd->flags & LOOKUP_RCU) {
		int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
		if (err != -ECHILD)
			return err;
		if (unlazy_walk(nd))
			return -ECHILD;
	}
	return inode_permission(nd->inode, MAY_EXEC);
}


static int unlazy_child(struct nameidata *nd, struct dentry *dentry, unsigned seq)
{
	BUG_ON(!(nd->flags & LOOKUP_RCU));

	nd->flags &= ~LOOKUP_RCU;
	if (unlikely(!legitimize_links(nd)))
		goto out2;
	if (unlikely(!legitimize_mnt(nd->path.mnt, nd->m_seq)))
		goto out2;
	if (unlikely(!lockref_get_not_dead(&nd->path.dentry->d_lockref)))
		goto out1;

	/*
	 * We need to move both the parent and the dentry from the RCU domain
	 * to be properly refcounted. And the sequence number in the dentry
	 * validates *both* dentry counters, since we checked the sequence
	 * number of the parent after we got the child sequence number. So we
	 * know the parent must still be valid if the child sequence number is
	 */
	if (unlikely(!lockref_get_not_dead(&dentry->d_lockref)))
		goto out;
	if (unlikely(read_seqcount_retry(&dentry->d_seq, seq)))
		goto out_dput;
	/*
	 * Sequence counts matched. Now make sure that the root is
	 * still valid and get it if required.
	 */
	if (unlikely(!legitimize_root(nd)))
		goto out_dput;
	rcu_read_unlock();
	return 0;

out2:
	nd->path.mnt = NULL;
out1:
	nd->path.dentry = NULL;
out:
	rcu_read_unlock();
	return -ECHILD;
out_dput:
	rcu_read_unlock();
	dput(dentry);
	return -ECHILD;
}


void putname(struct filename *name)
{
	BUG_ON(name->refcnt <= 0);

	if (--name->refcnt > 0)
		return;

	if (name->name != name->iname) {
		__putname(name->name);
		kfree(name);
	} else
		__putname(name);
}


int vfs_whiteout(struct inode *dir, struct dentry *dentry)
{
	int error = may_create(dir, dentry);
	if (error)
		return error;

	if (!dir->i_op->mknod)
		return -EPERM;

	return dir->i_op->mknod(dir, dentry,
				S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV);
}


static inline void path_to_nameidata(const struct path *path,
					struct nameidata *nd)
{
	if (!(nd->flags & LOOKUP_RCU)) {
		dput(nd->path.dentry);
		if (nd->path.mnt != path->mnt)
			mntput(nd->path.mnt);
	}
	nd->path.mnt = path->mnt;
	nd->path.dentry = path->dentry;
}


static struct filename *filename_parentat(int dfd, struct filename *name,
				unsigned int flags, struct path *parent,
				struct qstr *last, int *type)
{
	int retval;
	struct nameidata nd;

	if (IS_ERR(name))
		return name;
	set_nameidata(&nd, dfd, name);
	retval = path_parentat(&nd, flags | LOOKUP_RCU, parent);
	if (unlikely(retval == -ECHILD))
		retval = path_parentat(&nd, flags, parent);
	if (unlikely(retval == -ESTALE))
		retval = path_parentat(&nd, flags | LOOKUP_REVAL, parent);
	if (likely(!retval)) {
		*last = nd.last;
		*type = nd.last_type;
		audit_inode(name, parent->dentry, AUDIT_INODE_PARENT);
	} else {
		putname(name);
		name = ERR_PTR(retval);
	}
	restore_nameidata();
	return name;
}


static inline int open_to_namei_flags(int flag)
{
	if ((flag & O_ACCMODE) == 3)
		flag--;
	return flag;
}


SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
		int, newdfd, const char __user *, newname, unsigned int, flags)
{
	return do_renameat2(olddfd, oldname, newdfd, newname, flags);
}


SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
{
	return do_mkdirat(AT_FDCWD, pathname, mode);
}


static struct dentry *__lookup_slow(const struct qstr *name,
				    struct dentry *dir,
				    unsigned int flags)
{
	struct dentry *dentry, *old;
	struct inode *inode = dir->d_inode;
	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);

	/* Don't go there if it's already dead */
	if (unlikely(IS_DEADDIR(inode)))
		return ERR_PTR(-ENOENT);
again:
	dentry = d_alloc_parallel(dir, name, &wq);
	if (IS_ERR(dentry))
		return dentry;
	if (unlikely(!d_in_lookup(dentry))) {
		int error = d_revalidate(dentry, flags);
		if (unlikely(error <= 0)) {
			if (!error) {
				d_invalidate(dentry);
				dput(dentry);
				goto again;
			}
			dput(dentry);
			dentry = ERR_PTR(error);
		}
	} else {
		old = inode->i_op->lookup(inode, dentry, flags);
		d_lookup_done(dentry);
		if (unlikely(old)) {
			dput(dentry);
			dentry = old;
		}
	}
	return dentry;
}


static int follow_dotdot(struct nameidata *nd)
{
	while(1) {
		if (path_equal(&nd->path, &nd->root))
			break;
		if (nd->path.dentry != nd->path.mnt->mnt_root) {
			int ret = path_parent_directory(&nd->path);
			if (ret)
				return ret;
			break;
		}
		if (!follow_up(&nd->path))
			break;
	}
	follow_mount(&nd->path);
	nd->inode = nd->path.dentry->d_inode;
	return 0;
}


static struct dentry *__lookup_hash(const struct qstr *name,
		struct dentry *base, unsigned int flags)
{
	struct dentry *dentry = lookup_dcache(name, base, flags);
	struct dentry *old;
	struct inode *dir = base->d_inode;

	if (dentry)
		return dentry;

	/* Don't create child dentry for a dead directory. */
	if (unlikely(IS_DEADDIR(dir)))
		return ERR_PTR(-ENOENT);

	dentry = d_alloc(base, name);
	if (unlikely(!dentry))
		return ERR_PTR(-ENOMEM);

	old = dir->i_op->lookup(dir, dentry, flags);
	if (unlikely(old)) {
		dput(dentry);
		dentry = old;
	}
	return dentry;
}


static void restore_nameidata(void)
{
	struct nameidata *now = current->nameidata, *old = now->saved;

	current->nameidata = old;
	if (old)
		old->total_link_count = now->total_link_count;
	if (now->stack != now->internal)
		kfree(now->stack);
}


static int path_parentat(struct nameidata *nd, unsigned flags,
				struct path *parent)
{
	const char *s = path_init(nd, flags);
	int err = link_path_walk(s, nd);
	if (!err)
		err = complete_walk(nd);
	if (!err) {
		*parent = nd->path;
		nd->path.mnt = NULL;
		nd->path.dentry = NULL;
	}
	terminate_walk(nd);
	return err;
}


SYSCALL_DEFINE1(unlink, const char __user *, pathname)
{
	return do_unlinkat(AT_FDCWD, getname(pathname));
}


static int may_create_in_sticky(umode_t dir_mode, kuid_t dir_uid,
				struct inode * const inode)
{
	if ((!sysctl_protected_fifos && S_ISFIFO(inode->i_mode)) ||
	    (!sysctl_protected_regular && S_ISREG(inode->i_mode)) ||
	    likely(!(dir_mode & S_ISVTX)) ||
	    uid_eq(inode->i_uid, dir_uid) ||
	    uid_eq(current_fsuid(), inode->i_uid))
		return 0;

	if (likely(dir_mode & 0002) ||
	    (dir_mode & 0020 &&
	     ((sysctl_protected_fifos >= 2 && S_ISFIFO(inode->i_mode)) ||
	      (sysctl_protected_regular >= 2 && S_ISREG(inode->i_mode))))) {
		const char *operation = S_ISFIFO(inode->i_mode) ?
					"sticky_create_fifo" :
					"sticky_create_regular";
		audit_log_path_denied(AUDIT_ANOM_CREAT, operation);
		return -EACCES;
	}
	return 0;
}


static int may_linkat(struct path *link)
{
	struct inode *inode = link->dentry->d_inode;

	/* Inode writeback is not safe when the uid or gid are invalid. */
	if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
		return -EOVERFLOW;

	if (!sysctl_protected_hardlinks)
		return 0;

	/* Source inode owner (or CAP_FOWNER) can hardlink all they like,
	 * otherwise, it must be a safe source.
	 */
	if (safe_hardlink_source(inode) || inode_owner_or_capable(inode))
		return 0;

	audit_log_path_denied(AUDIT_ANOM_LINK, "linkat");
	return -EPERM;
}


int filename_lookup(int dfd, struct filename *name, unsigned flags,
		    struct path *path, struct path *root)
{
	int retval;
	struct nameidata nd;
	if (IS_ERR(name))
		return PTR_ERR(name);
	if (unlikely(root)) {
		nd.root = *root;
		flags |= LOOKUP_ROOT;
	}
	set_nameidata(&nd, dfd, name);
	retval = path_lookupat(&nd, flags | LOOKUP_RCU, path);
	if (unlikely(retval == -ECHILD))
		retval = path_lookupat(&nd, flags, path);
	if (unlikely(retval == -ESTALE))
		retval = path_lookupat(&nd, flags | LOOKUP_REVAL, path);

	if (likely(!retval))
		audit_inode(name, path->dentry, 0);
	restore_nameidata();
	putname(name);
	return retval;
}


int vfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	int error = may_delete(dir, dentry, 1);

	if (error)
		return error;

	if (!dir->i_op->rmdir)
		return -EPERM;

	dget(dentry);
	inode_lock(dentry->d_inode);

	error = -EBUSY;
	if (is_local_mountpoint(dentry))
		goto out;

	error = security_inode_rmdir(dir, dentry);
	if (error)
		goto out;

	error = dir->i_op->rmdir(dir, dentry);
	if (error)
		goto out;

	shrink_dcache_parent(dentry);
	dentry->d_inode->i_flags |= S_DEAD;
	dont_mount(dentry);
	detach_mounts(dentry);
	fsnotify_rmdir(dir, dentry);

out:
	inode_unlock(dentry->d_inode);
	dput(dentry);
	if (!error)
		d_delete(dentry);
	return error;
}


int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
{
	int error = may_create(dir, dentry);

	if (error)
		return error;

	if (!dir->i_op->symlink)
		return -EPERM;

	error = security_inode_symlink(dir, dentry, oldname);
	if (error)
		return error;

	error = dir->i_op->symlink(dir, dentry, oldname);
	if (!error)
		fsnotify_create(dir, dentry);
	return error;
}


int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
	struct inode *inode = d_inode(dentry);
	DEFINE_DELAYED_CALL(done);
	const char *link;
	int res;

	if (unlikely(!(inode->i_opflags & IOP_DEFAULT_READLINK))) {
		if (unlikely(inode->i_op->readlink))
			return inode->i_op->readlink(dentry, buffer, buflen);

		if (!d_is_symlink(dentry))
			return -EINVAL;

		spin_lock(&inode->i_lock);
		inode->i_opflags |= IOP_DEFAULT_READLINK;
		spin_unlock(&inode->i_lock);
	}

	link = READ_ONCE(inode->i_link);
	if (!link) {
		link = inode->i_op->get_link(dentry, inode, &done);
		if (IS_ERR(link))
			return PTR_ERR(link);
	}
	res = readlink_copy(buffer, buflen, link);
	do_delayed_call(&done);
	return res;
}


path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
{
	const char *s = path_init(nd, flags);
	int err;

	while (!(err = link_path_walk(s, nd)) &&
		(err = lookup_last(nd)) > 0) {
		s = trailing_symlink(nd);
	}
	if (!err && (nd->flags & LOOKUP_RCU))
		err = unlazy_walk(nd);
	if (!err)
		err = handle_lookup_down(nd);
	if (!err) {
		*path = nd->path;
		nd->path.mnt = NULL;
		nd->path.dentry = NULL;
	}
	terminate_walk(nd);
	return err;
}


static struct file *path_openat(struct nameidata *nd,
			const struct open_flags *op, unsigned flags)
{
	struct file *file;
	int error;

	file = alloc_empty_file(op->open_flag, current_cred());
	if (IS_ERR(file))
		return file;

	if (unlikely(file->f_flags & __O_TMPFILE)) {
		error = do_tmpfile(nd, flags, op, file);
	} else if (unlikely(file->f_flags & O_PATH)) {
		error = do_o_path(nd, flags, file);
	} else {
		const char *s = path_init(nd, flags);
		while (!(error = link_path_walk(s, nd)) &&
			(error = do_last(nd, file, op)) > 0) {
			nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
			s = trailing_symlink(nd);
		}
		terminate_walk(nd);
	}
	if (likely(!error)) {
		if (likely(file->f_mode & FMODE_OPENED))
			return file;
		WARN_ON(1);
		error = -EINVAL;
	}
	fput(file);
	if (error == -EOPENSTALE) {
		if (flags & LOOKUP_RCU)
			error = -ECHILD;
		else
			error = -ESTALE;
	}
	return ERR_PTR(error);
}


static int nd_jump_root(struct nameidata *nd)
{
	if (nd->flags & LOOKUP_RCU) {
		struct dentry *d;
		nd->path = nd->root;
		d = nd->path.dentry;
		nd->inode = d->d_inode;
		nd->seq = nd->root_seq;
		if (unlikely(read_seqcount_retry(&d->d_seq, nd->seq)))
			return -ECHILD;
	} else {
		path_put(&nd->path);
		nd->path = nd->root;
		path_get(&nd->path);
		nd->inode = nd->path.dentry->d_inode;
	}
	nd->flags |= LOOKUP_JUMPED;
	return 0;
}


static bool legitimize_path(struct nameidata *nd,
			    struct path *path, unsigned seq)
{
	int res = __legitimize_mnt(path->mnt, nd->m_seq);
	if (unlikely(res)) {
		if (res > 0)
			path->mnt = NULL;
		path->dentry = NULL;
		return false;
	}
	if (unlikely(!lockref_get_not_dead(&path->dentry->d_lockref))) {
		path->dentry = NULL;
		return false;
	}
	return !read_seqcount_retry(&path->dentry->d_seq, seq);
}


const char *vfs_get_link(struct dentry *dentry, struct delayed_call *done)
{
	const char *res = ERR_PTR(-EINVAL);
	struct inode *inode = d_inode(dentry);

	if (d_is_symlink(dentry)) {
		res = ERR_PTR(security_inode_readlink(dentry));
		if (!res)
			res = inode->i_op->get_link(dentry, inode, done);
	}
	return res;
}


struct file *do_filp_open(int dfd, struct filename *pathname,
		const struct open_flags *op)
{
	struct nameidata nd;
	int flags = op->lookup_flags;
	struct file *filp;

	set_nameidata(&nd, dfd, pathname);
	filp = path_openat(&nd, op, flags | LOOKUP_RCU);
	if (unlikely(filp == ERR_PTR(-ECHILD)))
		filp = path_openat(&nd, op, flags);
	if (unlikely(filp == ERR_PTR(-ESTALE)))
		filp = path_openat(&nd, op, flags | LOOKUP_REVAL);
	restore_nameidata();
	return filp;
}


int follow_down_one(struct path *path)
{
	struct vfsmount *mounted;

	mounted = lookup_mnt(path);
	if (mounted) {
		dput(path->dentry);
		mntput(path->mnt);
		path->mnt = mounted;
		path->dentry = dget(mounted->mnt_root);
		return 1;
	}
	return 0;
}


int follow_up(struct path *path)
{
	struct mount *mnt = real_mount(path->mnt);
	struct mount *parent;
	struct dentry *mountpoint;

	read_seqlock_excl(&mount_lock);
	parent = mnt->mnt_parent;
	if (parent == mnt) {
		read_sequnlock_excl(&mount_lock);
		return 0;
	}
	mntget(&parent->mnt);
	mountpoint = dget(mnt->mnt_mountpoint);
	read_sequnlock_excl(&mount_lock);
	dput(path->dentry);
	path->dentry = mountpoint;
	mntput(path->mnt);
	path->mnt = &parent->mnt;
	return 1;
}


getname_kernel(const char * filename)
{
	struct filename *result;
	int len = strlen(filename) + 1;

	result = __getname();
	if (unlikely(!result))
		return ERR_PTR(-ENOMEM);

	if (len <= EMBEDDED_NAME_MAX) {
		result->name = (char *)result->iname;
	} else if (len <= PATH_MAX) {
		const size_t size = offsetof(struct filename, iname[1]);
		struct filename *tmp;

		tmp = kmalloc(size, GFP_KERNEL);
		if (unlikely(!tmp)) {
			__putname(result);
			return ERR_PTR(-ENOMEM);
		}
		tmp->name = (char *)result;
		result = tmp;
	} else {
		__putname(result);
		return ERR_PTR(-ENAMETOOLONG);
	}
	memcpy((char *)result->name, filename, len);
	result->uptr = NULL;
	result->aname = NULL;
	result->refcnt = 1;
	audit_getname(result);

	return result;
}


static int may_mknod(umode_t mode)
{
	switch (mode & S_IFMT) {
	case S_IFREG:
	case S_IFCHR:
	case S_IFBLK:
	case S_IFIFO:
	case S_IFSOCK:
	case 0: /* zero mode translates to S_IFREG */
		return 0;
	case S_IFDIR:
		return -EPERM;
	default:
		return -EINVAL;
	}
}


const char *get_link(struct nameidata *nd)
{
	struct saved *last = nd->stack + nd->depth - 1;
	struct dentry *dentry = last->link.dentry;
	struct inode *inode = nd->link_inode;
	int error;
	const char *res;

	if (!(nd->flags & LOOKUP_RCU)) {
		touch_atime(&last->link);
		cond_resched();
	} else if (atime_needs_update(&last->link, inode)) {
		if (unlikely(unlazy_walk(nd)))
			return ERR_PTR(-ECHILD);
		touch_atime(&last->link);
	}

	error = security_inode_follow_link(dentry, inode,
					   nd->flags & LOOKUP_RCU);
	if (unlikely(error))
		return ERR_PTR(error);

	nd->last_type = LAST_BIND;
	res = READ_ONCE(inode->i_link);
	if (!res) {
		const char * (*get)(struct dentry *, struct inode *,
				struct delayed_call *);
		get = inode->i_op->get_link;
		if (nd->flags & LOOKUP_RCU) {
			res = get(NULL, inode, &last->done);
			if (res == ERR_PTR(-ECHILD)) {
				if (unlikely(unlazy_walk(nd)))
					return ERR_PTR(-ECHILD);
				res = get(dentry, inode, &last->done);
			}
		} else {
			res = get(dentry, inode, &last->done);
		}
		if (IS_ERR_OR_NULL(res))
			return res;
	}
	if (*res == '/') {
		if (!nd->root.mnt)
			set_root(nd);
		if (unlikely(nd_jump_root(nd)))
			return ERR_PTR(-ECHILD);
		while (unlikely(*++res == '/'))
			;
	}
	if (!*res)
		res = NULL;
	return res;
}


static int check_acl(struct inode *inode, int mask)
{
#ifdef CONFIG_FS_POSIX_ACL
	struct posix_acl *acl;

	if (mask & MAY_NOT_BLOCK) {
		acl = get_cached_acl_rcu(inode, ACL_TYPE_ACCESS);
	        if (!acl)
	                return -EAGAIN;
		/* no ->get_acl() calls in RCU mode... */
		if (is_uncached_acl(acl))
			return -ECHILD;
	        return posix_acl_permission(inode, acl, mask & ~MAY_NOT_BLOCK);
	}

	acl = get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
	        int error = posix_acl_permission(inode, acl, mask);
	        posix_acl_release(acl);
	        return error;
	}
#endif

	return -EAGAIN;
}


kern_path_mountpoint(int dfd, const char *name, struct path *path,
			unsigned int flags)
{
	return filename_mountpoint(dfd, getname_kernel(name), path, flags);
}


static int atomic_open(struct nameidata *nd, struct dentry *dentry,
			struct path *path, struct file *file,
			const struct open_flags *op,
			int open_flag, umode_t mode)
{
	struct dentry *const DENTRY_NOT_SET = (void *) -1UL;
	struct inode *dir =  nd->path.dentry->d_inode;
	int error;

	if (!(~open_flag & (O_EXCL | O_CREAT)))	/* both O_EXCL and O_CREAT */
		open_flag &= ~O_TRUNC;

	if (nd->flags & LOOKUP_DIRECTORY)
		open_flag |= O_DIRECTORY;

	file->f_path.dentry = DENTRY_NOT_SET;
	file->f_path.mnt = nd->path.mnt;
	error = dir->i_op->atomic_open(dir, dentry, file,
				       open_to_namei_flags(open_flag), mode);
	d_lookup_done(dentry);
	if (!error) {
		if (file->f_mode & FMODE_OPENED) {
			/*
			 * We didn't have the inode before the open, so check open
			 * permission here.
			 */
			int acc_mode = op->acc_mode;
			if (file->f_mode & FMODE_CREATED) {
				WARN_ON(!(open_flag & O_CREAT));
				fsnotify_create(dir, dentry);
				acc_mode = 0;
			}
			error = may_open(&file->f_path, acc_mode, open_flag);
			if (WARN_ON(error > 0))
				error = -EINVAL;
		} else if (WARN_ON(file->f_path.dentry == DENTRY_NOT_SET)) {
			error = -EIO;
		} else {
			if (file->f_path.dentry) {
				dput(dentry);
				dentry = file->f_path.dentry;
			}
			if (file->f_mode & FMODE_CREATED)
				fsnotify_create(dir, dentry);
			if (unlikely(d_is_negative(dentry))) {
				error = -ENOENT;
			} else {
				path->dentry = dentry;
				path->mnt = nd->path.mnt;
				return 0;
			}
		}
	}
	dput(dentry);
	return error;
}


int __page_symlink(struct inode *inode, const char *symname, int len, int nofs)
{
	struct address_space *mapping = inode->i_mapping;
	struct page *page;
	void *fsdata;
	int err;
	unsigned int flags = 0;
	if (nofs)
		flags |= AOP_FLAG_NOFS;

retry:
	err = pagecache_write_begin(NULL, mapping, 0, len-1,
				flags, &page, &fsdata);
	if (err)
		goto fail;

	memcpy(page_address(page), symname, len-1);

	err = pagecache_write_end(NULL, mapping, 0, len-1, len-1,
							page, fsdata);
	if (err < 0)
		goto fail;
	if (err < len-1)
		goto retry;

	mark_inode_dirty(inode);
	return 0;
fail:
	return err;
}


static int lookup_open(struct nameidata *nd, struct path *path,
			struct file *file,
			const struct open_flags *op,
			bool got_write)
{
	struct dentry *dir = nd->path.dentry;
	struct inode *dir_inode = dir->d_inode;
	int open_flag = op->open_flag;
	struct dentry *dentry;
	int error, create_error = 0;
	umode_t mode = op->mode;
	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);

	if (unlikely(IS_DEADDIR(dir_inode)))
		return -ENOENT;

	file->f_mode &= ~FMODE_CREATED;
	dentry = d_lookup(dir, &nd->last);
	for (;;) {
		if (!dentry) {
			dentry = d_alloc_parallel(dir, &nd->last, &wq);
			if (IS_ERR(dentry))
				return PTR_ERR(dentry);
		}
		if (d_in_lookup(dentry))
			break;

		error = d_revalidate(dentry, nd->flags);
		if (likely(error > 0))
			break;
		if (error)
			goto out_dput;
		d_invalidate(dentry);
		dput(dentry);
		dentry = NULL;
	}
	if (dentry->d_inode) {
		/* Cached positive dentry: will open in f_op->open */
		goto out_no_open;
	}

	/*
	 * Checking write permission is tricky, bacuse we don't know if we are
	 * going to actually need it: O_CREAT opens should work as long as the
	 * file exists.  But checking existence breaks atomicity.  The trick is
	 * to check access and if not granted clear O_CREAT from the flags.
	 *
	 * Another problem is returing the "right" error value (e.g. for an
	 * O_EXCL open we want to return EEXIST not EROFS).
	 */
	if (open_flag & O_CREAT) {
		if (!IS_POSIXACL(dir->d_inode))
			mode &= ~current_umask();
		if (unlikely(!got_write)) {
			create_error = -EROFS;
			open_flag &= ~O_CREAT;
			if (open_flag & (O_EXCL | O_TRUNC))
				goto no_open;
			/* No side effects, safe to clear O_CREAT */
		} else {
			create_error = may_o_create(&nd->path, dentry, mode);
			if (create_error) {
				open_flag &= ~O_CREAT;
				if (open_flag & O_EXCL)
					goto no_open;
			}
		}
	} else if ((open_flag & (O_TRUNC|O_WRONLY|O_RDWR)) &&
		   unlikely(!got_write)) {
		/*
		 * No O_CREATE -> atomicity not a requirement -> fall
		 * back to lookup + open
		 */
		goto no_open;
	}

	if (dir_inode->i_op->atomic_open) {
		error = atomic_open(nd, dentry, path, file, op, open_flag,
				    mode);
		if (unlikely(error == -ENOENT) && create_error)
			error = create_error;
		return error;
	}

no_open:
	if (d_in_lookup(dentry)) {
		struct dentry *res = dir_inode->i_op->lookup(dir_inode, dentry,
							     nd->flags);
		d_lookup_done(dentry);
		if (unlikely(res)) {
			if (IS_ERR(res)) {
				error = PTR_ERR(res);
				goto out_dput;
			}
			dput(dentry);
			dentry = res;
		}
	}

	/* Negative dentry, just create the file */
	if (!dentry->d_inode && (open_flag & O_CREAT)) {
		file->f_mode |= FMODE_CREATED;
		audit_inode_child(dir_inode, dentry, AUDIT_TYPE_CHILD_CREATE);
		if (!dir_inode->i_op->create) {
			error = -EACCES;
			goto out_dput;
		}
		error = dir_inode->i_op->create(dir_inode, dentry, mode,
						open_flag & O_EXCL);
		if (error)
			goto out_dput;
		fsnotify_create(dir_inode, dentry);
	}
	if (unlikely(create_error) && !dentry->d_inode) {
		error = create_error;
		goto out_dput;
	}
out_no_open:
	path->dentry = dentry;
	path->mnt = nd->path.mnt;
	return 0;

out_dput:
	dput(dentry);
	return error;
}


const char *page_get_link(struct dentry *dentry, struct inode *inode,
			  struct delayed_call *callback)
{
	char *kaddr;
	struct page *page;
	struct address_space *mapping = inode->i_mapping;

	if (!dentry) {
		page = find_get_page(mapping, 0);
		if (!page)
			return ERR_PTR(-ECHILD);
		if (!PageUptodate(page)) {
			put_page(page);
			return ERR_PTR(-ECHILD);
		}
	} else {
		page = read_mapping_page(mapping, 0, NULL);
		if (IS_ERR(page))
			return (char*)page;
	}
	set_delayed_call(callback, page_put_link, page);
	BUG_ON(mapping_gfp_mask(mapping) & __GFP_HIGHMEM);
	kaddr = page_address(page);
	nd_terminate_link(kaddr, inode->i_size, PAGE_SIZE - 1);
	return kaddr;
}


u64 hashlen_string(const void *salt, const char *name)
{
	unsigned long hash = init_name_hash(salt);
	unsigned long len = 0, c;

	c = (unsigned char)*name;
	while (c) {
		len++;
		hash = partial_name_hash(c, hash);
		c = (unsigned char)name[len];
	}
	return hashlen_create(end_name_hash(hash), len);
}


int path_pts(struct path *path)
{
	/* Find something mounted on "pts" in the same directory as
	 * the input path.
	 */
	struct dentry *child, *parent;
	struct qstr this;
	int ret;

	ret = path_parent_directory(path);
	if (ret)
		return ret;

	parent = path->dentry;
	this.name = "pts";
	this.len = 3;
	child = d_hash_and_lookup(parent, &this);
	if (!child)
		return -ENOENT;

	path->dentry = child;
	dput(parent);
	follow_mount(path);
	return 0;
}


SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname)
{
	return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
}


static int may_open(const struct path *path, int acc_mode, int flag)
{
	struct dentry *dentry = path->dentry;
	struct inode *inode = dentry->d_inode;
	int error;

	if (!inode)
		return -ENOENT;

	switch (inode->i_mode & S_IFMT) {
	case S_IFLNK:
		return -ELOOP;
	case S_IFDIR:
		if (acc_mode & MAY_WRITE)
			return -EISDIR;
		break;
	case S_IFBLK:
	case S_IFCHR:
		if (!may_open_dev(path))
			return -EACCES;
		/*FALLTHRU*/
	case S_IFIFO:
	case S_IFSOCK:
		flag &= ~O_TRUNC;
		break;
	}

	error = inode_permission(inode, MAY_OPEN | acc_mode);
	if (error)
		return error;

	/*
	 * An append-only file must be opened in append mode for writing.
	 */
	if (IS_APPEND(inode)) {
		if  ((flag & O_ACCMODE) != O_RDONLY && !(flag & O_APPEND))
			return -EPERM;
		if (flag & O_TRUNC)
			return -EPERM;
	}

	/* O_NOATIME can only be set by the owner or superuser */
	if (flag & O_NOATIME && !inode_owner_or_capable(inode))
		return -EPERM;

	return 0;
}


static int lookup_fast(struct nameidata *nd,
		       struct path *path, struct inode **inode,
		       unsigned *seqp)
{
	struct vfsmount *mnt = nd->path.mnt;
	struct dentry *dentry, *parent = nd->path.dentry;
	int status = 1;
	int err;

	/*
	 * Rename seqlock is not required here because in the off chance
	 * of a false negative due to a concurrent rename, the caller is
	 * going to fall back to non-racy lookup.
	 */
	if (nd->flags & LOOKUP_RCU) {
		unsigned seq;
		bool negative;
		dentry = __d_lookup_rcu(parent, &nd->last, &seq);
		if (unlikely(!dentry)) {
			if (unlazy_walk(nd))
				return -ECHILD;
			return 0;
		}

		/*
		 * This sequence count validates that the inode matches
		 * the dentry name information from lookup.
		 */
		*inode = d_backing_inode(dentry);
		negative = d_is_negative(dentry);
		if (unlikely(read_seqcount_retry(&dentry->d_seq, seq)))
			return -ECHILD;

		/*
		 * This sequence count validates that the parent had no
		 * changes while we did the lookup of the dentry above.
		 *
		 * The memory barrier in read_seqcount_begin of child is
		 *  enough, we can use __read_seqcount_retry here.
		 */
		if (unlikely(__read_seqcount_retry(&parent->d_seq, nd->seq)))
			return -ECHILD;

		*seqp = seq;
		status = d_revalidate(dentry, nd->flags);
		if (likely(status > 0)) {
			/*
			 * Note: do negative dentry check after revalidation in
			 * case that drops it.
			 */
			if (unlikely(negative))
				return -ENOENT;
			path->mnt = mnt;
			path->dentry = dentry;
			if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
				return 1;
		}
		if (unlazy_child(nd, dentry, seq))
			return -ECHILD;
		if (unlikely(status == -ECHILD))
			/* we'd been told to redo it in non-rcu mode */
			status = d_revalidate(dentry, nd->flags);
	} else {
		dentry = __d_lookup(parent, &nd->last);
		if (unlikely(!dentry))
			return 0;
		status = d_revalidate(dentry, nd->flags);
	}
	if (unlikely(status <= 0)) {
		if (!status)
			d_invalidate(dentry);
		dput(dentry);
		return status;
	}

	path->mnt = mnt;
	path->dentry = dentry;
	err = follow_managed(path, nd);
	if (likely(err > 0))
		*inode = d_backing_inode(path->dentry);
	return err;
}


static int sb_permission(struct super_block *sb, struct inode *inode, int mask)
{
	if (unlikely(mask & MAY_WRITE)) {
		umode_t mode = inode->i_mode;

		/* Nobody gets write access to a read-only fs. */
		if (sb_rdonly(sb) && (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
			return -EROFS;
	}
	return 0;
}


user_path_mountpoint_at(int dfd, const char __user *name, unsigned int flags,
			struct path *path)
{
	return filename_mountpoint(dfd, getname(name), path, flags);
}


static int may_delete(struct inode *dir, struct dentry *victim, bool isdir)
{
	struct inode *inode = d_backing_inode(victim);
	int error;

	if (d_is_negative(victim))
		return -ENOENT;
	BUG_ON(!inode);

	BUG_ON(victim->d_parent->d_inode != dir);

	/* Inode writeback is not safe when the uid or gid are invalid. */
	if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
		return -EOVERFLOW;

	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);

	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
	if (error)
		return error;
	if (IS_APPEND(dir))
		return -EPERM;

	if (check_sticky(dir, inode) || IS_APPEND(inode) ||
	    IS_IMMUTABLE(inode) || IS_SWAPFILE(inode) || HAS_UNMAPPED_ID(inode))
		return -EPERM;
	if (isdir) {
		if (!d_is_dir(victim))
			return -ENOTDIR;
		if (IS_ROOT(victim))
			return -EBUSY;
	} else if (d_is_dir(victim))
		return -EISDIR;
	if (IS_DEADDIR(dir))
		return -ENOENT;
	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
		return -EBUSY;
	return 0;
}


long do_unlinkat(int dfd, struct filename *name)
{
	int error;
	struct dentry *dentry;
	struct path path;
	struct qstr last;
	int type;
	struct inode *inode = NULL;
	struct inode *delegated_inode = NULL;
	unsigned int lookup_flags = 0;
retry:
	name = filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
	if (IS_ERR(name))
		return PTR_ERR(name);

	error = -EISDIR;
	if (type != LAST_NORM)
		goto exit1;

	error = mnt_want_write(path.mnt);
	if (error)
		goto exit1;
retry_deleg:
	inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT);
	dentry = __lookup_hash(&last, path.dentry, lookup_flags);
	error = PTR_ERR(dentry);
	if (!IS_ERR(dentry)) {
		/* Why not before? Because we want correct error value */
		if (last.name[last.len])
			goto slashes;
		inode = dentry->d_inode;
		if (d_is_negative(dentry))
			goto slashes;
		ihold(inode);
		error = security_path_unlink(&path, dentry);
		if (error)
			goto exit2;
		error = vfs_unlink(path.dentry->d_inode, dentry, &delegated_inode);
exit2:
		dput(dentry);
	}
	inode_unlock(path.dentry->d_inode);
	if (inode)
		iput(inode);	/* truncate the inode here */
	inode = NULL;
	if (delegated_inode) {
		error = break_deleg_wait(&delegated_inode);
		if (!error)
			goto retry_deleg;
	}
	mnt_drop_write(path.mnt);
exit1:
	path_put(&path);
	if (retry_estale(error, lookup_flags)) {
		lookup_flags |= LOOKUP_REVAL;
		inode = NULL;
		goto retry;
	}
	putname(name);
	return error;

slashes:
	if (d_is_negative(dentry))
		error = -ENOENT;
	else if (d_is_dir(dentry))
		error = -EISDIR;
	else
		error = -ENOTDIR;
	goto exit2;
}


int generic_permission(struct inode *inode, int mask)
{
	int ret;

	/*
	 * Do the basic permission checks.
	 */
	ret = acl_permission_check(inode, mask);
	if (ret != -EACCES)
		return ret;

	if (S_ISDIR(inode->i_mode)) {
		/* DACs are overridable for directories */
		if (!(mask & MAY_WRITE))
			if (capable_wrt_inode_uidgid(inode,
						     CAP_DAC_READ_SEARCH))
				return 0;
		if (capable_wrt_inode_uidgid(inode, CAP_DAC_OVERRIDE))
			return 0;
		return -EACCES;
	}

	/*
	 * Searching includes executable on directories, else just read.
	 */
	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
	if (mask == MAY_READ)
		if (capable_wrt_inode_uidgid(inode, CAP_DAC_READ_SEARCH))
			return 0;
	/*
	 * Read/write DACs are always overridable.
	 * Executable DACs are overridable when there is
	 * at least one exec bit set.
	 */
	if (!(mask & MAY_EXEC) || (inode->i_mode & S_IXUGO))
		if (capable_wrt_inode_uidgid(inode, CAP_DAC_OVERRIDE))
			return 0;

	return -EACCES;
}


SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
		int, newdfd, const char __user *, newname, int, flags)
{
	return do_linkat(olddfd, oldname, newdfd, newname, flags);
}


static void drop_links(struct nameidata *nd)
{
	int i = nd->depth;
	while (i--) {
		struct saved *last = nd->stack + i;
		do_delayed_call(&last->done);
		clear_delayed_call(&last->done);
	}
}


static bool safe_hardlink_source(struct inode *inode)
{
	umode_t mode = inode->i_mode;

	/* Special files should not get pinned to the filesystem. */
	if (!S_ISREG(mode))
		return false;

	/* Setuid files should not get pinned to the filesystem. */
	if (mode & S_ISUID)
		return false;

	/* Executable setgid files should not get pinned to the filesystem. */
	if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
		return false;

	/* Hardlinking to unreadable or unwritable sources is dangerous. */
	if (inode_permission(inode, MAY_READ | MAY_WRITE))
		return false;

	return true;
}


getname(const char __user * filename)
{
	return getname_flags(filename, 0, NULL);
}


static const char *path_init(struct nameidata *nd, unsigned flags)
{
	const char *s = nd->name->name;

	if (!*s)
		flags &= ~LOOKUP_RCU;
	if (flags & LOOKUP_RCU)
		rcu_read_lock();

	nd->last_type = LAST_ROOT; /* if there are only slashes... */
	nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
	nd->depth = 0;
	if (flags & LOOKUP_ROOT) {
		struct dentry *root = nd->root.dentry;
		struct inode *inode = root->d_inode;
		if (*s && unlikely(!d_can_lookup(root)))
			return ERR_PTR(-ENOTDIR);
		nd->path = nd->root;
		nd->inode = inode;
		if (flags & LOOKUP_RCU) {
			nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
			nd->root_seq = nd->seq;
			nd->m_seq = read_seqbegin(&mount_lock);
		} else {
			path_get(&nd->path);
		}
		return s;
	}

	nd->root.mnt = NULL;
	nd->path.mnt = NULL;
	nd->path.dentry = NULL;

	nd->m_seq = read_seqbegin(&mount_lock);
	if (*s == '/') {
		set_root(nd);
		if (likely(!nd_jump_root(nd)))
			return s;
		return ERR_PTR(-ECHILD);
	} else if (nd->dfd == AT_FDCWD) {
		if (flags & LOOKUP_RCU) {
			struct fs_struct *fs = current->fs;
			unsigned seq;

			do {
				seq = read_seqcount_begin(&fs->seq);
				nd->path = fs->pwd;
				nd->inode = nd->path.dentry->d_inode;
				nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
			} while (read_seqcount_retry(&fs->seq, seq));
		} else {
			get_fs_pwd(current->fs, &nd->path);
			nd->inode = nd->path.dentry->d_inode;
		}
		return s;
	} else {
		/* Caller must check execute permissions on the starting path component */
		struct fd f = fdget_raw(nd->dfd);
		struct dentry *dentry;

		if (!f.file)
			return ERR_PTR(-EBADF);

		dentry = f.file->f_path.dentry;

		if (*s && unlikely(!d_can_lookup(dentry))) {
			fdput(f);
			return ERR_PTR(-ENOTDIR);
		}

		nd->path = f.file->f_path;
		if (flags & LOOKUP_RCU) {
			nd->inode = nd->path.dentry->d_inode;
			nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
		} else {
			path_get(&nd->path);
			nd->inode = nd->path.dentry->d_inode;
		}
		fdput(f);
		return s;
	}
}


getname_flags(const char __user *filename, int flags, int *empty)
{
	struct filename *result;
	char *kname;
	int len;

	result = audit_reusename(filename);
	if (result)
		return result;

	result = __getname();
	if (unlikely(!result))
		return ERR_PTR(-ENOMEM);

	/*
	 * First, try to embed the struct filename inside the names_cache
	 * allocation
	 */
	kname = (char *)result->iname;
	result->name = kname;

	len = strncpy_from_user(kname, filename, EMBEDDED_NAME_MAX);
	if (unlikely(len < 0)) {
		__putname(result);
		return ERR_PTR(len);
	}

	/*
	 * Uh-oh. We have a name that's approaching PATH_MAX. Allocate a
	 * separate struct filename so we can dedicate the entire
	 * names_cache allocation for the pathname, and re-do the copy from
	 * userland.
	 */
	if (unlikely(len == EMBEDDED_NAME_MAX)) {
		const size_t size = offsetof(struct filename, iname[1]);
		kname = (char *)result;

		/*
		 * size is chosen that way we to guarantee that
		 * result->iname[0] is within the same object and that
		 * kname can't be equal to result->iname, no matter what.
		 */
		result = kzalloc(size, GFP_KERNEL);
		if (unlikely(!result)) {
			__putname(kname);
			return ERR_PTR(-ENOMEM);
		}
		result->name = kname;
		len = strncpy_from_user(kname, filename, PATH_MAX);
		if (unlikely(len < 0)) {
			__putname(kname);
			kfree(result);
			return ERR_PTR(len);
		}
		if (unlikely(len == PATH_MAX)) {
			__putname(kname);
			kfree(result);
			return ERR_PTR(-ENAMETOOLONG);
		}
	}

	result->refcnt = 1;
	/* The empty path is special. */
	if (unlikely(!len)) {
		if (empty)
			*empty = 1;
		if (!(flags & LOOKUP_EMPTY)) {
			putname(result);
			return ERR_PTR(-ENOENT);
		}
	}

	result->uptr = filename;
	result->aname = NULL;
	audit_getname(result);
	return result;
}


static int complete_walk(struct nameidata *nd)
{
	struct dentry *dentry = nd->path.dentry;
	int status;

	if (nd->flags & LOOKUP_RCU) {
		if (!(nd->flags & LOOKUP_ROOT))
			nd->root.mnt = NULL;
		if (unlikely(unlazy_walk(nd)))
			return -ECHILD;
	}

	if (likely(!(nd->flags & LOOKUP_JUMPED)))
		return 0;

	if (likely(!(dentry->d_flags & DCACHE_OP_WEAK_REVALIDATE)))
		return 0;

	status = dentry->d_op->d_weak_revalidate(dentry, nd->flags);
	if (status > 0)
		return 0;

	if (!status)
		status = -ESTALE;

	return status;
}


static int follow_automount(struct path *path, struct nameidata *nd,
			    bool *need_mntput)
{
	struct vfsmount *mnt;
	int err;

	if (!path->dentry->d_op || !path->dentry->d_op->d_automount)
		return -EREMOTE;

	/* We don't want to mount if someone's just doing a stat -
	 * unless they're stat'ing a directory and appended a '/' to
	 * the name.
	 *
	 * We do, however, want to mount if someone wants to open or
	 * create a file of any type under the mountpoint, wants to
	 * traverse through the mountpoint or wants to open the
	 * mounted directory.  Also, autofs may mark negative dentries
	 * as being automount points.  These will need the attentions
	 * of the daemon to instantiate them before they can be used.
	 */
	if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
			   LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) &&
	    path->dentry->d_inode)
		return -EISDIR;

	nd->total_link_count++;
	if (nd->total_link_count >= 40)
		return -ELOOP;

	mnt = path->dentry->d_op->d_automount(path);
	if (IS_ERR(mnt)) {
		/*
		 * The filesystem is allowed to return -EISDIR here to indicate
		 * it doesn't want to automount.  For instance, autofs would do
		 * this so that its userspace daemon can mount on this dentry.
		 *
		 * However, we can only permit this if it's a terminal point in
		 * the path being looked up; if it wasn't then the remainder of
		 * the path is inaccessible and we should say so.
		 */
		if (PTR_ERR(mnt) == -EISDIR && (nd->flags & LOOKUP_PARENT))
			return -EREMOTE;
		return PTR_ERR(mnt);
	}

	if (!mnt) /* mount collision */
		return 0;

	if (!*need_mntput) {
		/* lock_mount() may release path->mnt on error */
		mntget(path->mnt);
		*need_mntput = true;
	}
	err = finish_automount(mnt, path);

	switch (err) {
	case -EBUSY:
		/* Someone else made a mount here whilst we were busy */
		return 0;
	case 0:
		path_put(path);
		path->mnt = mnt;
		path->dentry = dget(mnt->mnt_root);
		return 0;
	default:
		return err;
	}

}


static int __nd_alloc_stack(struct nameidata *nd)
{
	struct saved *p;

	if (nd->flags & LOOKUP_RCU) {
		p= kmalloc_array(MAXSYMLINKS, sizeof(struct saved),
				  GFP_ATOMIC);
		if (unlikely(!p))
			return -ECHILD;
	} else {
		p= kmalloc_array(MAXSYMLINKS, sizeof(struct saved),
				  GFP_KERNEL);
		if (unlikely(!p))
			return -ENOMEM;
	}
	memcpy(p, nd->internal, sizeof(nd->internal));
	nd->stack = p;
	return 0;
}