Rein Klazes : x11drv: Avoid unaligned 32 bit reads, and reads beyond the input pixel
Module: wine Branch: refs/heads/master Commit: 883e0b0edc21d16da5eb2f6bf02d5a18ac31ce38 URL: http://source.winehq.org/git/?p=wine.git;a=commit;h=883e0b0edc21d16da5eb2f6b... Author: Rein Klazes <wijn(a)wanadoo.nl> Date: Wed Mar 1 16:39:42 2006 +0100 x11drv: Avoid unaligned 32 bit reads, and reads beyond the input pixel buffer in the convert_888_to_0888_* functions. --- dlls/x11drv/dib_convert.c | 102 ++++++++++++++++++++++++++++++++++----------- 1 files changed, 78 insertions(+), 24 deletions(-) diff --git a/dlls/x11drv/dib_convert.c b/dlls/x11drv/dib_convert.c index b504843..347e1b3 100644 --- a/dlls/x11drv/dib_convert.c +++ b/dlls/x11drv/dib_convert.c @@ -821,18 +821,36 @@ static void convert_888_to_0888_asis(int const DWORD* srcpixel; DWORD* dstpixel; int x,y; - int oddwidth; - - oddwidth=width & 3; - width=width/4; + int w1, w2, w3; + + w1 = min( (INT_PTR)srcbits & 3, width); + w2 = ( width - w1) / 4; + w3 = ( width - w1) & 3; for (y=0; y<height; y++) { srcpixel=srcbits; dstpixel=dstbits; - for (x=0; x<width; x++) { + /* advance w1 pixels to make srcpixel 32 bit alignd */ + srcpixel = (const DWORD*)((INT_PTR)srcpixel & ~3); + srcpixel += w1; + dstpixel += w1; + /* and do the w1 pixels */ + x = w1; + if( x) { + dstpixel[ -1] = ( srcpixel[ -1] >> 8); /* h4, g4, l4 */ + if( --x) { + dstpixel[ -2] = ( srcpixel[ -2] >> 16) | /* g3, l3 */ + ((srcpixel[ -1] << 16) & 0x00ff0000); /* h3 */ + if( --x) { + dstpixel[ -3] = ( srcpixel[ -3] >> 24) | /* l2 */ + ((srcpixel[ -2] << 8) & 0x00ffff00); /* h2, g2 */ + } + } + } + for (x=0; x < w2; x++) { /* Do 4 pixels at a time: 3 dwords in and 4 dwords out */ DWORD srcval1,srcval2; srcval1=srcpixel[0]; - dstpixel[0]=( srcval1 & 0x00ffffff); /* h1, g1, l1 */ + dstpixel[0]=( srcval1 & 0x00ffffff); /* h1, g1, l1 */ srcval2=srcpixel[1]; dstpixel[1]=( srcval1 >> 24) | /* l2 */ ((srcval2 << 8) & 0x00ffff00); /* h2, g2 */ @@ -843,12 +861,18 @@ static void convert_888_to_0888_asis(int srcpixel+=3; dstpixel+=4; } - /* And now up to 3 odd pixels */ - for (x=0; x<oddwidth; x++) { - DWORD srcval; - srcval=*srcpixel; - srcpixel=(const DWORD*)(((const char*)srcpixel)+3); - *dstpixel++=( srcval & 0x00ffffff); /* h, g, l */ + /* do last w3 pixels */ + x = w3; + if( x) { + dstpixel[0]=( srcpixel[0] & 0x00ffffff); /* h1, g1, l1 */ + if( --x) { + dstpixel[1]=( srcpixel[0]>> 24) | /* l2 */ + ((srcpixel[1]<< 8) & 0x00ffff00); /* h2, g2 */ + if( --x) { + dstpixel[2]=( srcpixel[1]>> 16) | /* g3, l3 */ + ((srcpixel[2]<< 16) & 0x00ff0000); /* h3 */ + } + } } srcbits = (const char*)srcbits + srclinebytes; dstbits = (char*)dstbits + dstlinebytes; @@ -862,14 +886,36 @@ static void convert_888_to_0888_reverse( const DWORD* srcpixel; DWORD* dstpixel; int x,y; - int oddwidth; + int w1, w2, w3; - oddwidth=width & 3; - width=width/4; + w1 = min( (INT_PTR)srcbits & 3, width); + w2 = ( width - w1) / 4; + w3 = ( width - w1) & 3; for (y=0; y<height; y++) { srcpixel=srcbits; dstpixel=dstbits; - for (x=0; x<width; x++) { + /* advance w1 pixels to make srcpixel 32 bit alignd */ + srcpixel = (const DWORD*)((INT_PTR)srcpixel & ~3); + srcpixel += w1; + dstpixel += w1; + /* and do the w1 pixels */ + x = w1; + if( x) { + dstpixel[ -1]=((srcpixel[ -1] >> 24) & 0x0000ff) | /* h4 */ + ((srcpixel[ -1] >> 8) & 0x00ff00) | /* g4 */ + ((srcpixel[ -1] << 8) & 0xff0000); /* l4 */ + if( --x) { + dstpixel[ -2]=( srcpixel[ -2] & 0xff0000) | /* l3 */ + ((srcpixel[ -2] >> 16) & 0x00ff00) | /* g3 */ + ( srcpixel[ -1] & 0x0000ff); /* h3 */ + if( --x) { + dstpixel[ -3]=((srcpixel[ -3] >> 8) & 0xff0000) | /* l2 */ + ((srcpixel[ -2] << 8) & 0x00ff00) | /* g2 */ + ((srcpixel[ -2] >> 8) & 0x0000ff); /* h2 */ + } + } + } + for (x=0; x < w2; x++) { /* Do 4 pixels at a time: 3 dwords in and 4 dwords out */ DWORD srcval1,srcval2; @@ -891,14 +937,22 @@ static void convert_888_to_0888_reverse( srcpixel+=3; dstpixel+=4; } - /* And now up to 3 odd pixels */ - for (x=0; x<oddwidth; x++) { - DWORD srcval; - srcval=*srcpixel; - srcpixel=(const DWORD*)(((const char*)srcpixel)+3); - *dstpixel++=((srcval >> 16) & 0x0000ff) | /* h */ - ( srcval & 0x00ff00) | /* g */ - ((srcval << 16) & 0xff0000); /* l */ + /* do last w3 pixels */ + x = w3; + if( x) { + dstpixel[0]=((srcpixel[0] >> 16) & 0x0000ff) | /* h1 */ + ( srcpixel[0] & 0x00ff00) | /* g1 */ + ((srcpixel[0] << 16) & 0xff0000); /* l1 */ + if( --x) { + dstpixel[1]=((srcpixel[0] >> 8) & 0xff0000) | /* l2 */ + ((srcpixel[1] << 8) & 0x00ff00) | /* g2 */ + ((srcpixel[1] >> 8) & 0x0000ff); /* h2 */ + if( --x) { + dstpixel[2]=( srcpixel[1] & 0xff0000) | /* l3 */ + ((srcpixel[1] >> 16) & 0x00ff00) | /* g3 */ + ( srcpixel[2] & 0x0000ff); /* h3 */ + } + } } srcbits = (const char*)srcbits + srclinebytes; dstbits = (char*)dstbits + dstlinebytes;
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Alexandre Julliard