Fixed bug 936

Make sure that eip doesn't overflow the copy buffer beforehand. :)

--HG--
branch : SDL-1.2
This commit is contained in:
Sam Lantinga 2010-07-18 10:08:06 -07:00
parent f0f094ad30
commit a213c9590f

View file

@ -78,7 +78,7 @@ static int generate_rowbytes(int src_w, int dst_w, int bpp)
int i;
int pos, inc;
unsigned char *eip;
unsigned char *eip, *end;
unsigned char load, store;
/* See if we need to regenerate the copy buffer */
@ -115,7 +115,8 @@ static int generate_rowbytes(int src_w, int dst_w, int bpp)
pos = 0x10000;
inc = (src_w << 16) / dst_w;
eip = copy_row;
for ( i=0; i<dst_w; ++i ) {
end = copy_row+sizeof(copy_row);
for ( i=0; i<dst_w && eip < end; ++i ) {
while ( pos >= 0x10000L ) {
if ( bpp == 2 ) {
*eip++ = PREFIX16;
@ -132,8 +133,8 @@ static int generate_rowbytes(int src_w, int dst_w, int bpp)
*eip++ = RETURN;
/* Verify that we didn't overflow (too late!!!) */
if ( eip > (copy_row+sizeof(copy_row)) ) {
SDL_SetError("Copy buffer overflow");
if ( i < dst_w ) {
SDL_SetError("Copy buffer too small");
return(-1);
}
#ifdef HAVE_MPROTECT