--- a/src/video/SDL_stretch.c Sun Oct 18 16:14:35 2009 +0000
+++ b/src/video/SDL_stretch.c Sun Oct 18 17:49:40 2009 +0000
@@ -42,6 +42,16 @@
#ifdef USE_ASM_STRETCH
+#ifdef HAVE_MPROTECT
+#include <sys/types.h>
+#include <sys/mman.h>
+#endif
+#ifdef __GNUC__
+#define PAGE_ALIGNED __attribute__((__aligned__(4096)))
+#else
+#define PAGE_ALIGNED
+#endif
+
#if defined(_M_IX86) || defined(i386)
#define PREFIX16 0x66
#define STORE_BYTE 0xAA
@@ -53,7 +63,7 @@
#error Need assembly opcodes for this architecture
#endif
-static unsigned char copy_row[4096];
+static unsigned char copy_row[4096] PAGE_ALIGNED;
static int
generate_rowbytes(int src_w, int dst_w, int bpp)
@@ -63,6 +73,7 @@
int bpp;
int src_w;
int dst_w;
+ int status;
} last;
int i;
@@ -72,11 +83,12 @@
/* See if we need to regenerate the copy buffer */
if ((src_w == last.src_w) && (dst_w == last.dst_w) && (bpp == last.bpp)) {
- return (0);
+ return (last.status);
}
last.bpp = bpp;
last.src_w = src_w;
last.dst_w = dst_w;
+ last.status = -1;
switch (bpp) {
case 1:
@@ -92,6 +104,13 @@
SDL_SetError("ASM stretch of %d bytes isn't supported\n", bpp);
return (-1);
}
+#ifdef HAVE_MPROTECT
+ /* Make the code writeable */
+ if (mprotect(copy_row, sizeof(copy_row), PROT_READ | PROT_WRITE) < 0) {
+ SDL_SetError("Couldn't make copy buffer writeable");
+ return (-1);
+ }
+#endif
pos = 0x10000;
inc = (src_w << 16) / dst_w;
eip = copy_row;
@@ -111,47 +130,55 @@
}
*eip++ = RETURN;
- /* Verify that we didn't overflow (too late) */
+ /* Verify that we didn't overflow (too late!!!) */
if (eip > (copy_row + sizeof(copy_row))) {
SDL_SetError("Copy buffer overflow");
return (-1);
}
+#ifdef HAVE_MPROTECT
+ /* Make the code executable but not writeable */
+ if (mprotect(copy_row, sizeof(copy_row), PROT_READ | PROT_EXEC) < 0) {
+ SDL_SetError("Couldn't make copy buffer executable");
+ return (-1);
+ }
+#endif
+ last.status = 0;
return (0);
}
-#else
+#endif /* USE_ASM_STRETCH */
-#define DEFINE_COPY_ROW(name, type) \
-void name(type *src, int src_w, type *dst, int dst_w) \
-{ \
- int i; \
- int pos, inc; \
- type pixel = 0; \
- \
- pos = 0x10000; \
- inc = (src_w << 16) / dst_w; \
- for ( i=dst_w; i>0; --i ) { \
- while ( pos >= 0x10000L ) { \
- pixel = *src++; \
- pos -= 0x10000L; \
- } \
- *dst++ = pixel; \
- pos += inc; \
- } \
+#define DEFINE_COPY_ROW(name, type) \
+void name(type *src, int src_w, type *dst, int dst_w) \
+{ \
+ int i; \
+ int pos, inc; \
+ type pixel = 0; \
+ \
+ pos = 0x10000; \
+ inc = (src_w << 16) / dst_w; \
+ for ( i=dst_w; i>0; --i ) { \
+ while ( pos >= 0x10000L ) { \
+ pixel = *src++; \
+ pos -= 0x10000L; \
+ } \
+ *dst++ = pixel; \
+ pos += inc; \
+ } \
}
/* *INDENT-OFF* */
DEFINE_COPY_ROW(copy_row1, Uint8)
DEFINE_COPY_ROW(copy_row2, Uint16)
DEFINE_COPY_ROW(copy_row4, Uint32)
/* *INDENT-ON* */
-#endif /* USE_ASM_STRETCH */
+
/* The ASM code doesn't handle 24-bpp stretch blits */
void
copy_row3(Uint8 * src, int src_w, Uint8 * dst, int dst_w)
{
int i;
int pos, inc;
- Uint8 pixel[3];
+ Uint8 pixel[3] = { 0, 0, 0 };
pos = 0x10000;
inc = (src_w << 16) / dst_w;
@@ -186,9 +213,12 @@
Uint8 *dstp;
SDL_Rect full_src;
SDL_Rect full_dst;
-#if defined(USE_ASM_STRETCH) && defined(__GNUC__)
+#ifdef USE_ASM_STRETCH
+ SDL_bool use_asm = SDL_TRUE;
+#ifdef __GNUC__
int u1, u2;
#endif
+#endif /* USE_ASM_STRETCH */
const int bpp = dst->format->BytesPerPixel;
if (src->format->BitsPerPixel != dst->format->BitsPerPixel) {
@@ -257,8 +287,8 @@
#ifdef USE_ASM_STRETCH
/* Write the opcodes for this stretch */
- if ((bpp != 3) && (generate_rowbytes(srcrect->w, dstrect->w, bpp) < 0)) {
- return (-1);
+ if ((bpp == 3) || (generate_rowbytes(srcrect->w, dstrect->w, bpp) < 0)) {
+ use_asm = SDL_FALSE;
}
#endif
@@ -273,13 +303,11 @@
pos -= 0x10000L;
}
#ifdef USE_ASM_STRETCH
- switch (bpp) {
- case 3:
- copy_row3(srcp, srcrect->w, dstp, dstrect->w);
- break;
- default:
+ if (use_asm) {
#ifdef __GNUC__
- __asm__ __volatile__("call *%4": "=&D"(u1), "=&S"(u2): "0"(dstp), "1"(srcp), "r"(copy_row):"memory");
+ __asm__ __volatile__("call *%4":"=&D"(u1), "=&S"(u2)
+ :"0"(dstp), "1"(srcp), "r"(copy_row)
+ :"memory");
#elif defined(_MSC_VER) || defined(__WATCOMC__)
/* *INDENT-OFF* */
{
@@ -298,26 +326,24 @@
#else
#error Need inline assembly for this compiler
#endif
- break;
- }
-#else
- switch (bpp) {
- case 1:
- copy_row1(srcp, srcrect->w, dstp, dstrect->w);
- break;
- case 2:
- copy_row2((Uint16 *) srcp, srcrect->w,
- (Uint16 *) dstp, dstrect->w);
- break;
- case 3:
- copy_row3(srcp, srcrect->w, dstp, dstrect->w);
- break;
- case 4:
- copy_row4((Uint32 *) srcp, srcrect->w,
- (Uint32 *) dstp, dstrect->w);
- break;
- }
+ } else
#endif
+ switch (bpp) {
+ case 1:
+ copy_row1(srcp, srcrect->w, dstp, dstrect->w);
+ break;
+ case 2:
+ copy_row2((Uint16 *) srcp, srcrect->w,
+ (Uint16 *) dstp, dstrect->w);
+ break;
+ case 3:
+ copy_row3(srcp, srcrect->w, dstp, dstrect->w);
+ break;
+ case 4:
+ copy_row4((Uint32 *) srcp, srcrect->w,
+ (Uint32 *) dstp, dstrect->w);
+ break;
+ }
pos += inc;
}