From 1fb12d68c62a9d33943e46315c23b8477de5ebcf Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Wed, 15 Mar 2017 14:28:07 +0100
Subject: [PATCH] cirrus: stop passing around src pointers in the blitter

Does basically the same as "cirrus: stop passing around dst pointers in
the blitter", just for the src pointer instead of the dst pointer.

For the src we have to care about cputovideo blits though and fetch the
data from s->cirrus_bltbuf instead of vga memory.  The cirrus_src*()
helper functions handle that.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1489584487-3489-1-git-send-email-kraxel@redhat.com
(cherry picked from commit ffaf857778286ca54e3804432a2369a279e73aa7)
[BR: BSC#1035406 CVE-2017-7980]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/display/cirrus_vga.c      | 61 +++++++++++++++++++++++++++++++++++---------
 hw/display/cirrus_vga_rop.h  | 48 +++++++++++++++++-----------------
 hw/display/cirrus_vga_rop2.h | 38 ++++++++++++++-------------
 3 files changed, 93 insertions(+), 54 deletions(-)

diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index 4761bfca3a..5963e8e34c 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -177,7 +177,7 @@
 
 struct CirrusVGAState;
 typedef void (*cirrus_bitblt_rop_t) (struct CirrusVGAState *s,
-                                     uint32_t dstaddr, const uint8_t *src,
+                                     uint32_t dstaddr, uint32_t srcaddr,
 				     int dstpitch, int srcpitch,
 				     int bltwidth, int bltheight);
 typedef void (*cirrus_fill_t)(struct CirrusVGAState *s,
@@ -320,7 +320,7 @@ static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only)
 }
 
 static void cirrus_bitblt_rop_nop(CirrusVGAState *s,
-                                  uint32_t dstaddr, const uint8_t *src,
+                                  uint32_t dstaddr, uint32_t srcaddr,
                                   int dstpitch,int srcpitch,
                                   int bltwidth,int bltheight)
 {
@@ -332,6 +332,45 @@ static void cirrus_bitblt_fill_nop(CirrusVGAState *s,
 {
 }
 
+static inline uint8_t cirrus_src(CirrusVGAState *s, uint32_t srcaddr)
+{
+    if (s->cirrus_srccounter) {
+        /* cputovideo */
+        return s->cirrus_bltbuf[srcaddr & (CIRRUS_BLTBUFSIZE - 1)];
+    } else {
+        /* videotovideo */
+        return s->vga.vram_ptr[srcaddr & s->cirrus_addr_mask];
+    }
+}
+
+static inline uint16_t cirrus_src16(CirrusVGAState *s, uint32_t srcaddr)
+{
+    uint16_t *src;
+
+    if (s->cirrus_srccounter) {
+        /* cputovideo */
+        src = (void *)&s->cirrus_bltbuf[srcaddr & (CIRRUS_BLTBUFSIZE - 1) & ~1];
+    } else {
+        /* videotovideo */
+        src = (void *)&s->vga.vram_ptr[srcaddr & s->cirrus_addr_mask & ~1];
+    }
+    return *src;
+}
+
+static inline uint32_t cirrus_src32(CirrusVGAState *s, uint32_t srcaddr)
+{
+    uint32_t *src;
+
+    if (s->cirrus_srccounter) {
+        /* cputovideo */
+        src = (void *)&s->cirrus_bltbuf[srcaddr & (CIRRUS_BLTBUFSIZE - 1) & ~3];
+    } else {
+        /* videotovideo */
+        src = (void *)&s->vga.vram_ptr[srcaddr & s->cirrus_addr_mask & ~3];
+    }
+    return *src;
+}
+
 #define ROP_NAME 0
 #define ROP_FN(d, s) 0
 #include "cirrus_vga_rop.h"
@@ -674,10 +713,10 @@ static void cirrus_invalidate_region(CirrusVGAState * s, int off_begin,
     }
 }
 
-static int cirrus_bitblt_common_patterncopy(CirrusVGAState *s, bool videosrc)
+static int cirrus_bitblt_common_patterncopy(CirrusVGAState *s)
 {
     uint32_t patternsize;
-    uint8_t *src;
+    bool videosrc = !s->cirrus_srccounter;
 
     if (videosrc) {
         switch (s->vga.get_bpp(&s->vga)) {
@@ -698,15 +737,13 @@ static int cirrus_bitblt_common_patterncopy(CirrusVGAState *s, bool videosrc)
         if (s->cirrus_blt_srcaddr + patternsize > s->vga.vram_size) {
             return 0;
         }
-        src = s->vga.vram_ptr + s->cirrus_blt_srcaddr;
-    } else {
-        src = s->cirrus_bltbuf;
     }
 
     if (blit_is_unsafe(s, true))
         return 0;
 
-    (*s->cirrus_rop) (s, s->cirrus_blt_dstaddr, src,
+    (*s->cirrus_rop) (s, s->cirrus_blt_dstaddr,
+                      videosrc ? s->cirrus_blt_srcaddr : 0,
                       s->cirrus_blt_dstpitch, 0,
                       s->cirrus_blt_width, s->cirrus_blt_height);
     cirrus_invalidate_region(s, s->cirrus_blt_dstaddr,
@@ -743,7 +780,7 @@ static int cirrus_bitblt_solidfill(CirrusVGAState *s, int blt_rop)
 
 static int cirrus_bitblt_videotovideo_patterncopy(CirrusVGAState * s)
 {
-    return cirrus_bitblt_common_patterncopy(s, true);
+    return cirrus_bitblt_common_patterncopy(s);
 }
 
 static int cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
@@ -793,7 +830,7 @@ static int cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
     }
 
     (*s->cirrus_rop) (s, s->cirrus_blt_dstaddr,
-                      s->vga.vram_ptr + s->cirrus_blt_srcaddr,
+                      s->cirrus_blt_srcaddr,
 		      s->cirrus_blt_dstpitch, s->cirrus_blt_srcpitch,
 		      s->cirrus_blt_width, s->cirrus_blt_height);
 
@@ -836,7 +873,7 @@ static void cirrus_bitblt_cputovideo_next(CirrusVGAState * s)
 
     if (s->cirrus_srccounter > 0) {
         if (s->cirrus_blt_mode & CIRRUS_BLTMODE_PATTERNCOPY) {
-            cirrus_bitblt_common_patterncopy(s, false);
+            cirrus_bitblt_common_patterncopy(s);
         the_end:
             s->cirrus_srccounter = 0;
             cirrus_bitblt_reset(s);
@@ -844,7 +881,7 @@ static void cirrus_bitblt_cputovideo_next(CirrusVGAState * s)
             /* at least one scan line */
             do {
                 (*s->cirrus_rop)(s, s->cirrus_blt_dstaddr,
-                                  s->cirrus_bltbuf, 0, 0, s->cirrus_blt_width, 1);
+                                 0, 0, 0, s->cirrus_blt_width, 1);
                 cirrus_invalidate_region(s, s->cirrus_blt_dstaddr, 0,
                                          s->cirrus_blt_width, 1);
                 s->cirrus_blt_dstaddr += s->cirrus_blt_dstpitch;
diff --git a/hw/display/cirrus_vga_rop.h b/hw/display/cirrus_vga_rop.h
index 1aa778d3e8..c61a677353 100644
--- a/hw/display/cirrus_vga_rop.h
+++ b/hw/display/cirrus_vga_rop.h
@@ -78,7 +78,7 @@ static inline void glue(rop_32_, ROP_NAME)(CirrusVGAState *s,
 static void
 glue(cirrus_bitblt_rop_fwd_, ROP_NAME)(CirrusVGAState *s,
                                        uint32_t dstaddr,
-                                       const uint8_t *src,
+                                       uint32_t srcaddr,
                                        int dstpitch, int srcpitch,
                                        int bltwidth, int bltheight)
 {
@@ -92,19 +92,19 @@ glue(cirrus_bitblt_rop_fwd_, ROP_NAME)(CirrusVGAState *s,
 
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
-            ROP_OP(s, dstaddr, *src);
+            ROP_OP(s, dstaddr, cirrus_src(s, srcaddr));
             dstaddr++;
-            src++;
+            srcaddr++;
         }
         dstaddr += dstpitch;
-        src += srcpitch;
+        srcaddr += srcpitch;
     }
 }
 
 static void
 glue(cirrus_bitblt_rop_bkwd_, ROP_NAME)(CirrusVGAState *s,
                                         uint32_t dstaddr,
-                                        const uint8_t *src,
+                                        uint32_t srcaddr,
                                         int dstpitch, int srcpitch,
                                         int bltwidth, int bltheight)
 {
@@ -113,19 +113,19 @@ glue(cirrus_bitblt_rop_bkwd_, ROP_NAME)(CirrusVGAState *s,
     srcpitch += bltwidth;
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
-            ROP_OP(s, dstaddr, *src);
+            ROP_OP(s, dstaddr, cirrus_src(s, srcaddr));
             dstaddr--;
-            src--;
+            srcaddr--;
         }
         dstaddr += dstpitch;
-        src += srcpitch;
+        srcaddr += srcpitch;
     }
 }
 
 static void
 glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_8)(CirrusVGAState *s,
                                                        uint32_t dstaddr,
-                                                       const uint8_t *src,
+                                                       uint32_t srcaddr,
                                                        int dstpitch,
                                                        int srcpitch,
                                                        int bltwidth,
@@ -142,19 +142,19 @@ glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_8)(CirrusVGAState *s,
 
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
-            ROP_OP_TR(s, dstaddr, *src, transp);
+            ROP_OP_TR(s, dstaddr, cirrus_src(s, srcaddr), transp);
             dstaddr++;
-            src++;
+            srcaddr++;
         }
         dstaddr += dstpitch;
-        src += srcpitch;
+        srcaddr += srcpitch;
     }
 }
 
 static void
 glue(glue(cirrus_bitblt_rop_bkwd_transp_, ROP_NAME),_8)(CirrusVGAState *s,
                                                         uint32_t dstaddr,
-                                                        const uint8_t *src,
+                                                        uint32_t srcaddr,
                                                         int dstpitch,
                                                         int srcpitch,
                                                         int bltwidth,
@@ -166,19 +166,19 @@ glue(glue(cirrus_bitblt_rop_bkwd_transp_, ROP_NAME),_8)(CirrusVGAState *s,
     srcpitch += bltwidth;
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
-            ROP_OP_TR(s, dstaddr, *src, transp);
+            ROP_OP_TR(s, dstaddr, cirrus_src(s, srcaddr), transp);
             dstaddr--;
-            src--;
+            srcaddr--;
         }
         dstaddr += dstpitch;
-        src += srcpitch;
+        srcaddr += srcpitch;
     }
 }
 
 static void
 glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
                                                         uint32_t dstaddr,
-                                                        const uint8_t *src,
+                                                        uint32_t srcaddr,
                                                         int dstpitch,
                                                         int srcpitch,
                                                         int bltwidth,
@@ -195,19 +195,19 @@ glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
 
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x+=2) {
-            ROP_OP_TR_16(s, dstaddr, *(uint16_t *)src, transp);
+            ROP_OP_TR_16(s, dstaddr, cirrus_src16(s, srcaddr), transp);
             dstaddr += 2;
-            src += 2;
+            srcaddr += 2;
         }
         dstaddr += dstpitch;
-        src += srcpitch;
+        srcaddr += srcpitch;
     }
 }
 
 static void
 glue(glue(cirrus_bitblt_rop_bkwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
                                                          uint32_t dstaddr,
-                                                         const uint8_t *src,
+                                                         uint32_t srcaddr,
                                                          int dstpitch,
                                                          int srcpitch,
                                                          int bltwidth,
@@ -219,12 +219,12 @@ glue(glue(cirrus_bitblt_rop_bkwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
     srcpitch += bltwidth;
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x+=2) {
-            ROP_OP_TR_16(s, dstaddr, *(uint16_t *)src, transp);
+            ROP_OP_TR_16(s, dstaddr, cirrus_src16(s, srcaddr), transp);
             dstaddr -= 2;
-            src -= 2;
+            srcaddr -= 2;
         }
         dstaddr += dstpitch;
-        src += srcpitch;
+        srcaddr += srcpitch;
     }
 }
 
diff --git a/hw/display/cirrus_vga_rop2.h b/hw/display/cirrus_vga_rop2.h
index bc92f0e0e7..b86bcd6e09 100644
--- a/hw/display/cirrus_vga_rop2.h
+++ b/hw/display/cirrus_vga_rop2.h
@@ -41,14 +41,14 @@
 static void
 glue(glue(glue(cirrus_patternfill_, ROP_NAME), _),DEPTH)
      (CirrusVGAState *s, uint32_t dstaddr,
-      const uint8_t *src,
+      uint32_t srcaddr,
       int dstpitch, int srcpitch,
       int bltwidth, int bltheight)
 {
     uint32_t addr;
     int x, y, pattern_y, pattern_pitch, pattern_x;
     unsigned int col;
-    const uint8_t *src1;
+    uint32_t src1addr;
 #if DEPTH == 24
     int skipleft = s->vga.gr[0x2f] & 0x1f;
 #else
@@ -66,22 +66,24 @@ glue(glue(glue(cirrus_patternfill_, ROP_NAME), _),DEPTH)
     for(y = 0; y < bltheight; y++) {
         pattern_x = skipleft;
         addr = dstaddr + skipleft;
-        src1 = src + pattern_y * pattern_pitch;
+        src1addr = srcaddr + pattern_y * pattern_pitch;
         for (x = skipleft; x < bltwidth; x += (DEPTH / 8)) {
 #if DEPTH == 8
-            col = src1[pattern_x];
+            col = cirrus_src(s, src1addr + pattern_x);
             pattern_x = (pattern_x + 1) & 7;
 #elif DEPTH == 16
-            col = ((uint16_t *)(src1 + pattern_x))[0];
+            col = cirrus_src16(s, src1addr + pattern_x);
             pattern_x = (pattern_x + 2) & 15;
 #elif DEPTH == 24
             {
-                const uint8_t *src2 = src1 + pattern_x * 3;
-                col = src2[0] | (src2[1] << 8) | (src2[2] << 16);
+                uint32_t src2addr = src1addr + pattern_x * 3;
+                col = cirrus_src(s, src2addr) |
+                    (cirrus_src(s, src2addr + 1) << 8) |
+                    (cirrus_src(s, src2addr + 2) << 16);
                 pattern_x = (pattern_x + 1) & 7;
             }
 #else
-            col = ((uint32_t *)(src1 + pattern_x))[0];
+            col = cirrus_src32(s, src1addr + pattern_x);
             pattern_x = (pattern_x + 4) & 31;
 #endif
             PUTPIXEL(s, addr, col);
@@ -96,7 +98,7 @@ glue(glue(glue(cirrus_patternfill_, ROP_NAME), _),DEPTH)
 static void
 glue(glue(glue(cirrus_colorexpand_transp_, ROP_NAME), _),DEPTH)
      (CirrusVGAState *s, uint32_t dstaddr,
-      const uint8_t *src,
+      uint32_t srcaddr,
       int dstpitch, int srcpitch,
       int bltwidth, int bltheight)
 {
@@ -124,12 +126,12 @@ glue(glue(glue(cirrus_colorexpand_transp_, ROP_NAME), _),DEPTH)
 
     for(y = 0; y < bltheight; y++) {
         bitmask = 0x80 >> srcskipleft;
-        bits = *src++ ^ bits_xor;
+        bits = cirrus_src(s, srcaddr++) ^ bits_xor;
         addr = dstaddr + dstskipleft;
         for (x = dstskipleft; x < bltwidth; x += (DEPTH / 8)) {
             if ((bitmask & 0xff) == 0) {
                 bitmask = 0x80;
-                bits = *src++ ^ bits_xor;
+                bits = cirrus_src(s, srcaddr++) ^ bits_xor;
             }
             index = (bits & bitmask);
             if (index) {
@@ -145,7 +147,7 @@ glue(glue(glue(cirrus_colorexpand_transp_, ROP_NAME), _),DEPTH)
 static void
 glue(glue(glue(cirrus_colorexpand_, ROP_NAME), _),DEPTH)
      (CirrusVGAState *s, uint32_t dstaddr,
-      const uint8_t *src,
+      uint32_t srcaddr,
       int dstpitch, int srcpitch,
       int bltwidth, int bltheight)
 {
@@ -162,12 +164,12 @@ glue(glue(glue(cirrus_colorexpand_, ROP_NAME), _),DEPTH)
     colors[1] = s->cirrus_blt_fgcol;
     for(y = 0; y < bltheight; y++) {
         bitmask = 0x80 >> srcskipleft;
-        bits = *src++;
+        bits = cirrus_src(s, srcaddr++);
         addr = dstaddr + dstskipleft;
         for (x = dstskipleft; x < bltwidth; x += (DEPTH / 8)) {
             if ((bitmask & 0xff) == 0) {
                 bitmask = 0x80;
-                bits = *src++;
+                bits = cirrus_src(s, srcaddr++);
             }
             col = colors[!!(bits & bitmask)];
             PUTPIXEL(s, addr, col);
@@ -181,7 +183,7 @@ glue(glue(glue(cirrus_colorexpand_, ROP_NAME), _),DEPTH)
 static void
 glue(glue(glue(cirrus_colorexpand_pattern_transp_, ROP_NAME), _),DEPTH)
      (CirrusVGAState *s, uint32_t dstaddr,
-      const uint8_t *src,
+      uint32_t srcaddr,
       int dstpitch, int srcpitch,
       int bltwidth, int bltheight)
 {
@@ -207,7 +209,7 @@ glue(glue(glue(cirrus_colorexpand_pattern_transp_, ROP_NAME), _),DEPTH)
     pattern_y = s->cirrus_blt_srcaddr & 7;
 
     for(y = 0; y < bltheight; y++) {
-        bits = src[pattern_y] ^ bits_xor;
+        bits = cirrus_src(s, srcaddr + pattern_y) ^ bits_xor;
         bitpos = 7 - srcskipleft;
         addr = dstaddr + dstskipleft;
         for (x = dstskipleft; x < bltwidth; x += (DEPTH / 8)) {
@@ -225,7 +227,7 @@ glue(glue(glue(cirrus_colorexpand_pattern_transp_, ROP_NAME), _),DEPTH)
 static void
 glue(glue(glue(cirrus_colorexpand_pattern_, ROP_NAME), _),DEPTH)
      (CirrusVGAState *s, uint32_t dstaddr,
-      const uint8_t *src,
+      uint32_t srcaddr,
       int dstpitch, int srcpitch,
       int bltwidth, int bltheight)
 {
@@ -242,7 +244,7 @@ glue(glue(glue(cirrus_colorexpand_pattern_, ROP_NAME), _),DEPTH)
     pattern_y = s->cirrus_blt_srcaddr & 7;
 
     for(y = 0; y < bltheight; y++) {
-        bits = src[pattern_y];
+        bits = cirrus_src(s, srcaddr + pattern_y);
         bitpos = 7 - srcskipleft;
         addr = dstaddr + dstskipleft;
         for (x = dstskipleft; x < bltwidth; x += (DEPTH / 8)) {
