From: BALATON Zoltan <balaton@eik.bme.hu>
Date: Thu, 21 May 2020 21:39:44 +0200
Subject: sm501: Shorten long variable names in sm501_2d_operation

Git-commit: 6f8183b5dc5b309378687830a25e85ea8fb860ea
References: bsc#1172385, CVE-2020-12829

This increases readability and cleans up some confusing naming.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-id: b9b67b94c46e945252a73c77dfd117132c63c4fb.1590089984.git.balaton@eik.bme.hu
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/display/sm501.c | 59 +++++++++++++++++++++++-----------------------
 1 file changed, 30 insertions(+), 29 deletions(-)

diff --git a/hw/display/sm501.c b/hw/display/sm501.c
index a5322df7a2add530c398472be640..9ee86ab368dcfe694036a56bbae6 100644
--- a/hw/display/sm501.c
+++ b/hw/display/sm501.c
@@ -666,17 +666,16 @@ static inline void hwc_invalidate(SM501State *s, int crt)
 static void sm501_2d_operation(SM501State * s)
 {
     /* obtain operation parameters */
-    int operation = (s->twoD_control >> 16) & 0x1f;
+    int cmd = (s->twoD_control >> 16) & 0x1F;
     int rtl = s->twoD_control & 0x8000000;
     int src_x = (s->twoD_source >> 16) & 0x01FFF;
     int src_y = s->twoD_source & 0xFFFF;
     int dst_x = (s->twoD_destination >> 16) & 0x01FFF;
     int dst_y = s->twoD_destination & 0xFFFF;
-    int operation_width = (s->twoD_dimension >> 16) & 0x1FFF;
-    int operation_height = s->twoD_dimension & 0xFFFF;
+    int width = (s->twoD_dimension >> 16) & 0x1FFF;
+    int height = s->twoD_dimension & 0xFFFF;
     uint32_t color = s->twoD_foreground;
-    int format_flags = (s->twoD_stretch >> 20) & 0x3;
-    int addressing = (s->twoD_stretch >> 16) & 0xF;
+    int format = (s->twoD_stretch >> 20) & 0x3;
     int rop_mode = (s->twoD_control >> 15) & 0x1; /* 1 for rop2, else rop3 */
     /* 1 if rop2 source is the pattern, otherwise the source is the bitmap */
     int rop2_source_is_pattern = (s->twoD_control >> 14) & 0x1;
@@ -687,12 +686,12 @@ static void sm501_2d_operation(SM501State * s)
     /* get frame buffer info */
     uint8_t *src = s->local_mem + src_base;
     uint8_t *dst = s->local_mem + dst_base;
-    int src_width = s->twoD_pitch & 0x1FFF;
-    int dst_width = (s->twoD_pitch >> 16) & 0x1FFF;
+    int src_pitch = s->twoD_pitch & 0x1FFF;
+    int dst_pitch = (s->twoD_pitch >> 16) & 0x1FFF;
     int crt = (s->dc_crt_control & SM501_DC_CRT_CONTROL_SEL) ? 1 : 0;
     int fb_len = get_width(s, crt) * get_height(s, crt) * get_bpp(s, crt);
 
-    if (addressing != 0x0) {
+    if ((s->twoD_stretch >> 16) & 0xF) {
         qemu_log_mask(LOG_UNIMP, "sm501: only XY addressing is supported.\n");
         return;
     }
@@ -724,19 +723,21 @@ static void sm501_2d_operation(SM501State * s)
         return;
     }
 
-    switch (operation) {
+    switch (cmd) {
     case 0x00: /* copy area */
-#define COPY_AREA(_bpp, _pixel_type, rtl) {                                 \
-        int y, x, index_d, index_s;                                         \
-        for (y = 0; y < operation_height; y++) {                            \
-            for (x = 0; x < operation_width; x++) {                         \
-                if (rtl) {                                                  \
-                    index_s = ((src_y - y) * src_width + src_x - x) * _bpp; \
-                    index_d = ((dst_y - y) * dst_width + dst_x - x) * _bpp; \
-                } else {                                                    \
-                    index_s = ((src_y + y) * src_width + src_x + x) * _bpp; \
-                    index_d = ((dst_y + y) * dst_width + dst_x + x) * _bpp; \
-                }                                                           \
+#define COPY_AREA(_bpp, _pixel_type, rtl) {                                   \
+        int y, x, index_d, index_s;                                           \
+        for (y = 0; y < height; y++) {                              \
+            for (x = 0; x < width; x++) {                           \
+                _pixel_type val;                                              \
+                                                                              \
+                if (rtl) {                                                    \
+                    index_s = ((src_y - y) * src_pitch + src_x - x) * _bpp;   \
+                    index_d = ((dst_y - y) * dst_pitch + dst_x - x) * _bpp;   \
+                } else {                                                      \
+                    index_s = ((src_y + y) * src_pitch + src_x + x) * _bpp;   \
+                    index_d = ((dst_y + y) * dst_pitch + dst_x + x) * _bpp;   \
+                }                                                             \
                 if (rop_mode == 1 && rop == 5) {                              \
                     /* Invert dest */                                         \
                     val = ~*(_pixel_type *)&dst[index_d];                     \
@@ -747,7 +748,7 @@ static void sm501_2d_operation(SM501State * s)
             }                                                               \
         }                                                                   \
     }
-        switch (format_flags) {
+        switch (format) {
         case 0:
             COPY_AREA(1, uint8_t, rtl);
             break;
@@ -763,15 +764,15 @@ static void sm501_2d_operation(SM501State * s)
     case 0x01: /* fill rectangle */
 #define FILL_RECT(_bpp, _pixel_type) {                                      \
         int y, x;                                                           \
-        for (y = 0; y < operation_height; y++) {                            \
-            for (x = 0; x < operation_width; x++) {                         \
-                int index = ((dst_y + y) * dst_width + dst_x + x) * _bpp;   \
-                *(_pixel_type*)&dst[index] = (_pixel_type)color;            \
+        for (y = 0; y < height; y++) {                            \
+            for (x = 0; x < width; x++) {                         \
+                int index = ((dst_y + y) * dst_pitch + dst_x + x) * _bpp;   \
+                *(_pixel_type *)&dst[index] = (_pixel_type)color;           \
             }                                                               \
         }                                                                   \
     }
 
-        switch (format_flags) {
+        switch (format) {
         case 0:
             FILL_RECT(1, uint8_t);
             break;
@@ -788,14 +789,14 @@ static void sm501_2d_operation(SM501State * s)
 
     default:
         qemu_log_mask(LOG_UNIMP, "sm501: not implemented 2D operation: %d\n",
-                      operation);
+                      cmd);
         return;
     }
 
     if (dst_base >= get_fb_addr(s, crt) &&
         dst_base <= get_fb_addr(s, crt) + fb_len) {
-        int dst_len = MIN(fb_len, ((dst_y + operation_height - 1) * dst_width +
-                           dst_x + operation_width) * (1 << format_flags));
+        int dst_len = MIN(fb_len, ((dst_y + height - 1) * dst_pitch +
+                          dst_x + width) * (1 << format));
         if (dst_len) {
             memory_region_set_dirty(&s->local_mem_region, dst_base, dst_len);
         }
