From 31ea61cd802fd711d40d47ebe8ed480709aff9dd Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Mon, 15 Jul 2024 13:07:25 +0200
Subject: [PATCH] dri3: consolidate reply buffers

Allocate reply buffers on stack and put multiple fragments into one buffer,
in order to make it easier doing write out by generic macros, in subsequent
commits.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 dri3/dri3_request.c | 52 ++++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 20 deletions(-)

diff --git a/dri3/dri3_request.c b/dri3/dri3_request.c
index d1ac0a93d..61ebde62f 100644
--- a/dri3/dri3_request.c
+++ b/dri3/dri3_request.c
@@ -391,13 +391,26 @@ proc_dri3_get_supported_modifiers(ClientPtr client)
                                  &nwindowmodifiers, &window_modifiers,
                                  &nscreenmodifiers, &screen_modifiers);
 
+    const size_t bufsz = (nwindowmodifiers + nscreenmodifiers) * sizeof(CARD64);
+    CARD64 *buf = calloc(1, bufsz);
+    if (!buf) {
+        free(window_modifiers);
+        free(screen_modifiers);
+        return BadAlloc;
+    }
+
+    memcpy(buf, window_modifiers, sizeof(CARD64) * nwindowmodifiers);
+    memcpy(&buf[nwindowmodifiers], screen_modifiers, sizeof(CARD64) * nscreenmodifiers);
+
+    free(window_modifiers);
+    free(screen_modifiers);
+
     xDRI3GetSupportedModifiersReply rep = {
         .type = X_Reply,
         .sequenceNumber = client->sequence,
         .numWindowModifiers = nwindowmodifiers,
         .numScreenModifiers = nscreenmodifiers,
-        .length = bytes_to_int32(nwindowmodifiers * sizeof(CARD64)) +
-                  bytes_to_int32(nscreenmodifiers * sizeof(CARD64)),
+        .length = bytes_to_int32(bufsz),
     };
 
     if (client->swapped) {
@@ -405,19 +418,13 @@ proc_dri3_get_supported_modifiers(ClientPtr client)
         swapl(&rep.length);
         swapl(&rep.numWindowModifiers);
         swapl(&rep.numScreenModifiers);
-        for (i = 0; i < nwindowmodifiers; i++)
-            swapll(&window_modifiers[i]);
-        for (i = 0; i < nscreenmodifiers; i++)
-            swapll(&screen_modifiers[i]);
+        for (i = 0; i < nwindowmodifiers+nscreenmodifiers; i++)
+            swapll(&buf[i]);
     }
 
     WriteToClient(client, sizeof(rep), &rep);
-    WriteToClient(client, nwindowmodifiers * sizeof(CARD64), window_modifiers);
-    WriteToClient(client, nscreenmodifiers * sizeof(CARD64), screen_modifiers);
-
-    free(window_modifiers);
-    free(screen_modifiers);
-
+    WriteToClient(client, bufsz, buf);
+    free(buf);
     return Success;
 }
 
@@ -547,11 +554,19 @@ proc_dri3_buffers_from_pixmap(ClientPtr client)
         }
     }
 
+    const size_t bufsz = num_fds * 2 * sizeof(CARD32);
+    CARD32 *buf = calloc(1, bufsz);
+    if (!buf)
+        return BadAlloc;
+
+    memcpy(buf, strides, num_fds * sizeof(CARD32));
+    memcpy(&buf[num_fds], offsets, num_fds * sizeof(CARD32));
+
     xDRI3BuffersFromPixmapReply rep = {
         .type = X_Reply,
         .sequenceNumber = client->sequence,
         .nfd = num_fds,
-        .length = bytes_to_int32(num_fds * 2 * sizeof(CARD32)),
+        .length = bytes_to_int32(bufsz),
         .width = pixmap->drawable.width,
         .height = pixmap->drawable.height,
         .depth = pixmap->drawable.depth,
@@ -565,16 +580,13 @@ proc_dri3_buffers_from_pixmap(ClientPtr client)
         swaps(&rep.width);
         swaps(&rep.height);
         swapll(&rep.modifier);
-        for (i = 0; i < num_fds; i++) {
-            swapl(&strides[i]);
-            swapl(&offsets[i]);
-        }
+        for (i = 0; i < num_fds * 2; i++)
+            swapl(&buf[i]);
     }
 
     WriteToClient(client, sizeof(rep), &rep);
-    WriteToClient(client, num_fds * sizeof(CARD32), strides);
-    WriteToClient(client, num_fds * sizeof(CARD32), offsets);
-
+    WriteToClient(client, bufsz, buf);
+    free(buf);
     return Success;
 }