From: bones_was_here <bones_was_here@xonotic.au>
Date: Fri, 26 Jan 2024 10:10:14 +0000 (+1000)
Subject: Q2BSP: fix misaligned memory access
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=1b4250b2073d263c3a1012dbf88d3f1d37ae79c8;p=xonotic%2Fdarkplaces.git

Q2BSP: fix misaligned memory access

Fixes a small overallocation (sizeof(int *) instead of int).

Signed-off-by: bones_was_here <bones_was_here@xonotic.au>
---

diff --git a/model_brush.c b/model_brush.c
index 98fc11fc..092682b0 100644
--- a/model_brush.c
+++ b/model_brush.c
@@ -4824,7 +4824,8 @@ static void Mod_Q2BSP_Load(model_t *mod, void *buffer, void *bufferend)
 	msurface_t *surface;
 	int totalstylesurfaces, totalstyles, stylecounts[256], remapstyles[256];
 	model_brush_lightstyleinfo_t styleinfo[256];
-	unsigned char *datapointer;
+	int *datapointer;
+	model_brush_lightstyleinfo_t *lsidatapointer;
 	sizebuf_t sb;
 
 	MSG_InitReadBuffer(&sb, (unsigned char *)buffer, (unsigned char *)bufferend - (unsigned char *)buffer);
@@ -4966,8 +4967,11 @@ static void Mod_Q2BSP_Load(model_t *mod, void *buffer, void *bufferend)
 				totalstylesurfaces += stylecounts[k];
 		}
 	}
-	datapointer = (unsigned char *)Mem_Alloc(mod->mempool, mod->num_surfaces * sizeof(int) + totalstyles * sizeof(model_brush_lightstyleinfo_t) + totalstylesurfaces * sizeof(int *));
-	mod->modelsurfaces_sorted = (int*)datapointer; datapointer += mod->num_surfaces * sizeof(int);
+	// bones_was_here: using a separate allocation for model_brush_lightstyleinfo_t
+	// because on a 64-bit machine it no longer has the same alignment requirement as int.
+	lsidatapointer = Mem_AllocType(mod->mempool, model_brush_lightstyleinfo_t, totalstyles * sizeof(model_brush_lightstyleinfo_t));
+	datapointer = Mem_AllocType(mod->mempool, int, mod->num_surfaces * sizeof(int) + totalstylesurfaces * sizeof(int));
+	mod->modelsurfaces_sorted = datapointer; datapointer += mod->num_surfaces;
 	// set up the world model, then on each submodel copy from the world model
 	// and set up the submodel with the respective model info.
 	mod = loadmodel;
@@ -5070,7 +5074,7 @@ static void Mod_Q2BSP_Load(model_t *mod, void *buffer, void *bufferend)
 					styleinfo[mod->brushq1.num_lightstyles].style = k;
 					styleinfo[mod->brushq1.num_lightstyles].value = 0;
 					styleinfo[mod->brushq1.num_lightstyles].numsurfaces = 0;
-					styleinfo[mod->brushq1.num_lightstyles].surfacelist = (int *)datapointer;datapointer += stylecounts[k] * sizeof(int);
+					styleinfo[mod->brushq1.num_lightstyles].surfacelist = datapointer;datapointer += stylecounts[k];
 					remapstyles[k] = mod->brushq1.num_lightstyles;
 					mod->brushq1.num_lightstyles++;
 				}
@@ -5087,7 +5091,7 @@ static void Mod_Q2BSP_Load(model_t *mod, void *buffer, void *bufferend)
 					}
 				}
 			}
-			mod->brushq1.data_lightstyleinfo = (model_brush_lightstyleinfo_t *)datapointer;datapointer += mod->brushq1.num_lightstyles * sizeof(model_brush_lightstyleinfo_t);
+			mod->brushq1.data_lightstyleinfo = lsidatapointer;lsidatapointer += mod->brushq1.num_lightstyles;
 			memcpy(mod->brushq1.data_lightstyleinfo, styleinfo, mod->brushq1.num_lightstyles * sizeof(model_brush_lightstyleinfo_t));
 		}
 		else