]> git.rm.cloudns.org Git - xonotic/darkplaces.git/commitdiff
sprites: fix misaligned memory access while loading (v2)
authorbones_was_here <bones_was_here@xonotic.au>
Mon, 6 May 2024 01:15:40 +0000 (11:15 +1000)
committerbones_was_here <bones_was_here@xonotic.au>
Thu, 9 May 2024 03:07:36 +0000 (13:07 +1000)
This reverts commit 0d5f8f0edd073d7ff233bde3995b529c0fcb67ff, that
approach didn't solve it for the other code path (used in mod "quake15")
so we need to memcpy each struct.

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

index 5b2e36d7cc72a1346723fed30e7519222da7086e..7e96f676f751a16f0e645c883392de85bca21f74 100644 (file)
@@ -90,16 +90,16 @@ extern cvar_t gl_texturecompression_sprites;
 
 static void Mod_Sprite_SharedSetup(const unsigned char *datapointer, int version, const unsigned int *palette, qbool additive)
 {
-       int                                     i, j, groupframes, realframes, x, y, origin[2], width, height;
-       qbool                   fullbright;
-       dspriteframetype_t      *pinframetype;
-       dspriteframe_t          *pinframe;
-       dspritegroup_t          *pingroup;
-       dspriteinterval_t       *pinintervals;
-       skinframe_t                     *skinframe;
-       float                           modelradius, interval;
-       char                            name[MAX_QPATH], fogname[MAX_QPATH];
-       const void                      *startframes;
+       int                 i, j, groupframes, realframes, x, y, origin[2], width, height;
+       qbool               fullbright;
+       dspriteframetype_t  pinframetype;
+       dspriteframe_t      pinframe;
+       dspritegroup_t      pingroup;
+       dspriteinterval_t   pinintervals;
+       skinframe_t         *skinframe;
+       float               modelradius, interval;
+       char                name[MAX_QPATH], fogname[MAX_QPATH];
+       const void          *startframes;
        int                 texflags = (r_mipsprites.integer ? TEXF_MIPMAP : 0) | ((gl_texturecompression.integer && gl_texturecompression_sprites.integer) ? TEXF_COMPRESS : 0) | TEXF_ISSPRITE | TEXF_PICMIP | TEXF_ALPHA | TEXF_CLAMP;
        modelradius = 0;
 
@@ -114,33 +114,34 @@ static void Mod_Sprite_SharedSetup(const unsigned char *datapointer, int version
 
 //
 // load the frames
+// bones_was_here: memcpy() used here to prevent misaligned access with struct-based parsing
 //
        startframes = datapointer;
        realframes = 0;
        for (i = 0;i < loadmodel->numframes;i++)
        {
-               pinframetype = (dspriteframetype_t *)datapointer;
+               memcpy(&pinframetype, datapointer, sizeof(dspriteframetype_t));
                datapointer += sizeof(dspriteframetype_t);
 
-               if (LittleLong (pinframetype->type) == SPR_SINGLE)
+               if (LittleLong (pinframetype.type) == SPR_SINGLE)
                        groupframes = 1;
                else
                {
-                       pingroup = (dspritegroup_t *)datapointer;
+                       memcpy(&pingroup, datapointer, sizeof(dspritegroup_t));
                        datapointer += sizeof(dspritegroup_t);
 
-                       groupframes = LittleLong(pingroup->numframes);
+                       groupframes = LittleLong(pingroup.numframes);
 
                        datapointer += sizeof(dspriteinterval_t) * groupframes;
                }
 
                for (j = 0;j < groupframes;j++)
                {
-                       pinframe = (dspriteframe_t *)datapointer;
+                       memcpy(&pinframe, datapointer, sizeof(dspriteframe_t));
                        if (version == SPRITE32_VERSION)
-                               datapointer += sizeof(dspriteframe_t) + LittleLong(pinframe->width) * LittleLong(pinframe->height) * 4;
+                               datapointer += sizeof(dspriteframe_t) + LittleLong(pinframe.width) * LittleLong(pinframe.height) * 4;
                        else //if (version == SPRITE_VERSION || version == SPRITEHL_VERSION)
-                               datapointer += sizeof(dspriteframe_t) + LittleLong(pinframe->width) * LittleLong(pinframe->height);
+                               datapointer += sizeof(dspriteframe_t) + LittleLong(pinframe.width) * LittleLong(pinframe.height);
                }
                realframes += groupframes;
        }
@@ -155,25 +156,25 @@ static void Mod_Sprite_SharedSetup(const unsigned char *datapointer, int version
        realframes = 0;
        for (i = 0;i < loadmodel->numframes;i++)
        {
-               pinframetype = (dspriteframetype_t *)datapointer;
+               memcpy(&pinframetype, datapointer, sizeof(dspriteframetype_t));
                datapointer += sizeof(dspriteframetype_t);
 
-               if (LittleLong (pinframetype->type) == SPR_SINGLE)
+               if (LittleLong (pinframetype.type) == SPR_SINGLE)
                {
                        groupframes = 1;
                        interval = 0.1f;
                }
                else
                {
-                       pingroup = (dspritegroup_t *)datapointer;
+                       memcpy(&pingroup, datapointer, sizeof(dspritegroup_t));
                        datapointer += sizeof(dspritegroup_t);
 
-                       groupframes = LittleLong(pingroup->numframes);
+                       groupframes = LittleLong(pingroup.numframes);
 
-                       pinintervals = (dspriteinterval_t *)datapointer;
+                       memcpy(&pinintervals, datapointer, sizeof(dspriteinterval_t));
                        datapointer += sizeof(dspriteinterval_t) * groupframes;
 
-                       interval = LittleFloat(pinintervals[0].interval);
+                       interval = LittleFloat(pinintervals.interval);
                        if (interval < 0.01f)
                                Host_Error("Mod_Sprite_SharedSetup: invalid interval");
                }
@@ -186,13 +187,13 @@ static void Mod_Sprite_SharedSetup(const unsigned char *datapointer, int version
 
                for (j = 0;j < groupframes;j++)
                {
-                       pinframe = (dspriteframe_t *)datapointer;
+                       memcpy(&pinframe, datapointer, sizeof(dspriteframe_t));
                        datapointer += sizeof(dspriteframe_t);
 
-                       origin[0] = LittleLong (pinframe->origin[0]);
-                       origin[1] = LittleLong (pinframe->origin[1]);
-                       width = LittleLong (pinframe->width);
-                       height = LittleLong (pinframe->height);
+                       origin[0] = LittleLong (pinframe.origin[0]);
+                       origin[1] = LittleLong (pinframe.origin[1]);
+                       width = LittleLong (pinframe.width);
+                       height = LittleLong (pinframe.height);
 
                        loadmodel->sprite.sprdata_frames[realframes].left = origin[0];
                        loadmodel->sprite.sprdata_frames[realframes].right = origin[0] + width;
@@ -298,7 +299,6 @@ void Mod_IDSP_Load(model_t *mod, void *buffer, void *bufferend)
                unsigned char palette[256][4];
                const unsigned char *in;
                dspritehl_t *pinhlsprite;
-               unsigned char *aligneddata;
 
                pinhlsprite = (dspritehl_t *)datapointer;
                datapointer += sizeof(dspritehl_t);
@@ -362,11 +362,7 @@ void Mod_IDSP_Load(model_t *mod, void *buffer, void *bufferend)
                        return;
                }
 
-               // the above datapointer arithmetic causes misaligned access
-               aligneddata = (unsigned char *)Mem_Alloc(tempmempool, (unsigned char *)bufferend - datapointer);
-               memcpy(aligneddata, datapointer, (unsigned char *)bufferend - datapointer);
-               Mod_Sprite_SharedSetup(aligneddata, LittleLong (pinhlsprite->version), (unsigned int *)(&palette[0][0]), rendermode == SPRHL_ADDITIVE);
-               Mem_Free(aligneddata);
+               Mod_Sprite_SharedSetup(datapointer, LittleLong (pinhlsprite->version), (unsigned int *)(&palette[0][0]), rendermode == SPRHL_ADDITIVE);
        }
        else
                Host_Error("Mod_IDSP_Load: %s has wrong version number (%i). Only %i (quake), %i (HalfLife), and %i (sprite32) supported",