From 391d5ce20eb4fa3b18a07c0ca76bf275e0475993 Mon Sep 17 00:00:00 2001 From: bones_was_here Date: Mon, 29 Jan 2024 23:54:05 +1000 Subject: [PATCH] ZYM: fix misaligned memory access Signed-off-by: bones_was_here --- model_alias.c | 44 ++++++++++++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 16 deletions(-) diff --git a/model_alias.c b/model_alias.c index 8a7ae2b1..a18de309 100644 --- a/model_alias.c +++ b/model_alias.c @@ -1941,29 +1941,41 @@ void Mod_ZYMOTICMODEL_Load(model_t *mod, void *buffer, void *bufferend) loadmodel->submodelsurfaces_end = loadmodel->num_surfaces; loadmodel->num_textures = loadmodel->num_surfaces * loadmodel->numskins; loadmodel->num_texturesperskin = loadmodel->num_surfaces; - data = (unsigned char *)Mem_Alloc(loadmodel->mempool, loadmodel->num_surfaces * sizeof(msurface_t) + loadmodel->num_surfaces * sizeof(int) + loadmodel->num_surfaces * loadmodel->numskins * sizeof(texture_t) + meshtriangles * sizeof(int[3]) + (meshvertices <= 65536 ? meshtriangles * sizeof(unsigned short[3]) : 0) + meshvertices * (sizeof(float[14]) + sizeof(unsigned short) + sizeof(unsigned char[2][4])) + loadmodel->num_poses * loadmodel->num_bones * sizeof(short[7]) + loadmodel->num_bones * sizeof(float[12])); - loadmodel->data_surfaces = (msurface_t *)data;data += loadmodel->num_surfaces * sizeof(msurface_t); - loadmodel->modelsurfaces_sorted = (int *)data;data += loadmodel->num_surfaces * sizeof(int); - loadmodel->data_textures = (texture_t *)data;data += loadmodel->num_surfaces * loadmodel->numskins * sizeof(texture_t); loadmodel->surfmesh.num_vertices = meshvertices; loadmodel->surfmesh.num_triangles = meshtriangles; - loadmodel->surfmesh.data_element3i = (int *)data;data += meshtriangles * sizeof(int[3]); - loadmodel->surfmesh.data_vertex3f = (float *)data;data += meshvertices * sizeof(float[3]); - loadmodel->surfmesh.data_svector3f = (float *)data;data += meshvertices * sizeof(float[3]); - loadmodel->surfmesh.data_tvector3f = (float *)data;data += meshvertices * sizeof(float[3]); - loadmodel->surfmesh.data_normal3f = (float *)data;data += meshvertices * sizeof(float[3]); - loadmodel->surfmesh.data_texcoordtexture2f = (float *)data;data += meshvertices * sizeof(float[2]); - loadmodel->surfmesh.data_skeletalindex4ub = (unsigned char *)data;data += meshvertices * sizeof(unsigned char[4]); - loadmodel->surfmesh.data_skeletalweight4ub = (unsigned char *)data;data += meshvertices * sizeof(unsigned char[4]); - loadmodel->data_baseboneposeinverse = (float *)data;data += loadmodel->num_bones * sizeof(float[12]); loadmodel->surfmesh.num_blends = 0; - loadmodel->surfmesh.blends = (unsigned short *)data;data += meshvertices * sizeof(unsigned short); + loadmodel->surfmesh.data_blendweights = NULL; + + // do most allocations as one merged chunk + // This is only robust for C standard types! + data = (unsigned char *)Mem_Alloc(loadmodel->mempool, + loadmodel->num_surfaces * sizeof(int) + + meshtriangles * sizeof(int[3]) + + (meshvertices <= 65536 ? loadmodel->surfmesh.num_triangles * sizeof(unsigned short[3]) : 0) + + meshvertices * (sizeof(float[14]) + sizeof(unsigned short) + sizeof(unsigned char[2][4])) + + loadmodel->num_poses * loadmodel->num_bones * sizeof(short[7]) + + loadmodel->num_bones * sizeof(float[12])); + // Pointers must be taken in descending order of alignment requirement! + loadmodel->surfmesh.data_vertex3f = (float *)data; data += meshvertices * sizeof(float[3]); + loadmodel->surfmesh.data_svector3f = (float *)data; data += meshvertices * sizeof(float[3]); + loadmodel->surfmesh.data_tvector3f = (float *)data; data += meshvertices * sizeof(float[3]); + loadmodel->surfmesh.data_normal3f = (float *)data; data += meshvertices * sizeof(float[3]); + loadmodel->surfmesh.data_texcoordtexture2f = (float *)data; data += meshvertices * sizeof(float[2]); + loadmodel->data_baseboneposeinverse = (float *)data; data += loadmodel->num_bones * sizeof(float[12]); + loadmodel->modelsurfaces_sorted = (int *)data; data += loadmodel->num_surfaces * sizeof(int); + loadmodel->surfmesh.data_element3i = (int *)data; data += meshtriangles * sizeof(int[3]); + loadmodel->surfmesh.blends = (unsigned short *)data; data += meshvertices * sizeof(unsigned short); if (loadmodel->surfmesh.num_vertices <= 65536) { loadmodel->surfmesh.data_element3s = (unsigned short *)data;data += loadmodel->surfmesh.num_triangles * sizeof(unsigned short[3]); } - loadmodel->data_poses7s = (short *)data;data += loadmodel->num_poses * loadmodel->num_bones * sizeof(short[7]); - loadmodel->surfmesh.data_blendweights = NULL; + loadmodel->data_poses7s = (short *)data; data += loadmodel->num_poses * loadmodel->num_bones * sizeof(short[7]); + loadmodel->surfmesh.data_skeletalindex4ub = (unsigned char *)data; data += meshvertices * sizeof(unsigned char[4]); + loadmodel->surfmesh.data_skeletalweight4ub = (unsigned char *)data; data += meshvertices * sizeof(unsigned char[4]); + // Struct alignment requirements could change so we can't assume them here + // otherwise a safe-looking commit could introduce undefined behaviour! + loadmodel->data_surfaces = Mem_AllocType(loadmodel->mempool, msurface_t, loadmodel->num_surfaces * sizeof(msurface_t)); + loadmodel->data_textures = Mem_AllocType(loadmodel->mempool, texture_t, loadmodel->num_surfaces * loadmodel->numskins * sizeof(texture_t)); //zymlump_t lump_poses; // float pose[numposes][numbones][3][4]; // animation data poses = (float *) (pheader->lump_poses.start + pbase); -- 2.39.2