--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/lj_udata.c	Thu Jan 22 20:10:30 2026 -0800
@@ -0,0 +1,62 @@
+/*
+** Userdata handling.
+** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#define lj_udata_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+#include "lj_gc.h"
+#include "lj_err.h"
+#include "lj_udata.h"
+
+GCudata *lj_udata_new(lua_State *L, MSize sz, GCtab *env)
+{
+  GCudata *ud = lj_mem_newt(L, sizeof(GCudata) + sz, GCudata);
+  global_State *g = G(L);
+  newwhite(g, ud);  /* Not finalized. */
+  ud->gct = ~LJ_TUDATA;
+  ud->udtype = UDTYPE_USERDATA;
+  ud->len = sz;
+  /* NOBARRIER: The GCudata is new (marked white). */
+  setgcrefnull(ud->metatable);
+  setgcref(ud->env, obj2gco(env));
+  /* Chain to userdata list (after main thread). */
+  setgcrefr(ud->nextgc, mainthread(g)->nextgc);
+  setgcref(mainthread(g)->nextgc, obj2gco(ud));
+  return ud;
+}
+
+void LJ_FASTCALL lj_udata_free(global_State *g, GCudata *ud)
+{
+  lj_mem_free(g, ud, sizeudata(ud));
+}
+
+#if LJ_64
+void *lj_lightud_intern(lua_State *L, void *p)
+{
+  global_State *g = G(L);
+  uint64_t u = (uint64_t)p;
+  uint32_t up = lightudup(u);
+  uint32_t *segmap = mref(g->gc.lightudseg, uint32_t);
+  MSize segnum = g->gc.lightudnum;
+  if (segmap) {
+    MSize seg;
+    for (seg = 0; seg <= segnum; seg++)
+      if (segmap[seg] == up)  /* Fast path. */
+	return (void *)(((uint64_t)seg << LJ_LIGHTUD_BITS_LO) | lightudlo(u));
+    segnum++;
+    /* Leave last segment unused to avoid clash with ITERN key. */
+    if (segnum >= (1 << LJ_LIGHTUD_BITS_SEG)-1) lj_err_msg(L, LJ_ERR_BADLU);
+  }
+  if (!((segnum-1) & segnum) && segnum != 1) {
+    lj_mem_reallocvec(L, segmap, segnum, segnum ? 2*segnum : 2u, uint32_t);
+    setmref(g->gc.lightudseg, segmap);
+  }
+  g->gc.lightudnum = segnum;
+  segmap[segnum] = up;
+  return (void *)(((uint64_t)segnum << LJ_LIGHTUD_BITS_LO) | lightudlo(u));
+}
+#endif
+