From aafb49ea89dba570b583103f8163ba8368669a48 Mon Sep 17 00:00:00 2001
From: Zhongwei Yao <zhongwei.yao@linaro.org>
Date: Fri, 18 Nov 2016 03:37:53 +0000
Subject: [PATCH] Work around the invalid lightuserdata usage for 48-bit
 platform

Static variable's virtual address will exceed 47-bit under 48-bit
platform, which causes failure when such variable is used as light user
data. This patch changes such static variables to heap variables to get
around this issue.

Change-Id: Iaf046d567a553cff33109af57e28acdf38c8507b
---
 src/lib_debug.c   | 24 ++++++++++++++++++++----
 src/lib_package.c | 17 +++++++++++++++--
 src/lj_state.c    |  5 +++++
 3 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/src/lib_debug.c b/src/lib_debug.c
index cda7137e..95cf3b7e 100644
--- a/src/lib_debug.c
+++ b/src/lib_debug.c
@@ -283,13 +283,29 @@ LJLIB_CF(debug_setuservalue)
 
 /* ------------------------------------------------------------------------ */
 
-static const char KEY_HOOK = 'h';
+static const char *KEY_HOOK = NULL;
+
+static const char *get_key_hook(lua_State *L, const char **KEY_HOOK) {
+  if (*KEY_HOOK == NULL) {
+    char *p = lj_mem_newt(L, sizeof(char), char);
+    *p = 'h';
+    *KEY_HOOK = p;
+  }
+  return *KEY_HOOK;
+}
+
+void free_key_hook(lua_State *L) {
+  if (KEY_HOOK != NULL) {
+    lj_mem_free(G(L), (void *)KEY_HOOK, sizeof(char));
+    KEY_HOOK = NULL;
+  }
+}
 
 static void hookf(lua_State *L, lua_Debug *ar)
 {
   static const char *const hooknames[] =
     {"call", "return", "line", "count", "tail return"};
-  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
+  lua_pushlightuserdata(L, (void *)get_key_hook(L, &KEY_HOOK));
   lua_rawget(L, LUA_REGISTRYINDEX);
   if (lua_isfunction(L, -1)) {
     lua_pushstring(L, hooknames[(int)ar->event]);
@@ -334,7 +350,7 @@ LJLIB_CF(debug_sethook)
     count = luaL_optint(L, arg+3, 0);
     func = hookf; mask = makemask(smask, count);
   }
-  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
+  lua_pushlightuserdata(L, (void *)get_key_hook(L, &KEY_HOOK));
   lua_pushvalue(L, arg+1);
   lua_rawset(L, LUA_REGISTRYINDEX);
   lua_sethook(L, func, mask, count);
@@ -349,7 +365,7 @@ LJLIB_CF(debug_gethook)
   if (hook != NULL && hook != hookf) {  /* external hook? */
     lua_pushliteral(L, "external hook");
   } else {
-    lua_pushlightuserdata(L, (void *)&KEY_HOOK);
+    lua_pushlightuserdata(L, (void *)get_key_hook(L, &KEY_HOOK));
     lua_rawget(L, LUA_REGISTRYINDEX);   /* get hook */
   }
   lua_pushstring(L, unmakemask(mask, buff));
diff --git a/src/lib_package.c b/src/lib_package.c
index 8c336b02..58a405cc 100644
--- a/src/lib_package.c
+++ b/src/lib_package.c
@@ -16,6 +16,7 @@
 #include "lj_obj.h"
 #include "lj_err.h"
 #include "lj_lib.h"
+#include "lj_gc.h"
 
 /* ------------------------------------------------------------------------ */
 
@@ -399,11 +400,23 @@ static int lj_cf_package_loader_preload(lua_State *L)
 
 /* ------------------------------------------------------------------------ */
 
-static const int sentinel_ = 0;
-#define sentinel	((void *)&sentinel_)
+static const int *sentinel_ = NULL;
+#define sentinel	((void *)sentinel_)
+
+void lj_cf_free_sentinel(lua_State *L) {
+  if (sentinel_ != NULL) {
+    lj_mem_free(G(L), (void *)sentinel_, sizeof(int));
+    sentinel_ = NULL;
+  }
+}
 
 static int lj_cf_package_require(lua_State *L)
 {
+  if (sentinel_ == NULL) {
+    int *p = lj_mem_newt(L, sizeof(int), int);
+    *p = 0;
+    sentinel_ = p;
+  }
   const char *name = luaL_checkstring(L, 1);
   int i;
   lua_settop(L, 1);  /* _LOADED table will be at index 2 */
diff --git a/src/lj_state.c b/src/lj_state.c
index a3bfc45e..10ecb9c7 100644
--- a/src/lj_state.c
+++ b/src/lj_state.c
@@ -157,6 +157,9 @@ static TValue *cpluaopen(lua_State *L, lua_CFunction dummy, void *ud)
   return NULL;
 }
 
+extern void lj_cf_free_sentinel(lua_State *L);
+extern void free_key_hook(lua_State *L);
+
 static void close_state(lua_State *L)
 {
   global_State *g = G(L);
@@ -171,6 +174,8 @@ static void close_state(lua_State *L)
   lj_mem_freevec(g, g->strhash, g->strmask+1, GCRef);
   lj_buf_free(g, &g->tmpbuf);
   lj_mem_freevec(g, tvref(L->stack), L->stacksize, TValue);
+  lj_cf_free_sentinel(L);
+  free_key_hook(L);
   lua_assert(g->gc.total == sizeof(GG_State));
 #ifndef LUAJIT_USE_SYSMALLOC
   if (g->allocf == lj_alloc_f)