Finalizers may call functions from a dynamic library after

the library has been unloaded
author: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 2012-04-12 13:25:25 -0300
committer: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 2012-04-12 13:25:25 -0300
commit: 1485ea2ee742779b0030152ebde92a8370518afa (patch)
tree: 28c819860d2d844626a1d6cdf324ca21f5147f8c
parent: b10dbe5c727eedace5c84addd0573bfa1b0c027a (diff)
download: lua-1485ea2ee742779b0030152ebde92a8370518afa.tar.gz
lua-1485ea2ee742779b0030152ebde92a8370518afa.tar.bz2
lua-1485ea2ee742779b0030152ebde92a8370518afa.zip
1 files changed, 102 insertions, 2 deletions
diff --git a/bugs b/bugs
index 8708dd92..ff499e50 100644
--- a/bugs
+++ b/bugs
@@ -1880,8 +1880,8 @@ patch = [[
 +++ lundump.c   2008/04/04 19:51:41     2.7.1.4
 @@ -1,5 +1,5 @@
 /*
-** $Id: bugs,v 1.111 2011/10/21 19:34:23 roberto Exp roberto $
+-** $Id: bugs,v 1.112 2012/01/20 18:32:13 roberto Exp roberto $
-+** $Id: bugs,v 1.111 2011/10/21 19:34:23 roberto Exp roberto $
+** $Id: bugs,v 1.112 2012/01/20 18:32:13 roberto Exp roberto $
 ** load precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -2520,6 +2520,106 @@ patch = [[
 ]]
 }
+Bug{
+what = [[Finalizers may call functions from a dynamic library after
+the library has been unloaded]],
+report = [[Josh Haberman, 2012/04/08]],
+since = [[5.1]],
+example = [[
+local u = setmetatable({}, {__gc = function () foo() end})
+local m = require 'mod'   -- 'mod' may be any dynamic library written in C
+foo = m.foo     -- 'foo' may be any function from 'mod'
+-- end program; it crashes
+]],
+patch = [[
+===================================================================
+RCS file: RCS/loadlib.c,v
+retrieving revision 1.108
+diff -r1.108 loadlib.c
+95c95
+< #define LIBPREFIX     "LOADLIB: "
+---
+> #define CLIBS         "_CLIBS"
+251,266c251,256
+< 
+< static void **ll_register (lua_State *L, const char *path) {
+<   void **plib;
+<   lua_pushfstring(L, "%s%s", LIBPREFIX, path);
+<   lua_gettable(L, LUA_REGISTRYINDEX);  /* check library in registry? */
+<   if (!lua_isnil(L, -1))  /* is there an entry? */
+<     plib = (void **)lua_touserdata(L, -1);
+<   else {  /* no entry yet; create one */
+<     lua_pop(L, 1);  /* remove result from gettable */
+<     plib = (void **)lua_newuserdata(L, sizeof(const void *));
+<     *plib = NULL;
+<     luaL_setmetatable(L, "_LOADLIB");
+<     lua_pushfstring(L, "%s%s", LIBPREFIX, path);
+<     lua_pushvalue(L, -2);
+<     lua_settable(L, LUA_REGISTRYINDEX);
+<   }
+---
+> static void *ll_checkclib (lua_State *L, const char *path) {
+>   void *plib;
+>   lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
+>   lua_getfield(L, -1, path);
+>   plib = lua_touserdata(L, -1);  /* plib = CLIBS[path] */
+>   lua_pop(L, 2);  /* pop CLIBS table and 'plib' */
+270a261,270
+> static void ll_addtoclib (lua_State *L, const char *path, void *plib) {
+>   lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
+>   lua_pushlightuserdata(L, plib);
+>   lua_pushvalue(L, -1);
+>   lua_setfield(L, -3, path);  /* CLIBS[path] = plib */
+>   lua_rawseti(L, -2, luaL_len(L, -2) + 1);  /* CLIBS[#CLIBS + 1] = plib */
+>   lua_pop(L, 1);  /* pop CLIBS table */
+> }
+> 
+> 
+272,273c272,273
+< ** __gc tag method: calls library's `ll_unloadlib' function with the lib
+< ** handle
+---
+> ** __gc tag method for CLIBS table: calls 'll_unloadlib' for all lib
+> ** handles in list CLIBS
+276,278c276,281
+<   void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
+<   if (*lib) ll_unloadlib(*lib);
+<   *lib = NULL;  /* mark library as closed */
+---
+>   int n = luaL_len(L, 1);
+>   for (; n >= 1; n--) {  /* for each handle, in reverse order */
+>     lua_rawgeti(L, 1, n);  /* get handle CLIBS[n] */
+>     ll_unloadlib(lua_touserdata(L, -1));
+>     lua_pop(L, 1);  /* pop handle */
+>   }
+284,286c287,292
+<   void **reg = ll_register(L, path);
+<   if (*reg == NULL) *reg = ll_load(L, path, *sym == '*');
+<   if (*reg == NULL) return ERRLIB;  /* unable to load library */
+---
+>   void *reg = ll_checkclib(L, path);  /* check loaded C libraries */
+>   if (reg == NULL) {  /* must load library? */
+>     reg = ll_load(L, path, *sym == '*');
+>     if (reg == NULL) return ERRLIB;  /* unable to load library */
+>     ll_addtoclib(L, path, reg);
+>   }
+292c298
+<     lua_CFunction f = ll_sym(L, *reg, sym);
+---
+>     lua_CFunction f = ll_sym(L, reg, sym);
+675,676c681,683
+<   /* create new type _LOADLIB */
+<   luaL_newmetatable(L, "_LOADLIB");
+---
+>   /* create table CLIBS to keep track of loaded C libraries */
+>   luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS);
+>   lua_createtable(L, 0, 1);  /* metatable for CLIBS */
+678a686
+>   lua_setmetatable(L, -2);
+]]
+}
 --[=[
 Bug{
 what = [[ ]],
author	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	2012-04-12 13:25:25 -0300
committer	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	2012-04-12 13:25:25 -0300
commit	1485ea2ee742779b0030152ebde92a8370518afa (patch)
tree	28c819860d2d844626a1d6cdf324ca21f5147f8c
parent	b10dbe5c727eedace5c84addd0573bfa1b0c027a (diff)
download	lua-1485ea2ee742779b0030152ebde92a8370518afa.tar.gz lua-1485ea2ee742779b0030152ebde92a8370518afa.tar.bz2 lua-1485ea2ee742779b0030152ebde92a8370518afa.zip

diff --git a/bugs b/bugs index 8708dd92..ff499e50 100644 --- a/bugs +++ b/bugs
@@ -1880,8 +1880,8 @@ patch = [[
1880	+++ lundump.c 2008/04/04 19:51:41 2.7.1.4	1880	+++ lundump.c 2008/04/04 19:51:41 2.7.1.4
1881	@@ -1,5 +1,5 @@	1881	@@ -1,5 +1,5 @@
1882	/*	1882	/*
1883	-** $Id: bugs,v 1.111 2011/10/21 19:34:23 roberto Exp roberto $	1883	-** $Id: bugs,v 1.112 2012/01/20 18:32:13 roberto Exp roberto $
1884	+** $Id: bugs,v 1.111 2011/10/21 19:34:23 roberto Exp roberto $	1884	+** $Id: bugs,v 1.112 2012/01/20 18:32:13 roberto Exp roberto $
1885	** load precompiled Lua chunks	1885	** load precompiled Lua chunks
1886	** See Copyright Notice in lua.h	1886	** See Copyright Notice in lua.h
1887	*/	1887	*/
@@ -2520,6 +2520,106 @@ patch = [[
2520	]]	2520	]]
2521	}	2521	}
2522		2522
		2523	Bug{
		2524	what = [[Finalizers may call functions from a dynamic library after
		2525	the library has been unloaded]],
		2526	report = [[Josh Haberman, 2012/04/08]],
		2527	since = [[5.1]],
		2528	example = [[
		2529	local u = setmetatable({}, {__gc = function () foo() end})
		2530	local m = require 'mod' -- 'mod' may be any dynamic library written in C
		2531	foo = m.foo -- 'foo' may be any function from 'mod'
		2532	-- end program; it crashes
		2533	]],
		2534	patch = [[
		2535	===================================================================
		2536	RCS file: RCS/loadlib.c,v
		2537	retrieving revision 1.108
		2538	diff -r1.108 loadlib.c
		2539	95c95
		2540	< #define LIBPREFIX "LOADLIB: "
		2541	---
		2542	> #define CLIBS "_CLIBS"
		2543	251,266c251,256
		2544	<
		2545	< static void *ll_register (lua_State L, const char *path) {
		2546	< void **plib;
		2547	< lua_pushfstring(L, "%s%s", LIBPREFIX, path);
		2548	< lua_gettable(L, LUA_REGISTRYINDEX); /* check library in registry? */
		2549	< if (!lua_isnil(L, -1)) /* is there an entry? */
		2550	< plib = (void **)lua_touserdata(L, -1);
		2551	< else { /* no entry yet; create one */
		2552	< lua_pop(L, 1); /* remove result from gettable */
		2553	< plib = (void *)lua_newuserdata(L, sizeof(const void ));
		2554	< *plib = NULL;
		2555	< luaL_setmetatable(L, "_LOADLIB");
		2556	< lua_pushfstring(L, "%s%s", LIBPREFIX, path);
		2557	< lua_pushvalue(L, -2);
		2558	< lua_settable(L, LUA_REGISTRYINDEX);
		2559	< }
		2560	---
		2561	> static void ll_checkclib (lua_State L, const char *path) {
		2562	> void *plib;
		2563	> lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
		2564	> lua_getfield(L, -1, path);
		2565	> plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */
		2566	> lua_pop(L, 2); /* pop CLIBS table and 'plib' */
		2567	270a261,270
		2568	> static void ll_addtoclib (lua_State L, const char path, void *plib) {
		2569	> lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
		2570	> lua_pushlightuserdata(L, plib);
		2571	> lua_pushvalue(L, -1);
		2572	> lua_setfield(L, -3, path); /* CLIBS[path] = plib */
		2573	> lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */
		2574	> lua_pop(L, 1); /* pop CLIBS table */
		2575	> }
		2576	>
		2577	>
		2578	272,273c272,273
		2579	< ** __gc tag method: calls library's `ll_unloadlib' function with the lib
		2580	< ** handle
		2581	---
		2582	> ** __gc tag method for CLIBS table: calls 'll_unloadlib' for all lib
		2583	> ** handles in list CLIBS
		2584	276,278c276,281
		2585	< void lib = (void )luaL_checkudata(L, 1, "_LOADLIB");
		2586	< if (lib) ll_unloadlib(lib);
		2587	< lib = NULL; / mark library as closed */
		2588	---
		2589	> int n = luaL_len(L, 1);
		2590	> for (; n >= 1; n--) { /* for each handle, in reverse order */
		2591	> lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
		2592	> ll_unloadlib(lua_touserdata(L, -1));
		2593	> lua_pop(L, 1); /* pop handle */
		2594	> }
		2595	284,286c287,292
		2596	< void **reg = ll_register(L, path);
		2597	< if (reg == NULL) reg = ll_load(L, path, sym == '');
		2598	< if (reg == NULL) return ERRLIB; / unable to load library */
		2599	---
		2600	> void reg = ll_checkclib(L, path); / check loaded C libraries */
		2601	> if (reg == NULL) { /* must load library? */
		2602	> reg = ll_load(L, path, sym == '');
		2603	> if (reg == NULL) return ERRLIB; /* unable to load library */
		2604	> ll_addtoclib(L, path, reg);
		2605	> }
		2606	292c298
		2607	< lua_CFunction f = ll_sym(L, *reg, sym);
		2608	---
		2609	> lua_CFunction f = ll_sym(L, reg, sym);
		2610	675,676c681,683
		2611	< /* create new type _LOADLIB */
		2612	< luaL_newmetatable(L, "_LOADLIB");
		2613	---
		2614	> /* create table CLIBS to keep track of loaded C libraries */
		2615	> luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS);
		2616	> lua_createtable(L, 0, 1); /* metatable for CLIBS */
		2617	678a686
		2618	> lua_setmetatable(L, -2);
		2619	]]
		2620	}
		2621
		2622
2523	--[=[	2623	--[=[
2524	Bug{	2624	Bug{
2525	what = [[ ]],	2625	what = [[ ]],