From 6f1ea817f5827523f8c7e429ab023e5984a84343 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Fri, 19 Nov 2004 13:52:40 -0200
Subject: better control over memory-size overflows

---
 lmem.h | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

(limited to 'lmem.h')

diff --git a/lmem.h b/lmem.h
index 1c896571..d946f56e 100644
--- a/lmem.h
+++ b/lmem.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h,v 1.25 2001/11/28 20:13:13 roberto Exp roberto $
+** $Id: lmem.h,v 1.26 2002/05/01 20:40:42 roberto Exp roberto $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -16,28 +16,34 @@
 #define MEMERRMSG	"not enough memory"
 
 
-void *luaM_realloc (lua_State *L, void *oldblock, lu_mem oldsize, lu_mem size);
+void *luaM_realloc (lua_State *L, void *block, size_t oldsize, size_t size);
 
-void *luaM_growaux (lua_State *L, void *block, int *size, int size_elem,
+void *luaM_toobig (lua_State *L);
+
+#define luaM_reallocv(L,b,on,n,e) \
+  ((cast(size_t, (n)+1) <= MAX_SIZET/(e)) ?  /* +1 only to avoid warnings */ \
+    luaM_realloc(L, (b), (on)*(e), (n)*(e)) : \
+    luaM_toobig(L))
+
+
+void *luaM_growaux (lua_State *L, void *block, int *size, size_t size_elem,
                     int limit, const char *errormsg);
 
 #define luaM_free(L, b, s)	luaM_realloc(L, (b), (s), 0)
 #define luaM_freelem(L, b)	luaM_realloc(L, (b), sizeof(*(b)), 0)
-#define luaM_freearray(L, b, n, t)	luaM_realloc(L, (b), \
-                                      cast(lu_mem, n)*cast(lu_mem, sizeof(t)), 0)
+#define luaM_freearray(L, b, n, t)   luaM_reallocv(L, (b), n, 0, sizeof(t))
 
-#define luaM_malloc(L, t)	luaM_realloc(L, NULL, 0, (t))
-#define luaM_new(L, t)          cast(t *, luaM_malloc(L, sizeof(t)))
-#define luaM_newvector(L, n,t)  cast(t *, luaM_malloc(L, \
-                                         cast(lu_mem, n)*cast(lu_mem, sizeof(t))))
+#define luaM_malloc(L,t)	luaM_realloc(L, NULL, 0, (t))
+#define luaM_new(L,t)		cast(t *, luaM_malloc(L, sizeof(t)))
+#define luaM_newvector(L,n,t) \
+		cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
 
 #define luaM_growvector(L,v,nelems,size,t,limit,e) \
           if (((nelems)+1) > (size)) \
             ((v)=cast(t *, luaM_growaux(L,v,&(size),sizeof(t),limit,e)))
 
 #define luaM_reallocvector(L, v,oldn,n,t) \
-   ((v)=cast(t *, luaM_realloc(L, v,cast(lu_mem, oldn)*cast(lu_mem, sizeof(t)), \
-                                    cast(lu_mem, n)*cast(lu_mem, sizeof(t)))))
+   ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
 
 
 #endif
-- 
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