nik/lush
1
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

using explicit tests for allocation overflow whenever possible

Browse Source
This commit is contained in:
Roberto Ierusalimschy
2017-12-07 16:59:52 -02:00
parent 46bc7f2bf7
commit 7622373033
5 changed files with 80 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
lmem.c
View File

@@ -1,5 +1,5 @@
/*
** $Id: lmem.c,v 1.91 2015/03/06 19:45:54 roberto Exp roberto $
** $Id: lmem.c,v 1.92 2017/12/06 18:36:31 roberto Exp roberto $
** Interface to Memory Manager
** See Copyright Notice in lua.h
*/
@@ -53,24 +53,26 @@
#define MINSIZEARRAY 4
void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *size,
void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *psize,
int size_elems, int limit, const char *what) {
void *newblock;
int newsize;
if (nelems + 1 <= *size) /* does one extra element still fit? */
int size = *psize;
if (nelems + 1 <= size) /* does one extra element still fit? */
return block; /* nothing to be done */
if (*size >= limit/2) { /* cannot double it? */
if (*size >= limit) /* cannot grow even a little? */
if (size >= limit / 2) { /* cannot double it? */
if (size >= limit) /* cannot grow even a little? */
luaG_runerror(L, "too many %s (limit is %d)", what, limit);
newsize = limit; /* still have at least one free place */
size = limit; /* still have at least one free place */
}
else {
newsize = (*size)*2;
if (newsize < MINSIZEARRAY)
newsize = MINSIZEARRAY; /* minimum size */
size *= 2;
if (size < MINSIZEARRAY)
size = MINSIZEARRAY; /* minimum size */
}
newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
*size = newsize; /* update only when everything else is OK */
/* 'limit' ensures that multiplication will not overflow */
newblock = luaM_realloc(L, block, cast(size_t, *psize) * size_elems,
cast(size_t, size) * size_elems);
*psize = size; /* update only when everything else is OK */
return newblock;
}
@@ -113,7 +115,7 @@ void luaM_free_ (lua_State *L, void *block, size_t osize) {
/*
** generic allocation routine.
*/
void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
void *luaM_realloc (lua_State *L, void *block, size_t osize, size_t nsize) {
void *newblock;
global_State *g = G(L);
lua_assert((osize == 0) == (block == NULL));