Fixed bug: 'luaD_callnoyield' called twice in a row
In luaD_callnoyield, when there is a possible stack overflow, it
zeros the number of CallInfos to force a check when calling the
function. However, if the "function" is not a function, the code will
raise an error before checking the stack. Then, the error handling calls
luaD_callnoyield again and nCcalls is decremented again, crossing the
stack redzone without raising an error. (This loop can only happens
once, because the error handler must be a function. But once is enough
to cross the redzone.)
diff --git a/ldo.c b/ldo.c
index 98dd9fb..5473815 100644
--- a/ldo.c
+++ b/ldo.c
@@ -515,14 +515,13 @@
/*
** Similar to 'luaD_call', but does not allow yields during the call.
-** If there is a stack overflow, freeing all CI structures will
-** force the subsequent call to invoke 'luaE_extendCI', which then
-** will raise any errors.
*/
void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
incXCcalls(L);
- if (getCcalls(L) <= CSTACKERR) /* possible stack overflow? */
- luaE_freeCI(L);
+ if (getCcalls(L) <= CSTACKERR) { /* possible C stack overflow? */
+ luaE_exitCcall(L); /* to compensate decrement in next call */
+ luaE_enterCcall(L); /* check properly */
+ }
luaD_call(L, func, nResults);
decXCcalls(L);
}
