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-rw-r--r--erts/emulator/beam/utils.c37
1 files changed, 29 insertions, 8 deletions
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index f531d1430b..afea51c44b 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -3021,13 +3021,25 @@ int io_list_to_buf(Eterm obj, char* buf, int len)
return -1;
}
-int io_list_len(Eterm obj)
+/*
+ * Return 0 if successful, and non-zero if unsuccessful.
+ */
+int erts_iolist_size(Eterm obj, Uint* sizep)
{
Eterm* objp;
- Sint len = 0;
+ Uint size = 0;
DECLARE_ESTACK(s);
goto L_again;
+#define SAFE_ADD(Var, Val) \
+ do { \
+ Uint valvar = (Val); \
+ Var += valvar; \
+ if (Var < valvar) { \
+ goto L_overflow_error; \
+ } \
+ } while (0)
+
while (!ESTACK_ISEMPTY(s)) {
obj = ESTACK_POP(s);
L_again:
@@ -3037,9 +3049,12 @@ int io_list_len(Eterm obj)
/* Head */
obj = CAR(objp);
if (is_byte(obj)) {
- len++;
+ size++;
+ if (size == 0) {
+ goto L_overflow_error;
+ }
} else if (is_binary(obj) && binary_bitsize(obj) == 0) {
- len += binary_size(obj);
+ SAFE_ADD(size, binary_size(obj));
} else if (is_list(obj)) {
ESTACK_PUSH(s, CDR(objp));
goto L_iter_list; /* on head */
@@ -3051,23 +3066,29 @@ int io_list_len(Eterm obj)
if (is_list(obj))
goto L_iter_list; /* on tail */
else if (is_binary(obj) && binary_bitsize(obj) == 0) {
- len += binary_size(obj);
+ SAFE_ADD(size, binary_size(obj));
} else if (is_not_nil(obj)) {
goto L_type_error;
}
} else if (is_binary(obj) && binary_bitsize(obj) == 0) { /* Tail was binary */
- len += binary_size(obj);
+ SAFE_ADD(size, binary_size(obj));
} else if (is_not_nil(obj)) {
goto L_type_error;
}
}
+#undef SAFE_ADD
DESTROY_ESTACK(s);
- return len;
+ *sizep = size;
+ return ERTS_IOLIST_OK;
+
+ L_overflow_error:
+ DESTROY_ESTACK(s);
+ return ERTS_IOLIST_OVERFLOW;
L_type_error:
DESTROY_ESTACK(s);
- return -1;
+ return ERTS_IOLIST_TYPE;
}
/* return 0 if item is not a non-empty flat list of bytes */