diff options
Diffstat (limited to 'erts/emulator/beam/utils.c')
| -rw-r--r-- | erts/emulator/beam/utils.c | 37 |
1 files changed, 29 insertions, 8 deletions
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c index 6b4f3b3b36..a17de717bc 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 */ |