| Message ID | 20180427140409.GA19583@mwanda |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [1/2] bpf: btf: silence uninitialize variable warnings | expand |
On Fri, Apr 27, 2018 at 05:04:09PM +0300, Dan Carpenter wrote: > Smatch complains that size can be uninitialized if btf_type_id_size() > returns NULL. It seems reasonable enough to check for that. > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > This goes to the BPF tree (linux-next). > > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > index 22e1046a1a86..e631b6fd60d3 100644 > --- a/kernel/bpf/btf.c > +++ b/kernel/bpf/btf.c > @@ -1229,7 +1229,8 @@ static int btf_array_check_member(struct btf_verifier_env *env, > } > > array_type_id = member->type; > - btf_type_id_size(btf, &array_type_id, &array_size); > + if (!btf_type_id_size(btf, &array_type_id, &array_size)) > + return -EINVAL; This check is not needed. It does not happen for array. > struct_size = struct_type->size; > bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); > if (struct_size - bytes_offset < array_size) { > @@ -1351,6 +1352,8 @@ static void btf_array_seq_show(const struct btf *btf, const struct btf_type *t, > > elem_type_id = array->type; > elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); > + if (!elem_type) > + return; This case has already been checked in verification phase. No need to recheck everything again.. > elem_ops = btf_type_ops(elem_type); > seq_puts(m, "["); > for (i = 0; i < array->nelems; i++) {
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 22e1046a1a86..e631b6fd60d3 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -1229,7 +1229,8 @@ static int btf_array_check_member(struct btf_verifier_env *env, } array_type_id = member->type; - btf_type_id_size(btf, &array_type_id, &array_size); + if (!btf_type_id_size(btf, &array_type_id, &array_size)) + return -EINVAL; struct_size = struct_type->size; bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); if (struct_size - bytes_offset < array_size) { @@ -1351,6 +1352,8 @@ static void btf_array_seq_show(const struct btf *btf, const struct btf_type *t, elem_type_id = array->type; elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); + if (!elem_type) + return; elem_ops = btf_type_ops(elem_type); seq_puts(m, "["); for (i = 0; i < array->nelems; i++) {
Smatch complains that size can be uninitialized if btf_type_id_size() returns NULL. It seems reasonable enough to check for that. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- This goes to the BPF tree (linux-next).