diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-27 00:20:00 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-27 23:06:20 +0300 |
| commit | da60fbe7ef942d64b4d80e99cc9b0205db5964b9 (patch) | |
| tree | ec1ffd9f3659a9ded8c02d4c3111364d8677b5d2 /include/net/nfc | |
| parent | 6dd7f1a1fe20222d152875935f3ee0a009342ade (diff) | |
| download | linux-da60fbe7ef942d64b4d80e99cc9b0205db5964b9.tar.xz | |
NFC: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/nfc')
| -rw-r--r-- | include/net/nfc/nci.h | 14 | ||||
| -rw-r--r-- | include/net/nfc/nfc.h | 2 |
2 files changed, 8 insertions, 8 deletions
diff --git a/include/net/nfc/nci.h b/include/net/nfc/nci.h index 6ab5a83f597c..0550e0380b8d 100644 --- a/include/net/nfc/nci.h +++ b/include/net/nfc/nci.h @@ -244,13 +244,13 @@ struct dest_spec_params { struct core_conn_create_dest_spec_params { __u8 type; __u8 length; - __u8 value[0]; + __u8 value[]; } __packed; struct nci_core_conn_create_cmd { __u8 destination_type; __u8 number_destination_params; - struct core_conn_create_dest_spec_params params[0]; + struct core_conn_create_dest_spec_params params[]; } __packed; #define NCI_OP_CORE_CONN_CLOSE_CMD nci_opcode_pack(NCI_GID_CORE, 0x05) @@ -321,7 +321,7 @@ struct nci_core_init_rsp_1 { __u8 status; __le32 nfcc_features; __u8 num_supported_rf_interfaces; - __u8 supported_rf_interfaces[0]; /* variable size array */ + __u8 supported_rf_interfaces[]; /* variable size array */ /* continuted in nci_core_init_rsp_2 */ } __packed; @@ -338,7 +338,7 @@ struct nci_core_init_rsp_2 { struct nci_core_set_config_rsp { __u8 status; __u8 num_params; - __u8 params_id[0]; /* variable size array */ + __u8 params_id[]; /* variable size array */ } __packed; #define NCI_OP_CORE_CONN_CREATE_RSP nci_opcode_pack(NCI_GID_CORE, 0x04) @@ -501,18 +501,18 @@ struct nci_rf_nfcee_action_ntf { __u8 nfcee_id; __u8 trigger; __u8 supported_data_length; - __u8 supported_data[0]; + __u8 supported_data[]; } __packed; #define NCI_OP_NFCEE_DISCOVER_NTF nci_opcode_pack(NCI_GID_NFCEE_MGMT, 0x00) struct nci_nfcee_supported_protocol { __u8 num_protocol; - __u8 supported_protocol[0]; + __u8 supported_protocol[]; } __packed; struct nci_nfcee_information_tlv { __u8 num_tlv; - __u8 information_tlv[0]; + __u8 information_tlv[]; } __packed; struct nci_nfcee_discover_ntf { diff --git a/include/net/nfc/nfc.h b/include/net/nfc/nfc.h index 5d277d68fd8d..2cd3a261bcbc 100644 --- a/include/net/nfc/nfc.h +++ b/include/net/nfc/nfc.h @@ -146,7 +146,7 @@ struct nfc_evt_transaction { u32 aid_len; u8 aid[NFC_MAX_AID_LENGTH]; u8 params_len; - u8 params[0]; + u8 params[]; } __packed; struct nfc_genl_data { |