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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-27 00:02:27 +0100 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2020-02-28 08:30:02 +0100 |
| commit | a7e454542bf8d57c75f59e7e7326c21db3d0bb3f (patch) | |
| tree | 668c086fa84b889902a48b81cb10b13ed42a2436 /drivers | |
| parent | Bluetooth: fix passkey uninitialized when used (diff) | |
| download | linux-a7e454542bf8d57c75f59e7e7326c21db3d0bb3f.tar.xz linux-a7e454542bf8d57c75f59e7e7326c21db3d0bb3f.zip | |
Bluetooth: 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: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/bluetooth/btqca.h | 6 | ||||
| -rw-r--r-- | drivers/bluetooth/btrtl.h | 4 |
2 files changed, 5 insertions, 5 deletions
diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h index f5795b1a3779..e16a4d650597 100644 --- a/drivers/bluetooth/btqca.h +++ b/drivers/bluetooth/btqca.h @@ -79,7 +79,7 @@ struct qca_fw_config { struct edl_event_hdr { __u8 cresp; __u8 rtype; - __u8 data[0]; + __u8 data[]; } __packed; struct qca_btsoc_version { @@ -112,12 +112,12 @@ struct tlv_type_nvm { __le16 tag_len; __le32 reserve1; __le32 reserve2; - __u8 data[0]; + __u8 data[]; } __packed; struct tlv_type_hdr { __le32 type_len; - __u8 data[0]; + __u8 data[]; } __packed; enum qca_btsoc_type { diff --git a/drivers/bluetooth/btrtl.h b/drivers/bluetooth/btrtl.h index 10ad40c3e42c..2a582682136d 100644 --- a/drivers/bluetooth/btrtl.h +++ b/drivers/bluetooth/btrtl.h @@ -38,13 +38,13 @@ struct rtl_epatch_header { struct rtl_vendor_config_entry { __le16 offset; __u8 len; - __u8 data[0]; + __u8 data[]; } __packed; struct rtl_vendor_config { __le32 signature; __le16 total_len; - struct rtl_vendor_config_entry entry[0]; + struct rtl_vendor_config_entry entry[]; } __packed; #if IS_ENABLED(CONFIG_BT_RTL) |