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@xxxxxxxxxxxxxx>
---
drivers/net/wireless/intersil/orinoco/fw.c | 2 +-
drivers/net/wireless/intersil/orinoco/hermes.h | 2 +-
drivers/net/wireless/intersil/orinoco/hermes_dld.c | 6 +++---
drivers/net/wireless/intersil/orinoco/orinoco_usb.c | 2 +-
4 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/intersil/orinoco/fw.c b/drivers/net/wireless/intersil/orinoco/fw.c
index 400a35217644..015af782881b 100644
--- a/drivers/net/wireless/intersil/orinoco/fw.c
+++ b/drivers/net/wireless/intersil/orinoco/fw.c
@@ -49,7 +49,7 @@ struct orinoco_fw_header {
__le32 pdr_offset; /* Offset to PDR data from eof header */
__le32 pri_offset; /* Offset to primary plug data */
__le32 compat_offset; /* Offset to compatibility data*/
- char signature[0]; /* FW signature length headersize-20 */
+ char signature[]; /* FW signature length headersize-20 */
} __packed;
/* Check the range of various header entries. Return a pointer to a
diff --git a/drivers/net/wireless/intersil/orinoco/hermes.h b/drivers/net/wireless/intersil/orinoco/hermes.h
index 121fdd8e5da2..9f668185b7d2 100644
--- a/drivers/net/wireless/intersil/orinoco/hermes.h
+++ b/drivers/net/wireless/intersil/orinoco/hermes.h
@@ -341,7 +341,7 @@ struct agere_ext_scan_info {
__le64 timestamp;
__le16 beacon_interval;
__le16 capabilities;
- u8 data[0];
+ u8 data[];
} __packed;
#define HERMES_LINKSTATUS_NOT_CONNECTED (0x0000)
diff --git a/drivers/net/wireless/intersil/orinoco/hermes_dld.c b/drivers/net/wireless/intersil/orinoco/hermes_dld.c
index 4a10b7aca043..dbeadfcfefe2 100644
--- a/drivers/net/wireless/intersil/orinoco/hermes_dld.c
+++ b/drivers/net/wireless/intersil/orinoco/hermes_dld.c
@@ -64,7 +64,7 @@
struct dblock {
__le32 addr; /* adapter address where to write the block */
__le16 len; /* length of the data only, in bytes */
- char data[0]; /* data to be written */
+ char data[]; /* data to be written */
} __packed;
/*
@@ -76,7 +76,7 @@ struct pdr {
__le32 id; /* record ID */
__le32 addr; /* adapter address where to write the data */
__le32 len; /* expected length of the data, in bytes */
- char next[0]; /* next PDR starts here */
+ char next[]; /* next PDR starts here */
} __packed;
/*
@@ -87,7 +87,7 @@ struct pdr {
struct pdi {
__le16 len; /* length of ID and data, in words */
__le16 id; /* record ID */
- char data[0]; /* plug data */
+ char data[]; /* plug data */
} __packed;
/*** FW data block access functions ***/
diff --git a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
index e753f43e0162..a77bbcd544d6 100644
--- a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
+++ b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
@@ -202,7 +202,7 @@ struct ezusb_packet {
__le16 crc; /* CRC up to here */
__le16 hermes_len;
__le16 hermes_rid;
- u8 data[0];
+ u8 data[];
} __packed;
/* Table of devices that work or may work with this driver */
--
2.25.0
