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/p54/eeprom.h | 8 ++++----
drivers/net/wireless/intersil/p54/lmac.h | 6 +++---
drivers/net/wireless/intersil/p54/p54.h | 2 +-
3 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/intersil/p54/eeprom.h b/drivers/net/wireless/intersil/p54/eeprom.h
index b8f46883a292..1d0aaf54389a 100644
--- a/drivers/net/wireless/intersil/p54/eeprom.h
+++ b/drivers/net/wireless/intersil/p54/eeprom.h
@@ -24,7 +24,7 @@
struct pda_entry {
__le16 len; /* includes both code and data */
__le16 code;
- u8 data[0];
+ u8 data[];
} __packed;
struct eeprom_pda_wrap {
@@ -32,7 +32,7 @@ struct eeprom_pda_wrap {
__le16 pad;
__le16 len;
__le32 arm_opcode;
- u8 data[0];
+ u8 data[];
} __packed;
struct p54_iq_autocal_entry {
@@ -87,7 +87,7 @@ struct pda_pa_curve_data {
u8 channels;
u8 points_per_channel;
u8 padding;
- u8 data[0];
+ u8 data[];
} __packed;
struct pda_rssi_cal_ext_entry {
@@ -119,7 +119,7 @@ struct pda_custom_wrapper {
__le16 entry_size;
__le16 offset;
__le16 len;
- u8 data[0];
+ u8 data[];
} __packed;
/*
diff --git a/drivers/net/wireless/intersil/p54/lmac.h b/drivers/net/wireless/intersil/p54/lmac.h
index e00761536cfc..8adde6ba35ab 100644
--- a/drivers/net/wireless/intersil/p54/lmac.h
+++ b/drivers/net/wireless/intersil/p54/lmac.h
@@ -81,7 +81,7 @@ struct p54_hdr {
__le16 type; /* enum p54_control_frame_types */
u8 rts_tries;
u8 tries;
- u8 data[0];
+ u8 data[];
} __packed;
#define GET_REQ_ID(skb) \
@@ -176,7 +176,7 @@ struct p54_rx_data {
u8 rssi_raw;
__le32 tsf32;
__le32 unalloc0;
- u8 align[0];
+ u8 align[];
} __packed;
enum p54_trap_type {
@@ -267,7 +267,7 @@ struct p54_tx_data {
} __packed normal;
} __packed;
u8 unalloc2[2];
- u8 align[0];
+ u8 align[];
} __packed;
/* unit is ms */
diff --git a/drivers/net/wireless/intersil/p54/p54.h b/drivers/net/wireless/intersil/p54/p54.h
index 0a9c1a19380f..3356ea708d81 100644
--- a/drivers/net/wireless/intersil/p54/p54.h
+++ b/drivers/net/wireless/intersil/p54/p54.h
@@ -126,7 +126,7 @@ struct p54_cal_database {
size_t entry_size;
size_t offset;
size_t len;
- u8 data[0];
+ u8 data[];
};
#define EEPROM_READBACK_LEN 0x3fc
--
2.25.0
