diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 19:18:46 -0600 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2020-03-23 19:01:13 +0200 |
| commit | 7b9307134058cefb9c2416266a7ae6fc4af57915 (patch) | |
| tree | 68a59e8215bc7c18ac8f95677a3032302c7a4e95 | |
| parent | c5047d5b831bb5f4dfa22230a2f64794ed20ea82 (diff) | |
| download | linux-7b9307134058cefb9c2416266a7ae6fc4af57915.tar.bz2 | |
p54: 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: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200225011846.GA2773@embeddedor
| -rw-r--r-- | drivers/net/wireless/intersil/p54/eeprom.h | 8 | ||||
| -rw-r--r-- | drivers/net/wireless/intersil/p54/lmac.h | 6 | ||||
| -rw-r--r-- | 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 |