diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-05-04 15:08:38 -0500 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2020-05-06 09:21:30 +0300 |
| commit | ee4dd7061891d7295328302104037520d831ce43 (patch) | |
| tree | 41e7ae9118d7d76d77d3fd1e659469c3bbf15040 /drivers/net/wireless/ath/ath6kl | |
| parent | d7d43782d541edb8596d2f4fc7f41b0734948ec5 (diff) | |
ath6kl: Replace zero-length array with flexible-array
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]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
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/20200504200838.GA31974@embeddedor
Diffstat (limited to 'drivers/net/wireless/ath/ath6kl')
| -rw-r--r-- | drivers/net/wireless/ath/ath6kl/core.h | 4 | ||||
| -rw-r--r-- | drivers/net/wireless/ath/ath6kl/debug.c | 2 | ||||
| -rw-r--r-- | drivers/net/wireless/ath/ath6kl/hif.h | 2 |
3 files changed, 4 insertions, 4 deletions
diff --git a/drivers/net/wireless/ath/ath6kl/core.h b/drivers/net/wireless/ath/ath6kl/core.h index 0d30e762c090..77e052336eb5 100644 --- a/drivers/net/wireless/ath/ath6kl/core.h +++ b/drivers/net/wireless/ath/ath6kl/core.h @@ -160,7 +160,7 @@ enum ath6kl_fw_capability { struct ath6kl_fw_ie { __le32 id; __le32 len; - u8 data[0]; + u8 data[]; }; enum ath6kl_hw_flags { @@ -406,7 +406,7 @@ struct ath6kl_mgmt_buff { u32 id; bool no_cck; size_t len; - u8 buf[0]; + u8 buf[]; }; struct ath6kl_sta { diff --git a/drivers/net/wireless/ath/ath6kl/debug.c b/drivers/net/wireless/ath/ath6kl/debug.c index 54337d60f288..7506cea46f58 100644 --- a/drivers/net/wireless/ath/ath6kl/debug.c +++ b/drivers/net/wireless/ath/ath6kl/debug.c @@ -30,7 +30,7 @@ struct ath6kl_fwlog_slot { __le32 length; /* max ATH6KL_FWLOG_PAYLOAD_SIZE bytes */ - u8 payload[0]; + u8 payload[]; }; #define ATH6KL_FWLOG_MAX_ENTRIES 20 diff --git a/drivers/net/wireless/ath/ath6kl/hif.h b/drivers/net/wireless/ath/ath6kl/hif.h index dc6bd8cd9b83..aea7fea2a81e 100644 --- a/drivers/net/wireless/ath/ath6kl/hif.h +++ b/drivers/net/wireless/ath/ath6kl/hif.h @@ -199,7 +199,7 @@ struct hif_scatter_req { u32 scat_q_depth; - struct hif_scatter_item scat_list[0]; + struct hif_scatter_item scat_list[]; }; struct ath6kl_irq_proc_registers { |