There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use "flexible array members"[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
Also, refactor the code a bit to make use of the struct_size() helper in
kzalloc().
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#zero-length-and-one-element-arrays
Signed-off-by: Len Baker <[email protected]>
---
drivers/net/wireless/ath/ath11k/reg.c | 7 ++-----
drivers/net/wireless/ath/ath11k/wmi.h | 2 +-
2 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/ath/ath11k/reg.c b/drivers/net/wireless/ath/ath11k/reg.c
index e1a1df169034..c83d265185f1 100644
--- a/drivers/net/wireless/ath/ath11k/reg.c
+++ b/drivers/net/wireless/ath/ath11k/reg.c
@@ -97,7 +97,6 @@ int ath11k_reg_update_chan_list(struct ath11k *ar)
struct channel_param *ch;
enum nl80211_band band;
int num_channels = 0;
- int params_len;
int i, ret;
bands = hw->wiphy->bands;
@@ -117,10 +116,8 @@ int ath11k_reg_update_chan_list(struct ath11k *ar)
if (WARN_ON(!num_channels))
return -EINVAL;
- params_len = sizeof(struct scan_chan_list_params) +
- num_channels * sizeof(struct channel_param);
- params = kzalloc(params_len, GFP_KERNEL);
-
+ params = kzalloc(struct_size(params, ch_param, num_channels),
+ GFP_KERNEL);
if (!params)
return -ENOMEM;
diff --git a/drivers/net/wireless/ath/ath11k/wmi.h b/drivers/net/wireless/ath/ath11k/wmi.h
index d35c47e0b19d..d9c83726f65d 100644
--- a/drivers/net/wireless/ath/ath11k/wmi.h
+++ b/drivers/net/wireless/ath/ath11k/wmi.h
@@ -3608,7 +3608,7 @@ struct wmi_stop_scan_cmd {
struct scan_chan_list_params {
u32 pdev_id;
u16 nallchans;
- struct channel_param ch_param[1];
+ struct channel_param ch_param[];
};
struct wmi_scan_chan_list_cmd {
--
2.25.1
There is already a patch for this:
https://lore.kernel.org/lkml/20210823172159.GA25800@embeddedor/
which I will now add to my -next tree.
Thanks
--
Gustavo
On Sat, Sep 04, 2021 at 01:49:37PM +0200, Len Baker wrote:
> There is a regular need in the kernel to provide a way to declare having
> a dynamically sized set of trailing elements in a structure. Kernel code
> should always use "flexible array members"[1] for these cases. The older
> style of one-element or zero-length arrays should no longer be used[2].
>
> Also, refactor the code a bit to make use of the struct_size() helper in
> kzalloc().
>
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#zero-length-and-one-element-arrays
>
> Signed-off-by: Len Baker <[email protected]>
> ---
> drivers/net/wireless/ath/ath11k/reg.c | 7 ++-----
> drivers/net/wireless/ath/ath11k/wmi.h | 2 +-
> 2 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath11k/reg.c b/drivers/net/wireless/ath/ath11k/reg.c
> index e1a1df169034..c83d265185f1 100644
> --- a/drivers/net/wireless/ath/ath11k/reg.c
> +++ b/drivers/net/wireless/ath/ath11k/reg.c
> @@ -97,7 +97,6 @@ int ath11k_reg_update_chan_list(struct ath11k *ar)
> struct channel_param *ch;
> enum nl80211_band band;
> int num_channels = 0;
> - int params_len;
> int i, ret;
>
> bands = hw->wiphy->bands;
> @@ -117,10 +116,8 @@ int ath11k_reg_update_chan_list(struct ath11k *ar)
> if (WARN_ON(!num_channels))
> return -EINVAL;
>
> - params_len = sizeof(struct scan_chan_list_params) +
> - num_channels * sizeof(struct channel_param);
> - params = kzalloc(params_len, GFP_KERNEL);
> -
> + params = kzalloc(struct_size(params, ch_param, num_channels),
> + GFP_KERNEL);
> if (!params)
> return -ENOMEM;
>
> diff --git a/drivers/net/wireless/ath/ath11k/wmi.h b/drivers/net/wireless/ath/ath11k/wmi.h
> index d35c47e0b19d..d9c83726f65d 100644
> --- a/drivers/net/wireless/ath/ath11k/wmi.h
> +++ b/drivers/net/wireless/ath/ath11k/wmi.h
> @@ -3608,7 +3608,7 @@ struct wmi_stop_scan_cmd {
> struct scan_chan_list_params {
> u32 pdev_id;
> u16 nallchans;
> - struct channel_param ch_param[1];
> + struct channel_param ch_param[];
> };
>
> struct wmi_scan_chan_list_cmd {
> --
> 2.25.1
>
"Gustavo A. R. Silva" <[email protected]> writes:
> On 9/12/21 14:31, Gustavo A. R. Silva wrote:
>>
>> There is already a patch for this:
>>
>> https://lore.kernel.org/lkml/20210823172159.GA25800@embeddedor/
>>
>> which I will now add to my -next tree.
>
> Well, in this case I think it's much better if Kalle can take it. :)
Please don't take any ath11k patches. I have a ton of ath11k patches in
my queue and if you start taking some of them, it will cause conflicts
between trees.
Only take wireless-driver patches which I have acked, please.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches