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From: Len Baker <len.baker@gmx.com>
To: Kalle Valo <kvalo@codeaurora.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: Len Baker <len.baker@gmx.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	Kees Cook <keescook@chromium.org>,
	ath11k@lists.infradead.org, linux-wireless@vger.kernel.org,
	netdev@vger.kernel.org, linux-hardening@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] ath11k: Replace one-element array with flexible-array member
Date: Sat,  4 Sep 2021 13:49:37 +0200	[thread overview]
Message-ID: <20210904114937.6644-1-len.baker@gmx.com> (raw)

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 <len.baker@gmx.com>
---
 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


             reply	other threads:[~2021-09-04 11:50 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-04 11:49 Len Baker [this message]
2021-09-12 19:31 ` [PATCH] ath11k: Replace one-element array with flexible-array member Gustavo A. R. Silva
2021-09-12 19:42   ` Gustavo A. R. Silva
2021-09-14  5:53     ` Kalle Valo

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