wifi: ath11k: fix ath11k_mac_op_remain_on_channel() stack usage

When compiling with clang 16.0.6, I've noticed the following:

drivers/net/wireless/ath/ath11k/mac.c:8903:12: warning: stack frame
size (1032) exceeds limit (1024) in 'ath11k_mac_op_remain_on_channel'
[-Wframe-larger-than]
static int ath11k_mac_op_remain_on_channel(struct ieee80211_hw *hw,
           ^
68/1032 (6.59%) spills, 964/1032 (93.41%) variables

So switch to kzalloc()'ed instance of 'struct scan_req_params' like
it's done in 'ath11k_mac_op_hw_scan()'. Compile tested only.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230926042906.13725-1-dmantipov@yandex.ru

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 39f673aa4b00659b992cfcf73ad5a38772d44ab6..9ce3b575d9cc0481014064ad6a9b977de0edab64 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -8905,7 +8905,7 @@ static int ath11k_mac_op_remain_on_channel(struct ieee80211_hw *hw,
 {
        struct ath11k *ar = hw->priv;
        struct ath11k_vif *arvif = ath11k_vif_to_arvif(vif);
-       struct scan_req_params arg;
+       struct scan_req_params *arg;
        int ret;
        u32 scan_time_msec;
 
@@ -8937,27 +8937,31 @@ static int ath11k_mac_op_remain_on_channel(struct ieee80211_hw *hw,
 
        scan_time_msec = ar->hw->wiphy->max_remain_on_channel_duration * 2;
 
-       memset(&arg, 0, sizeof(arg));
-       ath11k_wmi_start_scan_init(ar, &arg);
-       arg.num_chan = 1;
-       arg.chan_list = kcalloc(arg.num_chan, sizeof(*arg.chan_list),
-                               GFP_KERNEL);
-       if (!arg.chan_list) {
+       arg = kzalloc(sizeof(*arg), GFP_KERNEL);
+       if (!arg) {
                ret = -ENOMEM;
                goto exit;
        }
+       ath11k_wmi_start_scan_init(ar, arg);
+       arg->num_chan = 1;
+       arg->chan_list = kcalloc(arg->num_chan, sizeof(*arg->chan_list),
+                                GFP_KERNEL);
+       if (!arg->chan_list) {
+               ret = -ENOMEM;
+               goto free_arg;
+       }
 
-       arg.vdev_id = arvif->vdev_id;
-       arg.scan_id = ATH11K_SCAN_ID;
-       arg.chan_list[0] = chan->center_freq;
-       arg.dwell_time_active = scan_time_msec;
-       arg.dwell_time_passive = scan_time_msec;
-       arg.max_scan_time = scan_time_msec;
-       arg.scan_flags |= WMI_SCAN_FLAG_PASSIVE;
-       arg.scan_flags |= WMI_SCAN_FILTER_PROBE_REQ;
-       arg.burst_duration = duration;
-
-       ret = ath11k_start_scan(ar, &arg);
+       arg->vdev_id = arvif->vdev_id;
+       arg->scan_id = ATH11K_SCAN_ID;
+       arg->chan_list[0] = chan->center_freq;
+       arg->dwell_time_active = scan_time_msec;
+       arg->dwell_time_passive = scan_time_msec;
+       arg->max_scan_time = scan_time_msec;
+       arg->scan_flags |= WMI_SCAN_FLAG_PASSIVE;
+       arg->scan_flags |= WMI_SCAN_FILTER_PROBE_REQ;
+       arg->burst_duration = duration;
+
+       ret = ath11k_start_scan(ar, arg);
        if (ret) {
                ath11k_warn(ar->ab, "failed to start roc scan: %d\n", ret);
 
@@ -8983,7 +8987,9 @@ static int ath11k_mac_op_remain_on_channel(struct ieee80211_hw *hw,
        ret = 0;
 
 free_chan_list:
-       kfree(arg.chan_list);
+       kfree(arg->chan_list);
+free_arg:
+       kfree(arg);
 exit:
        mutex_unlock(&ar->conf_mutex);
        return ret;