[1/1] sta_info: fix insane values in iw sta dump "inactive time"

Commit Message

Ahmed Zaki Oct. 30, 2019, 9:31 p.m. UTC

In the first 5 mins after boot (initial jiffies),
ieee80211_sta_last_active() returns zero in case last_ack is zero. This
leads to insane values appearing in "inactive time".

Fix by returning last_rx if last_ack == 0.
---
 net/mac80211/sta_info.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Johannes Berg Oct. 31, 2019, 8:11 a.m. UTC | #1

On Wed, 2019-10-30 at 15:31 -0600, Ahmed Zaki wrote:
> In the first 5 mins after boot (initial jiffies),
> ieee80211_sta_last_active() returns zero in case last_ack is zero. This
> leads to insane values appearing in "inactive time".
> 
> Fix by returning last_rx if last_ack == 0.

Please read

https://wireless.wiki.kernel.org/en/developers/Documentation/SubmittingPatches

johannes

Patch

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index bd11fef2139f..428866ff7c0a 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2457,7 +2457,8 @@  unsigned long ieee80211_sta_last_active(struct sta_info *sta)
 {
 	struct ieee80211_sta_rx_stats *stats = sta_get_last_rx_stats(sta);
 
-	if (time_after(stats->last_rx, sta->status_stats.last_ack))
+	if (!sta->status_stats.last_ack ||
+		time_after(stats->last_rx, sta->status_stats.last_ack))
 		return stats->last_rx;
 	return sta->status_stats.last_ack;
 }