mac80211: fix last RX rate data consistency
When storing the last_rate_* values in the RX code, there's nothing
to guarantee consistency, so a concurrent reader could see, e.g.
last_rate_idx on the new value, but last_rate_flag still on the old,
getting completely bogus values in the end.
To fix this, I lifted the sta_stats_encode_rate() function from my
old rate statistics code, which encodes the entire rate data into a
single 16-bit value, avoiding the consistency issue.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index ac73b9c..0b50ae3 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1928,43 +1928,47 @@
>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
}
-static void sta_set_rate_info_rx(struct sta_info *sta, struct rate_info *rinfo)
+static void sta_stats_decode_rate(struct ieee80211_local *local, u16 rate,
+ struct rate_info *rinfo)
{
- rinfo->flags = 0;
+ rinfo->bw = (rate & STA_STATS_RATE_BW_MASK) >>
+ STA_STATS_RATE_BW_SHIFT;
- if (sta->rx_stats.last_rate_flag & RX_FLAG_HT) {
- rinfo->flags |= RATE_INFO_FLAGS_MCS;
- rinfo->mcs = sta->rx_stats.last_rate_idx;
- } else if (sta->rx_stats.last_rate_flag & RX_FLAG_VHT) {
- rinfo->flags |= RATE_INFO_FLAGS_VHT_MCS;
- rinfo->nss = sta->rx_stats.last_rate_vht_nss;
- rinfo->mcs = sta->rx_stats.last_rate_idx;
- } else {
+ if (rate & STA_STATS_RATE_VHT) {
+ rinfo->flags = RATE_INFO_FLAGS_VHT_MCS;
+ rinfo->mcs = rate & 0xf;
+ rinfo->nss = (rate & 0xf0) >> 4;
+ } else if (rate & STA_STATS_RATE_HT) {
+ rinfo->flags = RATE_INFO_FLAGS_MCS;
+ rinfo->mcs = rate & 0xff;
+ } else if (rate & STA_STATS_RATE_LEGACY) {
struct ieee80211_supported_band *sband;
- int shift = ieee80211_vif_get_shift(&sta->sdata->vif);
u16 brate;
+ unsigned int shift;
- sband = sta->local->hw.wiphy->bands[
- ieee80211_get_sdata_band(sta->sdata)];
- brate = sband->bitrates[sta->rx_stats.last_rate_idx].bitrate;
+ sband = local->hw.wiphy->bands[(rate >> 4) & 0xf];
+ brate = sband->bitrates[rate & 0xf].bitrate;
+ if (rinfo->bw == RATE_INFO_BW_5)
+ shift = 2;
+ else if (rinfo->bw == RATE_INFO_BW_10)
+ shift = 1;
+ else
+ shift = 0;
rinfo->legacy = DIV_ROUND_UP(brate, 1 << shift);
}
- if (sta->rx_stats.last_rate_flag & RX_FLAG_SHORT_GI)
+ if (rate & STA_STATS_RATE_SGI)
rinfo->flags |= RATE_INFO_FLAGS_SHORT_GI;
+}
- if (sta->rx_stats.last_rate_flag & RX_FLAG_5MHZ)
- rinfo->bw = RATE_INFO_BW_5;
- else if (sta->rx_stats.last_rate_flag & RX_FLAG_10MHZ)
- rinfo->bw = RATE_INFO_BW_10;
- else if (sta->rx_stats.last_rate_flag & RX_FLAG_40MHZ)
- rinfo->bw = RATE_INFO_BW_40;
- else if (sta->rx_stats.last_rate_vht_flag & RX_VHT_FLAG_80MHZ)
- rinfo->bw = RATE_INFO_BW_80;
- else if (sta->rx_stats.last_rate_vht_flag & RX_VHT_FLAG_160MHZ)
- rinfo->bw = RATE_INFO_BW_160;
+static void sta_set_rate_info_rx(struct sta_info *sta, struct rate_info *rinfo)
+{
+ u16 rate = ACCESS_ONCE(sta->rx_stats.last_rate);
+
+ if (rate == STA_STATS_RATE_INVALID)
+ rinfo->flags = 0;
else
- rinfo->bw = RATE_INFO_BW_20;
+ sta_stats_decode_rate(sta->local, rate, rinfo);
}
void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)