From d8675a63518c6148827838058feb7f18403faed1 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 17 Jun 2022 22:36:37 +0200 Subject: wifi: mac80211: RCU-ify link/link_conf pointers Since links can be added and removed dynamically, we need to somehow protect the sdata->link[] and vif->link_conf[] array pointers from disappearing when accessing them without locks. RCU-ify the pointers to achieve this, which requires quite a bit of rework. Signed-off-by: Johannes Berg --- net/mac80211/chan.c | 123 ++++++++++++++++++++++++++++------------------------ 1 file changed, 66 insertions(+), 57 deletions(-) (limited to 'net/mac80211/chan.c') diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 6853b563fb6c..8d384956fde5 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -67,14 +67,12 @@ static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local) } static struct ieee80211_chanctx * -ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata, - unsigned int link_id) +ieee80211_link_get_chanctx(struct ieee80211_link_data *link) { - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; - struct ieee80211_local *local __maybe_unused = sdata->local; + struct ieee80211_local *local __maybe_unused = link->sdata->local; struct ieee80211_chanctx_conf *conf; - conf = rcu_dereference_protected(link_conf->chanctx_conf, + conf = rcu_dereference_protected(link->conf->chanctx_conf, lockdep_is_held(&local->chanctx_mtx)); if (!conf) return NULL; @@ -82,12 +80,6 @@ ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata, return container_of(conf, struct ieee80211_chanctx, conf); } -static struct ieee80211_chanctx * -ieee80211_link_get_chanctx(struct ieee80211_link_data *link) -{ - return ieee80211_vif_get_chanctx(link->sdata, link->link_id); -} - static const struct cfg80211_chan_def * ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local, struct ieee80211_chanctx *ctx, @@ -122,8 +114,7 @@ ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local, list_for_each_entry(link, &ctx->assigned_links, assigned_chanctx_list) { - struct ieee80211_bss_conf *link_conf = - link->sdata->vif.link_conf[link->link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; if (link->reserved_chanctx) continue; @@ -254,7 +245,6 @@ ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata, enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT; struct sta_info *sta; - rcu_read_lock(); list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) { if (sdata != sta->sdata && !(sta->sdata->bss && sta->sdata->bss == sdata->bss)) @@ -262,7 +252,6 @@ ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata, max_bw = max(max_bw, ieee80211_get_sta_bw(sta, link_id)); } - rcu_read_unlock(); return max_bw; } @@ -275,10 +264,11 @@ ieee80211_get_chanctx_vif_max_required_bw(struct ieee80211_sub_if_data *sdata, struct ieee80211_vif *vif = &sdata->vif; int link_id; + rcu_read_lock(); for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) { enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT; struct ieee80211_bss_conf *link_conf = - sdata->vif.link_conf[link_id]; + rcu_dereference(sdata->vif.link_conf[link_id]); if (!link_conf) continue; @@ -319,6 +309,7 @@ ieee80211_get_chanctx_vif_max_required_bw(struct ieee80211_sub_if_data *sdata, max_bw = max(max_bw, width); } + rcu_read_unlock(); return max_bw; } @@ -345,7 +336,7 @@ ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local, /* use the configured bandwidth in case of monitor interface */ sdata = rcu_dereference(local->monitor_sdata); if (sdata && - rcu_access_pointer(sdata->vif.link_conf[0]->chanctx_conf) == conf) + rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == conf) max_bw = max(max_bw, conf->def.width); rcu_read_unlock(); @@ -419,7 +410,7 @@ static void ieee80211_chan_bw_change(struct ieee80211_local *local, for (link_id = 0; link_id < ARRAY_SIZE(sta->sdata->link); link_id++) { struct ieee80211_bss_conf *link_conf = - sdata->vif.link_conf[link_id]; + rcu_dereference(sdata->vif.link_conf[link_id]); struct link_sta_info *link_sta; if (!link_conf) @@ -572,8 +563,11 @@ bool ieee80211_is_radar_required(struct ieee80211_local *local) unsigned int link_id; for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) { - if (sdata->link[link_id] && - sdata->link[link_id]->radar_required) { + struct ieee80211_link_data *link; + + link = rcu_dereference(sdata->link[link_id]); + + if (link && link->radar_required) { rcu_read_unlock(); return true; } @@ -602,15 +596,15 @@ ieee80211_chanctx_radar_required(struct ieee80211_local *local, if (!ieee80211_sdata_running(sdata)) continue; for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) { - struct ieee80211_bss_conf *link_conf = - sdata->vif.link_conf[link_id]; + struct ieee80211_link_data *link; - if (!link_conf) + link = rcu_dereference(sdata->link[link_id]); + if (!link) continue; - if (rcu_access_pointer(link_conf->chanctx_conf) != conf) + if (rcu_access_pointer(link->conf->chanctx_conf) != conf) continue; - if (!sdata->link[link_id]->radar_required) + if (!link->radar_required) continue; required = true; break; @@ -774,7 +768,7 @@ void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local, for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) { struct ieee80211_bss_conf *link_conf = - sdata->vif.link_conf[link_id]; + rcu_dereference(sdata->vif.link_conf[link_id]); if (!link_conf) continue; @@ -850,7 +844,7 @@ static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link, if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN)) return -ENOTSUPP; - conf = rcu_dereference_protected(sdata->vif.link_conf[link_id]->chanctx_conf, + conf = rcu_dereference_protected(link->conf->chanctx_conf, lockdep_is_held(&local->chanctx_mtx)); if (conf) { @@ -872,7 +866,7 @@ static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link, } out: - rcu_assign_pointer(sdata->vif.link_conf[link_id]->chanctx_conf, conf); + rcu_assign_pointer(link->conf->chanctx_conf, conf); sdata->vif.cfg.idle = !conf; @@ -931,14 +925,14 @@ void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local, } for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) { - struct ieee80211_link_data *link = sdata->link[link_id]; - struct ieee80211_bss_conf *link_conf = - sdata->vif.link_conf[link_id]; + struct ieee80211_link_data *link; - if (!link_conf) + link = rcu_dereference(sdata->link[link_id]); + + if (!link) continue; - if (rcu_access_pointer(link_conf->chanctx_conf) != &chanctx->conf) + if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf) continue; switch (link->smps_mode) { @@ -968,7 +962,7 @@ void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local, /* Disable SMPS for the monitor interface */ sdata = rcu_dereference(local->monitor_sdata); if (sdata && - rcu_access_pointer(sdata->vif.link_conf[0]->chanctx_conf) == &chanctx->conf) + rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf) rx_chains_dynamic = rx_chains_static = local->rx_chains; rcu_read_unlock(); @@ -998,7 +992,7 @@ __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link, { struct ieee80211_sub_if_data *sdata = link->sdata; unsigned int link_id = link->link_id; - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; struct ieee80211_local *local __maybe_unused = sdata->local; struct ieee80211_sub_if_data *vlan; struct ieee80211_chanctx_conf *conf; @@ -1021,9 +1015,17 @@ __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link, if (clear) conf = NULL; - list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) - rcu_assign_pointer(vlan->vif.link_conf[link_id]->chanctx_conf, - conf); + rcu_read_lock(); + list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) { + struct ieee80211_bss_conf *vlan_conf; + + vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]); + if (WARN_ON(!vlan_conf)) + continue; + + rcu_assign_pointer(vlan_conf->chanctx_conf, conf); + } + rcu_read_unlock(); } void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link, @@ -1210,21 +1212,29 @@ ieee80211_link_update_chandef(struct ieee80211_link_data *link, unsigned int link_id = link->link_id; struct ieee80211_sub_if_data *vlan; - sdata->vif.link_conf[link_id]->chandef = *chandef; + link->conf->chandef = *chandef; if (sdata->vif.type != NL80211_IFTYPE_AP) return; - list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) - vlan->vif.link_conf[link_id]->chandef = *chandef; + rcu_read_lock(); + list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) { + struct ieee80211_bss_conf *vlan_conf; + + vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]); + if (WARN_ON(!vlan_conf)) + continue; + + vlan_conf->chandef = *chandef; + } + rcu_read_unlock(); } static int ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link) { struct ieee80211_sub_if_data *sdata = link->sdata; - unsigned int link_id = link->link_id; - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; struct ieee80211_local *local = sdata->local; struct ieee80211_vif_chanctx_switch vif_chsw[1] = {}; struct ieee80211_chanctx *old_ctx, *new_ctx; @@ -1296,7 +1306,7 @@ ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link) ieee80211_recalc_radar_chanctx(local, new_ctx); if (changed) - ieee80211_link_info_change_notify(sdata, link_id, changed); + ieee80211_link_info_change_notify(sdata, link, changed); out: ieee80211_link_chanctx_reservation_complete(link); @@ -1307,13 +1317,12 @@ static int ieee80211_link_use_reserved_assign(struct ieee80211_link_data *link) { struct ieee80211_sub_if_data *sdata = link->sdata; - unsigned int link_id = link->link_id; struct ieee80211_local *local = sdata->local; struct ieee80211_chanctx *old_ctx, *new_ctx; const struct cfg80211_chan_def *chandef; int err; - old_ctx = ieee80211_vif_get_chanctx(sdata, link_id); + old_ctx = ieee80211_link_get_chanctx(link); new_ctx = link->reserved_chanctx; if (WARN_ON(!link->reserved_ready)) @@ -1625,8 +1634,7 @@ static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local) list_for_each_entry(link, &ctx->reserved_links, reserved_chanctx_list) { struct ieee80211_sub_if_data *sdata = link->sdata; - struct ieee80211_bss_conf *link_conf = - sdata->vif.link_conf[link->link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; u32 changed = 0; if (!ieee80211_link_has_in_place_reservation(link)) @@ -1649,7 +1657,7 @@ static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local) ieee80211_link_update_chandef(link, &link->reserved_chandef); if (changed) ieee80211_link_info_change_notify(sdata, - link->link_id, + link, changed); ieee80211_recalc_txpower(sdata, false); @@ -1746,8 +1754,7 @@ err: static void __ieee80211_link_release_channel(struct ieee80211_link_data *link) { struct ieee80211_sub_if_data *sdata = link->sdata; - unsigned int link_id = link->link_id; - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; struct ieee80211_local *local = sdata->local; struct ieee80211_chanctx_conf *conf; struct ieee80211_chanctx *ctx; @@ -1786,7 +1793,6 @@ int ieee80211_link_use_channel(struct ieee80211_link_data *link, enum ieee80211_chanctx_mode mode) { struct ieee80211_sub_if_data *sdata = link->sdata; - unsigned int link_id = link->link_id; struct ieee80211_local *local = sdata->local; struct ieee80211_chanctx *ctx; u8 radar_detect_width = 0; @@ -1806,7 +1812,7 @@ int ieee80211_link_use_channel(struct ieee80211_link_data *link, if (ret > 0) radar_detect_width = BIT(chandef->width); - sdata->link[link_id]->radar_required = ret; + link->radar_required = ret; ret = ieee80211_check_combinations(sdata, chandef, mode, radar_detect_width); @@ -1910,8 +1916,7 @@ int ieee80211_link_change_bandwidth(struct ieee80211_link_data *link, u32 *changed) { struct ieee80211_sub_if_data *sdata = link->sdata; - unsigned int link_id = link->link_id; - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; struct ieee80211_local *local = sdata->local; struct ieee80211_chanctx_conf *conf; struct ieee80211_chanctx *ctx; @@ -1997,7 +2002,8 @@ void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link) { struct ieee80211_sub_if_data *sdata = link->sdata; unsigned int link_id = link->link_id; - struct ieee80211_bss_conf *link_conf = sdata->vif.link_conf[link_id]; + struct ieee80211_bss_conf *link_conf = link->conf; + struct ieee80211_bss_conf *ap_conf; struct ieee80211_local *local = sdata->local; struct ieee80211_sub_if_data *ap; struct ieee80211_chanctx_conf *conf; @@ -2009,9 +2015,12 @@ void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link) mutex_lock(&local->chanctx_mtx); - conf = rcu_dereference_protected(ap->vif.link_conf[link_id]->chanctx_conf, + rcu_read_lock(); + ap_conf = rcu_dereference(ap->vif.link_conf[link_id]); + conf = rcu_dereference_protected(ap_conf->chanctx_conf, lockdep_is_held(&local->chanctx_mtx)); rcu_assign_pointer(link_conf->chanctx_conf, conf); + rcu_read_unlock(); mutex_unlock(&local->chanctx_mtx); } -- cgit v1.2.3