From 0d6526f82c3cdefcca47f73f5fc08dc6f335eac6 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:22 -0700 Subject: sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug alb_break_llc() decides whether to break LLC preference during active load balance. It does so by testing that every runnable fair task on the source rq prefers its LLC: env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable But the two counters cover different sets. nr_pref_llc_running is updated in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued, so it follows queued tasks. h_nr_runnable is updated in set_delayed()/ clear_delayed() and drops delay-dequeued tasks. So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks, alb_break_llc() returns false, and active balance is free to pull a task off its preferred LLC. Active balance only moves runnable tasks, and this is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB skips the per-task test in can_migrate_task(). The runnable set is the one we want. Fix it on the counter side. A task should be counted in nr_pref_llc_running exactly while it is both queued on its preferred LLC (pref_llc_queued) and runnable (!sched_delayed). Define that membership once in task_pref_llc_runnable(), and adjust the counter only through pref_llc_running_inc()/pref_llc_running_dec() from the four sites that change either input: account_llc_enqueue(), account_llc_dequeue(), set_delayed() and clear_delayed(). Gating every update on the same predicate keeps the delay, wake and dequeue paths from double-counting or underflowing; see the comments at those sites for the ordering. nr_llc_running and sd->llc_counts are not touched and stay on queued semantics. Fixes: 714059f79ff0 ("sched/cache: Handle moving single tasks to/from their preferred LLC") Closes: https://lore.kernel.org/lkml/20260827135000.735138-1-zhanxusheng@xiaomi.com/ Reported-by: Zhan Xusheng Suggested-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Kayra Cizmeci Cc: # v7.2.x Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com --- net/mac80211/key.h | 175 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 net/mac80211/key.h (limited to 'net/mac80211/key.h') diff --git a/net/mac80211/key.h b/net/mac80211/key.h new file mode 100644 index 000000000..826e4e938 --- /dev/null +++ b/net/mac80211/key.h @@ -0,0 +1,175 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2002-2004, Instant802 Networks, Inc. + * Copyright 2005, Devicescape Software, Inc. + * Copyright (C) 2019, 2022-2023 Intel Corporation + */ + +#ifndef IEEE80211_KEY_H +#define IEEE80211_KEY_H + +#include +#include +#include +#include +#include +#include +#include + +#define NUM_DEFAULT_KEYS 4 +#define NUM_DEFAULT_MGMT_KEYS 2 +#define NUM_DEFAULT_BEACON_KEYS 2 +#define INVALID_PTK_KEYIDX 2 /* Keyidx always pointing to a NULL key for PTK */ + +struct ieee80211_local; +struct ieee80211_sub_if_data; +struct ieee80211_link_data; +struct sta_info; + +/** + * enum ieee80211_internal_key_flags - internal key flags + * + * @KEY_FLAG_UPLOADED_TO_HARDWARE: Indicates that this key is present + * in the hardware for TX crypto hardware acceleration. + * @KEY_FLAG_TAINTED: Key is tainted and packets should be dropped. + */ +enum ieee80211_internal_key_flags { + KEY_FLAG_UPLOADED_TO_HARDWARE = BIT(0), + KEY_FLAG_TAINTED = BIT(1), +}; + +enum ieee80211_internal_tkip_state { + TKIP_STATE_NOT_INIT, + TKIP_STATE_PHASE1_DONE, + TKIP_STATE_PHASE1_HW_UPLOADED, +}; + +struct tkip_ctx { + u16 p1k[5]; /* p1k cache */ + u32 p1k_iv32; /* iv32 for which p1k computed */ + enum ieee80211_internal_tkip_state state; +}; + +struct tkip_ctx_rx { + struct tkip_ctx ctx; + u32 iv32; /* current iv32 */ + u16 iv16; /* current iv16 */ +}; + +struct ieee80211_key { + struct ieee80211_local *local; + struct ieee80211_sub_if_data *sdata; + struct sta_info *sta; + + /* for sdata list */ + struct list_head list; + + /* protected by key mutex */ + unsigned int flags; + + union { + struct { + /* protects tx context */ + spinlock_t txlock; + + /* last used TSC */ + struct tkip_ctx tx; + + /* last received RSC */ + struct tkip_ctx_rx rx[IEEE80211_NUM_TIDS]; + + /* number of mic failures */ + u32 mic_failures; + } tkip; + struct { + /* + * Last received packet number. The first + * IEEE80211_NUM_TIDS counters are used with Data + * frames and the last counter is used with Robust + * Management frames. + */ + u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_CCMP_PN_LEN]; + struct crypto_aead *tfm; + u32 replays; /* dot11RSNAStatsCCMPReplays */ + } ccmp; + struct { + u8 rx_pn[IEEE80211_CMAC_PN_LEN]; + struct aes_cmac_key key; + u32 replays; /* dot11RSNAStatsCMACReplays */ + u32 icverrors; /* dot11RSNAStatsCMACICVErrors */ + } aes_cmac; + struct { + u8 rx_pn[IEEE80211_GMAC_PN_LEN]; + struct crypto_aead *tfm; + u32 replays; /* dot11RSNAStatsCMACReplays */ + u32 icverrors; /* dot11RSNAStatsCMACICVErrors */ + } aes_gmac; + struct { + /* Last received packet number. The first + * IEEE80211_NUM_TIDS counters are used with Data + * frames and the last counter is used with Robust + * Management frames. + */ + u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_GCMP_PN_LEN]; + struct crypto_aead *tfm; + u32 replays; /* dot11RSNAStatsGCMPReplays */ + } gcmp; + struct { + /* generic cipher scheme */ + u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_MAX_PN_LEN]; + } gen; + } u; + +#ifdef CONFIG_MAC80211_DEBUGFS + struct { + struct dentry *stalink; + struct dentry *dir; + int cnt; + } debugfs; +#endif + + unsigned int color; + + /* + * key config, must be last because it contains key + * material as variable length member + */ + struct ieee80211_key_conf conf; +}; + +struct ieee80211_key * +ieee80211_key_alloc(u32 cipher, int idx, size_t key_len, + const u8 *key_data, + size_t seq_len, const u8 *seq); +/* + * Insert a key into data structures (sdata, sta if necessary) + * to make it used, free old key. On failure, also free the new key. + */ +int ieee80211_key_link(struct ieee80211_key *key, + struct ieee80211_link_data *link, + struct sta_info *sta); +int ieee80211_set_tx_key(struct ieee80211_key *key); +void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom); +void ieee80211_key_free_unused(struct ieee80211_key *key); +void ieee80211_set_default_key(struct ieee80211_link_data *link, int idx, + bool uni, bool multi); +void ieee80211_set_default_mgmt_key(struct ieee80211_link_data *link, + int idx); +void ieee80211_set_default_beacon_key(struct ieee80211_link_data *link, + int idx); +void ieee80211_remove_link_keys(struct ieee80211_link_data *link, + struct list_head *keys); +void ieee80211_free_key_list(struct ieee80211_local *local, + struct list_head *keys); +void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata, + bool force_synchronize); +void ieee80211_free_sta_keys(struct ieee80211_local *local, + struct sta_info *sta); +void ieee80211_reenable_keys(struct ieee80211_sub_if_data *sdata); +int ieee80211_key_switch_links(struct ieee80211_sub_if_data *sdata, + unsigned long del_links_mask, + unsigned long add_links_mask); +void ieee80211_delayed_tailroom_dec(struct wiphy *wiphy, + struct wiphy_work *wk); + +#endif /* IEEE80211_KEY_H */ -- cgit v1.3.1