| Message ID | 20230609093744.1985-1-repk@triplefau.lt |
|---|---|
| State | New |
| Headers | show |
| Series | ath9k: Fix possible stall on ath9k_txq_list_has_key() | expand |
On Fri Jun 9, 2023 at 11:37 AM CEST, Remi Pommarel wrote: > On EDMA capable hardware, ath9k_txq_list_has_key() can enter infinite > loop if it is called while all txq_fifos have packets that use different > key that the one we are looking for. Fix it by exiting the loop if all > txq_fifos have been checked already. > > Because this loop is called under spin_lock_bh() (see ath_txq_lock) it > causes the following rcu stall: > > rcu: INFO: rcu_sched self-detected stall on CPU > ath10k_pci 0000:01:00.0: failed to read temperature -11 > rcu: 1-....: (5254 ticks this GP) idle=189/1/0x4000000000000002 softirq=8442983/8442984 fqs=2579 > (t=5257 jiffies g=17983297 q=334) > Task dump for CPU 1: > task:hostapd state:R running task stack: 0 pid: 297 ppid: 289 flags:0x0000000a > Call trace: > dump_backtrace+0x0/0x170 > show_stack+0x1c/0x24 > sched_show_task+0x140/0x170 > dump_cpu_task+0x48/0x54 > rcu_dump_cpu_stacks+0xf0/0x134 > rcu_sched_clock_irq+0x8d8/0x9fc > update_process_times+0xa0/0xec > tick_sched_timer+0x5c/0xd0 > __hrtimer_run_queues+0x154/0x320 > hrtimer_interrupt+0x120/0x2f0 > arch_timer_handler_virt+0x38/0x44 > handle_percpu_devid_irq+0x9c/0x1e0 > handle_domain_irq+0x64/0x90 > gic_handle_irq+0x78/0xb0 > call_on_irq_stack+0x28/0x38 > do_interrupt_handler+0x54/0x5c > el1_interrupt+0x2c/0x4c > el1h_64_irq_handler+0x14/0x1c > el1h_64_irq+0x74/0x78 > ath9k_txq_has_key+0x1bc/0x250 [ath9k] > ath9k_set_key+0x1cc/0x3dc [ath9k] > drv_set_key+0x78/0x170 > ieee80211_key_replace+0x564/0x6cc > ieee80211_key_link+0x174/0x220 > ieee80211_add_key+0x11c/0x300 > nl80211_new_key+0x12c/0x330 > genl_family_rcv_msg_doit+0xbc/0x11c > genl_rcv_msg+0xd8/0x1c4 > netlink_rcv_skb+0x40/0x100 > genl_rcv+0x3c/0x50 > netlink_unicast+0x1ec/0x2c0 > netlink_sendmsg+0x198/0x3c0 > ____sys_sendmsg+0x210/0x250 > ___sys_sendmsg+0x78/0xc4 > __sys_sendmsg+0x4c/0x90 > __arm64_sys_sendmsg+0x28/0x30 > invoke_syscall.constprop.0+0x60/0x100 > do_el0_svc+0x48/0xd0 > el0_svc+0x14/0x50 > el0t_64_sync_handler+0xa8/0xb0 > el0t_64_sync+0x158/0x15c > > This rcu stall is hard to reproduce as is, but changing ATH_TXFIFO_DEPTH > from 8 to 2 makes it reasonably easy to reproduce. > > Fixes: ca2848022c12 ("ath9k: Postpone key cache entry deletion for TXQ frames reference it") > Signed-off-by: Remi Pommarel <repk@triplefau.lt> > --- > drivers/net/wireless/ath/ath9k/main.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c > index a4197c14f0a9..7f9f06ea8a05 100644 > --- a/drivers/net/wireless/ath/ath9k/main.c > +++ b/drivers/net/wireless/ath/ath9k/main.c > @@ -850,7 +850,7 @@ static bool ath9k_txq_list_has_key(struct list_head *txq_list, u32 keyix) > static bool ath9k_txq_has_key(struct ath_softc *sc, u32 keyix) > { > struct ath_hw *ah = sc->sc_ah; > - int i; > + int i, j; > struct ath_txq *txq; > bool key_in_use = false; > > @@ -868,8 +868,9 @@ static bool ath9k_txq_has_key(struct ath_softc *sc, u32 keyix) > if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) { > int idx = txq->txq_tailidx; > > - while (!key_in_use && > - !list_empty(&txq->txq_fifo[idx])) { > + for (j = 0; !key_in_use && > + !list_empty(&txq->txq_fifo[idx]) && > + j < ATH_TXFIFO_DEPTH; j++) { > key_in_use = ath9k_txq_list_has_key( > &txq->txq_fifo[idx], keyix); > INCR(idx, ATH_TXFIFO_DEPTH); Works with AR9392 (Qualcomm Atheros AR93xx Wireless Network Adapter (rev 01)) Tested-by: Nicolas Escande <nico.escande@gmail.com> --- Nicolas E.
Remi Pommarel <repk@triplefau.lt> writes: > On EDMA capable hardware, ath9k_txq_list_has_key() can enter infinite > loop if it is called while all txq_fifos have packets that use different > key that the one we are looking for. Fix it by exiting the loop if all > txq_fifos have been checked already. > > Because this loop is called under spin_lock_bh() (see ath_txq_lock) it > causes the following rcu stall: > > rcu: INFO: rcu_sched self-detected stall on CPU > ath10k_pci 0000:01:00.0: failed to read temperature -11 > rcu: 1-....: (5254 ticks this GP) idle=189/1/0x4000000000000002 softirq=8442983/8442984 fqs=2579 > (t=5257 jiffies g=17983297 q=334) > Task dump for CPU 1: > task:hostapd state:R running task stack: 0 pid: 297 ppid: 289 flags:0x0000000a > Call trace: > dump_backtrace+0x0/0x170 > show_stack+0x1c/0x24 > sched_show_task+0x140/0x170 > dump_cpu_task+0x48/0x54 > rcu_dump_cpu_stacks+0xf0/0x134 > rcu_sched_clock_irq+0x8d8/0x9fc > update_process_times+0xa0/0xec > tick_sched_timer+0x5c/0xd0 > __hrtimer_run_queues+0x154/0x320 > hrtimer_interrupt+0x120/0x2f0 > arch_timer_handler_virt+0x38/0x44 > handle_percpu_devid_irq+0x9c/0x1e0 > handle_domain_irq+0x64/0x90 > gic_handle_irq+0x78/0xb0 > call_on_irq_stack+0x28/0x38 > do_interrupt_handler+0x54/0x5c > el1_interrupt+0x2c/0x4c > el1h_64_irq_handler+0x14/0x1c > el1h_64_irq+0x74/0x78 > ath9k_txq_has_key+0x1bc/0x250 [ath9k] > ath9k_set_key+0x1cc/0x3dc [ath9k] > drv_set_key+0x78/0x170 > ieee80211_key_replace+0x564/0x6cc > ieee80211_key_link+0x174/0x220 > ieee80211_add_key+0x11c/0x300 > nl80211_new_key+0x12c/0x330 > genl_family_rcv_msg_doit+0xbc/0x11c > genl_rcv_msg+0xd8/0x1c4 > netlink_rcv_skb+0x40/0x100 > genl_rcv+0x3c/0x50 > netlink_unicast+0x1ec/0x2c0 > netlink_sendmsg+0x198/0x3c0 > ____sys_sendmsg+0x210/0x250 > ___sys_sendmsg+0x78/0xc4 > __sys_sendmsg+0x4c/0x90 > __arm64_sys_sendmsg+0x28/0x30 > invoke_syscall.constprop.0+0x60/0x100 > do_el0_svc+0x48/0xd0 > el0_svc+0x14/0x50 > el0t_64_sync_handler+0xa8/0xb0 > el0t_64_sync+0x158/0x15c > > This rcu stall is hard to reproduce as is, but changing ATH_TXFIFO_DEPTH > from 8 to 2 makes it reasonably easy to reproduce. > > Fixes: ca2848022c12 ("ath9k: Postpone key cache entry deletion for TXQ frames reference it") > Signed-off-by: Remi Pommarel <repk@triplefau.lt> Thank you for the fix! Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Remi Pommarel <repk@triplefau.lt> wrote: > On EDMA capable hardware, ath9k_txq_list_has_key() can enter infinite > loop if it is called while all txq_fifos have packets that use different > key that the one we are looking for. Fix it by exiting the loop if all > txq_fifos have been checked already. > > Because this loop is called under spin_lock_bh() (see ath_txq_lock) it > causes the following rcu stall: > > rcu: INFO: rcu_sched self-detected stall on CPU > ath10k_pci 0000:01:00.0: failed to read temperature -11 > rcu: 1-....: (5254 ticks this GP) idle=189/1/0x4000000000000002 softirq=8442983/8442984 fqs=2579 > (t=5257 jiffies g=17983297 q=334) > Task dump for CPU 1: > task:hostapd state:R running task stack: 0 pid: 297 ppid: 289 flags:0x0000000a > Call trace: > dump_backtrace+0x0/0x170 > show_stack+0x1c/0x24 > sched_show_task+0x140/0x170 > dump_cpu_task+0x48/0x54 > rcu_dump_cpu_stacks+0xf0/0x134 > rcu_sched_clock_irq+0x8d8/0x9fc > update_process_times+0xa0/0xec > tick_sched_timer+0x5c/0xd0 > __hrtimer_run_queues+0x154/0x320 > hrtimer_interrupt+0x120/0x2f0 > arch_timer_handler_virt+0x38/0x44 > handle_percpu_devid_irq+0x9c/0x1e0 > handle_domain_irq+0x64/0x90 > gic_handle_irq+0x78/0xb0 > call_on_irq_stack+0x28/0x38 > do_interrupt_handler+0x54/0x5c > el1_interrupt+0x2c/0x4c > el1h_64_irq_handler+0x14/0x1c > el1h_64_irq+0x74/0x78 > ath9k_txq_has_key+0x1bc/0x250 [ath9k] > ath9k_set_key+0x1cc/0x3dc [ath9k] > drv_set_key+0x78/0x170 > ieee80211_key_replace+0x564/0x6cc > ieee80211_key_link+0x174/0x220 > ieee80211_add_key+0x11c/0x300 > nl80211_new_key+0x12c/0x330 > genl_family_rcv_msg_doit+0xbc/0x11c > genl_rcv_msg+0xd8/0x1c4 > netlink_rcv_skb+0x40/0x100 > genl_rcv+0x3c/0x50 > netlink_unicast+0x1ec/0x2c0 > netlink_sendmsg+0x198/0x3c0 > ____sys_sendmsg+0x210/0x250 > ___sys_sendmsg+0x78/0xc4 > __sys_sendmsg+0x4c/0x90 > __arm64_sys_sendmsg+0x28/0x30 > invoke_syscall.constprop.0+0x60/0x100 > do_el0_svc+0x48/0xd0 > el0_svc+0x14/0x50 > el0t_64_sync_handler+0xa8/0xb0 > el0t_64_sync+0x158/0x15c > > This rcu stall is hard to reproduce as is, but changing ATH_TXFIFO_DEPTH > from 8 to 2 makes it reasonably easy to reproduce. > > Fixes: ca2848022c12 ("ath9k: Postpone key cache entry deletion for TXQ frames reference it") > Signed-off-by: Remi Pommarel <repk@triplefau.lt> > Tested-by: Nicolas Escande <nico.escande@gmail.com> > Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> > Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com> Patch applied to ath-next branch of ath.git, thanks. 75086cc6dee0 wifi: ath9k: Fix possible stall on ath9k_txq_list_has_key()
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c index a4197c14f0a9..7f9f06ea8a05 100644 --- a/drivers/net/wireless/ath/ath9k/main.c +++ b/drivers/net/wireless/ath/ath9k/main.c @@ -850,7 +850,7 @@ static bool ath9k_txq_list_has_key(struct list_head *txq_list, u32 keyix) static bool ath9k_txq_has_key(struct ath_softc *sc, u32 keyix) { struct ath_hw *ah = sc->sc_ah; - int i; + int i, j; struct ath_txq *txq; bool key_in_use = false; @@ -868,8 +868,9 @@ static bool ath9k_txq_has_key(struct ath_softc *sc, u32 keyix) if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) { int idx = txq->txq_tailidx; - while (!key_in_use && - !list_empty(&txq->txq_fifo[idx])) { + for (j = 0; !key_in_use && + !list_empty(&txq->txq_fifo[idx]) && + j < ATH_TXFIFO_DEPTH; j++) { key_in_use = ath9k_txq_list_has_key( &txq->txq_fifo[idx], keyix); INCR(idx, ATH_TXFIFO_DEPTH);
On EDMA capable hardware, ath9k_txq_list_has_key() can enter infinite loop if it is called while all txq_fifos have packets that use different key that the one we are looking for. Fix it by exiting the loop if all txq_fifos have been checked already. Because this loop is called under spin_lock_bh() (see ath_txq_lock) it causes the following rcu stall: rcu: INFO: rcu_sched self-detected stall on CPU ath10k_pci 0000:01:00.0: failed to read temperature -11 rcu: 1-....: (5254 ticks this GP) idle=189/1/0x4000000000000002 softirq=8442983/8442984 fqs=2579 (t=5257 jiffies g=17983297 q=334) Task dump for CPU 1: task:hostapd state:R running task stack: 0 pid: 297 ppid: 289 flags:0x0000000a Call trace: dump_backtrace+0x0/0x170 show_stack+0x1c/0x24 sched_show_task+0x140/0x170 dump_cpu_task+0x48/0x54 rcu_dump_cpu_stacks+0xf0/0x134 rcu_sched_clock_irq+0x8d8/0x9fc update_process_times+0xa0/0xec tick_sched_timer+0x5c/0xd0 __hrtimer_run_queues+0x154/0x320 hrtimer_interrupt+0x120/0x2f0 arch_timer_handler_virt+0x38/0x44 handle_percpu_devid_irq+0x9c/0x1e0 handle_domain_irq+0x64/0x90 gic_handle_irq+0x78/0xb0 call_on_irq_stack+0x28/0x38 do_interrupt_handler+0x54/0x5c el1_interrupt+0x2c/0x4c el1h_64_irq_handler+0x14/0x1c el1h_64_irq+0x74/0x78 ath9k_txq_has_key+0x1bc/0x250 [ath9k] ath9k_set_key+0x1cc/0x3dc [ath9k] drv_set_key+0x78/0x170 ieee80211_key_replace+0x564/0x6cc ieee80211_key_link+0x174/0x220 ieee80211_add_key+0x11c/0x300 nl80211_new_key+0x12c/0x330 genl_family_rcv_msg_doit+0xbc/0x11c genl_rcv_msg+0xd8/0x1c4 netlink_rcv_skb+0x40/0x100 genl_rcv+0x3c/0x50 netlink_unicast+0x1ec/0x2c0 netlink_sendmsg+0x198/0x3c0 ____sys_sendmsg+0x210/0x250 ___sys_sendmsg+0x78/0xc4 __sys_sendmsg+0x4c/0x90 __arm64_sys_sendmsg+0x28/0x30 invoke_syscall.constprop.0+0x60/0x100 do_el0_svc+0x48/0xd0 el0_svc+0x14/0x50 el0t_64_sync_handler+0xa8/0xb0 el0t_64_sync+0x158/0x15c This rcu stall is hard to reproduce as is, but changing ATH_TXFIFO_DEPTH from 8 to 2 makes it reasonably easy to reproduce. Fixes: ca2848022c12 ("ath9k: Postpone key cache entry deletion for TXQ frames reference it") Signed-off-by: Remi Pommarel <repk@triplefau.lt> --- drivers/net/wireless/ath/ath9k/main.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)