From: Abhishek Kumar kuabhs@chromium.org
[ Upstream commit b72a4aff947ba807177bdabb43debaf2c66bee05 ]
Double free crash is observed when FW recovery(caused by wmi timeout/crash) is followed by immediate suspend event. The FW recovery is triggered by ath10k_core_restart() which calls driver clean up via ath10k_halt(). When the suspend event occurs between the FW recovery, the restart worker thread is put into frozen state until suspend completes. The suspend event triggers ath10k_stop() which again triggers ath10k_halt() The double invocation of ath10k_halt() causes ath10k_htt_rx_free() to be called twice(Note: ath10k_htt_rx_alloc was not called by restart worker thread because of its frozen state), causing the crash.
To fix this, during the suspend flow, skip call to ath10k_halt() in ath10k_stop() when the current driver state is ATH10K_STATE_RESTARTING. Also, for driver state ATH10K_STATE_RESTARTING, call ath10k_wait_for_suspend() in ath10k_stop(). This is because call to ath10k_wait_for_suspend() is skipped later in [ath10k_halt() > ath10k_core_stop()] for the driver state ATH10K_STATE_RESTARTING.
The frozen restart worker thread will be cancelled during resume when the device comes out of suspend.
Below is the crash stack for reference:
[ 428.469167] ------------[ cut here ]------------ [ 428.469180] kernel BUG at mm/slub.c:4150! [ 428.469193] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 428.469219] Workqueue: events_unbound async_run_entry_fn [ 428.469230] RIP: 0010:kfree+0x319/0x31b [ 428.469241] RSP: 0018:ffffa1fac015fc30 EFLAGS: 00010246 [ 428.469247] RAX: ffffedb10419d108 RBX: ffff8c05262b0000 [ 428.469252] RDX: ffff8c04a8c07000 RSI: 0000000000000000 [ 428.469256] RBP: ffffa1fac015fc78 R08: 0000000000000000 [ 428.469276] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 428.469285] Call Trace: [ 428.469295] ? dma_free_attrs+0x5f/0x7d [ 428.469320] ath10k_core_stop+0x5b/0x6f [ 428.469336] ath10k_halt+0x126/0x177 [ 428.469352] ath10k_stop+0x41/0x7e [ 428.469387] drv_stop+0x88/0x10e [ 428.469410] __ieee80211_suspend+0x297/0x411 [ 428.469441] rdev_suspend+0x6e/0xd0 [ 428.469462] wiphy_suspend+0xb1/0x105 [ 428.469483] ? name_show+0x2d/0x2d [ 428.469490] dpm_run_callback+0x8c/0x126 [ 428.469511] ? name_show+0x2d/0x2d [ 428.469517] __device_suspend+0x2e7/0x41b [ 428.469523] async_suspend+0x1f/0x93 [ 428.469529] async_run_entry_fn+0x3d/0xd1 [ 428.469535] process_one_work+0x1b1/0x329 [ 428.469541] worker_thread+0x213/0x372 [ 428.469547] kthread+0x150/0x15f [ 428.469552] ? pr_cont_work+0x58/0x58 [ 428.469558] ? kthread_blkcg+0x31/0x31
Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00288-QCARMSWPZ-1 Co-developed-by: Wen Gong quic_wgong@quicinc.com Signed-off-by: Wen Gong quic_wgong@quicinc.com Signed-off-by: Abhishek Kumar kuabhs@chromium.org Reviewed-by: Brian Norris briannorris@chromium.org Signed-off-by: Kalle Valo quic_kvalo@quicinc.com Link: https://lore.kernel.org/r/20220426221859.v2.1.I650b809482e1af8d0156ed88b5dc2... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/ath/ath10k/mac.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index b59d482d9c23..b61cd275fbda 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -5170,13 +5170,29 @@ static int ath10k_start(struct ieee80211_hw *hw) static void ath10k_stop(struct ieee80211_hw *hw) { struct ath10k *ar = hw->priv; + u32 opt;
ath10k_drain_tx(ar);
mutex_lock(&ar->conf_mutex); if (ar->state != ATH10K_STATE_OFF) { - if (!ar->hw_rfkill_on) - ath10k_halt(ar); + if (!ar->hw_rfkill_on) { + /* If the current driver state is RESTARTING but not yet + * fully RESTARTED because of incoming suspend event, + * then ath10k_halt() is already called via + * ath10k_core_restart() and should not be called here. + */ + if (ar->state != ATH10K_STATE_RESTARTING) { + ath10k_halt(ar); + } else { + /* Suspending here, because when in RESTARTING + * state, ath10k_core_stop() skips + * ath10k_wait_for_suspend(). + */ + opt = WMI_PDEV_SUSPEND_AND_DISABLE_INTR; + ath10k_wait_for_suspend(ar, opt); + } + } ar->state = ATH10K_STATE_OFF; } mutex_unlock(&ar->conf_mutex);