From 068a4633bf42501db3ec934beff07cd50c1b7e9d Mon Sep 17 00:00:00 2001 From: Vasanthakumar Thiagarajan Date: Tue, 6 Mar 2012 14:39:40 +0530 Subject: [PATCH] ath6kl: Fix kernel panic while receiving fwlog during boot "ath6kl: Defer wiphy and netdev registration till the end of ath6kl_core_init()" causes kernel panic by accessing the unallocated debug resources during boot time. To fix this, split the debug initialization funtion into two, one initializes the debug resource and the other takes care of debugfs initialization. When this issue shows up the kernel crash dump would look like ath6kl_debug_fwlog_event+0x9c/0x10a [] register_lock_class+0x57/0x288 [] ? trace_hardirqs_on+0xb/0xd [] ? ath6kl_debug_fwlog_event+0x9c/0x10a [] __lock_acquire+0x96/0xbe5 [] ? alarmtimer_suspend+0x80/0x127 [] ? vprintk+0x394/0x3b1 [] ? ath6kl_debug_fwlog_event+0x9c/0x10a [] lock_acquire+0xda/0xf9 [] ? ath6kl_debug_fwlog_event+0x9c/0x10a [] _raw_spin_lock+0x28/0x58 [] ? ath6kl_debug_fwlog_event+0x9c/0x10a [] ath6kl_debug_fwlog_event+0x9c/0x10a [] ath6kl_wmi_control_rx+0x69d/0xb50 [ath6kl_core] [] ? ath6kl_rx+0x3c/0x839 [ath6kl_core] [] ath6kl_rx+0xb8/0x839 [ath6kl_core] [] ? local_clock+0x2d/0x4e [] ? _local_bh_enable_ip+0x94/0x98 [] ? ath6kl_alloc_amsdu_rxbuf+0xb7/0xb7 [] ath6kl_htc_rxmsg_pending_handler+0x891/0x988 [ath6kl_core] [] ? ath6kl_refill_amsdu_rxbufs+0x89/0x92 [] ? aggr_timeout+0xed/0xed [ath6kl_core] [] ? ath6kl_alloc_amsdu_rxbuf+0xb7/0xb7 [] ? ath6kl_tx_complete+0x376/0x376 [ath6kl_core] [] ath6kl_hif_intr_bh_handler+0xf7/0x33e [] ? mmc_host_disable+0x15/0x3a [] ath6kl_sdio_irq_handler+0x3c/0x90 [ath6kl_sdio] [] sdio_irq_thread+0xb6/0x29c [] ? sdio_claim_irq+0x1cb/0x1cb [] kthread+0x67/0x6c [] ? __init_kthread_worker+0x42/0x42 [] kernel_thread_helper+0x6/0xd BUG: unable to handle kernel NULL pointer dereference at EIP: [] ath6kl_debug_fwlog_event+0xa7/0x10a kvalo: rename new function to ath6kl_debug_init_fs() and add a comment why it's needed Reported-by: Kalle Valo Signed-off-by: Vasanthakumar Thiagarajan Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath6kl/core.c | 9 +++++---- drivers/net/wireless/ath/ath6kl/debug.c | 10 +++++++++- drivers/net/wireless/ath/ath6kl/debug.h | 9 +++++++-- 3 files changed, 21 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/ath/ath6kl/core.c b/drivers/net/wireless/ath/ath6kl/core.c index e66cf4399b61..84dd9786622f 100644 --- a/drivers/net/wireless/ath/ath6kl/core.c +++ b/drivers/net/wireless/ath/ath6kl/core.c @@ -124,6 +124,8 @@ int ath6kl_core_init(struct ath6kl *ar) set_bit(FIRST_BOOT, &ar->flag); + ath6kl_debug_init(ar); + ret = ath6kl_init_hw_start(ar); if (ret) { ath6kl_err("Failed to start hardware: %d\n", ret); @@ -138,7 +140,7 @@ int ath6kl_core_init(struct ath6kl *ar) if (ret) goto err_rxbuf_cleanup; - ret = ath6kl_debug_init(ar); + ret = ath6kl_debug_init_fs(ar); if (ret) { wiphy_unregister(ar->wiphy); goto err_rxbuf_cleanup; @@ -159,7 +161,7 @@ int ath6kl_core_init(struct ath6kl *ar) ath6kl_err("Failed to instantiate a network device\n"); ret = -ENOMEM; wiphy_unregister(ar->wiphy); - goto err_debug_init; + goto err_rxbuf_cleanup; } ath6kl_dbg(ATH6KL_DBG_TRC, "%s: name=%s dev=0x%p, ar=0x%p\n", @@ -167,9 +169,8 @@ int ath6kl_core_init(struct ath6kl *ar) return ret; -err_debug_init: - ath6kl_debug_cleanup(ar); err_rxbuf_cleanup: + ath6kl_debug_cleanup(ar); ath6kl_htc_flush_rx_buf(ar->htc_target); ath6kl_cleanup_amsdu_rxbufs(ar); ath6kl_wmi_shutdown(ar->wmi); diff --git a/drivers/net/wireless/ath/ath6kl/debug.c b/drivers/net/wireless/ath/ath6kl/debug.c index 28b516ff3d59..645f923f79b5 100755 --- a/drivers/net/wireless/ath/ath6kl/debug.c +++ b/drivers/net/wireless/ath/ath6kl/debug.c @@ -1722,7 +1722,7 @@ static const struct file_operations fops_power_params = { .llseek = default_llseek, }; -int ath6kl_debug_init(struct ath6kl *ar) +void ath6kl_debug_init(struct ath6kl *ar) { skb_queue_head_init(&ar->debug.fwlog_queue); init_completion(&ar->debug.fwlog_completion); @@ -1732,7 +1732,15 @@ int ath6kl_debug_init(struct ath6kl *ar) * value from the firmware. */ ar->debug.fwlog_mask = 0; +} +/* + * Initialisation needs to happen in two stages as fwlog events can come + * before cfg80211 is initialised, and debugfs depends on cfg80211 + * initialisation. + */ +int ath6kl_debug_init_fs(struct ath6kl *ar) +{ ar->debugfs_phy = debugfs_create_dir("ath6kl", ar->wiphy->debugfsdir); if (!ar->debugfs_phy) diff --git a/drivers/net/wireless/ath/ath6kl/debug.h b/drivers/net/wireless/ath/ath6kl/debug.h index c5d5e6c8259e..1803a0baae82 100644 --- a/drivers/net/wireless/ath/ath6kl/debug.h +++ b/drivers/net/wireless/ath/ath6kl/debug.h @@ -78,7 +78,8 @@ int ath6kl_debug_roam_tbl_event(struct ath6kl *ar, const void *buf, size_t len); void ath6kl_debug_set_keepalive(struct ath6kl *ar, u8 keepalive); void ath6kl_debug_set_disconnect_timeout(struct ath6kl *ar, u8 timeout); -int ath6kl_debug_init(struct ath6kl *ar); +void ath6kl_debug_init(struct ath6kl *ar); +int ath6kl_debug_init_fs(struct ath6kl *ar); void ath6kl_debug_cleanup(struct ath6kl *ar); #else @@ -128,7 +129,11 @@ static inline void ath6kl_debug_set_disconnect_timeout(struct ath6kl *ar, { } -static inline int ath6kl_debug_init(struct ath6kl *ar) +static inline void ath6kl_debug_init(struct ath6kl *ar) +{ +} + +static inline int ath6kl_debug_init_fs(struct ath6kl *ar) { return 0; }