From: Mohamed Abbas Date: Fri, 28 Mar 2008 23:21:08 +0000 (-0700) Subject: iwlwifi: fix race condition during driver unload X-Git-Tag: v2.6.26-rc1~1138^2~253 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0359facc7b7a37fd1223ac60649c80cd8daeaf73;p=linux-2.6 iwlwifi: fix race condition during driver unload This patch fixed the OOPS when load the driver while rf-kill is on then unload the driver right after load. a race condition caused the interupt handler to schedule the tasklet which will run right after the driver pci_remove causing invalid poiter OOPS. Signed-off-by: Mohamed Abbas Signed-off-by: Joonwoo Park Signed-off-by: Reinette Chatre Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c index ab635dcfd5..2a5245b63e 100644 --- a/drivers/net/wireless/iwlwifi/iwl3945-base.c +++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c @@ -4153,6 +4153,16 @@ static void iwl3945_enable_interrupts(struct iwl3945_priv *priv) iwl3945_write32(priv, CSR_INT_MASK, CSR_INI_SET_MASK); } + +/* call this function to flush any scheduled tasklet */ +static inline void iwl_synchronize_irq(struct iwl3945_priv *priv) +{ + /* wait to make sure we flush pedding tasklet*/ + synchronize_irq(priv->pci_dev->irq); + tasklet_kill(&priv->irq_tasklet); +} + + static inline void iwl3945_disable_interrupts(struct iwl3945_priv *priv) { clear_bit(STATUS_INT_ENABLED, &priv->status); @@ -4552,7 +4562,9 @@ static void iwl3945_irq_tasklet(struct iwl3945_priv *priv) } /* Re-enable all interrupts */ - iwl3945_enable_interrupts(priv); + /* only Re-enable if disabled by irq */ + if (test_bit(STATUS_INT_ENABLED, &priv->status)) + iwl3945_enable_interrupts(priv); #ifdef CONFIG_IWL3945_DEBUG if (iwl3945_debug_level & (IWL_DL_ISR)) { @@ -4616,7 +4628,9 @@ unplugged: none: /* re-enable interrupts here since we don't have anything to service. */ - iwl3945_enable_interrupts(priv); + /* only Re-enable if disabled by irq */ + if (test_bit(STATUS_INT_ENABLED, &priv->status)) + iwl3945_enable_interrupts(priv); spin_unlock(&priv->lock); return IRQ_NONE; } @@ -5905,7 +5919,10 @@ static void __iwl3945_down(struct iwl3945_priv *priv) iwl3945_write32(priv, CSR_RESET, CSR_RESET_REG_FLAG_NEVO_RESET); /* tell the device to stop sending interrupts */ + spin_lock_irqsave(&priv->lock, flags); iwl3945_disable_interrupts(priv); + spin_unlock_irqrestore(&priv->lock, flags); + iwl_synchronize_irq(priv); if (priv->mac80211_registered) ieee80211_stop_queues(priv->hw); @@ -7943,6 +7960,7 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e struct ieee80211_hw *hw; struct iwl_3945_cfg *cfg = (struct iwl_3945_cfg *)(ent->driver_data); int i; + unsigned long flags; DECLARE_MAC_BUF(mac); /* Disabling hardware scan means that mac80211 will perform scans @@ -8093,7 +8111,9 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e priv->power_mode = IWL_POWER_AC; priv->user_txpower_limit = IWL_DEFAULT_TX_POWER; + spin_lock_irqsave(&priv->lock, flags); iwl3945_disable_interrupts(priv); + spin_unlock_irqrestore(&priv->lock, flags); err = sysfs_create_group(&pdev->dev.kobj, &iwl3945_attribute_group); if (err) { @@ -8180,6 +8200,7 @@ static void __devexit iwl3945_pci_remove(struct pci_dev *pdev) struct iwl3945_priv *priv = pci_get_drvdata(pdev); struct list_head *p, *q; int i; + unsigned long flags; if (!priv) return; @@ -8190,6 +8211,15 @@ static void __devexit iwl3945_pci_remove(struct pci_dev *pdev) iwl3945_down(priv); + /* make sure we flush any pending irq or + * tasklet for the driver + */ + spin_lock_irqsave(&priv->lock, flags); + iwl3945_disable_interrupts(priv); + spin_unlock_irqrestore(&priv->lock, flags); + + iwl_synchronize_irq(priv); + /* Free MAC hash list for ADHOC */ for (i = 0; i < IWL_IBSS_MAC_HASH_SIZE; i++) { list_for_each_safe(p, q, &priv->ibss_mac_hash[i]) { diff --git a/drivers/net/wireless/iwlwifi/iwl4965-base.c b/drivers/net/wireless/iwlwifi/iwl4965-base.c index 7f56565b40..29e843108e 100644 --- a/drivers/net/wireless/iwlwifi/iwl4965-base.c +++ b/drivers/net/wireless/iwlwifi/iwl4965-base.c @@ -4285,6 +4285,14 @@ static void iwl4965_enable_interrupts(struct iwl_priv *priv) iwl_write32(priv, CSR_INT_MASK, CSR_INI_SET_MASK); } +/* call this function to flush any scheduled tasklet */ +static inline void iwl_synchronize_irq(struct iwl_priv *priv) +{ + /* wait to make sure we flush pedding tasklet*/ + synchronize_irq(priv->pci_dev->irq); + tasklet_kill(&priv->irq_tasklet); +} + static inline void iwl4965_disable_interrupts(struct iwl_priv *priv) { clear_bit(STATUS_INT_ENABLED, &priv->status); @@ -4668,7 +4676,9 @@ static void iwl4965_irq_tasklet(struct iwl_priv *priv) } /* Re-enable all interrupts */ - iwl4965_enable_interrupts(priv); + /* only Re-enable if diabled by irq */ + if (test_bit(STATUS_INT_ENABLED, &priv->status)) + iwl4965_enable_interrupts(priv); #ifdef CONFIG_IWLWIFI_DEBUG if (iwl_debug_level & (IWL_DL_ISR)) { @@ -4733,7 +4743,9 @@ static irqreturn_t iwl4965_isr(int irq, void *data) none: /* re-enable interrupts here since we don't have anything to service. */ - iwl4965_enable_interrupts(priv); + /* only Re-enable if diabled by irq */ + if (test_bit(STATUS_INT_ENABLED, &priv->status)) + iwl4965_enable_interrupts(priv); spin_unlock(&priv->lock); return IRQ_NONE; } @@ -5772,7 +5784,10 @@ static void __iwl4965_down(struct iwl_priv *priv) iwl_write32(priv, CSR_RESET, CSR_RESET_REG_FLAG_NEVO_RESET); /* tell the device to stop sending interrupts */ + spin_lock_irqsave(&priv->lock, flags); iwl4965_disable_interrupts(priv); + spin_unlock_irqrestore(&priv->lock, flags); + iwl_synchronize_irq(priv); if (priv->mac80211_registered) ieee80211_stop_queues(priv->hw); @@ -7996,6 +8011,7 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e struct iwl_priv *priv; struct ieee80211_hw *hw; struct iwl_cfg *cfg = (struct iwl_cfg *)(ent->driver_data); + unsigned long flags; DECLARE_MAC_BUF(mac); /************************ @@ -8133,7 +8149,9 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e /******************** * 8. Setup services ********************/ + spin_lock_irqsave(&priv->lock, flags); iwl4965_disable_interrupts(priv); + spin_unlock_irqrestore(&priv->lock, flags); err = sysfs_create_group(&pdev->dev.kobj, &iwl4965_attribute_group); if (err) { @@ -8182,6 +8200,7 @@ static void __devexit iwl4965_pci_remove(struct pci_dev *pdev) struct iwl_priv *priv = pci_get_drvdata(pdev); struct list_head *p, *q; int i; + unsigned long flags; if (!priv) return; @@ -8192,6 +8211,15 @@ static void __devexit iwl4965_pci_remove(struct pci_dev *pdev) iwl4965_down(priv); + /* make sure we flush any pending irq or + * tasklet for the driver + */ + spin_lock_irqsave(&priv->lock, flags); + iwl4965_disable_interrupts(priv); + spin_unlock_irqrestore(&priv->lock, flags); + + iwl_synchronize_irq(priv); + /* Free MAC hash list for ADHOC */ for (i = 0; i < IWL_IBSS_MAC_HASH_SIZE; i++) { list_for_each_safe(p, q, &priv->ibss_mac_hash[i]) {