Input: HIL - fix rwlock recursion bug
The following bug happens when insmoding hp_sdc_mlc.ko: HP SDC MLC: Registering the System Domain Controller's HIL MLC. BUG: rwlock recursion on CPU#0, hotplug/1814, 00854734 Backtrace: [<10267560>] _raw_write_lock+0x50/0x88 [<10104008>] _write_lock_irqsave+0x14/0x24 [<008537d4>] hp_sdc_mlc_out+0x38/0x25c [hp_sdc_mlc] [<0084ebd8>] hilse_donode+0x308/0x470 [hil_mlc] [<0084ed80>] hil_mlcs_process+0x40/0x6c [hil_mlc] [<10130f80>] tasklet_action+0x78/0xb8 [<10130cec>] __do_softirq+0x60/0xcc [<1010428c>] __lock_text_end+0x38/0x48 [<10108348>] do_cpu_irq_mask+0xf0/0x11c [<1010b068>] intr_return+0x0/0xc Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
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5a90e5bca9
commit
9575499dfe
4 changed files with 19 additions and 25 deletions
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@ -716,7 +716,9 @@ static int hilse_donode(hil_mlc *mlc)
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break;
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case HILSE_CTS:
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write_lock_irqsave(&mlc->lock, flags);
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nextidx = mlc->cts(mlc) ? node->bad : node->good;
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write_unlock_irqrestore(&mlc->lock, flags);
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break;
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default:
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@ -100,6 +100,7 @@ EXPORT_SYMBOL(hp_sdc_release_timer_irq);
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EXPORT_SYMBOL(hp_sdc_release_hil_irq);
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EXPORT_SYMBOL(hp_sdc_release_cooked_irq);
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EXPORT_SYMBOL(__hp_sdc_enqueue_transaction);
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EXPORT_SYMBOL(hp_sdc_enqueue_transaction);
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EXPORT_SYMBOL(hp_sdc_dequeue_transaction);
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@ -593,18 +594,15 @@ unsigned long hp_sdc_put(void)
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}
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/******* Functions called in either user or kernel context ****/
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int hp_sdc_enqueue_transaction(hp_sdc_transaction *this)
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int __hp_sdc_enqueue_transaction(hp_sdc_transaction *this)
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{
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unsigned long flags;
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int i;
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if (this == NULL) {
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tasklet_schedule(&hp_sdc.task);
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BUG();
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return -EINVAL;
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}
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write_lock_irqsave(&hp_sdc.lock, flags);
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/* Can't have same transaction on queue twice */
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for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
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if (hp_sdc.tq[i] == this)
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@ -617,21 +615,29 @@ int hp_sdc_enqueue_transaction(hp_sdc_transaction *this)
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for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
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if (hp_sdc.tq[i] == NULL) {
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hp_sdc.tq[i] = this;
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write_unlock_irqrestore(&hp_sdc.lock, flags);
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tasklet_schedule(&hp_sdc.task);
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return 0;
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}
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write_unlock_irqrestore(&hp_sdc.lock, flags);
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printk(KERN_WARNING PREFIX "No free slot to add transaction.\n");
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return -EBUSY;
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fail:
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write_unlock_irqrestore(&hp_sdc.lock,flags);
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printk(KERN_WARNING PREFIX "Transaction add failed: transaction already queued?\n");
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return -EINVAL;
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}
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int hp_sdc_enqueue_transaction(hp_sdc_transaction *this) {
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unsigned long flags;
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int ret;
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write_lock_irqsave(&hp_sdc.lock, flags);
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ret = __hp_sdc_enqueue_transaction(this);
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write_unlock_irqrestore(&hp_sdc.lock,flags);
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return ret;
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}
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int hp_sdc_dequeue_transaction(hp_sdc_transaction *this)
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{
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unsigned long flags;
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@ -142,14 +142,11 @@ static void hp_sdc_mlc_isr (int irq, void *dev_id,
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static int hp_sdc_mlc_in(hil_mlc *mlc, suseconds_t timeout)
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{
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unsigned long flags;
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struct hp_sdc_mlc_priv_s *priv;
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int rc = 2;
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priv = mlc->priv;
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write_lock_irqsave(&mlc->lock, flags);
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/* Try to down the semaphore */
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if (down_trylock(&mlc->isem)) {
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struct timeval tv;
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@ -178,21 +175,16 @@ static int hp_sdc_mlc_in(hil_mlc *mlc, suseconds_t timeout)
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wasup:
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up(&mlc->isem);
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rc = 0;
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goto done;
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done:
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write_unlock_irqrestore(&mlc->lock, flags);
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return rc;
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}
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static int hp_sdc_mlc_cts(hil_mlc *mlc)
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{
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struct hp_sdc_mlc_priv_s *priv;
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unsigned long flags;
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priv = mlc->priv;
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write_lock_irqsave(&mlc->lock, flags);
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/* Try to down the semaphores -- they should be up. */
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BUG_ON(down_trylock(&mlc->isem));
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BUG_ON(down_trylock(&mlc->osem));
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@ -221,26 +213,21 @@ static int hp_sdc_mlc_cts(hil_mlc *mlc)
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priv->tseq[2] = 1;
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priv->tseq[3] = 0;
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priv->tseq[4] = 0;
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hp_sdc_enqueue_transaction(&priv->trans);
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__hp_sdc_enqueue_transaction(&priv->trans);
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busy:
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write_unlock_irqrestore(&mlc->lock, flags);
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return 1;
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done:
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priv->trans.act.semaphore = &mlc->osem;
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up(&mlc->csem);
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write_unlock_irqrestore(&mlc->lock, flags);
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return 0;
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}
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static void hp_sdc_mlc_out(hil_mlc *mlc)
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{
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struct hp_sdc_mlc_priv_s *priv;
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unsigned long flags;
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priv = mlc->priv;
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write_lock_irqsave(&mlc->lock, flags);
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/* Try to down the semaphore -- it should be up. */
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BUG_ON(down_trylock(&mlc->osem));
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@ -250,7 +237,7 @@ static void hp_sdc_mlc_out(hil_mlc *mlc)
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do_data:
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if (priv->emtestmode) {
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up(&mlc->osem);
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goto done;
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return;
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}
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/* Shouldn't be sending commands when loop may be busy */
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BUG_ON(down_trylock(&mlc->csem));
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@ -313,8 +300,6 @@ static void hp_sdc_mlc_out(hil_mlc *mlc)
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}
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enqueue:
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hp_sdc_enqueue_transaction(&priv->trans);
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done:
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write_unlock_irqrestore(&mlc->lock, flags);
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}
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static int __init hp_sdc_mlc_init(void)
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@ -71,6 +71,7 @@ typedef struct {
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struct semaphore *semaphore; /* Semaphore to sleep on. */
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} act;
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} hp_sdc_transaction;
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int __hp_sdc_enqueue_transaction(hp_sdc_transaction *this);
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int hp_sdc_enqueue_transaction(hp_sdc_transaction *this);
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int hp_sdc_dequeue_transaction(hp_sdc_transaction *this);
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