diff options
| author | Jens Taprogge <jens.taprogge@taprogge.org> | 2012-09-12 14:55:32 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-09-12 09:54:16 -0700 |
| commit | b8d61d49b2437df3a0aef17d321948783d275bb3 (patch) | |
| tree | eb0b00232739c2394e19593ae61e229ec007fe4e | |
| parent | 699a89f1e291af0d47744200011d5c24d9e462a6 (diff) | |
Staging: ipack/bridges/tpci200: RCU protect slot_irq pointers.
In tpci200_request_irq as well as tpci200_free_irq we set and unset the
pointer to struct slot_irq. This pointer is accessed in
tpci200_interrupt. To ensure that the pointer is not freed after it has
been fetched in tpci200_interrupt() it is now protected through RCU.
Signed-off-by: Jens Taprogge <jens.taprogge@taprogge.org>
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/ipack/bridges/tpci200.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/staging/ipack/bridges/tpci200.c b/drivers/staging/ipack/bridges/tpci200.c index 24e2a119dd16..9ce577ab9437 100644 --- a/drivers/staging/ipack/bridges/tpci200.c +++ b/drivers/staging/ipack/bridges/tpci200.c @@ -132,10 +132,11 @@ static irqreturn_t tpci200_interrupt(int irq, void *dev_id) if (status_reg & TPCI200_SLOT_INT_MASK) { /* callback to the IRQ handler for the corresponding slot */ + rcu_read_lock(); for (i = 0; i < TPCI200_NB_SLOT; i++) { if (!(status_reg & ((TPCI200_A_INT0 | TPCI200_A_INT1) << (2*i)))) continue; - slot_irq = tpci200->slots[i].irq; + slot_irq = rcu_dereference(tpci200->slots[i].irq); if (slot_irq) { ret = tpci200_slot_irq(slot_irq); } else { @@ -147,6 +148,7 @@ static irqreturn_t tpci200_interrupt(int irq, void *dev_id) TPCI200_INT0_EN | TPCI200_INT1_EN); } } + rcu_read_unlock(); } return ret; @@ -303,9 +305,9 @@ static int tpci200_free_irq(struct ipack_device *dev) __tpci200_free_irq(tpci200, dev); slot_irq = tpci200->slots[dev->slot].irq; - tpci200->slots[dev->slot].irq = NULL; + RCU_INIT_POINTER(tpci200->slots[dev->slot].irq, NULL); + synchronize_rcu(); kfree(slot_irq); - mutex_unlock(&tpci200->mutex); return 0; } @@ -490,7 +492,7 @@ static int tpci200_request_irq(struct ipack_device *dev, int vector, slot_irq->arg = arg; slot_irq->holder = dev; - tpci200->slots[dev->slot].irq = slot_irq; + rcu_assign_pointer(tpci200->slots[dev->slot].irq, slot_irq); res = __tpci200_request_irq(tpci200, dev); out_unlock: |