From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758369Ab2ILNDn (ORCPT ); Wed, 12 Sep 2012 09:03:43 -0400 Received: from smtp4.mundo-r.com ([212.51.32.151]:16819 "EHLO smtp4.mundo-r.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758079Ab2ILMzx (ORCPT ); Wed, 12 Sep 2012 08:55:53 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqECACCFUFBbdWObgWdsb2JhbABFu0AiAQEWJieCIAEBBSdSECAxVwYTiBG8YpFSA5VfiTOJVA X-IronPort-AV: E=Sophos;i="4.80,410,1344204000"; d="scan'208";a="950511745" From: Samuel Iglesias Gonsalvez To: Greg Kroah-Hartman Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, industrypack-devel@lists.sourceforge.net, Jens Taprogge , Samuel Iglesias Gonsalvez Subject: [PATCH 10/24] Staging: ipack/bridges/tpci200: RCU protect slot_irq pointers. Date: Wed, 12 Sep 2012 14:55:32 +0200 Message-Id: <1347454546-23236-10-git-send-email-siglesias@igalia.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1347454546-23236-1-git-send-email-siglesias@igalia.com> References: <1347454546-23236-1-git-send-email-siglesias@igalia.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jens Taprogge 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 Signed-off-by: Samuel Iglesias Gonsalvez --- drivers/staging/ipack/bridges/tpci200.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/staging/ipack/bridges/tpci200.c b/drivers/staging/ipack/bridges/tpci200.c index 24e2a11..9ce577a 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: -- 1.7.10.4