From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 21 Jun 2015 18:16:09 +0000 (+0200)
Subject: PCI/keystone: Fix race in installing chained IRQ handler
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2cf5a03cb29debb00681a8af1dfa9179b43404d1;p=linux-beck.git

PCI/keystone: Fix race in installing chained IRQ handler

Fix a race where a pending interrupt could be received and the handler
called before the handler's data has been setup, by converting to
irq_set_chained_handler_and_data().

Search and conversion was done with coccinelle:

@@
expression E1, E2, E3;
@@
(
-if (irq_set_chained_handler(E1, E3) != 0)
-   BUG();
|
-irq_set_chained_handler(E1, E3);
)
-irq_set_handler_data(E1, E2);
+irq_set_chained_handler_and_data(E1, E3, E2);

@@
expression E1, E2, E3;
@@
(
-if (irq_set_chained_handler(E1, E3) != 0)
-   BUG();
...
|
-irq_set_chained_handler(E1, E3);
...
)
-irq_set_handler_data(E1, E2);
+irq_set_chained_handler_and_data(E1, E3, E2);

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Murali Karicheri <m-karicheri2@ti.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
---

diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
index 75333b0c4f0a..47cf0c18d9e3 100644
--- a/drivers/pci/host/pci-keystone.c
+++ b/drivers/pci/host/pci-keystone.c
@@ -223,10 +223,9 @@ static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
 	/* MSI IRQ */
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		for (i = 0; i < ks_pcie->num_msi_host_irqs; i++) {
-			irq_set_chained_handler(ks_pcie->msi_host_irqs[i],
-						ks_pcie_msi_irq_handler);
-			irq_set_handler_data(ks_pcie->msi_host_irqs[i],
-					     ks_pcie);
+			irq_set_chained_handler_and_data(ks_pcie->msi_host_irqs[i],
+							 ks_pcie_msi_irq_handler,
+							 ks_pcie);
 		}
 	}
 }