On Thu, Nov 12, 2015 at 8:14 AM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote:
> The ACPI compiler uses the extended format when used
> interrupt numbers are greater than 256. The PCI link code
> currently only supports simple interrupt format. The IRQ
> numbers are represented using 32 bits when extended IRQ
> syntax. This patch changes the interrupt number type to
> 32 bits and places an upper limit of 1020 as possible
> interrupt id.
>
> 1020 is the maximum interrupt ID that can be assigned to
> an ARM SPI interrupt according to ARM architecture.
I think it worth to put these lines in the code as well.
>
> Additional checks have been placed to prevent out of bounds
> writes.
>
> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> ---
> drivers/acpi/pci_link.c | 28 +++++++++++++++++-----------
> 1 file changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
> index 7c8408b..a2becab 100644
> --- a/drivers/acpi/pci_link.c
> +++ b/drivers/acpi/pci_link.c
> @@ -1,6 +1,7 @@
> /*
> * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
> *
> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@xxxxxxxxx>
> * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@xxxxxxxxx>
> * Copyright (C) 2002 Dominik Brodowski <devel@xxxxxxxx>
> @@ -67,12 +68,12 @@ static struct acpi_scan_handler pci_link_handler = {
> * later even the link is disable. Instead, we just repick the active irq
> */
> struct acpi_pci_link_irq {
> - u8 active; /* Current IRQ */
> + u32 active; /* Current IRQ */
> u8 triggering; /* All IRQs */
> u8 polarity; /* All IRQs */
> u8 resource_type;
> u8 possible_count;
> - u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
> + u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
> u8 initialized:1;
> u8 reserved:7;
> };
> @@ -437,7 +438,7 @@ static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
> * enabled system.
> */
>
> -#define ACPI_MAX_IRQS 256
> +#define ACPI_MAX_IRQS 1020
> #define ACPI_MAX_ISA_IRQ 16
>
> #define PIRQ_PENALTY_PCI_AVAILABLE (0)
> @@ -493,7 +494,8 @@ int __init acpi_irq_penalty_init(void)
> penalty;
> }
>
> - } else if (link->irq.active) {
> + } else if (link->irq.active &&
> + (link->irq.active < ACPI_MAX_IRQS)) {
> acpi_irq_penalty[link->irq.active] +=
> PIRQ_PENALTY_PCI_POSSIBLE;
> }
> @@ -541,14 +543,16 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link)
> else
> irq = link->irq.possible[link->irq.possible_count - 1];
>
> - if (acpi_irq_balance || !link->irq.active) {
> + if ((acpi_irq_balance || !link->irq.active) && (irq < ACPI_MAX_IRQS)) {
> /*
> - * Select the best IRQ. This is done in reverse to promote
> - * the use of IRQs 9, 10, 11, and >15.
> + * Select the best IRQ. This is done in reverse to
> + * promote the use of IRQs 9, 10, 11, and >15.
What was changed here?
> */
> - for (i = (link->irq.possible_count - 1); i >= 0; i--) {
> - if (acpi_irq_penalty[irq] >
> - acpi_irq_penalty[link->irq.possible[i]])
> + i = link->irq.possible_count;
> + while (--i) {
> + if ((link->irq.possible[i] < ACPI_MAX_IRQS) &&
> + (acpi_irq_penalty[irq] >
> + acpi_irq_penalty[link->irq.possible[i]]))
> irq = link->irq.possible[i];
> }
> }
> @@ -568,7 +572,9 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link)
> acpi_device_bid(link->device));
> return -ENODEV;
> } else {
> - acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
> + if (link->irq.active < ACPI_MAX_IRQS)
> + acpi_irq_penalty[link->irq.active] +=
> + PIRQ_PENALTY_PCI_USING;
> printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
> acpi_device_name(link->device),
> acpi_device_bid(link->device), link->irq.active);
--
With Best Regards,
Andy Shevchenko
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