From 1ca8677d9f3491e51395b0e6b9a2b7a75089dc6f Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 5 Jan 2026 11:17:05 +0100 Subject: [PATCH] ACPI: PCI: IRQ: Fix INTx GSIs signedness In ACPI Global System Interrupts (GSIs) are described using a 32-bit value. ACPI/PCI legacy interrupts (INTx) parsing code treats GSIs as 'int', which poses issues if the GSI interrupt value is a 32-bit value with the MSB set (as required in some interrupt configurations - eg ARM64 GICv5 systems) because acpi_pci_link_allocate_irq() treats a negative gsi return value as a failed GSI allocation (and acpi_irq_get_penalty() would trigger an out-of-bounds array dereference if the 'irq' param is a negative value). Fix ACPI/PCI legacy INTx parsing by converting variables representing GSIs from 'int' to 'u32' bringing the code in line with the ACPI specification and fixing the current parsing issue. Signed-off-by: Lorenzo Pieralisi Reviewed-by: Bjorn Helgaas Link: https://patch.msgid.link/20260105101705.36703-1-lpieralisi@kernel.org Signed-off-by: Rafael J. Wysocki --- drivers/acpi/pci_irq.c | 19 ++++++++++-------- drivers/acpi/pci_link.c | 39 ++++++++++++++++++++++++------------- drivers/xen/acpi.c | 13 +++++++------ include/acpi/acpi_drivers.h | 2 +- 4 files changed, 44 insertions(+), 29 deletions(-) diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c index ad81aa03fe2f..c416942ff3e2 100644 --- a/drivers/acpi/pci_irq.c +++ b/drivers/acpi/pci_irq.c @@ -188,7 +188,7 @@ static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev, * the IRQ value, which is hardwired to specific interrupt inputs on * the interrupt controller. */ - pr_debug("%04x:%02x:%02x[%c] -> %s[%d]\n", + pr_debug("%04x:%02x:%02x[%c] -> %s[%u]\n", entry->id.segment, entry->id.bus, entry->id.device, pin_name(entry->pin), prt->source, entry->index); @@ -384,7 +384,7 @@ static inline bool acpi_pci_irq_valid(struct pci_dev *dev, u8 pin) int acpi_pci_irq_enable(struct pci_dev *dev) { struct acpi_prt_entry *entry; - int gsi; + u32 gsi; u8 pin; int triggering = ACPI_LEVEL_SENSITIVE; /* @@ -422,18 +422,21 @@ int acpi_pci_irq_enable(struct pci_dev *dev) return 0; } + rc = -ENODEV; + if (entry) { if (entry->link) - gsi = acpi_pci_link_allocate_irq(entry->link, + rc = acpi_pci_link_allocate_irq(entry->link, entry->index, &triggering, &polarity, - &link); - else + &link, &gsi); + else { gsi = entry->index; - } else - gsi = -1; + rc = 0; + } + } - if (gsi < 0) { + if (rc < 0) { /* * No IRQ known to the ACPI subsystem - maybe the BIOS / * driver reported one, then use it. Exit in any case. diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c index bed7dc85612e..b91b039a3d20 100644 --- a/drivers/acpi/pci_link.c +++ b/drivers/acpi/pci_link.c @@ -448,7 +448,7 @@ static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = { /* >IRQ15 */ }; -static int acpi_irq_pci_sharing_penalty(int irq) +static int acpi_irq_pci_sharing_penalty(u32 irq) { struct acpi_pci_link *link; int penalty = 0; @@ -474,7 +474,7 @@ static int acpi_irq_pci_sharing_penalty(int irq) return penalty; } -static int acpi_irq_get_penalty(int irq) +static int acpi_irq_get_penalty(u32 irq) { int penalty = 0; @@ -528,7 +528,7 @@ static int acpi_irq_balance = -1; /* 0: static, 1: balance */ static int acpi_pci_link_allocate(struct acpi_pci_link *link) { acpi_handle handle = link->device->handle; - int irq; + u32 irq; int i; if (link->irq.initialized) { @@ -598,44 +598,53 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link) return 0; } -/* - * acpi_pci_link_allocate_irq - * success: return IRQ >= 0 - * failure: return -1 +/** + * acpi_pci_link_allocate_irq(): Retrieve a link device GSI + * + * @handle: Handle for the link device + * @index: GSI index + * @triggering: pointer to store the GSI trigger + * @polarity: pointer to store GSI polarity + * @name: pointer to store link device name + * @gsi: pointer to store GSI number + * + * Returns: + * 0 on success with @triggering, @polarity, @name, @gsi initialized. + * -ENODEV on failure */ int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering, - int *polarity, char **name) + int *polarity, char **name, u32 *gsi) { struct acpi_device *device = acpi_fetch_acpi_dev(handle); struct acpi_pci_link *link; if (!device) { acpi_handle_err(handle, "Invalid link device\n"); - return -1; + return -ENODEV; } link = acpi_driver_data(device); if (!link) { acpi_handle_err(handle, "Invalid link context\n"); - return -1; + return -ENODEV; } /* TBD: Support multiple index (IRQ) entries per Link Device */ if (index) { acpi_handle_err(handle, "Invalid index %d\n", index); - return -1; + return -ENODEV; } mutex_lock(&acpi_link_lock); if (acpi_pci_link_allocate(link)) { mutex_unlock(&acpi_link_lock); - return -1; + return -ENODEV; } if (!link->irq.active) { mutex_unlock(&acpi_link_lock); acpi_handle_err(handle, "Link active IRQ is 0!\n"); - return -1; + return -ENODEV; } link->refcnt++; mutex_unlock(&acpi_link_lock); @@ -647,7 +656,9 @@ int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering, if (name) *name = acpi_device_bid(link->device); acpi_handle_debug(handle, "Link is referenced\n"); - return link->irq.active; + *gsi = link->irq.active; + + return 0; } /* diff --git a/drivers/xen/acpi.c b/drivers/xen/acpi.c index d2ee605c5ca1..eab28cfe9939 100644 --- a/drivers/xen/acpi.c +++ b/drivers/xen/acpi.c @@ -89,11 +89,11 @@ int xen_acpi_get_gsi_info(struct pci_dev *dev, int *trigger_out, int *polarity_out) { - int gsi; + u32 gsi; u8 pin; struct acpi_prt_entry *entry; int trigger = ACPI_LEVEL_SENSITIVE; - int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ? + int ret, polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ? ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW; if (!dev || !gsi_out || !trigger_out || !polarity_out) @@ -105,17 +105,18 @@ int xen_acpi_get_gsi_info(struct pci_dev *dev, entry = acpi_pci_irq_lookup(dev, pin); if (entry) { + ret = 0; if (entry->link) - gsi = acpi_pci_link_allocate_irq(entry->link, + ret = acpi_pci_link_allocate_irq(entry->link, entry->index, &trigger, &polarity, - NULL); + NULL, &gsi); else gsi = entry->index; } else - gsi = -1; + ret = -ENODEV; - if (gsi < 0) + if (ret < 0) return -EINVAL; *gsi_out = gsi; diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h index b14d165632e7..402b97d12138 100644 --- a/include/acpi/acpi_drivers.h +++ b/include/acpi/acpi_drivers.h @@ -51,7 +51,7 @@ int acpi_irq_penalty_init(void); int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering, - int *polarity, char **name); + int *polarity, char **name, u32 *gsi); int acpi_pci_link_free_irq(acpi_handle handle); /* ACPI PCI Device Binding */