From 9778c14b4ca2c81e437fc2fd2b1f3d676937db27 Mon Sep 17 00:00:00 2001 From: Taku Izumi Date: Fri, 17 Oct 2008 13:48:36 +0900 Subject: [PATCH] ACPI/PCI: Fix possible race condition on _OSC evaluation Fix possible race condition on _OSC evaluation. Current _OSC evaluation code has possible race condition because it maniputes osc_data linked list or its contents without any lock mechanism. Signed-off-by: Kenji Kaneshige Signed-off-by: Taku Izumi Signed-off-by: Jesse Barnes --- drivers/pci/pci-acpi.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 89a2f0fa10f9..14848bf95e82 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -35,6 +35,8 @@ struct acpi_osc_args { u32 query_result; }; +static DEFINE_MUTEX(pci_acpi_lock); + static struct acpi_osc_data *acpi_get_osc_data(acpi_handle handle) { struct acpi_osc_data *data; @@ -131,10 +133,12 @@ static acpi_status acpi_query_osc(acpi_handle handle, if (ACPI_FAILURE(status)) return status; + mutex_lock(&pci_acpi_lock); osc_data = acpi_get_osc_data(handle); if (!osc_data) { printk(KERN_ERR "acpi osc data array is full\n"); - return AE_ERROR; + status = AE_ERROR; + goto out; } /* do _OSC query for all possible controls */ @@ -149,7 +153,8 @@ static acpi_status acpi_query_osc(acpi_handle handle, osc_data->query_result = osc_args.query_result; osc_data->is_queried = 1; } - +out: + mutex_unlock(&pci_acpi_lock); return status; } @@ -190,19 +195,25 @@ acpi_status pci_osc_control_set(acpi_handle handle, u32 flags) if (ACPI_FAILURE(status)) return status; + mutex_lock(&pci_acpi_lock); osc_data = acpi_get_osc_data(handle); if (!osc_data) { printk(KERN_ERR "acpi osc data array is full\n"); - return AE_ERROR; + status = AE_ERROR; + goto out; } ctrlset = (flags & OSC_CONTROL_MASKS); - if (!ctrlset) - return AE_TYPE; + if (!ctrlset) { + status = AE_TYPE; + goto out; + } if (osc_data->is_queried && - ((osc_data->query_result & ctrlset) != ctrlset)) - return AE_SUPPORT; + ((osc_data->query_result & ctrlset) != ctrlset)) { + status = AE_SUPPORT; + goto out; + } control_set = osc_data->control_set | ctrlset; osc_args.capbuf[OSC_QUERY_TYPE] = 0; @@ -211,7 +222,8 @@ acpi_status pci_osc_control_set(acpi_handle handle, u32 flags) status = acpi_run_osc(handle, &osc_args); if (ACPI_SUCCESS(status)) osc_data->control_set = control_set; - +out: + mutex_unlock(&pci_acpi_lock); return status; } EXPORT_SYMBOL(pci_osc_control_set); -- 2.20.1