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authorTaku Izumi <izumi.taku@jp.fujitsu.com>2008-10-17 13:48:36 +0900
committerJesse Barnes <jbarnes@virtuousgeek.org>2008-10-22 16:42:33 -0700
commit9778c14b4ca2c81e437fc2fd2b1f3d676937db27 (patch)
treeecd32dcf1fae311e7caaa400f492051aeb2c66a1 /drivers/pci/pci-acpi.c
parent2515ddc6db8eb49a79f0fe5e67ff09ac7c81eab4 (diff)
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 <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/pci-acpi.c')
-rw-r--r--drivers/pci/pci-acpi.c28
1 files 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);