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authorDana Myers <dana.myers@oracle.com>2011-01-12 09:09:31 +0800
committerLen Brown <len.brown@intel.com>2011-01-18 23:47:41 -0500
commit5d3131f5b0ae6303d042fd91ed9147ad4ae4bf6d (patch)
tree1d2ebc9b9aa6b4644247cd230d16d889f7daf4a4 /drivers/acpi
parentbe33b76a974cdb4ceadc1a12fb79cc97bcfeea37 (diff)
downloadlinux-linaro-android-5d3131f5b0ae6303d042fd91ed9147ad4ae4bf6d.tar.gz
ACPICA: Fix namespace race condition
Fixes a race condition between method execution and namespace walks that can possibly fault. Problem was apparently introduced in version 20100528 as a result of a performance optimization that reduces the number of namespace walks upon method exit by using the delete_namespace_subtree function instead of the delete_namespace_by_owner function used previously. Bug is in the delete_namespace_subtree function. Signed-off-by: Dana Myers <dana.myers@oracle.com> Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Reviewed-by: Rafael Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/acpica/nsalloc.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/nsalloc.c b/drivers/acpi/acpica/nsalloc.c
index 1e5ff803d9a..222a23e838d 100644
--- a/drivers/acpi/acpica/nsalloc.c
+++ b/drivers/acpi/acpica/nsalloc.c
@@ -341,6 +341,7 @@ void acpi_ns_delete_namespace_subtree(struct acpi_namespace_node *parent_node)
{
struct acpi_namespace_node *child_node = NULL;
u32 level = 1;
+ acpi_status status;
ACPI_FUNCTION_TRACE(ns_delete_namespace_subtree);
@@ -348,6 +349,13 @@ void acpi_ns_delete_namespace_subtree(struct acpi_namespace_node *parent_node)
return_VOID;
}
+ /* Lock namespace for possible update */
+
+ status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+ if (ACPI_FAILURE(status)) {
+ return_VOID;
+ }
+
/*
* Traverse the tree of objects until we bubble back up
* to where we started.
@@ -397,6 +405,7 @@ void acpi_ns_delete_namespace_subtree(struct acpi_namespace_node *parent_node)
}
}
+ (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
return_VOID;
}