ACPI: scheduling in atomic via acpi_evaluate_integer ()

Now I know why I had strange "scheduling in atomic" problems:
acpi_evaluate_integer() does malloc(..., irqs_disabled() ? GFP_ATOMIC
: GFP_KERNEL)... which is (of course) broken.

There's no way to reliably tell if we need GFP_ATOMIC or not from
code, this one for example fails to detect spinlocks held.

Fortunately, allocation seems small enough to be done on stack.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Acked-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index e827be3..f844941 100644 (file)
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -259,34 +259,26 @@ acpi_evaluate_integer(acpi_handle handle,
                      struct acpi_object_list *arguments, unsigned long long *data)
 {
        acpi_status status = AE_OK;
-       union acpi_object *element;
+       union acpi_object element;
        struct acpi_buffer buffer = { 0, NULL };
 
-
        if (!data)
                return AE_BAD_PARAMETER;
 
-       element = kzalloc(sizeof(union acpi_object), irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
-       if (!element)
-               return AE_NO_MEMORY;
-
        buffer.length = sizeof(union acpi_object);
-       buffer.pointer = element;
+       buffer.pointer = &element;
        status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
        if (ACPI_FAILURE(status)) {
                acpi_util_eval_error(handle, pathname, status);
-               kfree(element);
                return status;
        }
 
-       if (element->type != ACPI_TYPE_INTEGER) {
+       if (element.type != ACPI_TYPE_INTEGER) {
                acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
-               kfree(element);
                return AE_BAD_DATA;
        }
 
-       *data = element->integer.value;
-       kfree(element);
+       *data = element.integer.value;
 
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));