ACPI: fix OSC regression that caused aer and pciehp not to load

Executing _OSC returns a buffer, which has an acpi object in it.
Don't directly returns the buffer, instead, we return the acpi object's
buffer. This fixes a regression since caller of acpi_run_osc expects
an acpi object's buffer returned.

Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 18 insertions, 8 deletions

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 65f7e335f122..0c1ad3105da1 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -397,6 +397,7 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
         union acpi_object *out_obj;
         u8 uuid[16];
         u32 errors;
+        struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 
         if (!context)
                 return AE_ERROR;
@@ -419,16 +420,16 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
         in_params[3].buffer.length      = context->cap.length;
         in_params[3].buffer.pointer     = context->cap.pointer;
 
-        status = acpi_evaluate_object(handle, "_OSC", &input, &context->ret);
+        status = acpi_evaluate_object(handle, "_OSC", &input, &output);
         if (ACPI_FAILURE(status))
                 return status;
 
-        /* return buffer should have the same length as cap buffer */
-        if (context->ret.length != context->cap.length)
+        if (!output.length)
                 return AE_NULL_OBJECT;
 
-        out_obj = context->ret.pointer;
-        if (out_obj->type != ACPI_TYPE_BUFFER) {
+        out_obj = output.pointer;
+        if (out_obj->type != ACPI_TYPE_BUFFER
+                || out_obj->buffer.length != context->cap.length) {
                 acpi_print_osc_error(handle, context,
                         "_OSC evaluation returned wrong type");
                 status = AE_TYPE;
@@ -457,11 +458,20 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
                 goto out_kfree;
         }
 out_success:
-        return AE_OK;
+        context->ret.length = out_obj->buffer.length;
+        context->ret.pointer = kmalloc(context->ret.length, GFP_KERNEL);
+        if (!context->ret.pointer) {
+                status =  AE_NO_MEMORY;
+                goto out_kfree;
+        }
+        memcpy(context->ret.pointer, out_obj->buffer.pointer,
+                context->ret.length);
+        status =  AE_OK;
 
 out_kfree:
-        kfree(context->ret.pointer);
-        context->ret.pointer = NULL;
+        kfree(output.pointer);
+        if (status != AE_OK)
+                context->ret.pointer = NULL;
         return status;
 }
 EXPORT_SYMBOL(acpi_run_osc);