sony-laptop: fix SNC buffer calls when SN06 returns Integers

SN06 in some cases returns an Integer instead of a buffer. While the
code handling the return value was trying to cope with the difference,
the memcpy call was not making any difference between the two types of
acpi_object union. This regression was introduced in 3.5.
While there also rework the return value logic to improve readability.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=48671
Cc: <stable@vger.kernel.org>
Cc: Fabrizio Narni <shibotto@gmail.com>
Cc: <mus.svz@gmail.com>
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index daaddec68def..b8ad71f7863f 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -786,28 +786,29 @@ static int sony_nc_int_call(acpi_handle handle, char *name, int *value,
 static int sony_nc_buffer_call(acpi_handle handle, char *name, u64 *value,
                 void *buffer, size_t buflen)
 {
+        int ret = 0;
         size_t len = len;
         union acpi_object *object = __call_snc_method(handle, name, value);
 
         if (!object)
                 return -EINVAL;
 
-        if (object->type == ACPI_TYPE_BUFFER)
+        if (object->type == ACPI_TYPE_BUFFER) {
                 len = MIN(buflen, object->buffer.length);
+                memcpy(buffer, object->buffer.pointer, len);
 
-        else if (object->type == ACPI_TYPE_INTEGER)
+        } else if (object->type == ACPI_TYPE_INTEGER) {
                 len = MIN(buflen, sizeof(object->integer.value));
+                memcpy(buffer, &object->integer.value, len);
 
-        else {
+        } else {
                 pr_warn("Invalid acpi_object: expected 0x%x got 0x%x\n",
                                 ACPI_TYPE_BUFFER, object->type);
-                kfree(object);
-                return -EINVAL;
+                ret = -EINVAL;
         }
 
-        memcpy(buffer, object->buffer.pointer, len);
         kfree(object);
-        return 0;
+        return ret;
 }
 
 struct sony_nc_handles {