1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index c1fb06654749..ed05697a2b38 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1867,6 +1867,13 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
                 return 0;
         }
 
+        /*
+         * Function 0 is the command interrogation function, don't
+         * export it to potential userspace use, and enable it to be
+         * used as an error value in acpi_nfit_ctl().
+         */
+        dsm_mask &= ~1UL;
+
         guid = to_nfit_uuid(nfit_mem->family);
         for_each_set_bit(i, &dsm_mask, BITS_PER_LONG)
                 if (acpi_check_dsm(adev_dimm->handle, guid,