1 files changed, 23 insertions, 6 deletions

diff --git a/drivers/acpi/acpica/tbxface.c b/drivers/acpi/acpica/tbxface.c
index f5378fc302b3..adb7f56b853e 100644
--- a/drivers/acpi/acpica/tbxface.c
+++ b/drivers/acpi/acpica/tbxface.c
@@ -513,39 +513,56 @@ static acpi_status acpi_tb_load_namespace(void)
 {
         acpi_status status;
         u32 i;
+        struct acpi_table_header *new_dsdt;
 
         ACPI_FUNCTION_TRACE(tb_load_namespace);
 
         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 
-        acpi_gbl_DSDT = &acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT];
-
         /*
          * Load the namespace. The DSDT is required, but any SSDT and
          * PSDT tables are optional. Verify the DSDT.
          */
         if (!acpi_gbl_root_table_list.count ||
-            !ACPI_COMPARE_NAME(&acpi_gbl_DSDT->signature, ACPI_SIG_DSDT) ||
-            ACPI_FAILURE(acpi_tb_verify_table(acpi_gbl_DSDT))) {
+            !ACPI_COMPARE_NAME(&
+                               (acpi_gbl_root_table_list.
+                                tables[ACPI_TABLE_INDEX_DSDT].signature),
+                               ACPI_SIG_DSDT)
+            ||
+            ACPI_FAILURE(acpi_tb_verify_table
+                         (&acpi_gbl_root_table_list.
+                          tables[ACPI_TABLE_INDEX_DSDT]))) {
                 status = AE_NO_ACPI_TABLES;
                 goto unlock_and_exit;
         }
 
         /*
+         * Save the DSDT pointer for simple access. This is the mapped memory
+         * address. We must take care here because the address of the .Tables
+         * array can change dynamically as tables are loaded at run-time. Note:
+         * .Pointer field is not validated until after call to acpi_tb_verify_table.
+         */
+        acpi_gbl_DSDT =
+            acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].pointer;
+
+        /*
          * Optionally copy the entire DSDT to local memory (instead of simply
          * mapping it.) There are some BIOSs that corrupt or replace the original
          * DSDT, creating the need for this option. Default is FALSE, do not copy
          * the DSDT.
          */
         if (acpi_gbl_copy_dsdt_locally) {
-                acpi_tb_copy_dsdt(acpi_gbl_DSDT);
+                new_dsdt = acpi_tb_copy_dsdt(ACPI_TABLE_INDEX_DSDT);
+                if (new_dsdt) {
+                        acpi_gbl_DSDT = new_dsdt;
+                }
         }
 
         /*
          * Save the original DSDT header for detection of table corruption
          * and/or replacement of the DSDT from outside the OS.
          */
-        ACPI_MEMCPY(&acpi_gbl_original_dsdt_header, acpi_gbl_DSDT->pointer,
+        ACPI_MEMCPY(&acpi_gbl_original_dsdt_header, acpi_gbl_DSDT,
                     sizeof(struct acpi_table_header));
 
         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);