1 files changed, 205 insertions, 25 deletions

diff --git a/drivers/acpi/acpica/tbdata.c b/drivers/acpi/acpica/tbdata.c
index c9d6fa6d7cc6..b19a2f0ea331 100644
--- a/drivers/acpi/acpica/tbdata.c
+++ b/drivers/acpi/acpica/tbdata.c
@@ -50,6 +50,57 @@
 #define _COMPONENT          ACPI_TABLES
 ACPI_MODULE_NAME("tbdata")
 
+/* Local prototypes */
+static acpi_status
+acpi_tb_check_duplication(struct acpi_table_desc *table_desc, u32 *table_index);
+
+static u8
+acpi_tb_compare_tables(struct acpi_table_desc *table_desc, u32 table_index);
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_compare_tables
+ *
+ * PARAMETERS:  table_desc          - Table 1 descriptor to be compared
+ *              table_index         - Index of table 2 to be compared
+ *
+ * RETURN:      TRUE if both tables are identical.
+ *
+ * DESCRIPTION: This function compares a table with another table that has
+ *              already been installed in the root table list.
+ *
+ ******************************************************************************/
+
+static u8
+acpi_tb_compare_tables(struct acpi_table_desc *table_desc, u32 table_index)
+{
+	acpi_status status = AE_OK;
+	u8 is_identical;
+	struct acpi_table_header *table;
+	u32 table_length;
+	u8 table_flags;
+
+	status =
+	    acpi_tb_acquire_table(&acpi_gbl_root_table_list.tables[table_index],
+				  &table, &table_length, &table_flags);
+	if (ACPI_FAILURE(status)) {
+		return (FALSE);
+	}
+
+	/*
+	 * Check for a table match on the entire table length,
+	 * not just the header.
+	 */
+	is_identical = (u8)((table_desc->length != table_length ||
+			     memcmp(table_desc->pointer, table, table_length)) ?
+			    FALSE : TRUE);
+
+	/* Release the acquired table */
+
+	acpi_tb_release_table(table, table_length, table_flags);
+	return (is_identical);
+}
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_tb_init_table_descriptor
@@ -64,6 +115,7 @@ ACPI_MODULE_NAME("tbdata")
  * DESCRIPTION: Initialize a new table descriptor
  *
  ******************************************************************************/
+
 void
 acpi_tb_init_table_descriptor(struct acpi_table_desc *table_desc,
 			      acpi_physical_address address,
@@ -338,7 +390,7 @@ void acpi_tb_invalidate_table(struct acpi_table_desc *table_desc)
 acpi_status acpi_tb_validate_temp_table(struct acpi_table_desc *table_desc)
 {
 
-	if (!table_desc->pointer && !acpi_gbl_verify_table_checksum) {
+	if (!table_desc->pointer && !acpi_gbl_enable_table_validation) {
 		/*
 		 * Only validates the header of the table.
 		 * Note that Length contains the size of the mapping after invoking
@@ -354,22 +406,100 @@ acpi_status acpi_tb_validate_temp_table(struct acpi_table_desc *table_desc)
 	return (acpi_tb_validate_table(table_desc));
 }
 
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_check_duplication
+ *
+ * PARAMETERS:  table_desc          - Table descriptor
+ *              table_index         - Where the table index is returned
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Avoid installing duplicated tables. However table override and
+ *              user aided dynamic table load is allowed, thus comparing the
+ *              address of the table is not sufficient, and checking the entire
+ *              table content is required.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_tb_check_duplication(struct acpi_table_desc *table_desc, u32 *table_index)
+{
+	u32 i;
+
+	ACPI_FUNCTION_TRACE(tb_check_duplication);
+
+	/* Check if table is already registered */
+
+	for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
+
+		/* Do not compare with unverified tables */
+
+		if (!
+		    (acpi_gbl_root_table_list.tables[i].
+		     flags & ACPI_TABLE_IS_VERIFIED)) {
+			continue;
+		}
+
+		/*
+		 * Check for a table match on the entire table length,
+		 * not just the header.
+		 */
+		if (!acpi_tb_compare_tables(table_desc, i)) {
+			continue;
+		}
+
+		/*
+		 * Note: the current mechanism does not unregister a table if it is
+		 * dynamically unloaded. The related namespace entries are deleted,
+		 * but the table remains in the root table list.
+		 *
+		 * The assumption here is that the number of different tables that
+		 * will be loaded is actually small, and there is minimal overhead
+		 * in just keeping the table in case it is needed again.
+		 *
+		 * If this assumption changes in the future (perhaps on large
+		 * machines with many table load/unload operations), tables will
+		 * need to be unregistered when they are unloaded, and slots in the
+		 * root table list should be reused when empty.
+		 */
+		if (acpi_gbl_root_table_list.tables[i].flags &
+		    ACPI_TABLE_IS_LOADED) {
+
+			/* Table is still loaded, this is an error */
+
+			return_ACPI_STATUS(AE_ALREADY_EXISTS);
+		} else {
+			*table_index = i;
+			return_ACPI_STATUS(AE_CTRL_TERMINATE);
+		}
+	}
+
+	/* Indicate no duplication to the caller */
+
+	return_ACPI_STATUS(AE_OK);
+}
+
 /******************************************************************************
  *
  * FUNCTION:    acpi_tb_verify_temp_table
  *
  * PARAMETERS:  table_desc          - Table descriptor
  *              signature           - Table signature to verify
+ *              table_index         - Where the table index is returned
  *
  * RETURN:      Status
  *
  * DESCRIPTION: This function is called to validate and verify the table, the
  *              returned table descriptor is in "VALIDATED" state.
+ *              Note that 'TableIndex' is required to be set to !NULL to
+ *              enable duplication check.
  *
  *****************************************************************************/
 
 acpi_status
-acpi_tb_verify_temp_table(struct acpi_table_desc *table_desc, char *signature)
+acpi_tb_verify_temp_table(struct acpi_table_desc *table_desc,
+			  char *signature, u32 *table_index)
 {
 	acpi_status status = AE_OK;
 
@@ -392,9 +522,10 @@ acpi_tb_verify_temp_table(struct acpi_table_desc *table_desc, char *signature)
 		goto invalidate_and_exit;
 	}
 
-	/* Verify the checksum */
+	if (acpi_gbl_enable_table_validation) {
+
+		/* Verify the checksum */
 
-	if (acpi_gbl_verify_table_checksum) {
 		status =
 		    acpi_tb_verify_checksum(table_desc->pointer,
 					    table_desc->length);
@@ -411,9 +542,34 @@ acpi_tb_verify_temp_table(struct acpi_table_desc *table_desc, char *signature)
 
 			goto invalidate_and_exit;
 		}
+
+		/* Avoid duplications */
+
+		if (table_index) {
+			status =
+			    acpi_tb_check_duplication(table_desc, table_index);
+			if (ACPI_FAILURE(status)) {
+				if (status != AE_CTRL_TERMINATE) {
+					ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY,
+							"%4.4s 0x%8.8X%8.8X"
+							" Table is duplicated",
+							acpi_ut_valid_nameseg
+							(table_desc->signature.
+							 ascii) ? table_desc->
+							signature.
+							ascii : "????",
+							ACPI_FORMAT_UINT64
+							(table_desc->address)));
+				}
+
+				goto invalidate_and_exit;
+			}
+		}
+
+		table_desc->flags |= ACPI_TABLE_IS_VERIFIED;
 	}
 
-	return_ACPI_STATUS(AE_OK);
+	return_ACPI_STATUS(status);
 
 invalidate_and_exit:
 	acpi_tb_invalidate_table(table_desc);
@@ -436,6 +592,8 @@ acpi_status acpi_tb_resize_root_table_list(void)
 {
 	struct acpi_table_desc *tables;
 	u32 table_count;
+	u32 current_table_count, max_table_count;
+	u32 i;
 
 	ACPI_FUNCTION_TRACE(tb_resize_root_table_list);
 
@@ -455,8 +613,8 @@ acpi_status acpi_tb_resize_root_table_list(void)
 		table_count = acpi_gbl_root_table_list.current_table_count;
 	}
 
-	tables = ACPI_ALLOCATE_ZEROED(((acpi_size)table_count +
-				       ACPI_ROOT_TABLE_SIZE_INCREMENT) *
+	max_table_count = table_count + ACPI_ROOT_TABLE_SIZE_INCREMENT;
+	tables = ACPI_ALLOCATE_ZEROED(((acpi_size)max_table_count) *
 				      sizeof(struct acpi_table_desc));
 	if (!tables) {
 		ACPI_ERROR((AE_INFO,
@@ -466,9 +624,16 @@ acpi_status acpi_tb_resize_root_table_list(void)
 
 	/* Copy and free the previous table array */
 
+	current_table_count = 0;
 	if (acpi_gbl_root_table_list.tables) {
-		memcpy(tables, acpi_gbl_root_table_list.tables,
-		       (acpi_size)table_count * sizeof(struct acpi_table_desc));
+		for (i = 0; i < table_count; i++) {
+			if (acpi_gbl_root_table_list.tables[i].address) {
+				memcpy(tables + current_table_count,
+				       acpi_gbl_root_table_list.tables + i,
+				       sizeof(struct acpi_table_desc));
+				current_table_count++;
+			}
+		}
 
 		if (acpi_gbl_root_table_list.flags & ACPI_ROOT_ORIGIN_ALLOCATED) {
 			ACPI_FREE(acpi_gbl_root_table_list.tables);
@@ -476,8 +641,8 @@ acpi_status acpi_tb_resize_root_table_list(void)
 	}
 
 	acpi_gbl_root_table_list.tables = tables;
-	acpi_gbl_root_table_list.max_table_count =
-	    table_count + ACPI_ROOT_TABLE_SIZE_INCREMENT;
+	acpi_gbl_root_table_list.max_table_count = max_table_count;
+	acpi_gbl_root_table_list.current_table_count = current_table_count;
 	acpi_gbl_root_table_list.flags |= ACPI_ROOT_ORIGIN_ALLOCATED;
 
 	return_ACPI_STATUS(AE_OK);
@@ -818,13 +983,9 @@ acpi_tb_load_table(u32 table_index, struct acpi_namespace_node *parent_node)
 		acpi_ev_update_gpes(owner_id);
 	}
 
-	/* Invoke table handler if present */
-
-	if (acpi_gbl_table_handler) {
-		(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD, table,
-					     acpi_gbl_table_handler_context);
-	}
+	/* Invoke table handler */
 
+	acpi_tb_notify_table(ACPI_TABLE_EVENT_LOAD, table);
 	return_ACPI_STATUS(status);
 }
 
@@ -894,15 +1055,11 @@ acpi_status acpi_tb_unload_table(u32 table_index)
 		return_ACPI_STATUS(AE_NOT_EXIST);
 	}
 
-	/* Invoke table handler if present */
+	/* Invoke table handler */
 
-	if (acpi_gbl_table_handler) {
-		status = acpi_get_table_by_index(table_index, &table);
-		if (ACPI_SUCCESS(status)) {
-			(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_UNLOAD,
-						     table,
-						     acpi_gbl_table_handler_context);
-		}
+	status = acpi_get_table_by_index(table_index, &table);
+	if (ACPI_SUCCESS(status)) {
+		acpi_tb_notify_table(ACPI_TABLE_EVENT_UNLOAD, table);
 	}
 
 	/* Delete the portion of the namespace owned by this table */
@@ -918,3 +1075,26 @@ acpi_status acpi_tb_unload_table(u32 table_index)
 }
 
 ACPI_EXPORT_SYMBOL(acpi_tb_unload_table)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_notify_table
+ *
+ * PARAMETERS:  event               - Table event
+ *              table               - Validated table pointer
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Notify a table event to the users.
+ *
+ ******************************************************************************/
+
+void acpi_tb_notify_table(u32 event, void *table)
+{
+	/* Invoke table handler if present */
+
+	if (acpi_gbl_table_handler) {
+		(void)acpi_gbl_table_handler(event, table,
+					     acpi_gbl_table_handler_context);
+	}
+}