ACPICA: Copy dynamically loaded tables to local buffer (f0e0da8a) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/acpi/executer/exconfig.c

+82 −31

Original line number	Original line	Diff line number	Diff line
	@@ -280,6 +280,7 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
	struct acpi_walk_state *walk_state)		struct acpi_walk_state *walk_state)
	{		{
	union acpi_operand_object *ddb_handle;		union acpi_operand_object *ddb_handle;
			struct acpi_table_header *table;
	struct acpi_table_desc table_desc;		struct acpi_table_desc table_desc;
	u32 table_index;		u32 table_index;
	acpi_status status;		acpi_status status;
	@@ -294,9 +295,8 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
	switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {		switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
	case ACPI_TYPE_REGION:		case ACPI_TYPE_REGION:

	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Load from Region %p %s\n",		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
	obj_desc,		"Load table from Region %p\n", obj_desc));
	acpi_ut_get_object_type_name(obj_desc)));

	/* Region must be system_memory (from ACPI spec) */		/* Region must be system_memory (from ACPI spec) */

	@@ -316,61 +316,112 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
	}		}

	/*		/*
	* We will simply map the memory region for the table. However, the		* Map the table header and get the actual table length. The region
	* memory region is technically not guaranteed to remain stable and		* length is not guaranteed to be the same as the table length.
	* we may eventually have to copy the table to a local buffer.		*/
			table = acpi_os_map_memory(obj_desc->region.address,
			sizeof(struct acpi_table_header));
			if (!table) {
			return_ACPI_STATUS(AE_NO_MEMORY);
			}

			length = table->length;
			acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));

			/* Must have at least an ACPI table header */

			if (length < sizeof(struct acpi_table_header)) {
			return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
			}

			/*
			* The memory region is not guaranteed to remain stable and we must
			* copy the table to a local buffer. For example, the memory region
			* is corrupted after suspend on some machines. Dynamically loaded
			* tables are usually small, so this overhead is minimal.
	*/		*/

			/* Allocate a buffer for the table */

			table_desc.pointer = ACPI_ALLOCATE(length);
			if (!table_desc.pointer) {
			return_ACPI_STATUS(AE_NO_MEMORY);
			}

			/* Map the entire table and copy it */

			table = acpi_os_map_memory(obj_desc->region.address, length);
			if (!table) {
			ACPI_FREE(table_desc.pointer);
			return_ACPI_STATUS(AE_NO_MEMORY);
			}

			ACPI_MEMCPY(table_desc.pointer, table, length);
			acpi_os_unmap_memory(table, length);

	table_desc.address = obj_desc->region.address;		table_desc.address = obj_desc->region.address;
	table_desc.length = obj_desc->region.length;
	table_desc.flags = ACPI_TABLE_ORIGIN_MAPPED;
	break;		break;

	case ACPI_TYPE_BUFFER: /* Buffer or resolved region_field */		case ACPI_TYPE_BUFFER: /* Buffer or resolved region_field */

	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
	"Load from Buffer or Field %p %s\n", obj_desc,		"Load table from Buffer or Field %p\n",
	acpi_ut_get_object_type_name(obj_desc)));		obj_desc));

	length = obj_desc->buffer.length;

	/* Must have at least an ACPI table header */		/* Must have at least an ACPI table header */

	if (length < sizeof(struct acpi_table_header)) {		if (obj_desc->buffer.length < sizeof(struct acpi_table_header)) {
	return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);		return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
	}		}

	/* Validate checksum here. It won't get validated in tb_add_table */		/* Get the actual table length from the table header */

	status =		table =
	acpi_tb_verify_checksum(ACPI_CAST_PTR		ACPI_CAST_PTR(struct acpi_table_header,
	(struct acpi_table_header,		obj_desc->buffer.pointer);
	obj_desc->buffer.pointer), length);		length = table->length;
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);		/* Table cannot extend beyond the buffer */

			if (length > obj_desc->buffer.length) {
			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
			}
			if (length < sizeof(struct acpi_table_header)) {
			return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
	}		}

	/*		/*
	* We need to copy the buffer since the original buffer could be		* Copy the table from the buffer because the buffer could be modified
	* changed or deleted in the future		* or even deleted in the future
	*/		*/
	table_desc.pointer = ACPI_ALLOCATE(length);		table_desc.pointer = ACPI_ALLOCATE(length);
	if (!table_desc.pointer) {		if (!table_desc.pointer) {
	return_ACPI_STATUS(AE_NO_MEMORY);		return_ACPI_STATUS(AE_NO_MEMORY);
	}		}

	ACPI_MEMCPY(table_desc.pointer, obj_desc->buffer.pointer,		ACPI_MEMCPY(table_desc.pointer, table, length);
	length);		table_desc.address = ACPI_TO_INTEGER(table_desc.pointer);
	table_desc.length = length;
	table_desc.flags = ACPI_TABLE_ORIGIN_ALLOCATED;
	break;		break;

	default:		default:
	return_ACPI_STATUS(AE_AML_OPERAND_TYPE);		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
	}		}

	/*		/* Validate table checksum (will not get validated in tb_add_table) */
	* Install the new table into the local data structures
	*/		status = acpi_tb_verify_checksum(table_desc.pointer, length);
			if (ACPI_FAILURE(status)) {
			ACPI_FREE(table_desc.pointer);
			return_ACPI_STATUS(status);
			}

			/* Complete the table descriptor */

			table_desc.length = length;
			table_desc.flags = ACPI_TABLE_ORIGIN_ALLOCATED;

			/* Install the new table into the local data structures */

	status = acpi_tb_add_table(&table_desc, &table_index);		status = acpi_tb_add_table(&table_desc, &table_index);
	if (ACPI_FAILURE(status)) {		if (ACPI_FAILURE(status)) {
	goto cleanup;		goto cleanup;
	@@ -379,7 +430,7 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
	/*		/*
	* Add the table to the namespace.		* Add the table to the namespace.
	*		*
	* Note: We load the table objects relative to the root of the namespace.		* Note: Load the table objects relative to the root of the namespace.
	* This appears to go against the ACPI specification, but we do it for		* This appears to go against the ACPI specification, but we do it for
	* compatibility with other ACPI implementations.		* compatibility with other ACPI implementations.
	*/		*/
	@@ -415,7 +466,7 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
	cleanup:		cleanup:
	if (ACPI_FAILURE(status)) {		if (ACPI_FAILURE(status)) {

	/* Delete allocated buffer or mapping */		/* Delete allocated table buffer */

	acpi_tb_delete_table(&table_desc);		acpi_tb_delete_table(&table_desc);
	}		}