linux/drivers/acpi/acpica/exconfig.c
Bob Moore 8a335a2331 ACPICA: Fix AcpiWalkNamespace race condition with table unload
Added a reader/writer locking mechanism to allow multiple
concurrent namespace walks (readers), but a dynamic table unload
will have exclusive access to the namespace. This fixes a problem
where a table unload could delete the portion of the namespace that
is currently being examined by a walk.  Adds a new file, utlock.c
that implements the reader/writer lock mechanism. ACPICA BZ 749.

http://www.acpica.org/bugzilla/show_bug.cgi?id=749

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-03-27 12:11:02 -04:00

538 lines
15 KiB
C

/******************************************************************************
*
* Module Name: exconfig - Namespace reconfiguration (Load/Unload opcodes)
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2008, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "actables.h"
#include "acdispat.h"
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME("exconfig")
/* Local prototypes */
static acpi_status
acpi_ex_add_table(u32 table_index,
struct acpi_namespace_node *parent_node,
union acpi_operand_object **ddb_handle);
/*******************************************************************************
*
* FUNCTION: acpi_ex_add_table
*
* PARAMETERS: Table - Pointer to raw table
* parent_node - Where to load the table (scope)
* ddb_handle - Where to return the table handle.
*
* RETURN: Status
*
* DESCRIPTION: Common function to Install and Load an ACPI table with a
* returned table handle.
*
******************************************************************************/
static acpi_status
acpi_ex_add_table(u32 table_index,
struct acpi_namespace_node *parent_node,
union acpi_operand_object **ddb_handle)
{
acpi_status status;
union acpi_operand_object *obj_desc;
ACPI_FUNCTION_TRACE(ex_add_table);
/* Create an object to be the table handle */
obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_REFERENCE);
if (!obj_desc) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Init the table handle */
obj_desc->reference.class = ACPI_REFCLASS_TABLE;
*ddb_handle = obj_desc;
/* Install the new table into the local data structures */
obj_desc->reference.value = table_index;
/* Add the table to the namespace */
status = acpi_ns_load_table(table_index, parent_node);
if (ACPI_FAILURE(status)) {
acpi_ut_remove_reference(obj_desc);
*ddb_handle = NULL;
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_load_table_op
*
* PARAMETERS: walk_state - Current state with operands
* return_desc - Where to store the return object
*
* RETURN: Status
*
* DESCRIPTION: Load an ACPI table from the RSDT/XSDT
*
******************************************************************************/
acpi_status
acpi_ex_load_table_op(struct acpi_walk_state *walk_state,
union acpi_operand_object **return_desc)
{
acpi_status status;
union acpi_operand_object **operand = &walk_state->operands[0];
struct acpi_namespace_node *parent_node;
struct acpi_namespace_node *start_node;
struct acpi_namespace_node *parameter_node = NULL;
union acpi_operand_object *ddb_handle;
struct acpi_table_header *table;
u32 table_index;
ACPI_FUNCTION_TRACE(ex_load_table_op);
/* Validate lengths for the signature_string, OEMIDString, OEMtable_iD */
if ((operand[0]->string.length > ACPI_NAME_SIZE) ||
(operand[1]->string.length > ACPI_OEM_ID_SIZE) ||
(operand[2]->string.length > ACPI_OEM_TABLE_ID_SIZE)) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Find the ACPI table in the RSDT/XSDT */
status = acpi_tb_find_table(operand[0]->string.pointer,
operand[1]->string.pointer,
operand[2]->string.pointer, &table_index);
if (ACPI_FAILURE(status)) {
if (status != AE_NOT_FOUND) {
return_ACPI_STATUS(status);
}
/* Table not found, return an Integer=0 and AE_OK */
ddb_handle = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
if (!ddb_handle) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
ddb_handle->integer.value = 0;
*return_desc = ddb_handle;
return_ACPI_STATUS(AE_OK);
}
/* Default nodes */
start_node = walk_state->scope_info->scope.node;
parent_node = acpi_gbl_root_node;
/* root_path (optional parameter) */
if (operand[3]->string.length > 0) {
/*
* Find the node referenced by the root_path_string. This is the
* location within the namespace where the table will be loaded.
*/
status =
acpi_ns_get_node(start_node, operand[3]->string.pointer,
ACPI_NS_SEARCH_PARENT, &parent_node);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
/* parameter_path (optional parameter) */
if (operand[4]->string.length > 0) {
if ((operand[4]->string.pointer[0] != '\\') &&
(operand[4]->string.pointer[0] != '^')) {
/*
* Path is not absolute, so it will be relative to the node
* referenced by the root_path_string (or the NS root if omitted)
*/
start_node = parent_node;
}
/* Find the node referenced by the parameter_path_string */
status =
acpi_ns_get_node(start_node, operand[4]->string.pointer,
ACPI_NS_SEARCH_PARENT, &parameter_node);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
/* Load the table into the namespace */
status = acpi_ex_add_table(table_index, parent_node, &ddb_handle);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Parameter Data (optional) */
if (parameter_node) {
/* Store the parameter data into the optional parameter object */
status = acpi_ex_store(operand[5],
ACPI_CAST_PTR(union acpi_operand_object,
parameter_node),
walk_state);
if (ACPI_FAILURE(status)) {
(void)acpi_ex_unload_table(ddb_handle);
return_ACPI_STATUS(status);
}
}
status = acpi_get_table_by_index(table_index, &table);
if (ACPI_SUCCESS(status)) {
ACPI_INFO((AE_INFO,
"Dynamic OEM Table Load - [%.4s] OemId [%.6s] OemTableId [%.8s]",
table->signature, table->oem_id,
table->oem_table_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);
}
*return_desc = ddb_handle;
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_load_op
*
* PARAMETERS: obj_desc - Region or Buffer/Field where the table will be
* obtained
* Target - Where a handle to the table will be stored
* walk_state - Current state
*
* RETURN: Status
*
* DESCRIPTION: Load an ACPI table from a field or operation region
*
* NOTE: Region Fields (Field, bank_field, index_fields) are resolved to buffer
* objects before this code is reached.
*
* If source is an operation region, it must refer to system_memory, as
* per the ACPI specification.
*
******************************************************************************/
acpi_status
acpi_ex_load_op(union acpi_operand_object *obj_desc,
union acpi_operand_object *target,
struct acpi_walk_state *walk_state)
{
union acpi_operand_object *ddb_handle;
struct acpi_table_header *table;
struct acpi_table_desc table_desc;
u32 table_index;
acpi_status status;
u32 length;
ACPI_FUNCTION_TRACE(ex_load_op);
ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
/* Source Object can be either an op_region or a Buffer/Field */
switch (obj_desc->common.type) {
case ACPI_TYPE_REGION:
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
"Load table from Region %p\n", obj_desc));
/* Region must be system_memory (from ACPI spec) */
if (obj_desc->region.space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
}
/*
* If the Region Address and Length have not been previously evaluated,
* evaluate them now and save the results.
*/
if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
status = acpi_ds_get_region_arguments(obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
/*
* Map the table header and get the actual table length. The region
* length is not guaranteed to be the same as the table length.
*/
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;
break;
case ACPI_TYPE_BUFFER: /* Buffer or resolved region_field */
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
"Load table from Buffer or Field %p\n",
obj_desc));
/* Must have at least an ACPI table header */
if (obj_desc->buffer.length < sizeof(struct acpi_table_header)) {
return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
}
/* Get the actual table length from the table header */
table =
ACPI_CAST_PTR(struct acpi_table_header,
obj_desc->buffer.pointer);
length = table->length;
/* 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);
}
/*
* Copy the table from the buffer because the buffer could be modified
* or even deleted in the future
*/
table_desc.pointer = ACPI_ALLOCATE(length);
if (!table_desc.pointer) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
ACPI_MEMCPY(table_desc.pointer, table, length);
table_desc.address = ACPI_TO_INTEGER(table_desc.pointer);
break;
default:
return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
}
/* Validate table checksum (will not get validated in tb_add_table) */
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);
if (ACPI_FAILURE(status)) {
goto cleanup;
}
/*
* Add the table to 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
* compatibility with other ACPI implementations.
*/
status =
acpi_ex_add_table(table_index, acpi_gbl_root_node, &ddb_handle);
if (ACPI_FAILURE(status)) {
/* On error, table_ptr was deallocated above */
return_ACPI_STATUS(status);
}
/* Store the ddb_handle into the Target operand */
status = acpi_ex_store(ddb_handle, target, walk_state);
if (ACPI_FAILURE(status)) {
(void)acpi_ex_unload_table(ddb_handle);
/* table_ptr was deallocated above */
acpi_ut_remove_reference(ddb_handle);
return_ACPI_STATUS(status);
}
/* Invoke table handler if present */
if (acpi_gbl_table_handler) {
(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD,
table_desc.pointer,
acpi_gbl_table_handler_context);
}
cleanup:
if (ACPI_FAILURE(status)) {
/* Delete allocated table buffer */
acpi_tb_delete_table(&table_desc);
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_unload_table
*
* PARAMETERS: ddb_handle - Handle to a previously loaded table
*
* RETURN: Status
*
* DESCRIPTION: Unload an ACPI table
*
******************************************************************************/
acpi_status acpi_ex_unload_table(union acpi_operand_object *ddb_handle)
{
acpi_status status = AE_OK;
union acpi_operand_object *table_desc = ddb_handle;
u32 table_index;
struct acpi_table_header *table;
ACPI_FUNCTION_TRACE(ex_unload_table);
/*
* Validate the handle
* Although the handle is partially validated in acpi_ex_reconfiguration(),
* when it calls acpi_ex_resolve_operands(), the handle is more completely
* validated here.
*/
if ((!ddb_handle) ||
(ACPI_GET_DESCRIPTOR_TYPE(ddb_handle) != ACPI_DESC_TYPE_OPERAND) ||
(ddb_handle->common.type != ACPI_TYPE_LOCAL_REFERENCE)) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Get the table index from the ddb_handle */
table_index = table_desc->reference.value;
/* Invoke table handler if present */
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);
}
}
/* Delete the portion of the namespace owned by this table */
status = acpi_tb_delete_namespace_by_owner(table_index);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
(void)acpi_tb_release_owner_id(table_index);
acpi_tb_set_table_loaded_flag(table_index, FALSE);
/* Table unloaded, remove a reference to the ddb_handle object */
acpi_ut_remove_reference(ddb_handle);
return_ACPI_STATUS(AE_OK);
}