ACPICA: Fix for access to deleted object <regression>

[linux-2.6/mini2440.git] / drivers / acpi / parser / psargs.c

/******************************************************************************
 *
 * Module Name: psargs - Parse AML opcode arguments
 *
 *****************************************************************************/

/*
 * 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 <acpi/acparser.h>
#include <acpi/amlcode.h>
#include <acpi/acnamesp.h>
#include <acpi/acdispat.h>

#define _COMPONENT          ACPI_PARSER
ACPI_MODULE_NAME("psargs")

/* Local prototypes */
static u32
acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state);

static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
                                                       *parser_state);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_next_package_length
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Decoded package length. On completion, the AML pointer points
 *              past the length byte or bytes.
 *
 * DESCRIPTION: Decode and return a package length field.
 *              Note: Largest package length is 28 bits, from ACPI specification
 *
 ******************************************************************************/

static u32
acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
{
        u8 *aml = parser_state->aml;
        u32 package_length = 0;
        acpi_native_uint byte_count;
        u8 byte_zero_mask = 0x3F;       /* Default [0:5] */

        ACPI_FUNCTION_TRACE(ps_get_next_package_length);

        /*
         * Byte 0 bits [6:7] contain the number of additional bytes
         * used to encode the package length, either 0,1,2, or 3
         */
        byte_count = (aml[0] >> 6);
        parser_state->aml += (byte_count + 1);

        /* Get bytes 3, 2, 1 as needed */

        while (byte_count) {
                /*
                 * Final bit positions for the package length bytes:
                 *      Byte3->[20:27]
                 *      Byte2->[12:19]
                 *      Byte1->[04:11]
                 *      Byte0->[00:03]
                 */
                package_length |= (aml[byte_count] << ((byte_count << 3) - 4));

                byte_zero_mask = 0x0F;  /* Use bits [0:3] of byte 0 */
                byte_count--;
        }

        /* Byte 0 is a special case, either bits [0:3] or [0:5] are used */

        package_length |= (aml[0] & byte_zero_mask);
        return_UINT32(package_length);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_next_package_end
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Pointer to end-of-package +1
 *
 * DESCRIPTION: Get next package length and return a pointer past the end of
 *              the package.  Consumes the package length field
 *
 ******************************************************************************/

u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
{
        u8 *start = parser_state->aml;
        u32 package_length;

        ACPI_FUNCTION_TRACE(ps_get_next_package_end);

        /* Function below updates parser_state->Aml */

        package_length = acpi_ps_get_next_package_length(parser_state);

        return_PTR(start + package_length);     /* end of package */
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_next_namestring
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Pointer to the start of the name string (pointer points into
 *              the AML.
 *
 * DESCRIPTION: Get next raw namestring within the AML stream.  Handles all name
 *              prefix characters.  Set parser state to point past the string.
 *              (Name is consumed from the AML.)
 *
 ******************************************************************************/

char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
{
        u8 *start = parser_state->aml;
        u8 *end = parser_state->aml;

        ACPI_FUNCTION_TRACE(ps_get_next_namestring);

        /* Point past any namestring prefix characters (backslash or carat) */

        while (acpi_ps_is_prefix_char(*end)) {
                end++;
        }

        /* Decode the path prefix character */

        switch (*end) {
        case 0:

                /* null_name */

                if (end == start) {
                        start = NULL;
                }
                end++;
                break;

        case AML_DUAL_NAME_PREFIX:

                /* Two name segments */

                end += 1 + (2 * ACPI_NAME_SIZE);
                break;

        case AML_MULTI_NAME_PREFIX_OP:

                /* Multiple name segments, 4 chars each, count in next byte */

                end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
                break;

        default:

                /* Single name segment */

                end += ACPI_NAME_SIZE;
                break;
        }

        parser_state->aml = end;
        return_PTR((char *)start);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_next_namepath
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              Arg                 - Where the namepath will be stored
 *              arg_count           - If the namepath points to a control method
 *                                    the method's argument is returned here.
 *              possible_method_call - Whether the namepath can possibly be the
 *                                    start of a method call
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Get next name (if method call, return # of required args).
 *              Names are looked up in the internal namespace to determine
 *              if the name represents a control method.  If a method
 *              is found, the number of arguments to the method is returned.
 *              This information is critical for parsing to continue correctly.
 *
 ******************************************************************************/

acpi_status
acpi_ps_get_next_namepath(struct acpi_walk_state *walk_state,
                          struct acpi_parse_state *parser_state,
                          union acpi_parse_object *arg, u8 possible_method_call)
{
        acpi_status status;
        char *path;
        union acpi_parse_object *name_op;
        union acpi_operand_object *method_desc;
        struct acpi_namespace_node *node;
        u8 *start = parser_state->aml;

        ACPI_FUNCTION_TRACE(ps_get_next_namepath);

        path = acpi_ps_get_next_namestring(parser_state);
        acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);

        /* Null path case is allowed, just exit */

        if (!path) {
                arg->common.value.name = path;
                return_ACPI_STATUS(AE_OK);
        }

        /*
         * Lookup the name in the internal namespace, starting with the current
         * scope. We don't want to add anything new to the namespace here,
         * however, so we use MODE_EXECUTE.
         * Allow searching of the parent tree, but don't open a new scope -
         * we just want to lookup the object (must be mode EXECUTE to perform
         * the upsearch)
         */
        status = acpi_ns_lookup(walk_state->scope_info, path,
                                ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
                                ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
                                NULL, &node);

        /*
         * If this name is a control method invocation, we must
         * setup the method call
         */
        if (ACPI_SUCCESS(status) &&
            possible_method_call && (node->type == ACPI_TYPE_METHOD)) {
                if (walk_state->opcode == AML_UNLOAD_OP) {
                        /*
                         * acpi_ps_get_next_namestring has increased the AML pointer,
                         * so we need to restore the saved AML pointer for method call.
                         */
                        walk_state->parser_state.aml = start;
                        walk_state->arg_count = 1;
                        acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
                        return_ACPI_STATUS(AE_OK);
                }

                /* This name is actually a control method invocation */

                method_desc = acpi_ns_get_attached_object(node);
                ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
                                  "Control Method - %p Desc %p Path=%p\n", node,
                                  method_desc, path));

                name_op = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
                if (!name_op) {
                        return_ACPI_STATUS(AE_NO_MEMORY);
                }

                /* Change Arg into a METHOD CALL and attach name to it */

                acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
                name_op->common.value.name = path;

                /* Point METHODCALL/NAME to the METHOD Node */

                name_op->common.node = node;
                acpi_ps_append_arg(arg, name_op);

                if (!method_desc) {
                        ACPI_ERROR((AE_INFO,
                                    "Control Method %p has no attached object",
                                    node));
                        return_ACPI_STATUS(AE_AML_INTERNAL);
                }

                ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
                                  "Control Method - %p Args %X\n",
                                  node, method_desc->method.param_count));

                /* Get the number of arguments to expect */

                walk_state->arg_count = method_desc->method.param_count;
                return_ACPI_STATUS(AE_OK);
        }

        /*
         * Special handling if the name was not found during the lookup -
         * some not_found cases are allowed
         */
        if (status == AE_NOT_FOUND) {

                /* 1) not_found is ok during load pass 1/2 (allow forward references) */

                if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) !=
                    ACPI_PARSE_EXECUTE) {
                        status = AE_OK;
                }

                /* 2) not_found during a cond_ref_of(x) is ok by definition */

                else if (walk_state->op->common.aml_opcode ==
                         AML_COND_REF_OF_OP) {
                        status = AE_OK;
                }

                /*
                 * 3) not_found while building a Package is ok at this point, we
                 * may flag as an error later if slack mode is not enabled.
                 * (Some ASL code depends on allowing this behavior)
                 */
                else if ((arg->common.parent) &&
                         ((arg->common.parent->common.aml_opcode ==
                           AML_PACKAGE_OP)
                          || (arg->common.parent->common.aml_opcode ==
                              AML_VAR_PACKAGE_OP))) {
                        status = AE_OK;
                }
        }

        /* Final exception check (may have been changed from code above) */

        if (ACPI_FAILURE(status)) {
                ACPI_ERROR_NAMESPACE(path, status);

                if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
                    ACPI_PARSE_EXECUTE) {

                        /* Report a control method execution error */

                        status = acpi_ds_method_error(status, walk_state);
                }
        }

        /* Save the namepath */

        arg->common.value.name = path;
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_next_simple_arg
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              arg_type            - The argument type (AML_*_ARG)
 *              Arg                 - Where the argument is returned
 *
 * RETURN:      None
 *
 * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
 *
 ******************************************************************************/

void
acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
                            u32 arg_type, union acpi_parse_object *arg)
{
        u32 length;
        u16 opcode;
        u8 *aml = parser_state->aml;

        ACPI_FUNCTION_TRACE_U32(ps_get_next_simple_arg, arg_type);

        switch (arg_type) {
        case ARGP_BYTEDATA:

                /* Get 1 byte from the AML stream */

                opcode = AML_BYTE_OP;
                arg->common.value.integer = (acpi_integer) * aml;
                length = 1;
                break;

        case ARGP_WORDDATA:

                /* Get 2 bytes from the AML stream */

                opcode = AML_WORD_OP;
                ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
                length = 2;
                break;

        case ARGP_DWORDDATA:

                /* Get 4 bytes from the AML stream */

                opcode = AML_DWORD_OP;
                ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
                length = 4;
                break;

        case ARGP_QWORDDATA:

                /* Get 8 bytes from the AML stream */

                opcode = AML_QWORD_OP;
                ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
                length = 8;
                break;

        case ARGP_CHARLIST:

                /* Get a pointer to the string, point past the string */

                opcode = AML_STRING_OP;
                arg->common.value.string = ACPI_CAST_PTR(char, aml);

                /* Find the null terminator */

                length = 0;
                while (aml[length]) {
                        length++;
                }
                length++;
                break;

        case ARGP_NAME:
        case ARGP_NAMESTRING:

                acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
                arg->common.value.name =
                    acpi_ps_get_next_namestring(parser_state);
                return_VOID;

        default:

                ACPI_ERROR((AE_INFO, "Invalid ArgType %X", arg_type));
                return_VOID;
        }

        acpi_ps_init_op(arg, opcode);
        parser_state->aml += length;
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_next_field
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      A newly allocated FIELD op
 *
 * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
 *
 ******************************************************************************/

static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
                                                       *parser_state)
{
        u32 aml_offset = (u32)
            ACPI_PTR_DIFF(parser_state->aml,
                          parser_state->aml_start);
        union acpi_parse_object *field;
        u16 opcode;
        u32 name;

        ACPI_FUNCTION_TRACE(ps_get_next_field);

        /* Determine field type */

        switch (ACPI_GET8(parser_state->aml)) {
        default:

                opcode = AML_INT_NAMEDFIELD_OP;
                break;

        case 0x00:

                opcode = AML_INT_RESERVEDFIELD_OP;
                parser_state->aml++;
                break;

        case 0x01:

                opcode = AML_INT_ACCESSFIELD_OP;
                parser_state->aml++;
                break;
        }

        /* Allocate a new field op */

        field = acpi_ps_alloc_op(opcode);
        if (!field) {
                return_PTR(NULL);
        }

        field->common.aml_offset = aml_offset;

        /* Decode the field type */

        switch (opcode) {
        case AML_INT_NAMEDFIELD_OP:

                /* Get the 4-character name */

                ACPI_MOVE_32_TO_32(&name, parser_state->aml);
                acpi_ps_set_name(field, name);
                parser_state->aml += ACPI_NAME_SIZE;

                /* Get the length which is encoded as a package length */

                field->common.value.size =
                    acpi_ps_get_next_package_length(parser_state);
                break;

        case AML_INT_RESERVEDFIELD_OP:

                /* Get the length which is encoded as a package length */

                field->common.value.size =
                    acpi_ps_get_next_package_length(parser_state);
                break;

        case AML_INT_ACCESSFIELD_OP:

                /*
                 * Get access_type and access_attrib and merge into the field Op
                 * access_type is first operand, access_attribute is second
                 */
                field->common.value.integer =
                    (((u32) ACPI_GET8(parser_state->aml) << 8));
                parser_state->aml++;
                field->common.value.integer |= ACPI_GET8(parser_state->aml);
                parser_state->aml++;
                break;

        default:

                /* Opcode was set in previous switch */
                break;
        }

        return_PTR(field);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_next_arg
 *
 * PARAMETERS:  walk_state          - Current state
 *              parser_state        - Current parser state object
 *              arg_type            - The argument type (AML_*_ARG)
 *              return_arg          - Where the next arg is returned
 *
 * RETURN:      Status, and an op object containing the next argument.
 *
 * DESCRIPTION: Get next argument (including complex list arguments that require
 *              pushing the parser stack)
 *
 ******************************************************************************/

acpi_status
acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
                     struct acpi_parse_state *parser_state,
                     u32 arg_type, union acpi_parse_object **return_arg)
{
        union acpi_parse_object *arg = NULL;
        union acpi_parse_object *prev = NULL;
        union acpi_parse_object *field;
        u32 subop;
        acpi_status status = AE_OK;

        ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);

        switch (arg_type) {
        case ARGP_BYTEDATA:
        case ARGP_WORDDATA:
        case ARGP_DWORDDATA:
        case ARGP_CHARLIST:
        case ARGP_NAME:
        case ARGP_NAMESTRING:

                /* Constants, strings, and namestrings are all the same size */

                arg = acpi_ps_alloc_op(AML_BYTE_OP);
                if (!arg) {
                        return_ACPI_STATUS(AE_NO_MEMORY);
                }
                acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
                break;

        case ARGP_PKGLENGTH:

                /* Package length, nothing returned */

                parser_state->pkg_end =
                    acpi_ps_get_next_package_end(parser_state);
                break;

        case ARGP_FIELDLIST:

                if (parser_state->aml < parser_state->pkg_end) {

                        /* Non-empty list */

                        while (parser_state->aml < parser_state->pkg_end) {
                                field = acpi_ps_get_next_field(parser_state);
                                if (!field) {
                                        return_ACPI_STATUS(AE_NO_MEMORY);
                                }

                                if (prev) {
                                        prev->common.next = field;
                                } else {
                                        arg = field;
                                }
                                prev = field;
                        }

                        /* Skip to End of byte data */

                        parser_state->aml = parser_state->pkg_end;
                }
                break;

        case ARGP_BYTELIST:

                if (parser_state->aml < parser_state->pkg_end) {

                        /* Non-empty list */

                        arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
                        if (!arg) {
                                return_ACPI_STATUS(AE_NO_MEMORY);
                        }

                        /* Fill in bytelist data */

                        arg->common.value.size = (u32)
                            ACPI_PTR_DIFF(parser_state->pkg_end,
                                          parser_state->aml);
                        arg->named.data = parser_state->aml;

                        /* Skip to End of byte data */

                        parser_state->aml = parser_state->pkg_end;
                }
                break;

        case ARGP_TARGET:
        case ARGP_SUPERNAME:
        case ARGP_SIMPLENAME:

                subop = acpi_ps_peek_opcode(parser_state);
                if (subop == 0 ||
                    acpi_ps_is_leading_char(subop) ||
                    acpi_ps_is_prefix_char(subop)) {

                        /* null_name or name_string */

                        arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
                        if (!arg) {
                                return_ACPI_STATUS(AE_NO_MEMORY);
                        }

                        /* To support super_name arg of Unload */

                        if (walk_state->opcode == AML_UNLOAD_OP) {
                                status =
                                    acpi_ps_get_next_namepath(walk_state,
                                                              parser_state, arg,
                                                              1);

                                /*
                                 * If the super_name arg of Unload is a method call,
                                 * we have restored the AML pointer, just free this Arg
                                 */
                                if (arg->common.aml_opcode ==
                                    AML_INT_METHODCALL_OP) {
                                        acpi_ps_free_op(arg);
                                        arg = NULL;
                                }
                        } else {
                                status =
                                    acpi_ps_get_next_namepath(walk_state,
                                                              parser_state, arg,
                                                              0);
                        }
                } else {
                        /* Single complex argument, nothing returned */

                        walk_state->arg_count = 1;
                }
                break;

        case ARGP_DATAOBJ:
        case ARGP_TERMARG:

                /* Single complex argument, nothing returned */

                walk_state->arg_count = 1;
                break;

        case ARGP_DATAOBJLIST:
        case ARGP_TERMLIST:
        case ARGP_OBJLIST:

                if (parser_state->aml < parser_state->pkg_end) {

                        /* Non-empty list of variable arguments, nothing returned */

                        walk_state->arg_count = ACPI_VAR_ARGS;
                }
                break;

        default:

                ACPI_ERROR((AE_INFO, "Invalid ArgType: %X", arg_type));
                status = AE_AML_OPERAND_TYPE;
                break;
        }

        *return_arg = arg;
        return_ACPI_STATUS(status);
}