// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: exnames - interpreter/scanner name load/execute
*
* Copyright (C) 2000 - 2023, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#include "amlcode.h"
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME("exnames")
/* Local prototypes */
static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs);
static acpi_status acpi_ex_name_segment(u8 **in_aml_address, char *name_string);
/*******************************************************************************
*
* FUNCTION: acpi_ex_allocate_name_string
*
* PARAMETERS: prefix_count - Count of parent levels. Special cases:
* (-1)==root, 0==none
* num_name_segs - count of 4-character name segments
*
* RETURN: A pointer to the allocated string segment. This segment must
* be deleted by the caller.
*
* DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
* string is long enough, and set up prefix if any.
*
******************************************************************************/
static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs)
{
char *temp_ptr;
char *name_string;
u32 size_needed;
ACPI_FUNCTION_TRACE(ex_allocate_name_string);
/*
* Allow room for all \ and ^ prefixes, all segments and a multi_name_prefix.
* Also, one byte for the null terminator.
* This may actually be somewhat longer than needed.
*/
if (prefix_count == ACPI_UINT32_MAX) {
/* Special case for root */
size_needed = 1 + (ACPI_NAMESEG_SIZE * num_name_segs) + 2 + 1;
} else {
size_needed =
prefix_count + (ACPI_NAMESEG_SIZE * num_name_segs) + 2 + 1;
}
/*
* Allocate a buffer for the name.
* This buffer must be deleted by the caller!
*/
name_string = ACPI_ALLOCATE(size_needed);
if (!name_string) {
ACPI_ERROR((AE_INFO,
"Could not allocate size %u", size_needed));
return_PTR(NULL);
}
temp_ptr = name_string;
/* Set up Root or Parent prefixes if needed */
if (prefix_count == ACPI_UINT32_MAX) {
*temp_ptr++ = AML_ROOT_PREFIX;
} else {
while (prefix_count--) {
*temp_ptr++ = AML_PARENT_PREFIX;
}
}
/* Set up Dual or Multi prefixes if needed */
if (num_name_segs > 2) {
/* Set up multi prefixes */
*temp_ptr++ = AML_MULTI_NAME_PREFIX;
*temp_ptr++ = (char)num_name_segs;
} else if (2 == num_name_segs) {
/* Set up dual prefixes */
*temp_ptr++ = AML_DUAL_NAME_PREFIX;
}
/*
* Terminate string following prefixes. acpi_ex_name_segment() will
* append the segment(s)
*/
*temp_ptr = 0;
return_PTR(name_string);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_name_segment
*
* PARAMETERS: in_aml_address - Pointer to the name in the AML code
* name_string - Where to return the name. The name is appended
* to any existing string to form a namepath
*
* RETURN: Status
*
* DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
*
******************************************************************************/
static acpi_status acpi_ex_name_segment(u8 ** in_aml_address, char *name_string)
{
char *aml_address = (void *)*in_aml_address;
acpi_status status = AE_OK;
u32 index;
char char_buf[5];
ACPI_FUNCTION_TRACE(ex_name_segment);
/*
* If first character is a digit, then we know that we aren't looking
* at a valid name segment
*/
char_buf[0] = *aml_address;
if ('0' <= char_buf[0] && char_buf[0] <= '9') {
ACPI_ERROR((AE_INFO, "Invalid leading digit: %c", char_buf[0]));
return_ACPI_STATUS(AE_CTRL_PENDING);
}
for (index = 0;
(index < ACPI_NAMESEG_SIZE)
&& (acpi_ut_valid_name_char(*aml_address, 0)); index++) {
char_buf[index] = *aml_address++;
}
/* Valid name segment */
if (index == 4) {
/* Found 4 valid characters */
char_buf[4] = '\0';
if (name_string) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Appending NameSeg %s\n", char_buf));
strcat(name_string, char_buf);
} else {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"No Name string - %s\n", char_buf));
}
} else if (index == 0) {
/*
* First character was not a valid name character,
* so we are looking at something other than a name.
*/
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Leading character is not alpha: %02Xh (not a name)\n",
char_buf[0]));
status = AE_CTRL_PENDING;
} else {
/*
* Segment started with one or more valid characters, but fewer than
* the required 4
*/
status = AE_AML_BAD_NAME;
ACPI_ERROR((AE_INFO,
"Bad character 0x%02x in name, at %p",
*aml_address, aml_address));
}
*in_aml_address = ACPI_CAST_PTR(u8, aml_address);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_get_name_string
*
* PARAMETERS: data_type - Object type to be associated with this
* name
* in_aml_address - Pointer to the namestring in the AML code
* out_name_string - Where the namestring is returned
* out_name_length - Length of the returned string
*
* RETURN: Status, namestring and length
*
* DESCRIPTION: Extract a full namepath from the AML byte stream,
* including any prefixes.
*
******************************************************************************/
acpi_status
acpi_ex_get_name_string(acpi_object_type data_type,
u8 * in_aml_address,
char **out_name_string, u32 * out_name_length)
{
acpi_status status = AE_OK;
u8 *aml_address = in_aml_address;
char *name_string = NULL;
u32 num_segments;
u32 prefix_count = 0;
u8 has_prefix = FALSE;
ACPI_FUNCTION_TRACE_PTR(ex_get_name_string, aml_address);
if (ACPI_TYPE_LOCAL_REGION_FIELD == data_type ||
ACPI_TYPE_LOCAL_BANK_FIELD == data_type ||
ACPI_TYPE_LOCAL_INDEX_FIELD == data_type) {
/* Disallow prefixes for types associated with field_unit names */
name_string = acpi_ex_allocate_name_string(0, 1);
if (!name_string) {
status = AE_NO_MEMORY;
} else {
status =
acpi_ex_name_segment(&aml_address, name_string);
}
} else {
/*
* data_type is not a field name.
* Examine first character of name for root or parent prefix operators
*/
switch (*aml_address) {
case AML_ROOT_PREFIX:
ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
"RootPrefix(\\) at %p\n",
aml_address));
/*
* Remember that we have a root_prefix --
* see comment in acpi_ex_allocate_name_string()
*/
aml_address++;
prefix_count = ACPI_UINT32_MAX;
has_prefix = TRUE;
break;
case AML_PARENT_PREFIX:
/* Increment past possibly multiple parent prefixes */
do {
ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
"ParentPrefix (^) at %p\n",
aml_address));
aml_address++;
prefix_count++;
} while (*aml_address == AML_PARENT_PREFIX);
has_prefix = TRUE;
break;
default:
/* Not a prefix character */
break;
}
/* Examine first character of name for name segment prefix operator */
switch (*aml_address) {
case AML_DUAL_NAME_PREFIX:
ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
"DualNamePrefix at %p\n",
aml_address));
aml_address++;
name_string =
acpi_ex_allocate_name_string(prefix_count, 2);
if (!name_string) {
status = AE_NO_MEMORY;
break;
}
/* Indicate that we processed a prefix */
has_prefix = TRUE;
status =
acpi_ex_name_segment(&aml_address, name_string);
if (ACPI_SUCCESS(status)) {
status =
acpi_ex_name_segment(&aml_address,
name_string);
}
break;
case AML_MULTI_NAME_PREFIX:
ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
"MultiNamePrefix at %p\n",
aml_address));
/* Fetch count of segments remaining in name path */
aml_address++;
num_segments = *aml_address;
name_string =
acpi_ex_allocate_name_string(prefix_count,
num_segments);
if (!name_string) {
status = AE_NO_MEMORY;
break;
}
/* Indicate that we processed a prefix */
aml_address++;
has_prefix = TRUE;
while (num_segments &&
(status =
acpi_ex_name_segment(&aml_address,
name_string)) == AE_OK) {
num_segments--;
}
break;
case 0:
/* null_name valid as of 8-12-98 ASL/AML Grammar Update */
if (prefix_count == ACPI_UINT32_MAX) {
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
"NameSeg is \"\\\" followed by NULL\n"));
}
/* Consume the NULL byte */
aml_address++;
name_string =
acpi_ex_allocate_name_string(prefix_count, 0);
if (!name_string) {
status = AE_NO_MEMORY;
break;
}
break;
default:
/* Name segment string */
name_string =
acpi_ex_allocate_name_string(prefix_count, 1);
if (!name_string) {
status = AE_NO_MEMORY;
break;
}
status =
acpi_ex_name_segment(&aml_address, name_string);
break;
}
}
if (AE_CTRL_PENDING == status && has_prefix) {
/* Ran out of segments after processing a prefix */
ACPI_ERROR((AE_INFO, "Malformed Name at %p", name_string));
status = AE_AML_BAD_NAME;
}
if (ACPI_FAILURE(status)) {
if (name_string) {
ACPI_FREE(name_string);
}
return_ACPI_STATUS(status);
}
*out_name_string = name_string;
*out_name_length = (u32) (aml_address - in_aml_address);
return_ACPI_STATUS(status);
}
Codebase Browser
linux