linux/drivers/acpi/acpica/utfileio.c
David E. Box ce5eb07339 ACPICA: Utilities: Validate full RSDP header
Implement proper RSDP validation in acpi_ut_read_table(). Prevents a segmentation
fault that can occur if a user passes the wrong file to iasl.

This patch is only useful for iasl, which is not shipped in the Linux
kernel.

After the new table reading utility functions are well tested, acpidump can
also switch to use the generic acpi_ut_read_table_xxx() APIs. Currently
this patch is no-op as acpidump does not link to the new APIs.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-08 14:22:25 +02:00

333 lines
9.3 KiB
C

/*******************************************************************************
*
* Module Name: utfileio - simple file I/O routines
*
******************************************************************************/
/*
* Copyright (C) 2000 - 2014, 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 "actables.h"
#include "acapps.h"
#ifdef ACPI_ASL_COMPILER
#include "aslcompiler.h"
#endif
#define _COMPONENT ACPI_CA_DEBUGGER
ACPI_MODULE_NAME("utfileio")
#ifdef ACPI_APPLICATION
/* Local prototypes */
static acpi_status
acpi_ut_check_text_mode_corruption(u8 *table,
u32 table_length, u32 file_length);
static acpi_status
acpi_ut_read_table(FILE * fp,
struct acpi_table_header **table, u32 *table_length);
/*******************************************************************************
*
* FUNCTION: acpi_ut_check_text_mode_corruption
*
* PARAMETERS: table - Table buffer
* table_length - Length of table from the table header
* file_length - Length of the file that contains the table
*
* RETURN: Status
*
* DESCRIPTION: Check table for text mode file corruption where all linefeed
* characters (LF) have been replaced by carriage return linefeed
* pairs (CR/LF).
*
******************************************************************************/
static acpi_status
acpi_ut_check_text_mode_corruption(u8 *table, u32 table_length, u32 file_length)
{
u32 i;
u32 pairs = 0;
if (table_length != file_length) {
ACPI_WARNING((AE_INFO,
"File length (0x%X) is not the same as the table length (0x%X)",
file_length, table_length));
}
/* Scan entire table to determine if each LF has been prefixed with a CR */
for (i = 1; i < file_length; i++) {
if (table[i] == 0x0A) {
if (table[i - 1] != 0x0D) {
/* The LF does not have a preceding CR, table not corrupted */
return (AE_OK);
} else {
/* Found a CR/LF pair */
pairs++;
}
i++;
}
}
if (!pairs) {
return (AE_OK);
}
/*
* Entire table scanned, each CR is part of a CR/LF pair --
* meaning that the table was treated as a text file somewhere.
*
* NOTE: We can't "fix" the table, because any existing CR/LF pairs in the
* original table are left untouched by the text conversion process --
* meaning that we cannot simply replace CR/LF pairs with LFs.
*/
acpi_os_printf("Table has been corrupted by text mode conversion\n");
acpi_os_printf("All LFs (%u) were changed to CR/LF pairs\n", pairs);
acpi_os_printf("Table cannot be repaired!\n");
return (AE_BAD_VALUE);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_read_table
*
* PARAMETERS: fp - File that contains table
* table - Return value, buffer with table
* table_length - Return value, length of table
*
* RETURN: Status
*
* DESCRIPTION: Load the DSDT from the file pointer
*
******************************************************************************/
static acpi_status
acpi_ut_read_table(FILE * fp,
struct acpi_table_header **table, u32 *table_length)
{
struct acpi_table_header table_header;
u32 actual;
acpi_status status;
u32 file_size;
u8 standard_header = TRUE;
s32 count;
/* Get the file size */
file_size = cm_get_file_size(fp);
if (file_size == ACPI_UINT32_MAX) {
return (AE_ERROR);
}
if (file_size < 4) {
return (AE_BAD_HEADER);
}
/* Read the signature */
fseek(fp, 0, SEEK_SET);
count = fread(&table_header, 1, sizeof(struct acpi_table_header), fp);
if (count != sizeof(struct acpi_table_header)) {
acpi_os_printf("Could not read the table header\n");
return (AE_BAD_HEADER);
}
/* The RSDP table does not have standard ACPI header */
if (ACPI_VALIDATE_RSDP_SIG(table_header.signature)) {
*table_length = file_size;
standard_header = FALSE;
} else {
#if 0
/* Validate the table header/length */
status = acpi_tb_validate_table_header(&table_header);
if (ACPI_FAILURE(status)) {
acpi_os_printf("Table header is invalid!\n");
return (status);
}
#endif
/* File size must be at least as long as the Header-specified length */
if (table_header.length > file_size) {
acpi_os_printf
("TableHeader length [0x%X] greater than the input file size [0x%X]\n",
table_header.length, file_size);
#ifdef ACPI_ASL_COMPILER
status = fl_check_for_ascii(fp, NULL, FALSE);
if (ACPI_SUCCESS(status)) {
acpi_os_printf
("File appears to be ASCII only, must be binary\n",
table_header.length, file_size);
}
#endif
return (AE_BAD_HEADER);
}
#ifdef ACPI_OBSOLETE_CODE
/* We only support a limited number of table types */
if (!ACPI_COMPARE_NAME
((char *)table_header.signature, ACPI_SIG_DSDT)
&& !ACPI_COMPARE_NAME((char *)table_header.signature,
ACPI_SIG_PSDT)
&& !ACPI_COMPARE_NAME((char *)table_header.signature,
ACPI_SIG_SSDT)) {
acpi_os_printf
("Table signature [%4.4s] is invalid or not supported\n",
(char *)table_header.signature);
ACPI_DUMP_BUFFER(&table_header,
sizeof(struct acpi_table_header));
return (AE_ERROR);
}
#endif
*table_length = table_header.length;
}
/* Allocate a buffer for the table */
*table = acpi_os_allocate((size_t) file_size);
if (!*table) {
acpi_os_printf
("Could not allocate memory for ACPI table %4.4s (size=0x%X)\n",
table_header.signature, *table_length);
return (AE_NO_MEMORY);
}
/* Get the rest of the table */
fseek(fp, 0, SEEK_SET);
actual = fread(*table, 1, (size_t) file_size, fp);
if (actual == file_size) {
if (standard_header) {
/* Now validate the checksum */
status = acpi_tb_verify_checksum((void *)*table,
ACPI_CAST_PTR(struct
acpi_table_header,
*table)->
length);
if (status == AE_BAD_CHECKSUM) {
status =
acpi_ut_check_text_mode_corruption((u8 *)
*table,
file_size,
(*table)->
length);
return (status);
}
}
return (AE_OK);
}
if (actual > 0) {
acpi_os_printf("Warning - reading table, asked for %X got %X\n",
file_size, actual);
return (AE_OK);
}
acpi_os_printf("Error - could not read the table file\n");
acpi_os_free(*table);
*table = NULL;
*table_length = 0;
return (AE_ERROR);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_read_table_from_file
*
* PARAMETERS: filename - File where table is located
* table - Where a pointer to the table is returned
*
* RETURN: Status
*
* DESCRIPTION: Get an ACPI table from a file
*
******************************************************************************/
acpi_status
acpi_ut_read_table_from_file(char *filename, struct acpi_table_header ** table)
{
FILE *file;
u32 file_size;
u32 table_length;
acpi_status status = AE_ERROR;
/* Open the file, get current size */
file = fopen(filename, "rb");
if (!file) {
perror("Could not open input file");
return (status);
}
file_size = cm_get_file_size(file);
if (file_size == ACPI_UINT32_MAX) {
goto exit;
}
/* Get the entire file */
fprintf(stderr,
"Loading Acpi table from file %10s - Length %.8u (%06X)\n",
filename, file_size, file_size);
status = acpi_ut_read_table(file, table, &table_length);
if (ACPI_FAILURE(status)) {
acpi_os_printf("Could not get table from the file\n");
}
exit:
fclose(file);
return (status);
}
#endif