diff options
Diffstat (limited to 'scripts/dtc/libfdt/libfdt_internal.h')
| -rw-r--r-- | scripts/dtc/libfdt/libfdt_internal.h | 144 |
1 files changed, 93 insertions, 51 deletions
diff --git a/scripts/dtc/libfdt/libfdt_internal.h b/scripts/dtc/libfdt/libfdt_internal.h index 7681e19229..5436e2ceea 100644 --- a/scripts/dtc/libfdt/libfdt_internal.h +++ b/scripts/dtc/libfdt/libfdt_internal.h @@ -1,65 +1,24 @@ +/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */ #ifndef LIBFDT_INTERNAL_H #define LIBFDT_INTERNAL_H /* * libfdt - Flat Device Tree manipulation * Copyright (C) 2006 David Gibson, IBM Corporation. - * - * libfdt is dual licensed: you can use it either under the terms of - * the GPL, or the BSD license, at your option. - * - * a) This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public - * License along with this library; if not, write to the Free - * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, - * MA 02110-1301 USA - * - * Alternatively, - * - * b) 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. - * 2. Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following - * disclaimer in the documentation and/or other materials - * provided with the distribution. - * - * 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 - * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE - * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR - * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * 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 DAMAGE. */ #include <fdt.h> #define FDT_ALIGN(x, a) (((x) + (a) - 1) & ~((a) - 1)) #define FDT_TAGALIGN(x) (FDT_ALIGN((x), FDT_TAGSIZE)) -#define FDT_CHECK_HEADER(fdt) \ - { \ - int err_; \ - if ((err_ = fdt_check_header(fdt)) != 0) \ - return err_; \ +int fdt_ro_probe_(const void *fdt); +#define FDT_RO_PROBE(fdt) \ + { \ + int totalsize_; \ + if (fdt_chk_basic()) { \ + totalsize_ = fdt_ro_probe_(fdt); \ + if (totalsize_ < 0) \ + return totalsize_; \ + } \ } int fdt_check_node_offset_(const void *fdt, int offset); @@ -92,4 +51,87 @@ static inline struct fdt_reserve_entry *fdt_mem_rsv_w_(void *fdt, int n) #define FDT_SW_MAGIC (~FDT_MAGIC) +/**********************************************************************/ +/* Checking controls */ +/**********************************************************************/ + +#ifndef FDT_ASSUME_MASK +#define FDT_ASSUME_MASK 0 +#endif + +/* + * Defines assumptions which can be enabled. Each of these can be enabled + * individually. For maximum saftey, don't enable any assumptions! + * + * For minimal code size and no safety, use FDT_ASSUME_PERFECT at your own risk. + * You should have another method of validating the device tree, such as a + * signature or hash check before using libfdt. + * + * For situations where security is not a concern it may be safe to enable + * FDT_ASSUME_FRIENDLY. + */ +enum { + /* + * This does essentially no checks. Only the latest device-tree + * version is correctly handled. Incosistencies or errors in the device + * tree may cause undefined behaviour or crashes. + * + * If an error occurs when modifying the tree it may leave the tree in + * an intermediate (but valid) state. As an example, adding a property + * where there is insufficient space may result in the property name + * being added to the string table even though the property itself is + * not added to the struct section. + * + * Only use this if you have a fully validated device tree with + * the latest supported version and wish to minimise code size. + */ + FDT_ASSUME_PERFECT = 0xff, + + /* + * This assumes that the device tree is sane. i.e. header metadata + * and basic hierarchy are correct. + * + * These checks will be sufficient if you have a valid device tree with + * no internal inconsistencies. With this assumption, libfdt will + * generally not return -FDT_ERR_INTERNAL, -FDT_ERR_BADLAYOUT, etc. + */ + FDT_ASSUME_SANE = 1 << 0, + + /* + * This disables checks for device-tree version and removes all code + * which handles older versions. + * + * Only enable this if you know you have a device tree with the latest + * version. + */ + FDT_ASSUME_LATEST = 1 << 1, + + /* + * This disables any extensive checking of parameters and the device + * tree, making various assumptions about correctness. Normal device + * trees produced by libfdt and the compiler should be handled safely. + * Malicious device trees and complete garbage may cause libfdt to + * behave badly or crash. + */ + FDT_ASSUME_FRIENDLY = 1 << 2, +}; + +/** fdt_chk_basic() - see if basic checking of params and DT data is enabled */ +static inline bool fdt_chk_basic(void) +{ + return !(FDT_ASSUME_MASK & FDT_ASSUME_SANE); +} + +/** fdt_chk_version() - see if we need to handle old versions of the DT */ +static inline bool fdt_chk_version(void) +{ + return !(FDT_ASSUME_MASK & FDT_ASSUME_LATEST); +} + +/** fdt_chk_extra() - see if extra checking is enabled */ +static inline bool fdt_chk_extra(void) +{ + return !(FDT_ASSUME_MASK & FDT_ASSUME_FRIENDLY); +} + #endif /* LIBFDT_INTERNAL_H */ |