u-boot/libfdt/fdt.c
Jon Loeliger 741a6d010d Fix an overflow case in fdt_offset_ptr() detected by GCC 4.3.
Using Gcc 4.3 detected this problem:

    ../dtc/libfdt/fdt.c: In function 'fdt_next_tag':
    ../dtc/libfdt/fdt.c:82: error: assuming signed overflow does not
    occur when assuming that (X + c) < X is always false

To fix the problem, treat the offset as an unsigned int.

The problem report and proposed fix were provided
by Steve Papacharalambous <stevep@freescale.com>.

Signed-off-by: Jon Loeliger <jdl@freescale.com>
2008-10-01 22:01:52 -04:00

205 lines
5.3 KiB
C

/*
* 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 "libfdt_env.h"
#ifndef USE_HOSTCC
#include <fdt.h>
#include <libfdt.h>
#else
#include "fdt_host.h"
#endif
#include "libfdt_internal.h"
int fdt_check_header(const void *fdt)
{
if (fdt_magic(fdt) == FDT_MAGIC) {
/* Complete tree */
if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
return -FDT_ERR_BADVERSION;
if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
return -FDT_ERR_BADVERSION;
} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
/* Unfinished sequential-write blob */
if (fdt_size_dt_struct(fdt) == 0)
return -FDT_ERR_BADSTATE;
} else {
return -FDT_ERR_BADMAGIC;
}
return 0;
}
const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
{
const char *p;
if (fdt_version(fdt) >= 0x11)
if (((offset + len) < offset)
|| ((offset + len) > fdt_size_dt_struct(fdt)))
return NULL;
p = _fdt_offset_ptr(fdt, offset);
if (p + len < p)
return NULL;
return p;
}
uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset)
{
const uint32_t *tagp, *lenp;
uint32_t tag;
const char *p;
if (offset % FDT_TAGSIZE)
return -1;
tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
if (! tagp)
return FDT_END; /* premature end */
tag = fdt32_to_cpu(*tagp);
offset += FDT_TAGSIZE;
switch (tag) {
case FDT_BEGIN_NODE:
/* skip name */
do {
p = fdt_offset_ptr(fdt, offset++, 1);
} while (p && (*p != '\0'));
if (! p)
return FDT_END;
break;
case FDT_PROP:
lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
if (! lenp)
return FDT_END;
/* skip name offset, length and value */
offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
break;
}
if (nextoffset)
*nextoffset = FDT_TAGALIGN(offset);
return tag;
}
int _fdt_check_node_offset(const void *fdt, int offset)
{
if ((offset < 0) || (offset % FDT_TAGSIZE)
|| (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
return -FDT_ERR_BADOFFSET;
return offset;
}
int fdt_next_node(const void *fdt, int offset, int *depth)
{
int nextoffset = 0;
uint32_t tag;
if (offset >= 0)
if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
return nextoffset;
do {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
switch (tag) {
case FDT_PROP:
case FDT_NOP:
break;
case FDT_BEGIN_NODE:
if (depth)
(*depth)++;
break;
case FDT_END_NODE:
if (depth)
(*depth)--;
break;
case FDT_END:
return -FDT_ERR_NOTFOUND;
default:
return -FDT_ERR_BADSTRUCTURE;
}
} while (tag != FDT_BEGIN_NODE);
return offset;
}
const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
{
int len = strlen(s) + 1;
const char *last = strtab + tabsize - len;
const char *p;
for (p = strtab; p <= last; p++)
if (memcmp(p, s, len) == 0)
return p;
return NULL;
}
int fdt_move(const void *fdt, void *buf, int bufsize)
{
FDT_CHECK_HEADER(fdt);
if (fdt_totalsize(fdt) > bufsize)
return -FDT_ERR_NOSPACE;
memmove(buf, fdt, fdt_totalsize(fdt));
return 0;
}