u-boot/libfdt/libfdt_internal.h
David Gibson a22d9cfbb5 libfdt: Rework/cleanup fdt_next_tag()
Currently, callers of fdt_next_tag() must usually follow the call with
some sort of call to fdt_offset_ptr() to verify that the blob isn't
truncated in the middle of the tag data they're going to process.
This is a bit silly, since fdt_next_tag() generally has to call
fdt_offset_ptr() on at least some of the data following the tag for
its own operation.

This patch alters fdt_next_tag() to always use fdt_offset_ptr() to
verify the data between its starting offset and the offset it returns
in nextoffset.  This simplifies fdt_get_property() which no longer has
to verify itself that the property data is all present.

At the same time, I neaten and clarify the error handling for
fdt_next_tag().  Previously, fdt_next_tag() could return -1 instead of
a tag value in some circumstances - which almost none of the callers
checked for.  Also, fdt_next_tag() could return FDT_END either because
it encountered an FDT_END tag, or because it reached the end of the
structure block - no way was provided to tell between these cases.

With this patch, fdt_next_tag() always returns FDT_END with a negative
value in nextoffset for an error.  This means the several places which
loop looking for FDT_END will still work correctly - they only need to
check for errors at the end.  The errors which fdt_next_tag() can
report are:
	- -FDT_ERR_TRUNCATED if it reached the end of the structure
	   block instead of finding a tag.

	- -FDT_BADSTRUCTURE if a bad tag was encountered, or if the
           tag data couldn't be verified with fdt_offset_ptr().

This patch also updates the callers of fdt_next_tag(), where
appropriate, to make use of the new error reporting.

Finally, the prototype for the long gone _fdt_next_tag() is removed
from libfdt_internal.h.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2009-04-01 19:29:31 -04:00

95 lines
3.5 KiB
C

#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_check_node_offset(const void *fdt, int offset);
const char *_fdt_find_string(const char *strtab, int tabsize, const char *s);
int _fdt_node_end_offset(void *fdt, int nodeoffset);
static inline const void *_fdt_offset_ptr(const void *fdt, int offset)
{
return (const char *)fdt + fdt_off_dt_struct(fdt) + offset;
}
static inline void *_fdt_offset_ptr_w(void *fdt, int offset)
{
return (void *)(uintptr_t)_fdt_offset_ptr(fdt, offset);
}
static inline const struct fdt_reserve_entry *_fdt_mem_rsv(const void *fdt, int n)
{
const struct fdt_reserve_entry *rsv_table =
(const struct fdt_reserve_entry *)
((const char *)fdt + fdt_off_mem_rsvmap(fdt));
return rsv_table + n;
}
static inline struct fdt_reserve_entry *_fdt_mem_rsv_w(void *fdt, int n)
{
return (void *)(uintptr_t)_fdt_mem_rsv(fdt, n);
}
#define FDT_SW_MAGIC (~FDT_MAGIC)
#endif /* _LIBFDT_INTERNAL_H */