// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
/*
* libfdt - Flat Device Tree manipulation
* Copyright (C) 2006 David Gibson, IBM Corporation.
*/
#include "libfdt_env.h"
#include <fdt.h>
#include <libfdt.h>
#include "libfdt_internal.h"
static int fdt_sw_probe_(void *fdt)
{
if (!can_assume(VALID_INPUT)) {
if (fdt_magic(fdt) == FDT_MAGIC)
return -FDT_ERR_BADSTATE;
else if (fdt_magic(fdt) != FDT_SW_MAGIC)
return -FDT_ERR_BADMAGIC;
}
return 0;
}
#define FDT_SW_PROBE(fdt) \
{ \
int err; \
if ((err = fdt_sw_probe_(fdt)) != 0) \
return err; \
}
/* 'memrsv' state: Initial state after fdt_create()
*
* Allowed functions:
* fdt_add_reservemap_entry()
* fdt_finish_reservemap() [moves to 'struct' state]
*/
static int fdt_sw_probe_memrsv_(void *fdt)
{
int err = fdt_sw_probe_(fdt);
if (err)
return err;
if (!can_assume(VALID_INPUT) && fdt_off_dt_strings(fdt) != 0)
return -FDT_ERR_BADSTATE;
return 0;
}
#define FDT_SW_PROBE_MEMRSV(fdt) \
{ \
int err; \
if ((err = fdt_sw_probe_memrsv_(fdt)) != 0) \
return err; \
}
/* 'struct' state: Enter this state after fdt_finish_reservemap()
*
* Allowed functions:
* fdt_begin_node()
* fdt_end_node()
* fdt_property*()
* fdt_finish() [moves to 'complete' state]
*/
static int fdt_sw_probe_struct_(void *fdt)
{
int err = fdt_sw_probe_(fdt);
if (err)
return err;
if (!can_assume(VALID_INPUT) &&
fdt_off_dt_strings(fdt) != fdt_totalsize(fdt))
return -FDT_ERR_BADSTATE;
return 0;
}
#define FDT_SW_PROBE_STRUCT(fdt) \
{ \
int err; \
if ((err = fdt_sw_probe_struct_(fdt)) != 0) \
return err; \
}
static inline uint32_t sw_flags(void *fdt)
{
/* assert: (fdt_magic(fdt) == FDT_SW_MAGIC) */
return fdt_last_comp_version(fdt);
}
/* 'complete' state: Enter this state after fdt_finish()
*
* Allowed functions: none
*/
static void *fdt_grab_space_(void *fdt, size_t len)
{
unsigned int offset = fdt_size_dt_struct(fdt);
unsigned int spaceleft;
spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
- fdt_size_dt_strings(fdt);
if ((offset + len < offset) || (offset + len > spaceleft))
return NULL;
fdt_set_size_dt_struct(fdt, offset + len);
return fdt_offset_ptr_w_(fdt, offset);
}
int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags)
{
const int hdrsize = FDT_ALIGN(sizeof(struct fdt_header),
sizeof(struct fdt_reserve_entry));
void *fdt = buf;
if (bufsize < hdrsize)
return -FDT_ERR_NOSPACE;
if (flags & ~FDT_CREATE_FLAGS_ALL)
return -FDT_ERR_BADFLAGS;
memset(buf, 0, bufsize);
/*
* magic and last_comp_version keep intermediate state during the fdt
* creation process, which is replaced with the proper FDT format by
* fdt_finish().
*
* flags should be accessed with sw_flags().
*/
fdt_set_magic(fdt, FDT_SW_MAGIC);
fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
fdt_set_last_comp_version(fdt, flags);
fdt_set_totalsize(fdt, bufsize);
fdt_set_off_mem_rsvmap(fdt, hdrsize);
fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
fdt_set_off_dt_strings(fdt, 0);
return 0;
}
int fdt_create(void *buf, int bufsize)
{
return fdt_create_with_flags(buf, bufsize, 0);
}
int fdt_resize(void *fdt, void *buf, int bufsize)
{
size_t headsize, tailsize;
char *oldtail, *newtail;
FDT_SW_PROBE(fdt);
if (bufsize < 0)
return -FDT_ERR_NOSPACE;
headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
tailsize = fdt_size_dt_strings(fdt);
if (!can_assume(VALID_DTB) &&
headsize + tailsize > fdt_totalsize(fdt))
return -FDT_ERR_INTERNAL;
if ((headsize + tailsize) > (unsigned)bufsize)
return -FDT_ERR_NOSPACE;
oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize;
newtail = (char *)buf + bufsize - tailsize;
/* Two cases to avoid clobbering data if the old and new
* buffers partially overlap */
if (buf <= fdt) {
memmove(buf, fdt, headsize);
memmove(newtail, oldtail, tailsize);
} else {
memmove(newtail, oldtail, tailsize);
memmove(buf, fdt, headsize);
}
fdt_set_totalsize(buf, bufsize);
if (fdt_off_dt_strings(buf))
fdt_set_off_dt_strings(buf, bufsize);
return 0;
}
int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
{
struct fdt_reserve_entry *re;
int offset;
FDT_SW_PROBE_MEMRSV(fdt);
offset = fdt_off_dt_struct(fdt);
if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
return -FDT_ERR_NOSPACE;
re = (struct fdt_reserve_entry *)((char *)fdt + offset);
re->address = cpu_to_fdt64(addr);
re->size = cpu_to_fdt64(size);
fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
return 0;
}
int fdt_finish_reservemap(void *fdt)
{
int err = fdt_add_reservemap_entry(fdt, 0, 0);
if (err)
return err;
fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt));
return 0;
}
int fdt_begin_node(void *fdt, const char *name)
{
struct fdt_node_header *nh;
int namelen;
FDT_SW_PROBE_STRUCT(fdt);
namelen = strlen(name) + 1;
nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
if (! nh)
return -FDT_ERR_NOSPACE;
nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
memcpy(nh->name, name, namelen);
return 0;
}
int fdt_end_node(void *fdt)
{
fdt32_t *en;
FDT_SW_PROBE_STRUCT(fdt);
en = fdt_grab_space_(fdt, FDT_TAGSIZE);
if (! en)
return -FDT_ERR_NOSPACE;
*en = cpu_to_fdt32(FDT_END_NODE);
return 0;
}
static int fdt_add_string_(void *fdt, const char *s)
{
char *strtab = (char *)fdt + fdt_totalsize(fdt);
unsigned int strtabsize = fdt_size_dt_strings(fdt);
unsigned int len = strlen(s) + 1;
unsigned int struct_top, offset;
offset = strtabsize + len;
struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
if (fdt_totalsize(fdt) - offset < struct_top)
return 0; /* no more room :( */
memcpy(strtab - offset, s, len);
fdt_set_size_dt_strings(fdt, strtabsize + len);
return -offset;
}
/* Must only be used to roll back in case of error */
static void fdt_del_last_string_(void *fdt, const char *s)
{
int strtabsize = fdt_size_dt_strings(fdt);
int len = strlen(s) + 1;
fdt_set_size_dt_strings(fdt, strtabsize - len);
}
static int fdt_find_add_string_(void *fdt, const char *s, int *allocated)
{
char *strtab = (char *)fdt + fdt_totalsize(fdt);
int strtabsize = fdt_size_dt_strings(fdt);
const char *p;
*allocated = 0;
p = fdt_find_string_(strtab - strtabsize, strtabsize, s);
if (p)
return p - strtab;
*allocated = 1;
return fdt_add_string_(fdt, s);
}
int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp)
{
struct fdt_property *prop;
int nameoff;
int allocated;
FDT_SW_PROBE_STRUCT(fdt);
/* String de-duplication can be slow, _NO_NAME_DEDUP skips it */
if (sw_flags(fdt) & FDT_CREATE_FLAG_NO_NAME_DEDUP) {
allocated = 1;
nameoff = fdt_add_string_(fdt, name);
} else {
nameoff = fdt_find_add_string_(fdt, name, &allocated);
}
if (nameoff == 0)
return -FDT_ERR_NOSPACE;
prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
if (! prop) {
if (allocated)
fdt_del_last_string_(fdt, name);
return -FDT_ERR_NOSPACE;
}
prop->tag = cpu_to_fdt32(FDT_PROP);
prop->nameoff = cpu_to_fdt32(nameoff);
prop->len = cpu_to_fdt32(len);
*valp = prop->data;
return 0;
}
int fdt_property(void *fdt, const char *name, const void *val, int len)
{
void *ptr;
int ret;
ret = fdt_property_placeholder(fdt, name, len, &ptr);
if (ret)
return ret;
memcpy(ptr, val, len);
return 0;
}
int fdt_finish(void *fdt)
{
char *p = (char *)fdt;
fdt32_t *end;
int oldstroffset, newstroffset;
uint32_t tag;
int offset, nextoffset;
FDT_SW_PROBE_STRUCT(fdt);
/* Add terminator */
end = fdt_grab_space_(fdt, sizeof(*end));
if (! end)
return -FDT_ERR_NOSPACE;
*end = cpu_to_fdt32(FDT_END);
/* Relocate the string table */
oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
fdt_set_off_dt_strings(fdt, newstroffset);
/* Walk the structure, correcting string offsets */
offset = 0;
while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
if (tag == FDT_PROP) {
struct fdt_property *prop =
fdt_offset_ptr_w_(fdt, offset);
int nameoff;
nameoff = fdt32_to_cpu(prop->nameoff);
nameoff += fdt_size_dt_strings(fdt);
prop->nameoff = cpu_to_fdt32(nameoff);
}
offset = nextoffset;
}
if (nextoffset < 0)
return nextoffset;
/* Finally, adjust the header */
fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
/* And fix up fields that were keeping intermediate state. */
fdt_set_last_comp_version(fdt, FDT_LAST_COMPATIBLE_VERSION);
fdt_set_magic(fdt, FDT_MAGIC);
return 0;
}
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