dtc/treesource.c
David Gibson b28464a550 Fix some potential unaligned accesses in dtc
Because of the convention of packed representations in property layouts,
it's not uncommon to have integer values in properties which aren't
naturally aligned.  Thus, there are several places in the dtc code where we
cast a potentially unaligned byte pointer into an integer pointer and load
it directly.  On a number of architectures (including sparc64 and arm) this
won't work and will cause a fault.  In some cases it may be trapped and
emulated by the kernel, but not always.

Therefore, replace such direct unaligned reads with a helper which will
handle unaligned data reads (a variant on the fdtXX_ld() functions already
used in libfdt).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-04-14 15:02:51 +10:00

345 lines
6.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation. 2005.
*/
#include "dtc.h"
#include "srcpos.h"
extern FILE *yyin;
extern int yyparse(void);
extern YYLTYPE yylloc;
struct dt_info *parser_output;
bool treesource_error;
struct dt_info *dt_from_source(const char *fname)
{
parser_output = NULL;
treesource_error = false;
srcfile_push(fname);
yyin = current_srcfile->f;
yylloc.file = current_srcfile;
if (yyparse() != 0)
die("Unable to parse input tree\n");
if (treesource_error)
die("Syntax error parsing input tree\n");
return parser_output;
}
static void write_prefix(FILE *f, int level)
{
int i;
for (i = 0; i < level; i++)
fputc('\t', f);
}
static bool isstring(char c)
{
return (isprint((unsigned char)c)
|| (c == '\0')
|| strchr("\a\b\t\n\v\f\r", c));
}
static void write_propval_string(FILE *f, const char *s, size_t len)
{
const char *end = s + len - 1;
if (!len)
return;
assert(*end == '\0');
fprintf(f, "\"");
while (s < end) {
char c = *s++;
switch (c) {
case '\a':
fprintf(f, "\\a");
break;
case '\b':
fprintf(f, "\\b");
break;
case '\t':
fprintf(f, "\\t");
break;
case '\n':
fprintf(f, "\\n");
break;
case '\v':
fprintf(f, "\\v");
break;
case '\f':
fprintf(f, "\\f");
break;
case '\r':
fprintf(f, "\\r");
break;
case '\\':
fprintf(f, "\\\\");
break;
case '\"':
fprintf(f, "\\\"");
break;
case '\0':
fprintf(f, "\\0");
break;
default:
if (isprint((unsigned char)c))
fprintf(f, "%c", c);
else
fprintf(f, "\\x%02"PRIx8, c);
}
}
fprintf(f, "\"");
}
static void write_propval_int(FILE *f, const char *p, size_t len, size_t width)
{
const char *end = p + len;
assert(len % width == 0);
for (; p < end; p += width) {
switch (width) {
case 1:
fprintf(f, "%02"PRIx8, *(const uint8_t*)p);
break;
case 2:
fprintf(f, "0x%02"PRIx16, dtb_ld16(p));
break;
case 4:
fprintf(f, "0x%02"PRIx32, dtb_ld32(p));
break;
case 8:
fprintf(f, "0x%02"PRIx64, dtb_ld64(p));
break;
}
if (p + width < end)
fputc(' ', f);
}
}
static bool has_data_type_information(struct marker *m)
{
return m->type >= TYPE_UINT8;
}
static struct marker *next_type_marker(struct marker *m)
{
while (m && !has_data_type_information(m))
m = m->next;
return m;
}
size_t type_marker_length(struct marker *m)
{
struct marker *next = next_type_marker(m->next);
if (next)
return next->offset - m->offset;
return 0;
}
static const char *delim_start[] = {
[TYPE_UINT8] = "[",
[TYPE_UINT16] = "/bits/ 16 <",
[TYPE_UINT32] = "<",
[TYPE_UINT64] = "/bits/ 64 <",
[TYPE_STRING] = "",
};
static const char *delim_end[] = {
[TYPE_UINT8] = "]",
[TYPE_UINT16] = ">",
[TYPE_UINT32] = ">",
[TYPE_UINT64] = ">",
[TYPE_STRING] = "",
};
static enum markertype guess_value_type(struct property *prop)
{
int len = prop->val.len;
const char *p = prop->val.val;
struct marker *m = prop->val.markers;
int nnotstring = 0, nnul = 0;
int nnotstringlbl = 0, nnotcelllbl = 0;
int i;
for (i = 0; i < len; i++) {
if (! isstring(p[i]))
nnotstring++;
if (p[i] == '\0')
nnul++;
}
for_each_marker_of_type(m, LABEL) {
if ((m->offset > 0) && (prop->val.val[m->offset - 1] != '\0'))
nnotstringlbl++;
if ((m->offset % sizeof(cell_t)) != 0)
nnotcelllbl++;
}
if ((p[len-1] == '\0') && (nnotstring == 0) && (nnul < (len-nnul))
&& (nnotstringlbl == 0)) {
return TYPE_STRING;
} else if (((len % sizeof(cell_t)) == 0) && (nnotcelllbl == 0)) {
return TYPE_UINT32;
}
return TYPE_UINT8;
}
static void write_propval(FILE *f, struct property *prop)
{
size_t len = prop->val.len;
struct marker *m = prop->val.markers;
struct marker dummy_marker;
enum markertype emit_type = TYPE_NONE;
char *srcstr;
if (len == 0) {
fprintf(f, ";");
if (annotate) {
srcstr = srcpos_string_first(prop->srcpos, annotate);
if (srcstr) {
fprintf(f, " /* %s */", srcstr);
free(srcstr);
}
}
fprintf(f, "\n");
return;
}
fprintf(f, " =");
if (!next_type_marker(m)) {
/* data type information missing, need to guess */
dummy_marker.type = guess_value_type(prop);
dummy_marker.next = prop->val.markers;
dummy_marker.offset = 0;
dummy_marker.ref = NULL;
m = &dummy_marker;
}
for_each_marker(m) {
size_t chunk_len = (m->next ? m->next->offset : len) - m->offset;
size_t data_len = type_marker_length(m) ? : len - m->offset;
const char *p = &prop->val.val[m->offset];
if (has_data_type_information(m)) {
emit_type = m->type;
fprintf(f, " %s", delim_start[emit_type]);
} else if (m->type == LABEL)
fprintf(f, " %s:", m->ref);
else if (m->offset)
fputc(' ', f);
if (emit_type == TYPE_NONE) {
assert(chunk_len == 0);
continue;
}
switch(emit_type) {
case TYPE_UINT16:
write_propval_int(f, p, chunk_len, 2);
break;
case TYPE_UINT32:
write_propval_int(f, p, chunk_len, 4);
break;
case TYPE_UINT64:
write_propval_int(f, p, chunk_len, 8);
break;
case TYPE_STRING:
write_propval_string(f, p, chunk_len);
break;
default:
write_propval_int(f, p, chunk_len, 1);
}
if (chunk_len == data_len) {
size_t pos = m->offset + chunk_len;
fprintf(f, pos == len ? "%s" : "%s,",
delim_end[emit_type] ? : "");
emit_type = TYPE_NONE;
}
}
fprintf(f, ";");
if (annotate) {
srcstr = srcpos_string_first(prop->srcpos, annotate);
if (srcstr) {
fprintf(f, " /* %s */", srcstr);
free(srcstr);
}
}
fprintf(f, "\n");
}
static void write_tree_source_node(FILE *f, struct node *tree, int level)
{
struct property *prop;
struct node *child;
struct label *l;
char *srcstr;
write_prefix(f, level);
for_each_label(tree->labels, l)
fprintf(f, "%s: ", l->label);
if (tree->name && (*tree->name))
fprintf(f, "%s {", tree->name);
else
fprintf(f, "/ {");
if (annotate) {
srcstr = srcpos_string_first(tree->srcpos, annotate);
if (srcstr) {
fprintf(f, " /* %s */", srcstr);
free(srcstr);
}
}
fprintf(f, "\n");
for_each_property(tree, prop) {
write_prefix(f, level+1);
for_each_label(prop->labels, l)
fprintf(f, "%s: ", l->label);
fprintf(f, "%s", prop->name);
write_propval(f, prop);
}
for_each_child(tree, child) {
fprintf(f, "\n");
write_tree_source_node(f, child, level+1);
}
write_prefix(f, level);
fprintf(f, "};");
if (annotate) {
srcstr = srcpos_string_last(tree->srcpos, annotate);
if (srcstr) {
fprintf(f, " /* %s */", srcstr);
free(srcstr);
}
}
fprintf(f, "\n");
}
void dt_to_source(FILE *f, struct dt_info *dti)
{
struct reserve_info *re;
fprintf(f, "/dts-v1/;\n\n");
for (re = dti->reservelist; re; re = re->next) {
struct label *l;
for_each_label(re->labels, l)
fprintf(f, "%s: ", l->label);
fprintf(f, "/memreserve/\t0x%016llx 0x%016llx;\n",
(unsigned long long)re->address,
(unsigned long long)re->size);
}
write_tree_source_node(f, dti->dt, 0);
}