platform_external_dtc/yamltree.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

233 lines
6.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* (C) Copyright Linaro, Ltd. 2018
* (C) Copyright Arm Holdings. 2017
* (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation. 2005.
*/
#include <stdlib.h>
#include <yaml.h>
#include "dtc.h"
#include "srcpos.h"
char *yaml_error_name[] = {
[YAML_NO_ERROR] = "no error",
[YAML_MEMORY_ERROR] = "memory error",
[YAML_READER_ERROR] = "reader error",
[YAML_SCANNER_ERROR] = "scanner error",
[YAML_PARSER_ERROR] = "parser error",
[YAML_COMPOSER_ERROR] = "composer error",
[YAML_WRITER_ERROR] = "writer error",
[YAML_EMITTER_ERROR] = "emitter error",
};
#define yaml_emitter_emit_or_die(emitter, event) ( \
{ \
if (!yaml_emitter_emit(emitter, event)) \
die("yaml '%s': %s in %s, line %i\n", \
yaml_error_name[(emitter)->error], \
(emitter)->problem, __func__, __LINE__); \
})
static void yaml_propval_int(yaml_emitter_t *emitter, struct marker *markers, char *data, int len, int width)
{
yaml_event_t event;
void *tag;
int off, start_offset = markers->offset;
switch(width) {
case 1: tag = "!u8"; break;
case 2: tag = "!u16"; break;
case 4: tag = "!u32"; break;
case 8: tag = "!u64"; break;
default:
die("Invalid width %i", width);
}
assert(len % width == 0);
yaml_sequence_start_event_initialize(&event, NULL,
(yaml_char_t *)tag, width == 4, YAML_FLOW_SEQUENCE_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
for (off = 0; off < len; off += width) {
char buf[32];
struct marker *m;
bool is_phandle = false;
switch(width) {
case 1:
sprintf(buf, "0x%"PRIx8, *(uint8_t*)(data + off));
break;
case 2:
sprintf(buf, "0x%"PRIx16, dtb_ld16(data + off));
break;
case 4:
sprintf(buf, "0x%"PRIx32, dtb_ld32(data + off));
m = markers;
is_phandle = false;
for_each_marker_of_type(m, REF_PHANDLE) {
if (m->offset == (start_offset + off)) {
is_phandle = true;
break;
}
}
break;
case 8:
sprintf(buf, "0x%"PRIx64, dtb_ld64(data + off));
break;
}
if (is_phandle)
yaml_scalar_event_initialize(&event, NULL,
(yaml_char_t*)"!phandle", (yaml_char_t *)buf,
strlen(buf), 0, 0, YAML_PLAIN_SCALAR_STYLE);
else
yaml_scalar_event_initialize(&event, NULL,
(yaml_char_t*)YAML_INT_TAG, (yaml_char_t *)buf,
strlen(buf), 1, 1, YAML_PLAIN_SCALAR_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
}
yaml_sequence_end_event_initialize(&event);
yaml_emitter_emit_or_die(emitter, &event);
}
static void yaml_propval_string(yaml_emitter_t *emitter, char *str, int len)
{
yaml_event_t event;
int i;
assert(str[len-1] == '\0');
/* Make sure the entire string is in the lower 7-bit ascii range */
for (i = 0; i < len; i++)
assert(isascii(str[i]));
yaml_scalar_event_initialize(&event, NULL,
(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)str,
len-1, 0, 1, YAML_DOUBLE_QUOTED_SCALAR_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
}
static void yaml_propval(yaml_emitter_t *emitter, struct property *prop)
{
yaml_event_t event;
int len = prop->val.len;
struct marker *m = prop->val.markers;
/* Emit the property name */
yaml_scalar_event_initialize(&event, NULL,
(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)prop->name,
strlen(prop->name), 1, 1, YAML_PLAIN_SCALAR_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
/* Boolean properties are easiest to deal with. Length is zero, so just emit 'true' */
if (len == 0) {
yaml_scalar_event_initialize(&event, NULL,
(yaml_char_t *)YAML_BOOL_TAG,
(yaml_char_t*)"true",
strlen("true"), 1, 0, YAML_PLAIN_SCALAR_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
return;
}
if (!m)
die("No markers present in property '%s' value\n", prop->name);
yaml_sequence_start_event_initialize(&event, NULL,
(yaml_char_t *)YAML_SEQ_TAG, 1, YAML_FLOW_SEQUENCE_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
for_each_marker(m) {
int chunk_len;
char *data = &prop->val.val[m->offset];
if (m->type < TYPE_UINT8)
continue;
chunk_len = type_marker_length(m) ? : len;
assert(chunk_len > 0);
len -= chunk_len;
switch(m->type) {
case TYPE_UINT16:
yaml_propval_int(emitter, m, data, chunk_len, 2);
break;
case TYPE_UINT32:
yaml_propval_int(emitter, m, data, chunk_len, 4);
break;
case TYPE_UINT64:
yaml_propval_int(emitter, m, data, chunk_len, 8);
break;
case TYPE_STRING:
yaml_propval_string(emitter, data, chunk_len);
break;
default:
yaml_propval_int(emitter, m, data, chunk_len, 1);
break;
}
}
yaml_sequence_end_event_initialize(&event);
yaml_emitter_emit_or_die(emitter, &event);
}
static void yaml_tree(struct node *tree, yaml_emitter_t *emitter)
{
struct property *prop;
struct node *child;
yaml_event_t event;
if (tree->deleted)
return;
yaml_mapping_start_event_initialize(&event, NULL,
(yaml_char_t *)YAML_MAP_TAG, 1, YAML_ANY_MAPPING_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
for_each_property(tree, prop)
yaml_propval(emitter, prop);
/* Loop over all the children, emitting them into the map */
for_each_child(tree, child) {
yaml_scalar_event_initialize(&event, NULL,
(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)child->name,
strlen(child->name), 1, 0, YAML_PLAIN_SCALAR_STYLE);
yaml_emitter_emit_or_die(emitter, &event);
yaml_tree(child, emitter);
}
yaml_mapping_end_event_initialize(&event);
yaml_emitter_emit_or_die(emitter, &event);
}
void dt_to_yaml(FILE *f, struct dt_info *dti)
{
yaml_emitter_t emitter;
yaml_event_t event;
yaml_emitter_initialize(&emitter);
yaml_emitter_set_output_file(&emitter, f);
yaml_stream_start_event_initialize(&event, YAML_UTF8_ENCODING);
yaml_emitter_emit_or_die(&emitter, &event);
yaml_document_start_event_initialize(&event, NULL, NULL, NULL, 0);
yaml_emitter_emit_or_die(&emitter, &event);
yaml_sequence_start_event_initialize(&event, NULL, (yaml_char_t *)YAML_SEQ_TAG, 1, YAML_ANY_SEQUENCE_STYLE);
yaml_emitter_emit_or_die(&emitter, &event);
yaml_tree(dti->dt, &emitter);
yaml_sequence_end_event_initialize(&event);
yaml_emitter_emit_or_die(&emitter, &event);
yaml_document_end_event_initialize(&event, 0);
yaml_emitter_emit_or_die(&emitter, &event);
yaml_stream_end_event_initialize(&event);
yaml_emitter_emit_or_die(&emitter, &event);
yaml_emitter_delete(&emitter);
}