radare2/libr/core/asm.c
2015-02-11 21:51:13 +01:00

659 lines
20 KiB
C

/* radare - LGPL - Copyright 2009-2012 - nibble */
#include <r_types.h>
#include <r_core.h>
#include <r_asm.h>
#define IFDBG if (0)
static RCoreAsmHit * find_addr(RList *hits, ut64 addr);
static int prune_hits_in_hit_range(RList *hits, RCoreAsmHit *hit);
static int is_hit_inrange(RCoreAsmHit *hit, ut64 start_range, ut64 end_range);
static int is_addr_in_range(ut64 start, ut64 end, ut64 start_range, ut64 end_range);
static void add_hit_to_sorted_hits(RList* hits, ut64 addr, int len, ut8 is_valid);
static int prune_hits_in_addr_range(RList *hits, ut64 addr, ut64 len, ut8 is_valid);
static int rcoreasm_address_comparator(RCoreAsmHit *a, RCoreAsmHit *b){
if (a->addr == b->addr)
return 0;
else if (a->addr < b->addr)
return -1;
// a->addr > b->addr
return 1;
}
R_API RCoreAsmHit *r_core_asm_hit_new() {
RCoreAsmHit *hit = R_NEW (RCoreAsmHit);
if (!hit) return NULL;
hit->code = NULL;
hit->len = 0;
hit->addr = -1;
hit->valid = R_FALSE;
return hit;
}
R_API RList *r_core_asm_hit_list_new() {
RList *list = r_list_new ();
list->free = &r_core_asm_hit_free;
return list;
}
R_API void r_core_asm_hit_free(void *_hit) {
RCoreAsmHit *hit = _hit;
if (hit) {
if (hit->code)
free (hit->code);
free (hit);
}
}
R_API char* r_core_asm_search(RCore *core, const char *input, ut64 from, ut64 to) {
RAsmCode *acode;
char *ret;
if (!(acode = r_asm_massemble (core->assembler, input)))
return NULL;
ret = strdup (acode->buf_hex);
r_asm_code_free (acode);
return ret;
}
#define OPSZ 8
// TODO: add support for byte-per-byte opcode search
R_API RList *r_core_asm_strsearch(RCore *core, const char *input, ut64 from, ut64 to, int maxhits) {
RCoreAsmHit *hit;
RAsmOp op;
RList *hits;
ut64 at, toff = core->offset;
ut8 *buf;
char *tok, *tokens[1024], *code = NULL, *ptr;
int idx, tidx = 0, ret, len;
int tokcount, matchcount, count = 0;
if (!*input)
return NULL;
if (core->blocksize<=OPSZ) {
eprintf ("error: block size too small\n");
return NULL;
}
if (!(buf = (ut8 *)calloc (core->blocksize, 1)))
return NULL;
if (!(ptr = strdup (input))) {
free (buf);
return NULL;
}
if (!(hits = r_core_asm_hit_list_new ())) {
free (buf);
free (ptr);
return NULL;
}
tokens[0] = NULL;
for (tokcount=0; tokcount<(sizeof (tokens) / sizeof (char*)) - 1; tokcount++) {
tok = strtok (tokcount? NULL: ptr, ",");
if (tok == NULL)
break;
tokens[tokcount] = r_str_trim_head_tail (tok);
}
tokens[tokcount] = NULL;
r_cons_break (NULL, NULL);
for (at = from, matchcount = 0; at < to; at += core->blocksize-OPSZ) {
if (r_cons_singleton ()->breaked)
break;
ret = r_io_read_at (core->io, at, buf, core->blocksize);
if (ret != core->blocksize)
break;
idx = 0, matchcount = 0;
while (idx<core->blocksize) {
r_asm_set_pc (core->assembler, at+idx);
op.buf_asm[0] = 0;
op.buf_hex[0] = 0;
if (!(len = r_asm_disassemble (core->assembler, &op, buf+idx, core->blocksize-idx))) {
idx = (matchcount)? tidx+1: idx+1;
matchcount = 0;
continue;
}
if (tokens[matchcount] && strstr (op.buf_asm, tokens[matchcount])) {
code = r_str_concatf (code, "%s", op.buf_asm);
if (matchcount == tokcount-1) {
if (tokcount == 1)
tidx = idx;
if (!(hit = r_core_asm_hit_new ())) {
r_list_purge (hits);
free (hits);
hits = NULL;
goto beach;
}
hit->addr = at+tidx;
hit->len = idx+len-tidx;
if (hit->len == -1) {
r_core_asm_hit_free (hit);
goto beach;
}
hit->code = strdup (code);
r_list_append (hits, hit);
R_FREE (code);
matchcount = 0;
idx = tidx+1;
if (maxhits) {
count ++;
if (count >= maxhits) {
eprintf ("Error: search.maxhits reached\n");
goto beach;
}
}
} else if (matchcount == 0) {
tidx = idx;
matchcount++;
idx += len;
} else {
matchcount++;
idx += len;
}
} else {
idx = matchcount? tidx+1: idx+1;
R_FREE (code);
matchcount = 0;
}
}
}
r_asm_set_pc (core->assembler, toff);
beach:
free (buf);
free (ptr);
free (code);
return hits;
}
static void add_hit_to_sorted_hits(RList* hits, ut64 addr, int len, ut8 is_valid) {
RCoreAsmHit *hit = r_core_asm_hit_new();
if (hit) {
IFDBG eprintf("*** Inserting instruction (valid?: %d): instr_addr: 0x%"PFMT64x" instr_len: %d\n", is_valid, addr, len );
hit->addr = addr;
hit->len = len;
hit->valid = is_valid;
hit->code = NULL;
r_list_add_sorted (hits, hit, ((RListComparator)rcoreasm_address_comparator));
}
}
static void add_hit_to_hits(RList* hits, ut64 addr, int len, ut8 is_valid) {
RCoreAsmHit *hit = r_core_asm_hit_new();
if (hit) {
IFDBG eprintf("*** Inserting instruction (valid?: %d): instr_addr: 0x%"PFMT64x" instr_len: %d\n", is_valid, addr, len);
hit->addr = addr;
hit->len = len;
hit->valid = is_valid;
hit->code = NULL;
r_list_append (hits, hit);
}
}
static int prune_hits_in_addr_range(RList *hits, ut64 addr, ut64 len, ut8 is_valid) {
RCoreAsmHit hit;
hit.addr = addr;
hit.len = len;
hit.code = NULL;
hit.valid = is_valid;
return prune_hits_in_hit_range(hits, &hit);
}
static int prune_hits_in_hit_range(RList *hits, RCoreAsmHit *hit){
RListIter *iter, *iter_tmp;
RCoreAsmHit *to_check_hit;
int result = 0;
ut64 start_range, end_range;
if (hit == NULL || hits == NULL) return 0;
start_range = hit->addr;
end_range = hit->addr + hit->len;
r_list_foreach_safe (hits, iter, iter_tmp, to_check_hit){
if (to_check_hit && is_hit_inrange(to_check_hit, start_range, end_range)) {
IFDBG eprintf ("Found hit that clashed (start: 0x%"PFMT64x
" - end: 0x%"PFMT64x" ), 0x%"PFMT64x" len: %d (valid: %d 0x%"PFMT64x
" - 0x%"PFMT64x")\n", start_range, end_range, to_check_hit->addr,
to_check_hit->len, to_check_hit->valid, to_check_hit->addr,
to_check_hit->addr+to_check_hit->len);
// XXX - could this be a valid decode instruction we are deleting?
r_list_delete (hits, iter);
//iter->data = NULL;
to_check_hit = NULL;
result ++;
}
}
return result;
}
static RCoreAsmHit * find_addr(RList *hits, ut64 addr) {
// Find an address in the list of hits
RListIter *addr_iter = NULL;
RCoreAsmHit dummy_value;
dummy_value.addr = addr;
addr_iter = r_list_find (hits, &dummy_value, ((RListComparator)rcoreasm_address_comparator));
return r_list_iter_get_data(addr_iter);
}
static int handle_forward_disassemble(RCore* core, RList *hits, ut8* buf, ut64 len, ut64 current_buf_pos, ut64 current_instr_addr, ut64 end_addr){
// forward disassemble from the current instruction up to the end address
ut64 temp_instr_len = 0,
temp_instr_addr = current_instr_addr,
tmp_current_buf_pos = current_buf_pos,
start = 0, end = 0,
start_range = current_instr_addr,
end_range = end_addr;
RAsmOp op;
RCoreAsmHit *hit = NULL, *found_addr = NULL;
ut8 is_valid = R_FALSE;
if (end_addr < current_instr_addr)
return end_addr;
r_asm_set_pc (core->assembler, current_instr_addr);
while ( tmp_current_buf_pos < len && temp_instr_addr < end_addr) {
temp_instr_len = len - tmp_current_buf_pos;
IFDBG eprintf("Current position: %"PFMT64d" instr_addr: 0x%"PFMT64x"\n", tmp_current_buf_pos, temp_instr_addr);
temp_instr_len = r_asm_disassemble (core->assembler, &op, buf+tmp_current_buf_pos, temp_instr_len);
if (temp_instr_len == 0){
is_valid = R_FALSE;
temp_instr_len = 1;
} else
is_valid = R_TRUE;
// check to see if addr exits
found_addr = find_addr(hits, temp_instr_addr);
start = temp_instr_addr;
end = temp_instr_addr + temp_instr_len;
if (!found_addr) {
add_hit_to_sorted_hits(hits, temp_instr_addr, temp_instr_len, is_valid);
} else if (is_valid && !found_addr->valid && is_addr_in_range(start, end, start_range, end_range )) {
ut32 prune_results = 0;
prune_results = prune_hits_in_addr_range(hits, temp_instr_addr, temp_instr_len, is_valid);
add_hit_to_sorted_hits(hits, temp_instr_addr, temp_instr_len, is_valid);
if (prune_results ) {
r_list_add_sorted (hits, hit, ((RListComparator)rcoreasm_address_comparator));
IFDBG eprintf("Pruned %u hits from list in fwd sweep.\n", prune_results);
} else {
free (hit);
hit = NULL;
}
}
temp_instr_addr += temp_instr_len;
tmp_current_buf_pos += temp_instr_len;
}
return temp_instr_addr;
}
#if 0
static int handle_disassembly_overlap(RCore* core, RList *hits, ut8* buf, int len, ut64 current_buf_pos, ut64 current_instr_addr ) {
// disassemble over lap means the current instruction decoded using the bytes in a previously decoded instruction
ut64 next_buf_pos = current_buf_pos,
end_addr = current_instr_addr + ( len - current_buf_pos - 1);
/* Sub optimal method (e.g. easy) */
handle_forward_disassemble (core, hits, buf, len, current_buf_pos, current_instr_addr, end_addr );
next_buf_pos = current_buf_pos;
return next_buf_pos;
}
#endif
static int is_addr_in_range(ut64 start, ut64 end, ut64 start_range, ut64 end_range){
int result = R_FALSE;
if (start == start_range) {
return R_TRUE;
} else if (start < end && start_range < end_range) {
// ez cases
if ( start_range <= start && start < end_range )
result = R_TRUE;
else if (start_range < end && end < end_range )
result = R_TRUE;
else if ( start <= start_range && end_range < end )
result = R_TRUE;
// XXX - these cases need to be tested
// (long long) start_range < 0 < end_range
} else if (start_range > end_range) {
if (start < end) {
if (start < end_range)
result = R_TRUE;
else if (end <= end_range)
result = R_TRUE;
else if ( start_range <= start )
result = R_TRUE;
else if ( start_range < end )
result = R_TRUE;
// (long long) start < 0 < end
} else {
if (end < end_range)
result = R_TRUE;
else if (end <= end_range)
result = R_TRUE;
else if ( start_range <= start )
result = R_TRUE;
}
// XXX - these cases need to be tested
// (long long) start < 0 < end
} else if (start_range < end_range) {
if ( start < end_range)
result = R_TRUE;
else if ( start <= start_range )
result = R_TRUE;
else if ( start_range < end)
result = R_TRUE;
}
return result;
}
static int is_hit_inrange(RCoreAsmHit *hit, ut64 start_range, ut64 end_range){
int result = R_FALSE;
if (hit) {
result = is_addr_in_range(hit->addr, hit->addr + hit->len, start_range, end_range);
}
return result;
}
R_API RList *r_core_asm_bwdisassemble (RCore *core, ut64 addr, int n, int len) {
RList *hits = r_core_asm_hit_list_new();
RAsmOp op;
// len = n * 32;
// if (n > core->blocksize) n = core->blocksize;
ut8 *buf = (ut8 *)malloc(len);
ut64 instrlen = 0, at = 0;
ut32 idx = 0, hit_count = 0;
int numinstr, asmlen, ii;
RAsmCode *c;
if (hits == NULL || buf == NULL ){
if (hits) {
r_list_purge (hits);
free (hits);
}
free (buf);
return NULL;
}
if (r_io_read_at (core->io, addr-len, buf, len) != len) {
if (hits) {
r_list_purge (hits);
free (hits);
}
free (buf);
return NULL;
}
for (idx = 1; idx < len; ++idx) {
if (r_cons_singleton ()->breaked) break;
at = addr - idx; hit_count = 0;
c = r_asm_mdisassemble (core->assembler, buf+(len-idx), idx);
if (strstr(c->buf_asm, "invalid") || strstr(c->buf_asm, ".byte")) {
r_asm_code_free(c);
continue;
}
numinstr = 0;
asmlen = strlen(c->buf_asm);
for(ii = 0; ii < asmlen; ++ii) {
if (c->buf_asm[ii] == '\n') ++numinstr;
}
r_asm_code_free(c);
if (numinstr >= n || idx > 32 * n) {
break;
}
}
at = addr - idx;
hit_count = 0;
r_asm_set_pc (core->assembler, at);
at = addr-idx;
for ( hit_count = 0; hit_count < n; hit_count++) {
instrlen = r_asm_disassemble (core->assembler, &op, buf+(len-(addr-at)), addr-at);
add_hit_to_hits(hits, at, instrlen, R_TRUE);
at += instrlen;
}
r_asm_set_pc (core->assembler, addr);
free (buf);
return hits;
}
static RList * r_core_asm_back_disassemble_all(RCore *core, ut64 addr, ut64 len, ut64 max_hit_count, ut32 extra_padding){
RList *hits = r_core_asm_hit_list_new ();
RCoreAsmHit dummy_value;
RCoreAsmHit *hit = NULL;
RAsmOp op;
ut8 *buf = (ut8 *)malloc (len + extra_padding);
int current_instr_len = 0;
ut64 current_instr_addr = addr,
current_buf_pos = len - 1,
hit_count = 0;
memset (&dummy_value, 0, sizeof (RCoreAsmHit));
if (hits == NULL || buf == NULL ){
if (hits) {
r_list_purge (hits);
free (hits);
}
free (buf);
return NULL;
}
if (r_io_read_at (core->io, addr-(len+extra_padding), buf, len+extra_padding) != len+extra_padding) {
r_list_purge (hits);
free (hits);
free (buf);
return NULL;
}
if (len == 0){
return hits;
}
current_buf_pos = len - 1;
do {
if (r_cons_singleton ()->breaked) break;
// reset assembler
r_asm_set_pc (core->assembler, current_instr_addr);
current_instr_len = len - current_buf_pos + extra_padding;
IFDBG eprintf("current_buf_pos: 0x%"PFMT64x", current_instr_len: %d\n", current_buf_pos, current_instr_len);
current_instr_len = r_asm_disassemble (core->assembler, &op, buf+current_buf_pos, current_instr_len);
hit = r_core_asm_hit_new ();
hit->addr = current_instr_addr;
hit->len = current_instr_len;
hit->code = NULL;
r_list_add_sorted (hits, hit, ((RListComparator)rcoreasm_address_comparator));
current_buf_pos--;
current_instr_addr--;
hit_count++;
} while ( ((int) current_buf_pos >= 0) && (int)(len - current_buf_pos) >= 0 && hit_count <= max_hit_count);
free(buf);
return hits;
}
static RList *r_core_asm_back_disassemble (RCore *core, ut64 addr, int len, ut64 max_hit_count, ut8 disassmble_each_addr, ut32 extra_padding) {
RList *hits;;
RAsmOp op;
ut8 *buf = NULL;
ut8 max_invalid_b4_exit = 4,
last_num_invalid = 0;
int current_instr_len = 0;
ut64 current_instr_addr = addr,
current_buf_pos = 0,
next_buf_pos = len;
RCoreAsmHit dummy_value;
ut32 hit_count = 0;
if (disassmble_each_addr){
return r_core_asm_back_disassemble_all(core, addr, len, max_hit_count, extra_padding+1);
}
hits = r_core_asm_hit_list_new ();
buf = malloc (len + extra_padding);
if (hits == NULL || buf == NULL ){
if (hits) {
r_list_purge (hits);
free (hits);
}
free (buf);
return NULL;
}
if (r_io_read_at (core->io, (addr + extra_padding)-len, buf, len+extra_padding) != len+extra_padding) {
r_list_purge (hits);
free (hits);
free (buf);
return NULL;
}
//
// XXX - This is a heavy handed approach without a
// an appropriate btree or hash table for storing
// hits, because are using:
// 1) Sorted RList with many inserts and searches
// 2) Pruning hits to find the most optimal disassembly
// greedy approach
// 1) Consume previous bytes
// 1a) Instruction is invalid (incr current_instr_addr)
// 1b) Disasm is perfect
// 1c) Disasm is underlap (disasm(current_instr_addr, next_instr_addr - current_instr_addr) short some bytes)
// 1d) Disasm is overlap (disasm(current_instr_addr, next_instr_addr - current_instr_addr) over some bytes)
memset (&dummy_value, 0, sizeof (RCoreAsmHit));
// disassemble instructions previous to current address, extra_padding can move the location of addr
// so we need to account for that with current_buf_pos
current_buf_pos = len - extra_padding - 1;
next_buf_pos = len + extra_padding - 1;
current_instr_addr = addr-1;
do {
if (r_cons_singleton ()->breaked) break;
// reset assembler
r_asm_set_pc (core->assembler, current_instr_addr);
current_instr_len = next_buf_pos - current_buf_pos;
current_instr_len = r_asm_disassemble (core->assembler, &op, buf+current_buf_pos, current_instr_len);
IFDBG {
ut32 byte_cnt = current_instr_len ? current_instr_len : 1;
eprintf("current_instr_addr: 0x%"PFMT64x", current_buf_pos: 0x%"PFMT64x", current_instr_len: %d \n", current_instr_addr, current_buf_pos, current_instr_len);
ut8 *hex_str = (ut8*)r_hex_bin2strdup(buf+current_buf_pos, byte_cnt);
eprintf("==== current_instr_bytes: %s ",hex_str);
if (current_instr_len > 0)
eprintf("op.buf_asm: %s\n", op.buf_asm);
else
eprintf("op.buf_asm: <invalid>\n");
if (hex_str) free(hex_str);
}
// disassembly invalid
if (current_instr_len == 0 || strstr (op.buf_asm, "invalid")) {
if (current_instr_len == 0) current_instr_len = 1;
add_hit_to_sorted_hits(hits, current_instr_addr, current_instr_len, /* is_valid */ R_FALSE);
hit_count ++;
last_num_invalid ++;
// disassembly perfect
} else if (current_buf_pos + current_instr_len == next_buf_pos) {
// i think this may be the only case where an invalid instruction will be
// added because handle_forward_disassemble and handle_disassembly_overlap
// are only called in cases where a valid instruction has been found.
// and they are lazy, since they purge the hit list
ut32 purge_results = 0;
ut8 is_valid = R_TRUE;
IFDBG eprintf(" handling underlap case: current_instr_addr: 0x%"PFMT64x".\n", current_instr_addr);
purge_results = prune_hits_in_addr_range(hits, current_instr_addr, current_instr_len, /* is_valid */ R_TRUE);
if (purge_results) {
handle_forward_disassemble(core, hits, buf, len, current_buf_pos+current_instr_len, current_instr_addr+current_instr_len, addr);
hit_count = r_list_length(hits);
}
add_hit_to_sorted_hits(hits, current_instr_addr, current_instr_len, is_valid);
//handle_forward_disassemble(core, hits, buf, len, current_buf_pos+current_instr_len, current_instr_addr+current_instr_len, addr/*end_addr*/);
hit_count ++;
next_buf_pos = current_buf_pos;
last_num_invalid = 0;
// disassembly underlap
} else if (current_buf_pos + current_instr_len < next_buf_pos) {
ut32 purge_results = 0;
ut8 is_valid = R_TRUE;
purge_results = prune_hits_in_addr_range(hits, current_instr_addr, current_instr_len, /* is_valid */ R_TRUE);
add_hit_to_sorted_hits(hits, current_instr_addr, current_instr_len, is_valid);
if (hit_count < purge_results ) hit_count = 0; // WTF??
else hit_count -= purge_results;
next_buf_pos = current_buf_pos;
handle_forward_disassemble(core, hits, buf, len - extra_padding, current_buf_pos+current_instr_len, current_instr_addr+current_instr_len, addr);
hit_count = r_list_length(hits);
last_num_invalid = 0;
// disassembly overlap
} else if (current_buf_pos + current_instr_len > next_buf_pos) {
//ut64 value = handle_disassembly_overlap(core, hits, buf, len, current_buf_pos, current_instr_addr);
next_buf_pos = current_buf_pos;
hit_count = r_list_length (hits);
last_num_invalid = 0;
}
// walk backwards by one instruction
IFDBG eprintf(" current_instr_addr: 0x%"PFMT64x" current_instr_len: %d next_instr_addr: 0x%04"PFMT64x"\n",
current_instr_addr, current_instr_len, next_buf_pos);
IFDBG eprintf(" hit count: %d \n", hit_count );
current_instr_addr -= 1;
current_buf_pos -= 1;
if ( hit_count >= max_hit_count &&
(last_num_invalid >= max_invalid_b4_exit || last_num_invalid == 0))
break;
} while ( ((int) current_buf_pos >= 0) && (int)(len - current_buf_pos) >= 0 );
r_asm_set_pc (core->assembler, addr);
free (buf);
return hits;
}
R_API RList *r_core_asm_back_disassemble_instr (RCore *core, ut64 addr, int len, ut32 hit_count, ut32 extra_padding){
// extra padding to allow for additional disassembly on border buffer cases
ut8 disassmble_each_addr = R_FALSE;
return r_core_asm_back_disassemble(core, addr, len, hit_count, disassmble_each_addr, extra_padding);
}
R_API RList *r_core_asm_back_disassemble_byte (RCore *core, ut64 addr, int len, ut32 hit_count, ut32 extra_padding){
// extra padding to allow for additional disassembly on border buffer cases
ut8 disassmble_each_addr = R_TRUE;
return r_core_asm_back_disassemble(core, addr, len, hit_count, disassmble_each_addr, extra_padding);
}
/* Compute the len and the starting address
* when disassembling `nb` opcodes backward. */
R_API ut32 r_core_asm_bwdis_len (RCore* core, int* instr_len, ut64* start_addr, ut32 nb) {
ut32 instr_run = 0;
RCoreAsmHit *hit;
RListIter *iter = NULL;
RList* hits = r_core_asm_bwdisassemble (core, core->offset, nb, core->blocksize);
if (instr_len)
*instr_len = 0;
if (hits && r_list_length (hits) > 0) {
hit = r_list_get_bottom(hits);
if (start_addr)
*start_addr = hit->addr;
r_list_foreach (hits, iter, hit)
instr_run += hit->len;
if (instr_len)
*instr_len = instr_run;
}
r_list_free (hits);
return instr_run;
}