radare2/libr/vm/vm.c
pancake d607e969bc * Fix division by zero in VM code when using ATT syntax
- use intel syntax when running VM code from disasm loop
2010-10-13 18:07:55 +02:00

549 lines
12 KiB
C

/* radare - LGPL - Copyright 2008-2010 pancake<nopcode.org> */
#include "r_vm.h"
#include "p/plugins.h"
static ut64 r_vm_get_value(RVm *vm, const char *str) {
ut64 ret = 0LL;
for (;*str&&*str==' ';str=str+1);
if (str[0]=='$' && str[1]=='$') {
#if TODO
struct aop_t aop;
char w[32];
if (str[2]=='$') { // $$$
ret = r_vm_reg_get (vm, vm->cpu.pc);
arch_aop (ret , config.block, &aop);
return aop.length;
} else return config.seek; // $$
#endif
}
if (str[0]=='0' && str[1]=='x')
sscanf (str, "0x%"PFMT64x"", &ret);
else
if (str[0]>='0' && str[0]<='9')
sscanf (str, "%"PFMT64d"", &ret);
else ret = r_vm_reg_get (vm, str);
return ret;
}
static ut64 r_vm_get_math(struct r_vm_t *vm, const char *str) {
int len;
char *p,*a;
len = strlen (str)+1;
p = alloca (len);
memcpy (p, str, len);
a = strchr (p,'+');
if (a) {
*a='\0';
return r_vm_get_value(vm, p) + r_vm_get_value(vm, a+1);
}
a = strchr (p,'-');
if (a) {
*a='\0';
return r_vm_get_value(vm, p) - r_vm_get_value(vm, a+1);
}
a = strchr (p,'*');
if (a) {
*a='\0';
return r_vm_get_value(vm, p) * r_vm_get_value(vm, a+1);
}
a = strchr (p,'/');
if (a) {
ut64 d = r_vm_get_value(vm, a+1);
ut64 n = r_vm_get_value(vm, p);
*a='\0';
return d?n/d:0;
}
a = strchr (p,'&');
if (a) {
*a='\0';
return r_vm_get_value (vm, p) & r_vm_get_value(vm, a+1);
}
a = strchr (p,'|');
if (a) {
*a='\0';
return r_vm_get_value (vm, p) | r_vm_get_value(vm, a+1);
}
a = strchr (p,'^');
if (a) {
*a='\0';
return r_vm_get_value (vm, p) ^ r_vm_get_value(vm, a+1);
}
a = strchr (p,'%');
if (a) {
ut64 d = r_vm_get_value(vm, a+1);
ut64 n = r_vm_get_value(vm, p);
*a='\0';
return d?n%d:0;
}
a = strchr (p,'>');
if (a) {
*a='\0';
return r_vm_get_value(vm, p) >> r_vm_get_value(vm, a+1);
}
a = strchr(p,'<');
if (a) {
*a='\0';
return r_vm_get_value (vm, p) << r_vm_get_value(vm, a+1);
}
return r_vm_get_value (vm, p);
}
R_API void r_vm_print(RVm *vm, int type) {
struct list_head *pos;
if (type == -2)
printf("fs vm\n");
list_for_each (pos, &vm->regs) {
struct r_vm_reg_t *r = list_entry(pos, struct r_vm_reg_t, list);
if (type == -2) {
eprintf("f vm.%s @ 0x%08"PFMT64x"\n", r->name, r->value);
} else {
if (type == -1 || type == r->type)
eprintf(".%s\t%s = 0x%08"PFMT64x"\n",
r_vm_reg_type(r->type), r->name,
(r->get!=NULL)?r_vm_reg_get(vm, r->name):r->value);
}
}
if (type == -2)
printf ("fs *\n");
}
R_API int r_vm_reg_add(struct r_vm_t *vm, const char *name, int type, ut64 value) {
RVmReg *r = (RVmReg*)malloc (sizeof (RVmReg));
if (r == NULL)
return 0;
strncpy (r->name, name, 15);
r->type = type;
r->value = value;
r->get = NULL;
r->set = NULL;
list_add_tail (&(r->list), &vm->regs);
return 1;
}
// XXX: deprecate
R_API int r_vm_import(struct r_vm_t *vm, int in_vm) {
char name[64];
struct list_head *pos;
//eprintf ("Importing register values\n");
list_for_each(pos, &vm->regs) {
struct r_vm_reg_t *r = list_entry(pos, struct r_vm_reg_t, list);
snprintf(name, 63, "vm.%s", r->name);
if (in_vm) {
r->value = r_num_get (NULL, name); // XXX doesnt work for eflags and so
} else r->value = r_num_get (NULL, r->name); // XXX doesnt work for eflags and so
printf ("f %s @ 0x%08llx\n", name, r->value);
}
return 0;
}
R_API void r_vm_cpu_call(struct r_vm_t *vm, ut64 addr) {
/* x86 style */
r_vm_stack_push (vm, r_vm_reg_get (vm, vm->cpu.pc));
r_vm_reg_set (vm, vm->cpu.pc, addr);
// XXX this should be the next instruction after pc (we need insn length here)
}
R_API RVm *r_vm_new() {
RVm *vm = R_NEW (RVm);
if (vm) r_vm_init (vm, 1);
return vm;
}
R_API int r_vm_set_arch(RVm *vm, const char *name, int bits) {
const char *profile = NULL;
if (strstr (name, "x86")) {
switch (bits) {
case 16:
profile = vmprofile_x86_16;
break;
case 32:
profile = vmprofile_x86_32;
break;
case 64:
profile = vmprofile_x86_64;
break;
}
} else
if (strstr (name, "arm")) {
switch (bits) {
case 16:
profile = vmprofile_arm_32; // XXX 16;
break;
case 32:
profile = vmprofile_arm_32;
break;
}
}
if (profile) {
char *str = strdup (profile);
r_vm_init (vm, 2);
r_vm_cmd_eval (vm, str);
free (str);
} else eprintf ("r_vm: No profile found for '%s' on %d bits\n", name, bits);
return 0;
}
// This is conceptually rotten
R_API int r_vm_init(RVm *vm, int init) {
if (init) {
vm->log = 0;
vm->use_mmu_cache = 0;
INIT_LIST_HEAD (&vm->mmu_cache);
INIT_LIST_HEAD (&vm->regs);
INIT_LIST_HEAD (&vm->ops);
memset (&vm->cpu, '\0', sizeof(RVmCpu));
if (init==2)
return 0;
}
//vm_mmu_real(vm, config_get_i("vm.realio"));
//vm_setup_call("[ebp-4]", "[ebp-8]", "[ebp-12]", "edx");
r_vm_setup_fastcall (vm, "eax", "ebx", "ecx", "edx");
//vm_setup_loop("ecx");
//vm_setup_copy("esi", "edi");
// TODO: do the same for fpregs and mmregs
return 0;
}
R_API int r_vm_eval_cmp(RVm *vm, const char *str) {
int len;
char *p, *ptr;
for (;*str==' ';str=str+1);
len = strlen (str)+1;
ptr = alloca (len);
memcpy (ptr, str, len);
p = strchr (ptr, ',');
if (!p) p = strchr (ptr, ' ');
if (p) {
r_vm_reg_set (vm, vm->cpu.zf,(r_vm_get_math(vm, ptr)-r_vm_get_math(vm, p+1)));
p = '\0';
return 0;
}
return 1;
}
R_API int r_vm_eval_eq(RVm *vm, const char *str, const char *val) {
char *p;
ut8 buf[64];
ut64 _int8 = 0;
ut16 _int16 = 0;
ut32 _int32 = 0;
ut64 _int64 = 0;
for(;*str==' ';str=str+1);
for(;*val==' ';val=val+1);
if (*str=='[') {
// USE MMU
// [foo] = 33, [reg] = 33
if (*val=='[') {
// [0x804800] = [0x30480]
ut64 off = r_vm_get_math(vm, val+1);
p = strchr(val+1,':');
if (p) {
int size = atoi(val+1);
off = r_vm_get_math(vm, p+1);
switch(size) {
case 8:
r_vm_mmu_read(vm, off, buf, 1);
r_vm_mmu_write(vm, off, buf, 1);
break;
case 16:
r_vm_mmu_read(vm, off, buf, 2);
r_vm_mmu_write(vm, off, buf, 2);
break;
case 64:
r_vm_mmu_read(vm, off, buf, 8);
r_vm_mmu_write(vm, off, buf, 8);
break;
default:
r_vm_mmu_read(vm, off, buf, 4);
r_vm_mmu_write(vm, off, buf, 4);
}
} else {
r_vm_mmu_read(vm, off, (ut8*)&_int32, 4);
//off = r_vm_get_math(val);
r_vm_mmu_write(vm, off, (void*)&_int32, 4);
}
} else {
// [0x804800] = eax
// use ssssskcvtgvmu
ut64 off = r_vm_get_math(vm, str+1);
// XXX support 64 bits here
ut32 v = (ut32)r_vm_get_math(vm, val); // TODO control endian
p = strchr (str+1,':');
if (vm->log)
eprintf (" ; ==> [0x%08"PFMT64x"] = %x ((%s))\n", off, v, str+1);
if (p) {
int size = atoi (val+1);
off = r_vm_get_math (vm, p+1);
printf(" write size: %d\n", size);
switch(size) {
case 8: r_vm_mmu_write (vm, off, buf, 1);
break;
case 16: r_vm_mmu_write (vm, off, buf, 2);
break;
case 64: r_vm_mmu_write (vm, off, buf, 8);
break;
default:
r_vm_mmu_write (vm, off, buf, 4);
}
} else {
if (vm->log)
eprintf (" ; write %x @ 0x%08"PFMT64x"\n", v, off);
r_vm_mmu_write (vm, off, (ut8*)&v, 4);
}
}
} else {
// USE REG
// reg = [foo] , reg = 33
if (*val=='[') {
// use mmu
ut64 off;
ut32 _int32 = 0;
p = strchr(val+1,':');
if (p) {
int size = atoi(val+1);
off = r_vm_get_math(vm, p+1);
switch(size) {
case 8:
r_vm_mmu_read(vm, off, (ut8*)&_int8, 1);
r_vm_reg_set(vm, str, (ut64)_int8);
break;
case 16:
r_vm_mmu_read(vm, off, (ut8*)&_int16, 2);
r_vm_reg_set(vm, str, (ut64)_int16);
break;
case 64:
r_vm_mmu_read(vm, off, (ut8*)&_int64, 8);
r_vm_reg_set(vm, str, (ut64)_int64);
break;
default:
r_vm_mmu_read(vm, off, (ut8*)&_int32, 4);
r_vm_reg_set(vm, str, (ut64)_int32);
}
} else {
off = r_vm_get_math(vm, val+1);
r_vm_mmu_read(vm, off, (ut8*)&_int32, 4);
r_vm_reg_set(vm, str, (ut64)_int32);
}
} else r_vm_reg_set(vm, str, r_vm_get_math(vm, val));
}
return 0;
}
R_API int r_vm_eval_single(RVm *vm, const char *str) {
char *ptr, *eq;
char buf[128];
int i, len;
// if (log)
//fprintf(stderr," ; %s\n", str);
for(;str&&str[0]==' ';str=str+1);
len = strlen(str)+1;
ptr = alloca(len);
memcpy(ptr, str, len);
//eprintf("EVAL(%s)\n", str);
/* TODO: sync with r1 */
eq = strchr(ptr, '=');
if (eq) {
eq[0]='\0';
switch(eq[-1]) {
case '+':
case '-':
case '*':
case '/':
case '&':
case '^':
case '%':
case '|':
case '<':
case '>':
snprintf(buf, 127, "%s%c%s", ptr, eq[-1], eq+1);
r_vm_eval_eq(vm, ptr, buf);
//printf("EQ(%s)(%s)\n", ptr, buf);
break;
case ' ':
i=-1; do { eq[i--]='\0'; } while(eq[i]==' ');
default:
//printf("EQ(%s)(%s)\n", ptr, eq+1);
r_vm_eval_eq(vm, ptr, eq+1);
}
eq[0]='=';
} else {
//eprintf("Unknown opcode\n");
if (!memcmp(ptr, "if ", 3)) {
if (r_vm_reg_get(vm, ptr+3)!=0)
return -1;
} else
if (!memcmp(ptr, "ifnot ", 6)) {
if (r_vm_reg_get(vm, ptr+6)==0)
return -1;
} else
if (!memcmp(ptr, "cmp ", 4)) {
r_vm_eval_cmp(vm, str+5);
} else
return 0;
if (!memcmp(ptr, "syscall", 6)) {
if (vm->log)
eprintf("TODO: syscall interface not yet implemented\n");
} else
if((!memcmp (ptr, "call ", 4))
|| (!memcmp (ptr, "jmp ", 4))){
if (ptr[0]=='c')
r_vm_stack_push(vm, r_vm_get_value(vm, vm->cpu.pc));
eprintf ("CALL(%s)\n", ptr+4);
r_vm_reg_set(vm, vm->cpu.pc, r_vm_get_value(vm, ptr+4));
} else
if (!memcmp (ptr, "jz ", 3)){
if (r_vm_reg_get (vm, ptr+3)==0)
r_vm_reg_set(vm, vm->cpu.pc, r_vm_get_value(vm, ptr+3));
} else
if (!memcmp (ptr, "jnz ", 4)){
if (r_vm_reg_get(vm, ptr+4)==0)
r_vm_reg_set (vm, vm->cpu.pc, r_vm_get_value(vm, ptr+4));
} else
if (!memcmp(ptr, "push ", 5)) {
r_vm_stack_push (vm, r_vm_get_value(vm, str+5));
} else
if (!memcmp(str, "pop ", 4)) {
r_vm_stack_pop (vm, str+5);
} else
if (!memcmp(ptr, "ret", 3)) {
r_vm_stack_pop(vm, vm->cpu.pc);
if (vm->log) eprintf("RET (%x)\n", (ut32)vm->cpu.pc);
} else if (vm->log) eprintf("r_vm: Unknown opcode\n");
}
return 0;
}
R_API int r_vm_eval(RVm *vm, const char *str) {
char *next, *ptr;
int ret, len = strlen(str)+1;
ptr = alloca (len);
memcpy (ptr, str, len);
#if 0
r_vm_mmu_real (vm, 0);
r_vm_mmu_real(vm, config_get_i("vm.realio"));
.int32 eax alias-get alias-set
.alias eax get set
#endif
do {
next = strchr(ptr, ',');
if (next) {
next[0]='\0';
ret = r_vm_eval_single(vm, ptr);
if (ret == -1)
return 0;
next[0]=',';
ptr = next +1;
}
} while (next);
r_vm_eval_single (vm, ptr);
return R_TRUE;
}
R_API int r_vm_eval_file(struct r_vm_t *vm, const char *str) {
char buf[1024];
FILE *fd = fopen(str, "r");
if (fd) {
while (!feof(fd)) {
*buf='\0';
fgets(buf, 1023, fd);
if (*buf) {
buf[strlen(buf)-1]='\0';
//r_vm_eval(vm, buf);
r_vm_op_eval (vm, buf);
}
}
fclose (fd);
return R_TRUE;
}
return R_FALSE;
}
/* XXX: this must go in core, not here! i.. or add&use RIOBind? emulate n opcodes */
R_API int r_vm_emulate(struct r_vm_t *vm, int n) {
#if 0
ut64 pc;
char str[128];
ut8 buf[128];
int opsize;
int op = config_get_i("asm.pseudo");
struct aop_t aop;
printf("Emulating %d opcodes\n", n);
///vm_init(1);
vm_mmu_real(config_get_i("vm.realio"));
vm_import(0);
while(n--) {
pc = vm_reg_get(vm->cpu.pc);
udis_init();
udis_set_pc(pc);
vm_mmu_read(pc, buf, 32);
//fprintf(stderr,"(%02x %02x)\n", buf[0], buf[1]);
radare_cmdf("pd 1 @ 0x%08"PFMT64x"", pc);
pas_aop(config.arch, pc, buf, 32, &aop, str, 1);
arch_aop(pc, buf, &aop);
opsize = aop.length;
//fprintf(stderr,"%"PFMT64x" + %d (%02x %02x)\n", pc, opsize, buf[0], buf[1]);
//printf("=> 0x%08"PFMT64x" '%s' (%d)\n", vm_reg_get(vm->cpu.pc), str, opsize);
vm_reg_set(vm->cpu.pc, vm_reg_get(vm->cpu.pc)+opsize);
vm_op_eval(str);
}
config_set("asm.pseudo", op?"true":"false");
#if 0
fprintf(stderr,"TODO: vm_emulate\n");
vm_init(1);
vm_print();
#endif
// TODO: perform asm-to-pas-eval
// TODO: evaluate string
return n;
#endif
return -1;
}
R_API void r_vm_reset(RVm *vm) {
struct list_head *pos;
list_for_each(pos, &vm->regs) {
RVmReg *r = list_entry (pos, struct r_vm_reg_t, list);
r->value = 0LL;
}
}
/* TODO : Allow to remove and so on */
R_API int r_vm_cmd_op(RVm *vm, const char *op) {
char *cmd, *ptr;
int len = strlen (op)+1;
if (*op==' ')
op = op + 1;
cmd = alloca (len);
memcpy (cmd, op, len);
ptr = strchr (cmd, ' ');
if (ptr) {
ptr[0]='\0';
if(vm->log)
eprintf ("vm: opcode '%s' added\n", cmd);
r_vm_op_add (vm, cmd, ptr+1);
} else r_vm_cmd_op_help ();
return 0;
}