open-dsi
/
clamav
mirror of https://github.com/Cisco-Talos/clamav
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

bytecode: allocate proper stack for functions.

Browse Source
0.96
Török Edvin 17 years ago
parent f3b2dc9e28
commit ec5cccc7ef
4 changed files with 56 additions and 52 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 2
      clambc/bcrun.c
  2. 33
      libclamav/bytecode.c
  3. 5
      libclamav/bytecode_priv.h
  4. 68
      libclamav/bytecode_vm.c

2
clambc/bcrun.c
Unescape View File

@ -123,7 +123,7 @@ int main(int argc, char *argv[])
uint64_t v;
printf("Bytecode run finished\n");
v = cli_bytecode_context_getresult_int(ctx);
printf("Bytecode returned: %llx\n", (long long)v);
printf("Bytecode returned: 0x%llx\n", (long long)v);
}
cli_bytecode_context_destroy(ctx);
cli_bytecode_destroy(bc);

33
libclamav/bytecode.c
Unescape View File

@ -167,25 +167,23 @@ static inline operand_t readOperand(struct cli_bc_func *func, unsigned char *p,
unsigned *off, unsigned len, char *ok)
{
uint64_t v;
unsigned numValues = func->numArgs + func->numInsts + func->numConstants;
if ((p[*off]&0xf0) == 0x40 || p[*off] == 0x50) {
p[*off] |= 0x20;
/* TODO: unique constants */
func->values = cli_realloc2(func->values, (numValues+1)*sizeof(*func->values));
if (!func->values) {
func->constants = cli_realloc2(func->constants, (func->numConstants+1)*sizeof(*func->constants));
if (!func->constants) {
*ok = 0;
return MAX_OP;
}
func->numConstants++;
func->values[numValues].v = readNumber(p, off, len, ok);
func->values[numValues].ref = CONSTANT_OP;
return numValues;
func->constants[func->numConstants].v = readNumber(p, off, len, ok);
func->constants[func->numConstants].ref = CONSTANT_OP;
return func->numValues + func->numConstants++;
}
v = readNumber(p, off, len, ok);
if (!*ok)
return MAX_OP;
if (v >= numValues) {
cli_errmsg("Operand index exceeds bounds: %u >= %u!\n", (unsigned)v, (unsigned)numValues);
if (v >= func->numValues) {
cli_errmsg("Operand index exceeds bounds: %u >= %u!\n", (unsigned)v, (unsigned)func->numValues);
*ok = 0;
return MAX_OP;
}
@ -380,6 +378,7 @@ static int parseFunctionHeader(struct cli_bc *bc, unsigned fn, unsigned char *bu
cli_errmsg("Invalid instructions count\n");
return CL_EMALFDB;
}
func->numValues = func->numArgs + func->numLocals;
func->insn_idx = 0;
func->numConstants=0;
func->allinsts = cli_calloc(func->numInsts, sizeof(*func->allinsts));
@ -387,19 +386,6 @@ static int parseFunctionHeader(struct cli_bc *bc, unsigned fn, unsigned char *bu
cli_errmsg("Out of memory allocating instructions\n");
return CL_EMEM;
}
func->values = cli_calloc(func->numInsts+func->numArgs, sizeof(*func->values));
if (!func->values) {
cli_errmsg("Out of memory allocating values\n");
return CL_EMEM;
}
for (i=0;i<func->numArgs;i++) {
func->values[i].v = 0xdeadbeef;
func->values[i].ref = ARG_OP;
}
for(;i<func->numInsts+func->numArgs;i++) {
func->values[i].v = 0xdeadbeef;
func->values[i].ref = i-func->numArgs;
}
func->numBB = readNumber(buffer, &offset, len, &ok);
if (!ok) {
cli_errmsg("Invalid basic block count\n");
@ -643,8 +629,8 @@ int cli_bytecode_run(struct cli_bc *bc, struct cli_bc_ctx *ctx)
}
}
memset(&func, 0, sizeof(func));
func.values = ctx->values;
func.numInsts = 1;
func.numValues = 1;
inst.opcode = OP_CALL_DIRECT;
inst.dest = func.numArgs;
@ -680,7 +666,6 @@ void cli_bytecode_destroy(struct cli_bc *bc)
}
free(f->BB);
free(f->allinsts);
free(f->values);
}
free(bc->funcs);
}

5
libclamav/bytecode_priv.h
Unescape View File

@ -74,13 +74,14 @@ struct cli_bc_func {
uint8_t numArgs;
uint16_t numLocals;
uint32_t numInsts;
uint32_t numValues;//without constants
uint32_t numConstants;
uint16_t numBB;
uint16_t *types;
uint32_t insn_idx;
struct cli_bc_bb *BB;
struct cli_bc_inst *allinsts;
struct cli_bc_value *values;
struct cli_bc_value *constants;
};
struct cli_bc_ctx {
@ -93,5 +94,5 @@ struct cli_bc_ctx {
unsigned numParams;
};
int cli_vm_execute(struct cli_bc *bc, struct cli_bc_ctx *ctx, struct cli_bc_func *func, struct cli_bc_inst *inst);
int cli_vm_execute(const struct cli_bc *bc, struct cli_bc_ctx *ctx, const struct cli_bc_func *func, const struct cli_bc_inst *inst);
#endif

68
libclamav/bytecode_vm.c
Unescape View File

@ -32,18 +32,18 @@
/* These checks will also be done by the bytecode verifier, but for
* debugging purposes we have explicit checks, these should never fail! */
#ifdef CL_DEBUG
static int bcfail(const char *msg, unsigned a, unsigned b,
static int bcfail(const char *msg, long a, long b,
const char *file, unsigned line)
{
cli_errmsg("bytecode: check failed %s (%u and %u) at %s:%u\n", msg, a, b, file, line);
cli_errmsg("bytecode: check failed %s (%lx and %lx) at %s:%u\n", msg, a, b, file, line);
return CL_EARG;
}
#define CHECK_FUNCID(funcid) do { if (funcid >= bc->num_func) return \
bcfail("funcid out of bounds!",funcid, bc->num_func,__FILE__,__LINE__); } while(0)
#define CHECK_EQ(a, b) do { if (a != b) return \
bcfail("Values "#a" and "#b" don't match!",a,b,__FILE__,__LINE__); } while(0)
#define CHECK_GT(a, b) do {if (a <= b) return \
bcfail("Condition failed "#a" > "#b,a,b, __FILE__, __LINE__); } while(0)
#define CHECK_EQ(a, b) do { if ((a) != (b)) return \
bcfail("Values "#a" and "#b" don't match!",(a),(b),__FILE__,__LINE__); } while(0)
#define CHECK_GT(a, b) do {if ((a) <= (b)) return \
bcfail("Condition failed "#a" > "#b,(a),(b), __FILE__, __LINE__); } while(0)
#else
#define CHECK_FUNCID(x)
#define CHECK_EQ(a,b)
@ -51,8 +51,9 @@ static int bcfail(const char *msg, unsigned a, unsigned b,
#endif
struct stack_entry {
struct cli_bc_func *func;
const struct cli_bc_func *func;
struct cli_bc_value *ret;
struct cli_bc_value *values;
struct cli_bc_bb *bb;
unsigned bb_inst;
};
@ -79,28 +80,39 @@ struct stack_entry {
#define SIGNEXT(a) CLI_SRS(((int64_t)(a)) << (64-inst->type), (64-inst->type))
#define BINOPS(i) SIGNEXT(BINOPNOMOD(i))
static void jump(struct cli_bc_func *func, uint16_t bbid, struct cli_bc_bb **bb, struct cli_bc_inst **inst,
struct cli_bc_value **value, unsigned *bb_inst)
static int jump(const struct cli_bc_func *func, uint16_t bbid, struct cli_bc_bb **bb, const struct cli_bc_inst **inst,
unsigned *bb_inst)
{
CHECK_GT(func->numBB, bbid);
*bb = &func->BB[bbid];
*inst = (*bb)->insts;
*value = &func->values[*inst - func->allinsts];
*bb_inst = 0;
return 0;
}
int cli_vm_execute(struct cli_bc *bc, struct cli_bc_ctx *ctx, struct cli_bc_func *func, struct cli_bc_inst *inst)
static struct cli_bc_value *allocate_stack(const struct cli_bc_func *func)
{
unsigned i;
struct cli_bc_value *values = cli_calloc(func->numValues+func->numConstants, sizeof(*values));
if (!values)
return NULL;
for (i=func->numValues;i<func->numValues+func->numConstants;i++)
values[i] = func->constants[i-func->numValues];
return values;
}
int cli_vm_execute(const struct cli_bc *bc, struct cli_bc_ctx *ctx, const struct cli_bc_func *func, const struct cli_bc_inst *inst)
{
unsigned i, stack_depth=0, bb_inst=0, stop=0;
struct cli_bc_func *func2;
struct stack_entry *stack = NULL;
struct cli_bc_bb *bb = NULL;
struct cli_bc_value *values = func->values;
struct cli_bc_value *value;
struct cli_bc_value *values = ctx->values;
struct cli_bc_value *value, *old_values;
do {
value = &values[inst->dest];
CHECK_GT(func->values + func->numArgs+func->numInsts+func->numConstants, value);
CHECK_GT(func->numValues+func->numConstants, value - values);
switch (inst->opcode) {
case OP_ADD:
value->v = BINOPNOMOD(0) + BINOPNOMOD(1);
@ -175,22 +187,23 @@ int cli_vm_execute(struct cli_bc *bc, struct cli_bc_ctx *ctx, struct cli_bc_func
value->v = values[inst->u.cast.source].v & values[inst->u.cast.mask].v;
break;
case OP_BRANCH:
jump(func, (values[inst->u.branch.condition].v&1) ?
inst->u.branch.br_true : inst->u.branch.br_false,
&bb, &inst, &value, &bb_inst);
stop = jump(func, (values[inst->u.branch.condition].v&1) ?
inst->u.branch.br_true : inst->u.branch.br_false,
&bb, &inst, &bb_inst);
continue;
case OP_JMP:
jump(func, inst->u.jump, &bb, &inst, &value, &bb_inst);
stop = jump(func, inst->u.jump, &bb, &inst, &bb_inst);
continue;
case OP_RET:
CHECK_GT(stack_depth, 0);
stack_depth--;
value = stack[stack_depth].ret;
func = stack[stack_depth].func;
CHECK_GT(func->values + func->numArgs+func->numInsts+func->numConstants, value);
CHECK_GT(value, &func->values[-1]);
value->v = values[inst->u.unaryop].v;
values = func->values;
free(values);
values = stack[stack_depth].values;
CHECK_GT(func->numValues+func->numConstants, value-values);
CHECK_GT(value-values, -1);
if (!stack[stack_depth].bb) {
stop = CL_BREAK;
bb_inst--;
@ -238,8 +251,6 @@ int cli_vm_execute(struct cli_bc *bc, struct cli_bc_ctx *ctx, struct cli_bc_func
CHECK_FUNCID(inst->u.ops.funcid);
func2 = &bc->funcs[inst->u.ops.funcid];
CHECK_EQ(func2->numArgs, inst->u.ops.numOps);
for (i=0;i<func2->numArgs;i++)
func2->values[i] = func->values[inst->u.ops.ops[i]];
stack = cli_realloc2(stack, sizeof(*stack)*(stack_depth+1));
if (!stack)
return CL_EMEM;
@ -247,12 +258,18 @@ int cli_vm_execute(struct cli_bc *bc, struct cli_bc_ctx *ctx, struct cli_bc_func
stack[stack_depth].ret = value;
stack[stack_depth].bb = bb;
stack[stack_depth].bb_inst = bb_inst;
stack[stack_depth].values = values;
stack_depth++;
cli_dbgmsg("Executing %d\n", inst->u.ops.funcid);
old_values = values;
values = allocate_stack(func2);
if (!values)
return CL_EMEM;
for (i=0;i<func2->numArgs;i++)
values[i] = old_values[inst->u.ops.ops[i]];
func = func2;
values = func->values;
CHECK_GT(func->numBB, 0);
jump(func, 0, &bb, &inst, &value, &bb_inst);
stop = jump(func, 0, &bb, &inst, &bb_inst);
continue;
case OP_COPY:
BINOPNOMOD(1) = BINOPNOMOD(0);
@ -260,6 +277,7 @@ int cli_vm_execute(struct cli_bc *bc, struct cli_bc_ctx *ctx, struct cli_bc_func
default:
cli_errmsg("Opcode %u is not implemented yet!\n", inst->opcode);
stop = CL_EARG;
break;
}
bb_inst++;
inst++;

Write Preview
Loading…
Cancel
Save