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bytecode: allocate proper stack for functions.

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This commit is contained in:
Török Edvin
2009-07-09 23:05:08 +03:00
parent f3b2dc9e28
commit ec5cccc7ef
4 changed files with 56 additions and 52 deletions
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2
clambc/bcrun.c
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
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
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
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++;