/*
* lttng-filter-validator.c
*
* LTTng UST filter bytecode validator.
*
* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; only
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define _LGPL_SOURCE
#include <urcu-bp.h>
#include <time.h>
#include "lttng-filter.h"
#include <urcu/rculfhash.h>
#include "lttng-hash-helper.h"
/*
* Number of merge points for hash table size. Hash table initialized to
* that size, and we do not resize, because we do not want to trigger
* RCU worker thread execution: fall-back on linear traversal if number
* of merge points exceeds this value.
*/
#define DEFAULT_NR_MERGE_POINTS 128
#define MIN_NR_BUCKETS 128
#define MAX_NR_BUCKETS 128
/* merge point table node */
struct lfht_mp_node {
struct cds_lfht_node node;
/* Context at merge point */
struct vstack stack;
unsigned long target_pc;
};
static unsigned long lttng_hash_seed;
static unsigned int lttng_hash_seed_ready;
static
int lttng_hash_match(struct cds_lfht_node *node, const void *key)
{
struct lfht_mp_node *mp_node =
caa_container_of(node, struct lfht_mp_node, node);
unsigned long key_pc = (unsigned long) key;
if (mp_node->target_pc == key_pc)
return 1;
else
return 0;
}
static
int merge_points_compare(const struct vstack *stacka,
const struct vstack *stackb)
{
int i, len;
if (stacka->top != stackb->top)
return 1;
len = stacka->top + 1;
assert(len >= 0);
for (i = 0; i < len; i++) {
if (stacka->e[i].type != REG_UNKNOWN
&& stackb->e[i].type != REG_UNKNOWN
&& stacka->e[i].type != stackb->e[i].type)
return 1;
}
return 0;
}
static
int merge_point_add_check(struct cds_lfht *ht, unsigned long target_pc,
const struct vstack *stack)
{
struct lfht_mp_node *node;
unsigned long hash = lttng_hash_mix((const char *) target_pc,
sizeof(target_pc),
lttng_hash_seed);
struct cds_lfht_node *ret;
dbg_printf("Filter: adding merge point at offset %lu, hash %lu\n",
target_pc, hash);
node = zmalloc(sizeof(struct lfht_mp_node));
if (!node)
return -ENOMEM;
node->target_pc = target_pc;
memcpy(&node->stack, stack, sizeof(node->stack));
ret = cds_lfht_add_unique(ht, hash, lttng_hash_match,
(const char *) target_pc, &node->node);
if (ret != &node->node) {
struct lfht_mp_node *ret_mp =
caa_container_of(ret, struct lfht_mp_node, node);
/* Key already present */
dbg_printf("Filter: compare merge points for offset %lu, hash %lu\n",
target_pc, hash);
free(node);
if (merge_points_compare(stack, &ret_mp->stack)) {
ERR("Merge points differ for offset %lu\n",
target_pc);
return -EINVAL;
}
}
return 0;
}
/*
* Binary comparators use top of stack and top of stack -1.
* Return 0 if typing is known to match, 1 if typing is dynamic
* (unknown), negative error value on error.
*/
static
int bin_op_compare_check(struct vstack *stack, const char *str)
{
if (unlikely(!vstack_ax(stack) || !vstack_bx(stack)))
goto error_empty;
switch (vstack_ax(stack)->type) {
default:
goto error_type;
case REG_UNKNOWN:
goto unknown;
case REG_STRING:
switch (vstack_bx(stack)->type) {
default:
goto error_type;
case REG_UNKNOWN:
goto unknown;
case REG_STRING:
break;
case REG_S64:
case REG_DOUBLE:
goto error_mismatch;
}
break;
case REG_S64:
case REG_DOUBLE:
switch (vstack_bx(stack)->type) {
default:
goto error_type;
case REG_UNKNOWN:
goto unknown;
case REG_STRING:
goto error_mismatch;
case REG_S64:
case REG_DOUBLE:
break;
}
break;
}
return 0;
unknown:
return 1;
error_mismatch:
ERR("type mismatch for '%s' binary operator\n", str);
return -EINVAL;
error_empty:
ERR("empty stack for '%s' binary operator\n", str);
return -EINVAL;
error_type:
ERR("unknown type for '%s' binary operator\n", str);
return -EINVAL;
}
/*
* Validate bytecode range overflow within the validation pass.
* Called for each instruction encountered.
*/
static
int bytecode_validate_overflow(struct bytecode_runtime *bytecode,
char *start_pc, char *pc)
{
int ret = 0;
switch (*(filter_opcode_t *) pc) {
case FILTER_OP_UNKNOWN:
default:
{
ERR("unknown bytecode op %u\n",
(unsigned int) *(filter_opcode_t *) pc);
ret = -EINVAL;
break;
}
case FILTER_OP_RETURN:
{
if (unlikely(pc + sizeof(struct return_op)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
/* binary */
case FILTER_OP_MUL:
case FILTER_OP_DIV:
case FILTER_OP_MOD:
case FILTER_OP_PLUS:
case FILTER_OP_MINUS:
case FILTER_OP_RSHIFT:
case FILTER_OP_LSHIFT:
case FILTER_OP_BIN_AND:
case FILTER_OP_BIN_OR:
case FILTER_OP_BIN_XOR:
{
ERR("unsupported bytecode op %u\n",
(unsigned int) *(filter_opcode_t *) pc);
ret = -EINVAL;
break;
}
case FILTER_OP_EQ:
case FILTER_OP_NE:
case FILTER_OP_GT:
case FILTER_OP_LT:
case FILTER_OP_GE:
case FILTER_OP_LE:
case FILTER_OP_EQ_STRING:
case FILTER_OP_NE_STRING:
case FILTER_OP_GT_STRING:
case FILTER_OP_LT_STRING:
case FILTER_OP_GE_STRING:
case FILTER_OP_LE_STRING:
case FILTER_OP_EQ_S64:
case FILTER_OP_NE_S64:
case FILTER_OP_GT_S64:
case FILTER_OP_LT_S64:
case FILTER_OP_GE_S64:
case FILTER_OP_LE_S64:
case FILTER_OP_EQ_DOUBLE:
case FILTER_OP_NE_DOUBLE:
case FILTER_OP_GT_DOUBLE:
case FILTER_OP_LT_DOUBLE:
case FILTER_OP_GE_DOUBLE:
case FILTER_OP_LE_DOUBLE:
case FILTER_OP_EQ_DOUBLE_S64:
case FILTER_OP_NE_DOUBLE_S64:
case FILTER_OP_GT_DOUBLE_S64:
case FILTER_OP_LT_DOUBLE_S64:
case FILTER_OP_GE_DOUBLE_S64:
case FILTER_OP_LE_DOUBLE_S64:
case FILTER_OP_EQ_S64_DOUBLE:
case FILTER_OP_NE_S64_DOUBLE:
case FILTER_OP_GT_S64_DOUBLE:
case FILTER_OP_LT_S64_DOUBLE:
case FILTER_OP_GE_S64_DOUBLE:
case FILTER_OP_LE_S64_DOUBLE:
{
if (unlikely(pc + sizeof(struct binary_op)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
/* unary */
case FILTER_OP_UNARY_PLUS:
case FILTER_OP_UNARY_MINUS:
case FILTER_OP_UNARY_NOT:
case FILTER_OP_UNARY_PLUS_S64:
case FILTER_OP_UNARY_MINUS_S64:
case FILTER_OP_UNARY_NOT_S64:
case FILTER_OP_UNARY_PLUS_DOUBLE:
case FILTER_OP_UNARY_MINUS_DOUBLE:
case FILTER_OP_UNARY_NOT_DOUBLE:
{
if (unlikely(pc + sizeof(struct unary_op)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
/* logical */
case FILTER_OP_AND:
case FILTER_OP_OR:
{
if (unlikely(pc + sizeof(struct logical_op)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
/* load field ref */
case FILTER_OP_LOAD_FIELD_REF:
{
ERR("Unknown field ref type\n");
ret = -EINVAL;
break;
}
/* get context ref */
case FILTER_OP_GET_CONTEXT_REF:
case FILTER_OP_LOAD_FIELD_REF_STRING:
case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
case FILTER_OP_LOAD_FIELD_REF_S64:
case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
case FILTER_OP_GET_CONTEXT_REF_STRING:
case FILTER_OP_GET_CONTEXT_REF_S64:
case FILTER_OP_GET_CONTEXT_REF_DOUBLE:
{
if (unlikely(pc + sizeof(struct load_op) + sizeof(struct field_ref)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
/* load from immediate operand */
case FILTER_OP_LOAD_STRING:
{
struct load_op *insn = (struct load_op *) pc;
uint32_t str_len, maxlen;
if (unlikely(pc + sizeof(struct load_op)
> start_pc + bytecode->len)) {
ret = -ERANGE;
break;
}
maxlen = start_pc + bytecode->len - pc - sizeof(struct load_op);
str_len = strnlen(insn->data, maxlen);
if (unlikely(str_len >= maxlen)) {
/* Final '\0' not found within range */
ret = -ERANGE;
}
break;
}
case FILTER_OP_LOAD_S64:
{
if (unlikely(pc + sizeof(struct load_op) + sizeof(struct literal_numeric)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
case FILTER_OP_LOAD_DOUBLE:
{
if (unlikely(pc + sizeof(struct load_op) + sizeof(struct literal_double)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
case FILTER_OP_CAST_TO_S64:
case FILTER_OP_CAST_DOUBLE_TO_S64:
case FILTER_OP_CAST_NOP:
{
if (unlikely(pc + sizeof(struct cast_op)
> start_pc + bytecode->len)) {
ret = -ERANGE;
}
break;
}
}
return ret;
}
static
unsigned long delete_all_nodes(struct cds_lfht *ht)
{
struct cds_lfht_iter iter;
struct lfht_mp_node *node;
unsigned long nr_nodes = 0;
cds_lfht_for_each_entry(ht, &iter, node, node) {
int ret;
ret = cds_lfht_del(ht, cds_lfht_iter_get_node(&iter));
assert(!ret);
/* note: this hash table is never used concurrently */
free(node);
nr_nodes++;
}
return nr_nodes;
}
/*
* Return value:
* >=0: success
* <0: error
*/
static
int validate_instruction_context(struct bytecode_runtime *bytecode,
struct vstack *stack,
char *start_pc,
char *pc)
{
int ret = 0;
switch (*(filter_opcode_t *) pc) {
case FILTER_OP_UNKNOWN:
default:
{
ERR("unknown bytecode op %u\n",
(unsigned int) *(filter_opcode_t *) pc);
ret = -EINVAL;
goto end;
}
case FILTER_OP_RETURN:
{
goto end;
}
/* binary */
case FILTER_OP_MUL:
case FILTER_OP_DIV:
case FILTER_OP_MOD:
case FILTER_OP_PLUS:
case FILTER_OP_MINUS:
case FILTER_OP_RSHIFT:
case FILTER_OP_LSHIFT:
case FILTER_OP_BIN_AND:
case FILTER_OP_BIN_OR:
case FILTER_OP_BIN_XOR:
{
ERR("unsupported bytecode op %u\n",
(unsigned int) *(filter_opcode_t *) pc);
ret = -EINVAL;
goto end;
}
case FILTER_OP_EQ:
{
ret = bin_op_compare_check(stack, "==");
if (ret < 0)
goto end;
break;
}
case FILTER_OP_NE:
{
ret = bin_op_compare_check(stack, "!=");
if (ret < 0)
goto end;
break;
}
case FILTER_OP_GT:
{
ret = bin_op_compare_check(stack, ">");
if (ret < 0)
goto end;
break;
}
case FILTER_OP_LT:
{
ret = bin_op_compare_check(stack, "<");
if (ret < 0)
goto end;
break;
}
case FILTER_OP_GE:
{
ret = bin_op_compare_check(stack, ">=");
if (ret < 0)
goto end;
break;
}
case FILTER_OP_LE:
{
ret = bin_op_compare_check(stack, "<=");
if (ret < 0)
goto end;
break;
}
case FILTER_OP_EQ_STRING:
case FILTER_OP_NE_STRING:
case FILTER_OP_GT_STRING:
case FILTER_OP_LT_STRING:
case FILTER_OP_GE_STRING:
case FILTER_OP_LE_STRING:
{
if (!vstack_ax(stack) || !vstack_bx(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_STRING
|| vstack_bx(stack)->type != REG_STRING) {
ERR("Unexpected register type for string comparator\n");
ret = -EINVAL;
goto end;
}
break;
}
case FILTER_OP_EQ_S64:
case FILTER_OP_NE_S64:
case FILTER_OP_GT_S64:
case FILTER_OP_LT_S64:
case FILTER_OP_GE_S64:
case FILTER_OP_LE_S64:
{
if (!vstack_ax(stack) || !vstack_bx(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_S64
|| vstack_bx(stack)->type != REG_S64) {
ERR("Unexpected register type for s64 comparator\n");
ret = -EINVAL;
goto end;
}
break;
}
case FILTER_OP_EQ_DOUBLE:
case FILTER_OP_NE_DOUBLE:
case FILTER_OP_GT_DOUBLE:
case FILTER_OP_LT_DOUBLE:
case FILTER_OP_GE_DOUBLE:
case FILTER_OP_LE_DOUBLE:
{
if (!vstack_ax(stack) || !vstack_bx(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_DOUBLE && vstack_bx(stack)->type != REG_DOUBLE) {
ERR("Double operator should have two double registers\n");
ret = -EINVAL;
goto end;
}
break;
}
case FILTER_OP_EQ_DOUBLE_S64:
case FILTER_OP_NE_DOUBLE_S64:
case FILTER_OP_GT_DOUBLE_S64:
case FILTER_OP_LT_DOUBLE_S64:
case FILTER_OP_GE_DOUBLE_S64:
case FILTER_OP_LE_DOUBLE_S64:
{
if (!vstack_ax(stack) || !vstack_bx(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_S64 && vstack_bx(stack)->type != REG_DOUBLE) {
ERR("Double-S64 operator has unexpected register types\n");
ret = -EINVAL;
goto end;
}
break;
}
case FILTER_OP_EQ_S64_DOUBLE:
case FILTER_OP_NE_S64_DOUBLE:
case FILTER_OP_GT_S64_DOUBLE:
case FILTER_OP_LT_S64_DOUBLE:
case FILTER_OP_GE_S64_DOUBLE:
case FILTER_OP_LE_S64_DOUBLE:
{
if (!vstack_ax(stack) || !vstack_bx(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_DOUBLE && vstack_bx(stack)->type != REG_S64) {
ERR("S64-Double operator has unexpected register types\n");
ret = -EINVAL;
goto end;
}
break;
}
/* unary */
case FILTER_OP_UNARY_PLUS:
case FILTER_OP_UNARY_MINUS:
case FILTER_OP_UNARY_NOT:
{
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
switch (vstack_ax(stack)->type) {
default:
ERR("unknown register type\n");
ret = -EINVAL;
goto end;
case REG_STRING:
ERR("Unary op can only be applied to numeric or floating point registers\n");
ret = -EINVAL;
goto end;
case REG_S64:
break;
case REG_DOUBLE:
break;
case REG_UNKNOWN:
break;
}
break;
}
case FILTER_OP_UNARY_PLUS_S64:
case FILTER_OP_UNARY_MINUS_S64:
case FILTER_OP_UNARY_NOT_S64:
{
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_S64) {
ERR("Invalid register type\n");
ret = -EINVAL;
goto end;
}
break;
}
case FILTER_OP_UNARY_PLUS_DOUBLE:
case FILTER_OP_UNARY_MINUS_DOUBLE:
case FILTER_OP_UNARY_NOT_DOUBLE:
{
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_DOUBLE) {
ERR("Invalid register type\n");
ret = -EINVAL;
goto end;
}
break;
}
/* logical */
case FILTER_OP_AND:
case FILTER_OP_OR:
{
struct logical_op *insn = (struct logical_op *) pc;
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
if (vstack_ax(stack)->type != REG_S64
&& vstack_ax(stack)->type != REG_UNKNOWN) {
ERR("Logical comparator expects S64 or dynamic register\n");
ret = -EINVAL;
goto end;
}
dbg_printf("Validate jumping to bytecode offset %u\n",
(unsigned int) insn->skip_offset);
if (unlikely(start_pc + insn->skip_offset <= pc)) {
ERR("Loops are not allowed in bytecode\n");
ret = -EINVAL;
goto end;
}
break;
}
/* load field ref */
case FILTER_OP_LOAD_FIELD_REF:
{
ERR("Unknown field ref type\n");
ret = -EINVAL;
goto end;
}
case FILTER_OP_LOAD_FIELD_REF_STRING:
case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
{
struct load_op *insn = (struct load_op *) pc;
struct field_ref *ref = (struct field_ref *) insn->data;
dbg_printf("Validate load field ref offset %u type string\n",
ref->offset);
break;
}
case FILTER_OP_LOAD_FIELD_REF_S64:
{
struct load_op *insn = (struct load_op *) pc;
struct field_ref *ref = (struct field_ref *) insn->data;
dbg_printf("Validate load field ref offset %u type s64\n",
ref->offset);
break;
}
case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
{
struct load_op *insn = (struct load_op *) pc;
struct field_ref *ref = (struct field_ref *) insn->data;
dbg_printf("Validate load field ref offset %u type double\n",
ref->offset);
break;
}
/* load from immediate operand */
case FILTER_OP_LOAD_STRING:
{
break;
}
case FILTER_OP_LOAD_S64:
{
break;
}
case FILTER_OP_LOAD_DOUBLE:
{
break;
}
case FILTER_OP_CAST_TO_S64:
case FILTER_OP_CAST_DOUBLE_TO_S64:
{
struct cast_op *insn = (struct cast_op *) pc;
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
switch (vstack_ax(stack)->type) {
default:
ERR("unknown register type\n");
ret = -EINVAL;
goto end;
case REG_STRING:
ERR("Cast op can only be applied to numeric or floating point registers\n");
ret = -EINVAL;
goto end;
case REG_S64:
break;
case REG_DOUBLE:
break;
case REG_UNKNOWN:
break;
}
if (insn->op == FILTER_OP_CAST_DOUBLE_TO_S64) {
if (vstack_ax(stack)->type != REG_DOUBLE) {
ERR("Cast expects double\n");
ret = -EINVAL;
goto end;
}
}
break;
}
case FILTER_OP_CAST_NOP:
{
break;
}
/* get context ref */
case FILTER_OP_GET_CONTEXT_REF:
{
struct load_op *insn = (struct load_op *) pc;
struct field_ref *ref = (struct field_ref *) insn->data;
dbg_printf("Validate get context ref offset %u type dynamic\n",
ref->offset);
break;
}
case FILTER_OP_GET_CONTEXT_REF_STRING:
{
struct load_op *insn = (struct load_op *) pc;
struct field_ref *ref = (struct field_ref *) insn->data;
dbg_printf("Validate get context ref offset %u type string\n",
ref->offset);
break;
}
case FILTER_OP_GET_CONTEXT_REF_S64:
{
struct load_op *insn = (struct load_op *) pc;
struct field_ref *ref = (struct field_ref *) insn->data;
dbg_printf("Validate get context ref offset %u type s64\n",
ref->offset);
break;
}
case FILTER_OP_GET_CONTEXT_REF_DOUBLE:
{
struct load_op *insn = (struct load_op *) pc;
struct field_ref *ref = (struct field_ref *) insn->data;
dbg_printf("Validate get context ref offset %u type double\n",
ref->offset);
break;
}
}
end:
return ret;
}
/*
* Return value:
* 0: success
* <0: error
*/
static
int validate_instruction_all_contexts(struct bytecode_runtime *bytecode,
struct cds_lfht *merge_points,
struct vstack *stack,
char *start_pc,
char *pc)
{
int ret;
unsigned long target_pc = pc - start_pc;
struct cds_lfht_iter iter;
struct cds_lfht_node *node;
struct lfht_mp_node *mp_node;
unsigned long hash;
/* Validate the context resulting from the previous instruction */
ret = validate_instruction_context(bytecode, stack, start_pc, pc);
if (ret < 0)
return ret;
/* Validate merge points */
hash = lttng_hash_mix((const char *) target_pc, sizeof(target_pc),
lttng_hash_seed);
cds_lfht_lookup(merge_points, hash, lttng_hash_match,
(const char *) target_pc, &iter);
node = cds_lfht_iter_get_node(&iter);
if (node) {
mp_node = caa_container_of(node, struct lfht_mp_node, node);
dbg_printf("Filter: validate merge point at offset %lu\n",
target_pc);
if (merge_points_compare(stack, &mp_node->stack)) {
ERR("Merge points differ for offset %lu\n",
target_pc);
return -EINVAL;
}
/* Once validated, we can remove the merge point */
dbg_printf("Filter: remove merge point at offset %lu\n",
target_pc);
ret = cds_lfht_del(merge_points, node);
assert(!ret);
}
return 0;
}
/*
* Return value:
* >0: going to next insn.
* 0: success, stop iteration.
* <0: error
*/
static
int exec_insn(struct bytecode_runtime *bytecode,
struct cds_lfht *merge_points,
struct vstack *stack,
char **_next_pc,
char *pc)
{
int ret = 1;
char *next_pc = *_next_pc;
switch (*(filter_opcode_t *) pc) {
case FILTER_OP_UNKNOWN:
default:
{
ERR("unknown bytecode op %u\n",
(unsigned int) *(filter_opcode_t *) pc);
ret = -EINVAL;
goto end;
}
case FILTER_OP_RETURN:
{
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
ret = 0;
goto end;
}
/* binary */
case FILTER_OP_MUL:
case FILTER_OP_DIV:
case FILTER_OP_MOD:
case FILTER_OP_PLUS:
case FILTER_OP_MINUS:
case FILTER_OP_RSHIFT:
case FILTER_OP_LSHIFT:
case FILTER_OP_BIN_AND:
case FILTER_OP_BIN_OR:
case FILTER_OP_BIN_XOR:
{
ERR("unsupported bytecode op %u\n",
(unsigned int) *(filter_opcode_t *) pc);
ret = -EINVAL;
goto end;
}
case FILTER_OP_EQ:
case FILTER_OP_NE:
case FILTER_OP_GT:
case FILTER_OP_LT:
case FILTER_OP_GE:
case FILTER_OP_LE:
case FILTER_OP_EQ_STRING:
case FILTER_OP_NE_STRING:
case FILTER_OP_GT_STRING:
case FILTER_OP_LT_STRING:
case FILTER_OP_GE_STRING:
case FILTER_OP_LE_STRING:
case FILTER_OP_EQ_S64:
case FILTER_OP_NE_S64:
case FILTER_OP_GT_S64:
case FILTER_OP_LT_S64:
case FILTER_OP_GE_S64:
case FILTER_OP_LE_S64:
case FILTER_OP_EQ_DOUBLE:
case FILTER_OP_NE_DOUBLE:
case FILTER_OP_GT_DOUBLE:
case FILTER_OP_LT_DOUBLE:
case FILTER_OP_GE_DOUBLE:
case FILTER_OP_LE_DOUBLE:
case FILTER_OP_EQ_DOUBLE_S64:
case FILTER_OP_NE_DOUBLE_S64:
case FILTER_OP_GT_DOUBLE_S64:
case FILTER_OP_LT_DOUBLE_S64:
case FILTER_OP_GE_DOUBLE_S64:
case FILTER_OP_LE_DOUBLE_S64:
case FILTER_OP_EQ_S64_DOUBLE:
case FILTER_OP_NE_S64_DOUBLE:
case FILTER_OP_GT_S64_DOUBLE:
case FILTER_OP_LT_S64_DOUBLE:
case FILTER_OP_GE_S64_DOUBLE:
case FILTER_OP_LE_S64_DOUBLE:
{
/* Pop 2, push 1 */
if (vstack_pop(stack)) {
ret = -EINVAL;
goto end;
}
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_S64;
next_pc += sizeof(struct binary_op);
break;
}
/* unary */
case FILTER_OP_UNARY_PLUS:
case FILTER_OP_UNARY_MINUS:
{
/* Pop 1, push 1 */
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_UNKNOWN;
next_pc += sizeof(struct unary_op);
break;
}
case FILTER_OP_UNARY_PLUS_S64:
case FILTER_OP_UNARY_MINUS_S64:
case FILTER_OP_UNARY_NOT:
case FILTER_OP_UNARY_NOT_S64:
case FILTER_OP_UNARY_NOT_DOUBLE:
{
/* Pop 1, push 1 */
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_S64;
next_pc += sizeof(struct unary_op);
break;
}
case FILTER_OP_UNARY_PLUS_DOUBLE:
case FILTER_OP_UNARY_MINUS_DOUBLE:
{
/* Pop 1, push 1 */
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_DOUBLE;
next_pc += sizeof(struct unary_op);
break;
}
/* logical */
case FILTER_OP_AND:
case FILTER_OP_OR:
{
struct logical_op *insn = (struct logical_op *) pc;
int merge_ret;
/* Add merge point to table */
merge_ret = merge_point_add_check(merge_points,
insn->skip_offset, stack);
if (merge_ret) {
ret = merge_ret;
goto end;
}
/* Continue to next instruction */
/* Pop 1 when jump not taken */
if (vstack_pop(stack)) {
ret = -EINVAL;
goto end;
}
next_pc += sizeof(struct logical_op);
break;
}
/* load field ref */
case FILTER_OP_LOAD_FIELD_REF:
{
ERR("Unknown field ref type\n");
ret = -EINVAL;
goto end;
}
/* get context ref */
case FILTER_OP_GET_CONTEXT_REF:
{
if (vstack_push(stack)) {
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_UNKNOWN;
next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
break;
}
case FILTER_OP_LOAD_FIELD_REF_STRING:
case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
case FILTER_OP_GET_CONTEXT_REF_STRING:
{
if (vstack_push(stack)) {
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_STRING;
next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
break;
}
case FILTER_OP_LOAD_FIELD_REF_S64:
case FILTER_OP_GET_CONTEXT_REF_S64:
{
if (vstack_push(stack)) {
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_S64;
next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
break;
}
case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
case FILTER_OP_GET_CONTEXT_REF_DOUBLE:
{
if (vstack_push(stack)) {
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_DOUBLE;
next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
break;
}
/* load from immediate operand */
case FILTER_OP_LOAD_STRING:
{
struct load_op *insn = (struct load_op *) pc;
if (vstack_push(stack)) {
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_STRING;
next_pc += sizeof(struct load_op) + strlen(insn->data) + 1;
break;
}
case FILTER_OP_LOAD_S64:
{
if (vstack_push(stack)) {
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_S64;
next_pc += sizeof(struct load_op)
+ sizeof(struct literal_numeric);
break;
}
case FILTER_OP_LOAD_DOUBLE:
{
if (vstack_push(stack)) {
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_DOUBLE;
next_pc += sizeof(struct load_op)
+ sizeof(struct literal_double);
break;
}
case FILTER_OP_CAST_TO_S64:
case FILTER_OP_CAST_DOUBLE_TO_S64:
{
/* Pop 1, push 1 */
if (!vstack_ax(stack)) {
ERR("Empty stack\n");
ret = -EINVAL;
goto end;
}
vstack_ax(stack)->type = REG_S64;
next_pc += sizeof(struct cast_op);
break;
}
case FILTER_OP_CAST_NOP:
{
next_pc += sizeof(struct cast_op);
break;
}
}
end:
*_next_pc = next_pc;
return ret;
}
/*
* Never called concurrently (hash seed is shared).
*/
int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode)
{
struct cds_lfht *merge_points;
char *pc, *next_pc, *start_pc;
int ret = -EINVAL;
struct vstack stack;
vstack_init(&stack);
if (!lttng_hash_seed_ready) {
lttng_hash_seed = time(NULL);
lttng_hash_seed_ready = 1;
}
/*
* Note: merge_points hash table used by single thread, and
* never concurrently resized. Therefore, we can use it without
* holding RCU read-side lock and free nodes without using
* call_rcu.
*/
merge_points = cds_lfht_new(DEFAULT_NR_MERGE_POINTS,
MIN_NR_BUCKETS, MAX_NR_BUCKETS,
0, NULL);
if (!merge_points) {
ERR("Error allocating hash table for bytecode validation\n");
return -ENOMEM;
}
start_pc = &bytecode->data[0];
for (pc = next_pc = start_pc; pc - start_pc < bytecode->len;
pc = next_pc) {
ret = bytecode_validate_overflow(bytecode, start_pc, pc);
if (ret != 0) {
if (ret == -ERANGE)
ERR("filter bytecode overflow\n");
goto end;
}
dbg_printf("Validating op %s (%u)\n",
print_op((unsigned int) *(filter_opcode_t *) pc),
(unsigned int) *(filter_opcode_t *) pc);
/*
* For each instruction, validate the current context
* (traversal of entire execution flow), and validate
* all merge points targeting this instruction.
*/
ret = validate_instruction_all_contexts(bytecode, merge_points,
&stack, start_pc, pc);
if (ret)
goto end;
ret = exec_insn(bytecode, merge_points, &stack, &next_pc, pc);
if (ret <= 0)
goto end;
}
end:
if (delete_all_nodes(merge_points)) {
if (!ret) {
ERR("Unexpected merge points\n");
ret = -EINVAL;
}
}
if (cds_lfht_destroy(merge_points, NULL)) {
ERR("Error destroying hash table\n");
}
return ret;
}