+++ /dev/null
-/*
- * 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 void *) 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 void *) 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,
- void *start_pc, void *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,
- void *start_pc,
- void *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,
- void *start_pc,
- void *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 void *) target_pc, sizeof(target_pc),
- lttng_hash_seed);
- cds_lfht_lookup(merge_points, hash, lttng_hash_match,
- (const void *) 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,
- void **_next_pc,
- void *pc)
-{
- int ret = 1;
- void *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;
- void *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;
-}
projects / lttng-ust.git / blobdiff