--- /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
+ */
+
+#include "lttng-filter.h"
+
+static
+int bin_op_compare_check(struct vreg reg[NR_REG], const char *str)
+{
+ switch (reg[REG_R0].type) {
+ default:
+ goto error_unknown;
+
+ case REG_STRING:
+ switch (reg[REG_R1].type) {
+ default:
+ goto error_unknown;
+
+ case REG_STRING:
+ break;
+ case REG_S64:
+ case REG_DOUBLE:
+ goto error_mismatch;
+ }
+ break;
+ case REG_S64:
+ case REG_DOUBLE:
+ switch (reg[REG_R1].type) {
+ default:
+ goto error_unknown;
+
+ case REG_STRING:
+ goto error_mismatch;
+
+ case REG_S64:
+ case REG_DOUBLE:
+ break;
+ }
+ break;
+ }
+ return 0;
+
+error_unknown:
+
+ return -EINVAL;
+error_mismatch:
+ ERR("type mismatch 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 = -EINVAL;
+ }
+ 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:
+ {
+ if (unlikely(pc + sizeof(struct binary_op)
+ > start_pc + bytecode->len)) {
+ ret = -EINVAL;
+ }
+ 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 = -EINVAL;
+ }
+ break;
+ }
+
+ /* logical */
+ case FILTER_OP_AND:
+ case FILTER_OP_OR:
+ {
+ if (unlikely(pc + sizeof(struct logical_op)
+ > start_pc + bytecode->len)) {
+ ret = -EINVAL;
+ }
+ break;
+ }
+
+ /* load */
+ case FILTER_OP_LOAD_FIELD_REF:
+ {
+ ERR("Unknown field ref type\n");
+ ret = -EINVAL;
+ break;
+ }
+ 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:
+ {
+ if (unlikely(pc + sizeof(struct load_op) + sizeof(struct field_ref)
+ > start_pc + bytecode->len)) {
+ ret = -EINVAL;
+ }
+ break;
+ }
+
+ 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 = -EINVAL;
+ 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 = -EINVAL;
+ }
+ break;
+ }
+
+ case FILTER_OP_LOAD_S64:
+ {
+ if (unlikely(pc + sizeof(struct load_op) + sizeof(struct literal_numeric)
+ > start_pc + bytecode->len)) {
+ ret = -EINVAL;
+ }
+ break;
+ }
+
+ case FILTER_OP_LOAD_DOUBLE:
+ {
+ if (unlikely(pc + sizeof(struct load_op) + sizeof(struct literal_double)
+ > start_pc + bytecode->len)) {
+ ret = -EINVAL;
+ }
+ 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 = -EINVAL;
+ }
+ break;
+ }
+ }
+
+ return ret;
+}
+
+int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode)
+{
+ void *pc, *next_pc, *start_pc;
+ int ret = -EINVAL;
+ struct vreg reg[NR_REG];
+ int i;
+
+ for (i = 0; i < NR_REG; i++) {
+ reg[i].type = REG_TYPE_UNKNOWN;
+ reg[i].literal = 0;
+ }
+
+ start_pc = &bytecode->data[0];
+ for (pc = next_pc = start_pc; pc - start_pc < bytecode->len;
+ pc = next_pc) {
+ if (bytecode_validate_overflow(bytecode, start_pc, pc) != 0) {
+ ERR("filter bytecode overflow\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ dbg_printf("Validating op %s (%u)\n",
+ print_op((unsigned int) *(filter_opcode_t *) pc),
+ (unsigned int) *(filter_opcode_t *) 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:
+ 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:
+ {
+ ret = bin_op_compare_check(reg, "==");
+ if (ret)
+ goto end;
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ break;
+ }
+ case FILTER_OP_NE:
+ {
+ ret = bin_op_compare_check(reg, "!=");
+ if (ret)
+ goto end;
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ break;
+ }
+ case FILTER_OP_GT:
+ {
+ ret = bin_op_compare_check(reg, ">");
+ if (ret)
+ goto end;
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ break;
+ }
+ case FILTER_OP_LT:
+ {
+ ret = bin_op_compare_check(reg, "<");
+ if (ret)
+ goto end;
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ break;
+ }
+ case FILTER_OP_GE:
+ {
+ ret = bin_op_compare_check(reg, ">=");
+ if (ret)
+ goto end;
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ break;
+ }
+ case FILTER_OP_LE:
+ {
+ ret = bin_op_compare_check(reg, "<=");
+ if (ret)
+ goto end;
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ 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 (reg[REG_R0].type != REG_STRING
+ || reg[REG_R1].type != REG_STRING) {
+ ERR("Unexpected register type for string comparator\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ 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 (reg[REG_R0].type != REG_S64
+ || reg[REG_R1].type != REG_S64) {
+ ERR("Unexpected register type for s64 comparator\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ reg[REG_R0].type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ 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 ((reg[REG_R0].type != REG_DOUBLE && reg[REG_R0].type != REG_S64)
+ || (reg[REG_R1].type != REG_DOUBLE && reg[REG_R1].type != REG_S64)) {
+ ERR("Unexpected register type for double comparator\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ if (reg[REG_R0].type != REG_DOUBLE && reg[REG_R1].type != REG_DOUBLE) {
+ ERR("Double operator should have at least one double register\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ reg[REG_R0].type = REG_DOUBLE;
+ next_pc += sizeof(struct binary_op);
+ break;
+ }
+
+ /* unary */
+ case FILTER_OP_UNARY_PLUS:
+ case FILTER_OP_UNARY_MINUS:
+ case FILTER_OP_UNARY_NOT:
+ {
+ struct unary_op *insn = (struct unary_op *) pc;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ switch (reg[insn->reg].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;
+ }
+ next_pc += sizeof(struct unary_op);
+ break;
+ }
+
+ case FILTER_OP_UNARY_PLUS_S64:
+ case FILTER_OP_UNARY_MINUS_S64:
+ case FILTER_OP_UNARY_NOT_S64:
+ {
+ struct unary_op *insn = (struct unary_op *) pc;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ if (reg[insn->reg].type != REG_S64) {
+ ERR("Invalid register type\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ next_pc += sizeof(struct unary_op);
+ break;
+ }
+
+ case FILTER_OP_UNARY_PLUS_DOUBLE:
+ case FILTER_OP_UNARY_MINUS_DOUBLE:
+ case FILTER_OP_UNARY_NOT_DOUBLE:
+ {
+ struct unary_op *insn = (struct unary_op *) pc;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ if (reg[insn->reg].type != REG_DOUBLE) {
+ ERR("Invalid register type\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ next_pc += sizeof(struct unary_op);
+ break;
+ }
+
+ /* logical */
+ case FILTER_OP_AND:
+ case FILTER_OP_OR:
+ {
+ struct logical_op *insn = (struct logical_op *) pc;
+
+ if (reg[REG_R0].type != REG_S64) {
+ ERR("Logical comparator expects S64 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;
+ }
+ next_pc += sizeof(struct logical_op);
+ break;
+ }
+
+ /* load */
+ 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;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ dbg_printf("Validate load field ref offset %u type string\n",
+ ref->offset);
+ reg[insn->reg].type = REG_STRING;
+ reg[insn->reg].literal = 0;
+ next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
+ 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;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ dbg_printf("Validate load field ref offset %u type s64\n",
+ ref->offset);
+ reg[insn->reg].type = REG_S64;
+ reg[insn->reg].literal = 0;
+ next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
+ 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;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ dbg_printf("Validate load field ref offset %u type double\n",
+ ref->offset);
+ reg[insn->reg].type = REG_DOUBLE;
+ reg[insn->reg].literal = 0;
+ next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
+ break;
+ }
+
+ case FILTER_OP_LOAD_STRING:
+ {
+ struct load_op *insn = (struct load_op *) pc;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ reg[insn->reg].type = REG_STRING;
+ reg[insn->reg].literal = 1;
+ next_pc += sizeof(struct load_op) + strlen(insn->data) + 1;
+ break;
+ }
+
+ case FILTER_OP_LOAD_S64:
+ {
+ struct load_op *insn = (struct load_op *) pc;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ reg[insn->reg].type = REG_S64;
+ reg[insn->reg].literal = 1;
+ next_pc += sizeof(struct load_op)
+ + sizeof(struct literal_numeric);
+ break;
+ }
+
+ case FILTER_OP_LOAD_DOUBLE:
+ {
+ struct load_op *insn = (struct load_op *) pc;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ reg[insn->reg].type = REG_DOUBLE;
+ reg[insn->reg].literal = 1;
+ next_pc += sizeof(struct load_op)
+ + sizeof(struct literal_double);
+ break;
+ }
+
+ case FILTER_OP_CAST_TO_S64:
+ case FILTER_OP_CAST_DOUBLE_TO_S64:
+ {
+ struct cast_op *insn = (struct cast_op *) pc;
+
+ if (unlikely(insn->reg >= REG_ERROR)) {
+ ERR("invalid register %u\n",
+ (unsigned int) insn->reg);
+ ret = -EINVAL;
+ goto end;
+ }
+ switch (reg[insn->reg].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;
+ }
+ if (insn->op == FILTER_OP_CAST_DOUBLE_TO_S64) {
+ if (reg[insn->reg].type != REG_DOUBLE) {
+ ERR("Cast expects double\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ }
+ reg[insn->reg].type = REG_S64;
+ next_pc += sizeof(struct cast_op);
+ break;
+ }
+ case FILTER_OP_CAST_NOP:
+ {
+ next_pc += sizeof(struct cast_op);
+ break;
+ }
+
+ }
+ }
+end:
+ return ret;
+}
projects / lttng-ust.git / blobdiff