+++ /dev/null
-/*
- * lttng-filter-validator.c
- *
- * LTTng modules filter bytecode validator.
- *
- * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-#include <linux/types.h>
-#include <linux/jhash.h>
-#include <linux/slab.h>
-
-#include <wrapper/list.h>
-#include <lttng-filter.h>
-
-#define MERGE_POINT_TABLE_BITS 7
-#define MERGE_POINT_TABLE_SIZE (1U << MERGE_POINT_TABLE_BITS)
-
-/* merge point table node */
-struct mp_node {
- struct hlist_node node;
-
- /* Context at merge point */
- struct vstack stack;
- unsigned long target_pc;
-};
-
-struct mp_table {
- struct hlist_head mp_head[MERGE_POINT_TABLE_SIZE];
-};
-
-static
-int lttng_hash_match(struct mp_node *mp_node, unsigned long key_pc)
-{
- 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;
- WARN_ON_ONCE(len < 0);
- for (i = 0; i < len; i++) {
- if (stacka->e[i].type != stackb->e[i].type)
- return 1;
- }
- return 0;
-}
-
-static
-int merge_point_add_check(struct mp_table *mp_table, unsigned long target_pc,
- const struct vstack *stack)
-{
- struct mp_node *mp_node;
- unsigned long hash = jhash_1word(target_pc, 0);
- struct hlist_head *head;
- struct mp_node *lookup_node;
- int found = 0;
-
- dbg_printk("Filter: adding merge point at offset %lu, hash %lu\n",
- target_pc, hash);
- mp_node = kzalloc(sizeof(struct mp_node), GFP_KERNEL);
- if (!mp_node)
- return -ENOMEM;
- mp_node->target_pc = target_pc;
- memcpy(&mp_node->stack, stack, sizeof(mp_node->stack));
-
- head = &mp_table->mp_head[hash & (MERGE_POINT_TABLE_SIZE - 1)];
- lttng_hlist_for_each_entry(lookup_node, head, node) {
- if (lttng_hash_match(lookup_node, target_pc)) {
- found = 1;
- break;
- }
- }
- if (found) {
- /* Key already present */
- dbg_printk("Filter: compare merge points for offset %lu, hash %lu\n",
- target_pc, hash);
- kfree(mp_node);
- if (merge_points_compare(stack, &lookup_node->stack)) {
- printk(KERN_WARNING "Merge points differ for offset %lu\n",
- target_pc);
- return -EINVAL;
- }
- } else {
- hlist_add_head(&mp_node->node, head);
- }
- return 0;
-}
-
-/*
- * Binary comparators use top of stack and top of stack -1.
- */
-static
-int bin_op_compare_check(struct vstack *stack, const filter_opcode_t opcode,
- const char *str)
-{
- if (unlikely(!vstack_ax(stack) || !vstack_bx(stack)))
- goto error_unknown;
-
- switch (vstack_ax(stack)->type) {
- default:
- case REG_DOUBLE:
- goto error_unknown;
-
- case REG_STRING:
- switch (vstack_bx(stack)->type) {
- default:
- case REG_DOUBLE:
- goto error_unknown;
-
- case REG_STRING:
- break;
- case REG_STAR_GLOB_STRING:
- if (opcode != FILTER_OP_EQ && opcode != FILTER_OP_NE) {
- goto error_mismatch;
- }
- break;
- case REG_S64:
- goto error_mismatch;
- }
- break;
- case REG_STAR_GLOB_STRING:
- switch (vstack_bx(stack)->type) {
- default:
- case REG_DOUBLE:
- goto error_unknown;
-
- case REG_STRING:
- if (opcode != FILTER_OP_EQ && opcode != FILTER_OP_NE) {
- goto error_mismatch;
- }
- break;
- case REG_STAR_GLOB_STRING:
- case REG_S64:
- goto error_mismatch;
- }
- break;
- case REG_S64:
- switch (vstack_bx(stack)->type) {
- default:
- case REG_DOUBLE:
- goto error_unknown;
-
- case REG_STRING:
- case REG_STAR_GLOB_STRING:
- goto error_mismatch;
-
- case REG_S64:
- break;
- }
- break;
- }
- return 0;
-
-error_unknown:
- return -EINVAL;
-
-error_mismatch:
- printk(KERN_WARNING "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,
- char *start_pc, char *pc)
-{
- int ret = 0;
-
- switch (*(filter_opcode_t *) pc) {
- case FILTER_OP_UNKNOWN:
- default:
- {
- printk(KERN_WARNING "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:
- 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:
- /* Floating point */
- 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:
- case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
- case FILTER_OP_GET_CONTEXT_REF_DOUBLE:
- case FILTER_OP_LOAD_DOUBLE:
- case FILTER_OP_CAST_DOUBLE_TO_S64:
- case FILTER_OP_UNARY_PLUS_DOUBLE:
- case FILTER_OP_UNARY_MINUS_DOUBLE:
- case FILTER_OP_UNARY_NOT_DOUBLE:
- {
- printk(KERN_WARNING "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_STAR_GLOB_STRING:
- case FILTER_OP_NE_STAR_GLOB_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:
- {
- 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:
- {
- 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:
- {
- printk(KERN_WARNING "Unknown field ref type\n");
- ret = -EINVAL;
- break;
- }
- /* get context ref */
- case FILTER_OP_GET_CONTEXT_REF:
- {
- printk(KERN_WARNING "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_USER_STRING:
- case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE:
- case FILTER_OP_LOAD_FIELD_REF_S64:
- case FILTER_OP_GET_CONTEXT_REF_STRING:
- case FILTER_OP_GET_CONTEXT_REF_S64:
- {
- 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:
- case FILTER_OP_LOAD_STAR_GLOB_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_CAST_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 mp_table *mp_table)
-{
- struct mp_node *mp_node;
- struct hlist_node *tmp;
- unsigned long nr_nodes = 0;
- int i;
-
- for (i = 0; i < MERGE_POINT_TABLE_SIZE; i++) {
- struct hlist_head *head;
-
- head = &mp_table->mp_head[i];
- lttng_hlist_for_each_entry_safe(mp_node, tmp, head, node) {
- kfree(mp_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;
- const filter_opcode_t opcode = *(filter_opcode_t *) pc;
-
- switch (opcode) {
- case FILTER_OP_UNKNOWN:
- default:
- {
- printk(KERN_WARNING "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:
- /* Floating point */
- 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:
- case FILTER_OP_UNARY_PLUS_DOUBLE:
- case FILTER_OP_UNARY_MINUS_DOUBLE:
- case FILTER_OP_UNARY_NOT_DOUBLE:
- case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
- case FILTER_OP_LOAD_DOUBLE:
- case FILTER_OP_CAST_DOUBLE_TO_S64:
- case FILTER_OP_GET_CONTEXT_REF_DOUBLE:
- {
- printk(KERN_WARNING "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, opcode, "==");
- if (ret)
- goto end;
- break;
- }
- case FILTER_OP_NE:
- {
- ret = bin_op_compare_check(stack, opcode, "!=");
- if (ret)
- goto end;
- break;
- }
- case FILTER_OP_GT:
- {
- ret = bin_op_compare_check(stack, opcode, ">");
- if (ret)
- goto end;
- break;
- }
- case FILTER_OP_LT:
- {
- ret = bin_op_compare_check(stack, opcode, "<");
- if (ret)
- goto end;
- break;
- }
- case FILTER_OP_GE:
- {
- ret = bin_op_compare_check(stack, opcode, ">=");
- if (ret)
- goto end;
- break;
- }
- case FILTER_OP_LE:
- {
- ret = bin_op_compare_check(stack, opcode, "<=");
- if (ret)
- 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)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- if (vstack_ax(stack)->type != REG_STRING
- || vstack_bx(stack)->type != REG_STRING) {
- printk(KERN_WARNING "Unexpected register type for string comparator\n");
- ret = -EINVAL;
- goto end;
- }
- break;
- }
-
-
- case FILTER_OP_EQ_STAR_GLOB_STRING:
- case FILTER_OP_NE_STAR_GLOB_STRING:
- {
- if (!vstack_ax(stack) || !vstack_bx(stack)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- if (vstack_ax(stack)->type != REG_STAR_GLOB_STRING
- && vstack_bx(stack)->type != REG_STAR_GLOB_STRING) {
- printk(KERN_WARNING "Unexpected register type for globbing pattern 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)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- if (vstack_ax(stack)->type != REG_S64
- || vstack_bx(stack)->type != REG_S64) {
- printk(KERN_WARNING "Unexpected register type for s64 comparator\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)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- switch (vstack_ax(stack)->type) {
- default:
- case REG_DOUBLE:
- printk(KERN_WARNING "unknown register type\n");
- ret = -EINVAL;
- goto end;
-
- case REG_STRING:
- case REG_STAR_GLOB_STRING:
- printk(KERN_WARNING "Unary op can only be applied to numeric or floating point registers\n");
- ret = -EINVAL;
- goto end;
- case REG_S64:
- break;
- }
- break;
- }
-
- case FILTER_OP_UNARY_PLUS_S64:
- case FILTER_OP_UNARY_MINUS_S64:
- case FILTER_OP_UNARY_NOT_S64:
- {
- if (!vstack_ax(stack)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- if (vstack_ax(stack)->type != REG_S64) {
- printk(KERN_WARNING "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)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- if (vstack_ax(stack)->type != REG_S64) {
- printk(KERN_WARNING "Logical comparator expects S64 register\n");
- ret = -EINVAL;
- goto end;
- }
-
- dbg_printk("Validate jumping to bytecode offset %u\n",
- (unsigned int) insn->skip_offset);
- if (unlikely(start_pc + insn->skip_offset <= pc)) {
- printk(KERN_WARNING "Loops are not allowed in bytecode\n");
- ret = -EINVAL;
- goto end;
- }
- break;
- }
-
- /* load field ref */
- case FILTER_OP_LOAD_FIELD_REF:
- {
- printk(KERN_WARNING "Unknown field ref type\n");
- ret = -EINVAL;
- goto end;
- }
- case FILTER_OP_LOAD_FIELD_REF_STRING:
- case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
- case FILTER_OP_LOAD_FIELD_REF_USER_STRING:
- case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE:
- {
- struct load_op *insn = (struct load_op *) pc;
- struct field_ref *ref = (struct field_ref *) insn->data;
-
- dbg_printk("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_printk("Validate load field ref offset %u type s64\n",
- ref->offset);
- break;
- }
-
- /* load from immediate operand */
- case FILTER_OP_LOAD_STRING:
- case FILTER_OP_LOAD_STAR_GLOB_STRING:
- {
- break;
- }
-
- case FILTER_OP_LOAD_S64:
- {
- break;
- }
-
- case FILTER_OP_CAST_TO_S64:
- {
- struct cast_op *insn = (struct cast_op *) pc;
-
- if (!vstack_ax(stack)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- switch (vstack_ax(stack)->type) {
- default:
- case REG_DOUBLE:
- printk(KERN_WARNING "unknown register type\n");
- ret = -EINVAL;
- goto end;
-
- case REG_STRING:
- case REG_STAR_GLOB_STRING:
- printk(KERN_WARNING "Cast op can only be applied to numeric or floating point registers\n");
- ret = -EINVAL;
- goto end;
- case REG_S64:
- break;
- }
- if (insn->op == FILTER_OP_CAST_DOUBLE_TO_S64) {
- if (vstack_ax(stack)->type != REG_DOUBLE) {
- printk(KERN_WARNING "Cast expects double\n");
- ret = -EINVAL;
- goto end;
- }
- }
- break;
- }
- case FILTER_OP_CAST_NOP:
- {
- break;
- }
-
- /* get context ref */
- case FILTER_OP_GET_CONTEXT_REF:
- {
- printk(KERN_WARNING "Unknown get context ref type\n");
- ret = -EINVAL;
- goto end;
- }
- 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_printk("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_printk("Validate get context ref offset %u type s64\n",
- ref->offset);
- break;
- }
-
- }
-end:
- return ret;
-}
-
-/*
- * Return value:
- * 0: success
- * <0: error
- */
-static
-int validate_instruction_all_contexts(struct bytecode_runtime *bytecode,
- struct mp_table *mp_table,
- struct vstack *stack,
- char *start_pc,
- char *pc)
-{
- int ret, found = 0;
- unsigned long target_pc = pc - start_pc;
- unsigned long hash;
- struct hlist_head *head;
- struct mp_node *mp_node;
-
- /* Validate the context resulting from the previous instruction */
- ret = validate_instruction_context(bytecode, stack, start_pc, pc);
- if (ret)
- return ret;
-
- /* Validate merge points */
- hash = jhash_1word(target_pc, 0);
- head = &mp_table->mp_head[hash & (MERGE_POINT_TABLE_SIZE - 1)];
- lttng_hlist_for_each_entry(mp_node, head, node) {
- if (lttng_hash_match(mp_node, target_pc)) {
- found = 1;
- break;
- }
- }
- if (found) {
- dbg_printk("Filter: validate merge point at offset %lu\n",
- target_pc);
- if (merge_points_compare(stack, &mp_node->stack)) {
- printk(KERN_WARNING "Merge points differ for offset %lu\n",
- target_pc);
- return -EINVAL;
- }
- /* Once validated, we can remove the merge point */
- dbg_printk("Filter: remove merge point at offset %lu\n",
- target_pc);
- hlist_del(&mp_node->node);
- }
- return 0;
-}
-
-/*
- * Return value:
- * >0: going to next insn.
- * 0: success, stop iteration.
- * <0: error
- */
-static
-int exec_insn(struct bytecode_runtime *bytecode,
- struct mp_table *mp_table,
- 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:
- {
- printk(KERN_WARNING "unknown bytecode op %u\n",
- (unsigned int) *(filter_opcode_t *) pc);
- ret = -EINVAL;
- goto end;
- }
-
- case FILTER_OP_RETURN:
- {
- if (!vstack_ax(stack)) {
- printk(KERN_WARNING "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:
- /* Floating point */
- 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:
- case FILTER_OP_UNARY_PLUS_DOUBLE:
- case FILTER_OP_UNARY_MINUS_DOUBLE:
- case FILTER_OP_UNARY_NOT_DOUBLE:
- case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
- case FILTER_OP_GET_CONTEXT_REF_DOUBLE:
- case FILTER_OP_LOAD_DOUBLE:
- case FILTER_OP_CAST_DOUBLE_TO_S64:
- {
- printk(KERN_WARNING "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_STAR_GLOB_STRING:
- case FILTER_OP_NE_STAR_GLOB_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:
- {
- /* Pop 2, push 1 */
- if (vstack_pop(stack)) {
- ret = -EINVAL;
- goto end;
- }
- if (!vstack_ax(stack)) {
- printk(KERN_WARNING "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:
- case FILTER_OP_UNARY_NOT:
- case FILTER_OP_UNARY_PLUS_S64:
- case FILTER_OP_UNARY_MINUS_S64:
- case FILTER_OP_UNARY_NOT_S64:
- {
- /* Pop 1, push 1 */
- if (!vstack_ax(stack)) {
- printk(KERN_WARNING "Empty stack\n");
- ret = -EINVAL;
- goto end;
- }
- vstack_ax(stack)->type = REG_S64;
- 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(mp_table,
- 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:
- {
- printk(KERN_WARNING "Unknown field ref type\n");
- ret = -EINVAL;
- goto end;
- }
- /* get context ref */
- case FILTER_OP_GET_CONTEXT_REF:
- {
- printk(KERN_WARNING "Unknown get context ref type\n");
- ret = -EINVAL;
- goto end;
- }
- case FILTER_OP_LOAD_FIELD_REF_STRING:
- case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
- case FILTER_OP_GET_CONTEXT_REF_STRING:
- case FILTER_OP_LOAD_FIELD_REF_USER_STRING:
- case FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE:
- {
- 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;
- }
-
- /* 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_STAR_GLOB_STRING:
- {
- struct load_op *insn = (struct load_op *) pc;
-
- if (vstack_push(stack)) {
- ret = -EINVAL;
- goto end;
- }
- vstack_ax(stack)->type = REG_STAR_GLOB_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_CAST_TO_S64:
- {
- /* Pop 1, push 1 */
- if (!vstack_ax(stack)) {
- printk(KERN_WARNING "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 mp_table *mp_table;
- char *pc, *next_pc, *start_pc;
- int ret = -EINVAL;
- struct vstack stack;
-
- vstack_init(&stack);
-
- mp_table = kzalloc(sizeof(*mp_table), GFP_KERNEL);
- if (!mp_table) {
- printk(KERN_WARNING "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)
- printk(KERN_WARNING "filter bytecode overflow\n");
- goto end;
- }
- dbg_printk("Validating op %s (%u)\n",
- lttng_filter_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, mp_table,
- &stack, start_pc, pc);
- if (ret)
- goto end;
- ret = exec_insn(bytecode, mp_table, &stack, &next_pc, pc);
- if (ret <= 0)
- goto end;
- }
-end:
- if (delete_all_nodes(mp_table)) {
- if (!ret) {
- printk(KERN_WARNING "Unexpected merge points\n");
- ret = -EINVAL;
- }
- }
- kfree(mp_table);
- return ret;
-}