+++ /dev/null
-/*
- * lttng-filter.c
- *
- * LTTng modules filter code.
- *
- * Copyright (C) 2010-2014 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 <linux/list.h>
-#include <linux/slab.h>
-
-#include "lttng-filter.h"
-
-static const char *opnames[] = {
- [ FILTER_OP_UNKNOWN ] = "UNKNOWN",
-
- [ FILTER_OP_RETURN ] = "RETURN",
-
- /* binary */
- [ FILTER_OP_MUL ] = "MUL",
- [ FILTER_OP_DIV ] = "DIV",
- [ FILTER_OP_MOD ] = "MOD",
- [ FILTER_OP_PLUS ] = "PLUS",
- [ FILTER_OP_MINUS ] = "MINUS",
- [ FILTER_OP_RSHIFT ] = "RSHIFT",
- [ FILTER_OP_LSHIFT ] = "LSHIFT",
- [ FILTER_OP_BIN_AND ] = "BIN_AND",
- [ FILTER_OP_BIN_OR ] = "BIN_OR",
- [ FILTER_OP_BIN_XOR ] = "BIN_XOR",
-
- /* binary comparators */
- [ FILTER_OP_EQ ] = "EQ",
- [ FILTER_OP_NE ] = "NE",
- [ FILTER_OP_GT ] = "GT",
- [ FILTER_OP_LT ] = "LT",
- [ FILTER_OP_GE ] = "GE",
- [ FILTER_OP_LE ] = "LE",
-
- /* string binary comparators */
- [ FILTER_OP_EQ_STRING ] = "EQ_STRING",
- [ FILTER_OP_NE_STRING ] = "NE_STRING",
- [ FILTER_OP_GT_STRING ] = "GT_STRING",
- [ FILTER_OP_LT_STRING ] = "LT_STRING",
- [ FILTER_OP_GE_STRING ] = "GE_STRING",
- [ FILTER_OP_LE_STRING ] = "LE_STRING",
-
- /* s64 binary comparators */
- [ FILTER_OP_EQ_S64 ] = "EQ_S64",
- [ FILTER_OP_NE_S64 ] = "NE_S64",
- [ FILTER_OP_GT_S64 ] = "GT_S64",
- [ FILTER_OP_LT_S64 ] = "LT_S64",
- [ FILTER_OP_GE_S64 ] = "GE_S64",
- [ FILTER_OP_LE_S64 ] = "LE_S64",
-
- /* double binary comparators */
- [ FILTER_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
- [ FILTER_OP_NE_DOUBLE ] = "NE_DOUBLE",
- [ FILTER_OP_GT_DOUBLE ] = "GT_DOUBLE",
- [ FILTER_OP_LT_DOUBLE ] = "LT_DOUBLE",
- [ FILTER_OP_GE_DOUBLE ] = "GE_DOUBLE",
- [ FILTER_OP_LE_DOUBLE ] = "LE_DOUBLE",
-
- /* Mixed S64-double binary comparators */
- [ FILTER_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
- [ FILTER_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
- [ FILTER_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
- [ FILTER_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
- [ FILTER_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
- [ FILTER_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
-
- [ FILTER_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
- [ FILTER_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
- [ FILTER_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
- [ FILTER_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
- [ FILTER_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
- [ FILTER_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
-
- /* unary */
- [ FILTER_OP_UNARY_PLUS ] = "UNARY_PLUS",
- [ FILTER_OP_UNARY_MINUS ] = "UNARY_MINUS",
- [ FILTER_OP_UNARY_NOT ] = "UNARY_NOT",
- [ FILTER_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
- [ FILTER_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
- [ FILTER_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
- [ FILTER_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
- [ FILTER_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
- [ FILTER_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
-
- /* logical */
- [ FILTER_OP_AND ] = "AND",
- [ FILTER_OP_OR ] = "OR",
-
- /* load field ref */
- [ FILTER_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
- [ FILTER_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
- [ FILTER_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
- [ FILTER_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
- [ FILTER_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
-
- /* load from immediate operand */
- [ FILTER_OP_LOAD_STRING ] = "LOAD_STRING",
- [ FILTER_OP_LOAD_S64 ] = "LOAD_S64",
- [ FILTER_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
-
- /* cast */
- [ FILTER_OP_CAST_TO_S64 ] = "CAST_TO_S64",
- [ FILTER_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
- [ FILTER_OP_CAST_NOP ] = "CAST_NOP",
-
- /* get context ref */
- [ FILTER_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
- [ FILTER_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
- [ FILTER_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
- [ FILTER_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
-};
-
-const char *lttng_filter_print_op(enum filter_op op)
-{
- if (op >= NR_FILTER_OPS)
- return "UNKNOWN";
- else
- return opnames[op];
-}
-
-static
-int apply_field_reloc(struct lttng_event *event,
- struct bytecode_runtime *runtime,
- uint32_t runtime_len,
- uint32_t reloc_offset,
- const char *field_name)
-{
- const struct lttng_event_desc *desc;
- const struct lttng_event_field *fields, *field = NULL;
- unsigned int nr_fields, i;
- struct field_ref *field_ref;
- struct load_op *op;
- uint32_t field_offset = 0;
-
- dbg_printk("Apply field reloc: %u %s\n", reloc_offset, field_name);
-
- /* Lookup event by name */
- desc = event->desc;
- if (!desc)
- return -EINVAL;
- fields = desc->fields;
- if (!fields)
- return -EINVAL;
- nr_fields = desc->nr_fields;
- for (i = 0; i < nr_fields; i++) {
- if (!strcmp(fields[i].name, field_name)) {
- field = &fields[i];
- break;
- }
- /* compute field offset */
- switch (fields[i].type.atype) {
- case atype_integer:
- case atype_enum:
- field_offset += sizeof(int64_t);
- break;
- case atype_array:
- case atype_sequence:
- field_offset += sizeof(unsigned long);
- field_offset += sizeof(void *);
- break;
- case atype_string:
- field_offset += sizeof(void *);
- break;
- default:
- return -EINVAL;
- }
- }
- if (!field)
- return -EINVAL;
-
- /* Check if field offset is too large for 16-bit offset */
- if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
- return -EINVAL;
-
- /* set type */
- op = (struct load_op *) &runtime->data[reloc_offset];
- field_ref = (struct field_ref *) op->data;
- switch (field->type.atype) {
- case atype_integer:
- case atype_enum:
- op->op = FILTER_OP_LOAD_FIELD_REF_S64;
- break;
- case atype_array:
- case atype_sequence:
- op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
- break;
- case atype_string:
- op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
- break;
- default:
- return -EINVAL;
- }
- /* set offset */
- field_ref->offset = (uint16_t) field_offset;
- return 0;
-}
-
-static
-int apply_context_reloc(struct lttng_event *event,
- struct bytecode_runtime *runtime,
- uint32_t runtime_len,
- uint32_t reloc_offset,
- const char *context_name)
-{
- struct field_ref *field_ref;
- struct load_op *op;
- struct lttng_ctx_field *ctx_field;
- int idx;
-
- dbg_printk("Apply context reloc: %u %s\n", reloc_offset, context_name);
-
- /* Get context index */
- idx = lttng_get_context_index(lttng_static_ctx, context_name);
- if (idx < 0)
- return -ENOENT;
-
- /* Check if idx is too large for 16-bit offset */
- if (idx > FILTER_BYTECODE_MAX_LEN - 1)
- return -EINVAL;
-
- /* Get context return type */
- ctx_field = <tng_static_ctx->fields[idx];
- op = (struct load_op *) &runtime->data[reloc_offset];
- field_ref = (struct field_ref *) op->data;
- switch (ctx_field->event_field.type.atype) {
- case atype_integer:
- case atype_enum:
- op->op = FILTER_OP_GET_CONTEXT_REF_S64;
- break;
- /* Sequence and array supported as string */
- case atype_string:
- case atype_array:
- case atype_sequence:
- op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
- break;
- default:
- return -EINVAL;
- }
- /* set offset to context index within channel contexts */
- field_ref->offset = (uint16_t) idx;
- return 0;
-}
-
-static
-int apply_reloc(struct lttng_event *event,
- struct bytecode_runtime *runtime,
- uint32_t runtime_len,
- uint32_t reloc_offset,
- const char *name)
-{
- struct load_op *op;
-
- dbg_printk("Apply reloc: %u %s\n", reloc_offset, name);
-
- /* Ensure that the reloc is within the code */
- if (runtime_len - reloc_offset < sizeof(uint16_t))
- return -EINVAL;
-
- op = (struct load_op *) &runtime->data[reloc_offset];
- switch (op->op) {
- case FILTER_OP_LOAD_FIELD_REF:
- return apply_field_reloc(event, runtime, runtime_len,
- reloc_offset, name);
- case FILTER_OP_GET_CONTEXT_REF:
- return apply_context_reloc(event, runtime, runtime_len,
- reloc_offset, name);
- default:
- printk(KERN_WARNING "Unknown reloc op type %u\n", op->op);
- return -EINVAL;
- }
- return 0;
-}
-
-static
-int bytecode_is_linked(struct lttng_filter_bytecode_node *filter_bytecode,
- struct lttng_event *event)
-{
- struct lttng_bytecode_runtime *bc_runtime;
-
- list_for_each_entry(bc_runtime,
- &event->bytecode_runtime_head, node) {
- if (bc_runtime->bc == filter_bytecode)
- return 1;
- }
- return 0;
-}
-
-/*
- * Take a bytecode with reloc table and link it to an event to create a
- * bytecode runtime.
- */
-static
-int _lttng_filter_event_link_bytecode(struct lttng_event *event,
- struct lttng_filter_bytecode_node *filter_bytecode,
- struct list_head *insert_loc)
-{
- int ret, offset, next_offset;
- struct bytecode_runtime *runtime = NULL;
- size_t runtime_alloc_len;
-
- if (!filter_bytecode)
- return 0;
- /* Bytecode already linked */
- if (bytecode_is_linked(filter_bytecode, event))
- return 0;
-
- dbg_printk("Linking...\n");
-
- /* We don't need the reloc table in the runtime */
- runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
- runtime = kzalloc(runtime_alloc_len, GFP_KERNEL);
- if (!runtime) {
- ret = -ENOMEM;
- goto alloc_error;
- }
- runtime->p.bc = filter_bytecode;
- runtime->len = filter_bytecode->bc.reloc_offset;
- /* copy original bytecode */
- memcpy(runtime->data, filter_bytecode->bc.data, runtime->len);
- /*
- * apply relocs. Those are a uint16_t (offset in bytecode)
- * followed by a string (field name).
- */
- for (offset = filter_bytecode->bc.reloc_offset;
- offset < filter_bytecode->bc.len;
- offset = next_offset) {
- uint16_t reloc_offset =
- *(uint16_t *) &filter_bytecode->bc.data[offset];
- const char *name =
- (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
-
- ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
- if (ret) {
- goto link_error;
- }
- next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
- }
- /* Validate bytecode */
- ret = lttng_filter_validate_bytecode(runtime);
- if (ret) {
- goto link_error;
- }
- /* Specialize bytecode */
- ret = lttng_filter_specialize_bytecode(runtime);
- if (ret) {
- goto link_error;
- }
- runtime->p.filter = lttng_filter_interpret_bytecode;
- runtime->p.link_failed = 0;
- list_add_rcu(&runtime->p.node, insert_loc);
- dbg_printk("Linking successful.\n");
- return 0;
-
-link_error:
- runtime->p.filter = lttng_filter_false;
- runtime->p.link_failed = 1;
- list_add_rcu(&runtime->p.node, insert_loc);
-alloc_error:
- dbg_printk("Linking failed.\n");
- return ret;
-}
-
-void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
-{
- struct lttng_filter_bytecode_node *bc = runtime->bc;
-
- if (!bc->enabler->enabled || runtime->link_failed)
- runtime->filter = lttng_filter_false;
- else
- runtime->filter = lttng_filter_interpret_bytecode;
-}
-
-/*
- * Link bytecode for all enablers referenced by an event.
- */
-void lttng_enabler_event_link_bytecode(struct lttng_event *event,
- struct lttng_enabler *enabler)
-{
- struct lttng_filter_bytecode_node *bc;
- struct lttng_bytecode_runtime *runtime;
-
- /* Can only be called for events with desc attached */
- WARN_ON_ONCE(!event->desc);
-
- /* Link each bytecode. */
- list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
- int found = 0, ret;
- struct list_head *insert_loc;
-
- list_for_each_entry(runtime,
- &event->bytecode_runtime_head, node) {
- if (runtime->bc == bc) {
- found = 1;
- break;
- }
- }
- /* Skip bytecode already linked */
- if (found)
- continue;
-
- /*
- * Insert at specified priority (seqnum) in increasing
- * order.
- */
- list_for_each_entry_reverse(runtime,
- &event->bytecode_runtime_head, node) {
- if (runtime->bc->bc.seqnum < bc->bc.seqnum) {
- /* insert here */
- insert_loc = &runtime->node;
- goto add_within;
- }
- }
- /* Add to head to list */
- insert_loc = &event->bytecode_runtime_head;
- add_within:
- dbg_printk("linking bytecode\n");
- ret = _lttng_filter_event_link_bytecode(event, bc,
- insert_loc);
- if (ret) {
- dbg_printk("[lttng filter] warning: cannot link event bytecode\n");
- }
- }
-}
-
-/*
- * We own the filter_bytecode if we return success.
- */
-int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
- struct lttng_filter_bytecode_node *filter_bytecode)
-{
- list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
- return 0;
-}
-
-void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
-{
- struct lttng_filter_bytecode_node *filter_bytecode, *tmp;
-
- list_for_each_entry_safe(filter_bytecode, tmp,
- &enabler->filter_bytecode_head, node) {
- kfree(filter_bytecode);
- }
-}
-
-void lttng_free_event_filter_runtime(struct lttng_event *event)
-{
- struct bytecode_runtime *runtime, *tmp;
-
- list_for_each_entry_safe(runtime, tmp,
- &event->bytecode_runtime_head, p.node) {
- kfree(runtime);
- }
-}
projects / lttng-modules.git / blobdiff