/*
* lttng-filter.c
*
* LTTng UST filter code.
*
* 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 <urcu/rculist.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 *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_printf("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;
case atype_float:
field_offset += sizeof(double);
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;
case atype_float:
op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE;
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;
struct lttng_session *session = runtime->p.session;
dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
/* Get context index */
idx = lttng_get_context_index(session->ctx, context_name);
if (idx < 0) {
if (lttng_context_is_app(context_name)) {
int ret;
ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
&session->ctx);
if (ret)
return ret;
idx = lttng_get_context_index(session->ctx,
context_name);
if (idx < 0)
return -ENOENT;
} else {
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 = &session->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;
case atype_float:
op->op = FILTER_OP_GET_CONTEXT_REF_DOUBLE;
break;
case atype_dynamic:
op->op = FILTER_OP_GET_CONTEXT_REF;
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_printf("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:
ERR("Unknown reloc op type %u\n", op->op);
return -EINVAL;
}
return 0;
}
static
int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
struct lttng_event *event)
{
struct lttng_bytecode_runtime *bc_runtime;
cds_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_ust_filter_bytecode_node *filter_bytecode,
struct cds_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_printf("Linking...\n");
/* We don't need the reloc table in the runtime */
runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
runtime = zmalloc(runtime_alloc_len);
if (!runtime) {
ret = -ENOMEM;
goto alloc_error;
}
runtime->p.bc = filter_bytecode;
runtime->p.session = event->chan->session;
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;
cds_list_add_rcu(&runtime->p.node, insert_loc);
dbg_printf("Linking successful.\n");
return 0;
link_error:
runtime->p.filter = lttng_filter_false;
runtime->p.link_failed = 1;
cds_list_add_rcu(&runtime->p.node, insert_loc);
alloc_error:
dbg_printf("Linking failed.\n");
return ret;
}
void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
{
struct lttng_ust_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_ust_filter_bytecode_node *bc;
struct lttng_bytecode_runtime *runtime;
/* Can only be called for events with desc attached */
assert(event->desc);
/* Link each bytecode. */
cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
int found = 0, ret;
struct cds_list_head *insert_loc;
cds_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.
*/
cds_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_printf("linking bytecode\n");
ret = _lttng_filter_event_link_bytecode(event, bc,
insert_loc);
if (ret) {
dbg_printf("[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_ust_filter_bytecode_node *filter_bytecode)
{
cds_list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
return 0;
}
void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
{
struct lttng_ust_filter_bytecode_node *filter_bytecode, *tmp;
cds_list_for_each_entry_safe(filter_bytecode, tmp,
&enabler->filter_bytecode_head, node) {
free(filter_bytecode);
}
}
void lttng_free_event_filter_runtime(struct lttng_event *event)
{
struct bytecode_runtime *runtime, *tmp;
cds_list_for_each_entry_safe(runtime, tmp,
&event->bytecode_runtime_head, p.node) {
free(runtime);
}
}