#ifndef _LTTNG_FILTER_H
#define _LTTNG_FILTER_H
/*
* lttng-filter.h
*
* LTTng UST filter header.
*
* 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 <errno.h>
#include <stdio.h>
#include <helper.h>
#include <lttng/ust-events.h>
#include <lttng/ust-context-provider.h>
#include <stdint.h>
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <inttypes.h>
#include <limits.h>
#include <usterr-signal-safe.h>
#include "filter-bytecode.h"
/* Filter stack length, in number of entries */
#define FILTER_STACK_LEN 10 /* includes 2 dummy */
#define FILTER_STACK_EMPTY 1
#ifndef min_t
#define min_t(type, a, b) \
((type) (a) < (type) (b) ? (type) (a) : (type) (b))
#endif
#ifndef likely
#define likely(x) __builtin_expect(!!(x), 1)
#endif
#ifndef unlikely
#define unlikely(x) __builtin_expect(!!(x), 0)
#endif
#ifdef DEBUG
#define dbg_printf(fmt, args...) \
printf("[debug bytecode in %s:%s@%u] " fmt, \
__FILE__, __func__, __LINE__, ## args)
#else
#define dbg_printf(fmt, args...) \
do { \
/* do nothing but check printf format */ \
if (0) \
printf("[debug bytecode in %s:%s@%u] " fmt, \
__FILE__, __func__, __LINE__, ## args); \
} while (0)
#endif
/* Linked bytecode. Child of struct lttng_bytecode_runtime. */
struct bytecode_runtime {
struct lttng_bytecode_runtime p;
uint16_t len;
char data[0];
};
enum entry_type {
REG_S64,
REG_DOUBLE,
REG_STRING,
REG_UNKNOWN,
};
/* Validation stack */
struct vstack_entry {
enum entry_type type;
};
struct vstack {
int top; /* top of stack */
struct vstack_entry e[FILTER_STACK_LEN];
};
static inline
void vstack_init(struct vstack *stack)
{
stack->top = -1;
}
static inline
struct vstack_entry *vstack_ax(struct vstack *stack)
{
if (unlikely(stack->top < 0))
return NULL;
return &stack->e[stack->top];
}
static inline
struct vstack_entry *vstack_bx(struct vstack *stack)
{
if (unlikely(stack->top < 1))
return NULL;
return &stack->e[stack->top - 1];
}
static inline
int vstack_push(struct vstack *stack)
{
if (stack->top >= FILTER_STACK_LEN - 1) {
ERR("Stack full\n");
return -EINVAL;
}
++stack->top;
return 0;
}
static inline
int vstack_pop(struct vstack *stack)
{
if (unlikely(stack->top < 0)) {
ERR("Stack empty\n");
return -EINVAL;
}
stack->top--;
return 0;
}
/* Execution stack */
struct estack_entry {
enum entry_type type; /* For dynamic typing. */
union {
int64_t v;
double d;
struct {
const char *str;
size_t seq_len;
int literal; /* is string literal ? */
} s;
} u;
};
struct estack {
int top; /* top of stack */
struct estack_entry e[FILTER_STACK_LEN];
};
/*
* Always use aliased type for ax/bx (top of stack).
* When ax/bx are S64, use aliased value.
*/
#define estack_ax_v ax
#define estack_bx_v bx
#define estack_ax_t ax_t
#define estack_bx_t bx_t
/*
* ax and bx registers can hold either integer, double or string.
*/
#define estack_ax(stack, top) \
({ \
assert((top) > FILTER_STACK_EMPTY); \
&(stack)->e[top]; \
})
#define estack_bx(stack, top) \
({ \
assert((top) > FILTER_STACK_EMPTY + 1); \
&(stack)->e[(top) - 1]; \
})
/*
* Currently, only integers (REG_S64) can be pushed into the stack.
*/
#define estack_push(stack, top, ax, bx, ax_t, bx_t) \
do { \
assert((top) < FILTER_STACK_LEN - 1); \
(stack)->e[(top) - 1].u.v = (bx); \
(stack)->e[(top) - 1].type = (bx_t); \
(bx) = (ax); \
(bx_t) = (ax_t); \
++(top); \
} while (0)
#define estack_pop(stack, top, ax, bx, ax_t, bx_t) \
do { \
assert((top) > FILTER_STACK_EMPTY); \
(ax) = (bx); \
(ax_t) = (bx_t); \
(bx) = (stack)->e[(top) - 2].u.v; \
(bx_t) = (stack)->e[(top) - 2].type; \
(top)--; \
} while (0)
const char *print_op(enum filter_op op);
int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode);
int lttng_filter_specialize_bytecode(struct bytecode_runtime *bytecode);
uint64_t lttng_filter_false(void *filter_data,
const char *filter_stack_data);
uint64_t lttng_filter_interpret_bytecode(void *filter_data,
const char *filter_stack_data);
#endif /* _LTTNG_FILTER_H */