[lttng-modules.git] / lttng-filter.h

#ifndef _LTTNG_FILTER_H
#define _LTTNG_FILTER_H

/*
 * lttng-filter.h
 *
 * LTTng modules filter header.
 *
 * 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/kernel.h>

#include "lttng-events.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

#ifdef DEBUG
#define dbg_printk(fmt, args...)				\
	printk(KERN_DEBUG "[debug bytecode in %s:%s@%u] " fmt,		\
		__FILE__, __func__, __LINE__, ## args)
#else
#define dbg_printk(fmt, args...)				\
do {								\
	/* do nothing but check printf format */		\
	if (0)							\
		printk(KERN_DEBUG "[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_TYPE_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) {
		printk(KERN_WARNING "Stack full\n");
		return -EINVAL;
	}
	++stack->top;
	return 0;
}

static inline
int vstack_pop(struct vstack *stack)
{
	if (unlikely(stack->top < 0)) {
		printk(KERN_WARNING "Stack empty\n");
		return -EINVAL;
	}
	stack->top--;
	return 0;
}

/* Execution stack */
struct estack_entry {
	union {
		int64_t v;

		struct {
			const char *str;
			const char __user *user_str;
			size_t seq_len;
			int literal;		/* is string literal ? */
			int user;		/* is string from userspace ? */
		} s;
	} u;
};

struct estack {
	int top;	/* top of stack */
	struct estack_entry e[FILTER_STACK_LEN];
};

#define estack_ax_v	ax
#define estack_bx_v	bx

#define estack_ax(stack, top)					\
	({							\
		BUG_ON((top) <= FILTER_STACK_EMPTY);		\
		&(stack)->e[top];				\
	})

#define estack_bx(stack, top)					\
	({							\
		BUG_ON((top) <= FILTER_STACK_EMPTY + 1);	\
		&(stack)->e[(top) - 1];				\
	})

#define estack_push(stack, top, ax, bx)				\
	do {							\
		BUG_ON((top) >= FILTER_STACK_LEN - 1);		\
		(stack)->e[(top) - 1].u.v = (bx);		\
		(bx) = (ax);					\
		++(top);					\
	} while (0)

#define estack_pop(stack, top, ax, bx)				\
	do {							\
		BUG_ON((top) <= FILTER_STACK_EMPTY);		\
		(ax) = (bx);					\
		(bx) = (stack)->e[(top) - 2].u.v;		\
		(top)--;					\
	} while (0)

const char *lttng_filter_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 */
Commit	Line	Data
07dfc1d0 MD	1	#ifndef _LTTNG_FILTER_H
	2	#define _LTTNG_FILTER_H
	3
	4	/*
	5	* lttng-filter.h
	6	*
	7	* LTTng modules filter header.
	8	*
	9	* Copyright (C) 2010-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*
	11	* This library is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU Lesser General Public
	13	* License as published by the Free Software Foundation; only
	14	* version 2.1 of the License.
	15	*
	16	* This library is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	19	* Lesser General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU Lesser General Public
	22	* License along with this library; if not, write to the Free Software
	23	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	24	*/
	25
	26	#include <linux/kernel.h>
	27
	28	#include "lttng-events.h"
	29	#include "filter-bytecode.h"
	30
	31	/* Filter stack length, in number of entries */
	32	#define FILTER_STACK_LEN 10 /* includes 2 dummy */
	33	#define FILTER_STACK_EMPTY 1
	34
	35	#ifdef DEBUG
	36	#define dbg_printk(fmt, args...) \
	37	printk(KERN_DEBUG "[debug bytecode in %s:%s@%u] " fmt, \
	38	__FILE__, __func__, __LINE__, ## args)
	39	#else
	40	#define dbg_printk(fmt, args...) \
	41	do { \
	42	/* do nothing but check printf format */ \
	43	if (0) \
	44	printk(KERN_DEBUG "[debug bytecode in %s:%s@%u] " fmt, \
	45	__FILE__, __func__, __LINE__, ## args); \
	46	} while (0)
	47	#endif
	48
	49	/* Linked bytecode. Child of struct lttng_bytecode_runtime. */
	50	struct bytecode_runtime {
	51	struct lttng_bytecode_runtime p;
	52	uint16_t len;
	53	char data[0];
	54	};
	55
	56	enum entry_type {
	57	REG_S64,
	58	REG_DOUBLE,
	59	REG_STRING,
	60	REG_TYPE_UNKNOWN,
	61	};
	62
	63	/* Validation stack */
	64	struct vstack_entry {
65	enum entry_type type;
66	};
67
68	struct vstack {
69	int top; /* top of stack */
70	struct vstack_entry e[FILTER_STACK_LEN];
71	};
72
73	static inline
74	void vstack_init(struct vstack *stack)
75	{
76	stack->top = -1;
77	}
78
79	static inline
80	struct vstack_entry vstack_ax(struct vstack stack)
81	{
82	if (unlikely(stack->top < 0))
83	return NULL;
84	return &stack->e[stack->top];
85	}
86
87	static inline
88	struct vstack_entry vstack_bx(struct vstack stack)
89	{
90	if (unlikely(stack->top < 1))
91	return NULL;
92	return &stack->e[stack->top - 1];
93	}
94
95	static inline
96	int vstack_push(struct vstack *stack)
97	{
98	if (stack->top >= FILTER_STACK_LEN - 1) {
99	printk(KERN_WARNING "Stack full\n");
100	return -EINVAL;
101	}
102	++stack->top;
103	return 0;
104	}
105
106	static inline
107	int vstack_pop(struct vstack *stack)
108	{
109	if (unlikely(stack->top < 0)) {
110	printk(KERN_WARNING "Stack empty\n");
111	return -EINVAL;
112	}
113	stack->top--;
114	return 0;
115	}
116
117	/* Execution stack */
118	struct estack_entry {
119	union {
120	int64_t v;
121
122	struct {
123	const char *str;
f127e61e	124	const char __user *user_str;
07dfc1d0 MD	125	size_t seq_len;
07dfc1d0 MD	126	int literal; /* is string literal ? */
f127e61e	127	int user; /* is string from userspace ? */
07dfc1d0 MD	128	} s;
	129	} u;
	130	};
	131
	132	struct estack {
	133	int top; /* top of stack */
	134	struct estack_entry e[FILTER_STACK_LEN];
	135	};
	136
	137	#define estack_ax_v ax
	138	#define estack_bx_v bx
	139
	140	#define estack_ax(stack, top) \
	141	({ \
9272c0cd	142	BUG_ON((top) <= FILTER_STACK_EMPTY); \
07dfc1d0 MD	143	&(stack)->e[top]; \
	144	})
	145
	146	#define estack_bx(stack, top) \
	147	({ \
9272c0cd	148	BUG_ON((top) <= FILTER_STACK_EMPTY + 1); \
07dfc1d0 MD	149	&(stack)->e[(top) - 1]; \
	150	})
	151
	152	#define estack_push(stack, top, ax, bx) \
	153	do { \
9272c0cd	154	BUG_ON((top) >= FILTER_STACK_LEN - 1); \
07dfc1d0 MD	155	(stack)->e[(top) - 1].u.v = (bx); \
	156	(bx) = (ax); \
	157	++(top); \
	158	} while (0)
	159
	160	#define estack_pop(stack, top, ax, bx) \
	161	do { \
9272c0cd	162	BUG_ON((top) <= FILTER_STACK_EMPTY); \
07dfc1d0 MD	163	(ax) = (bx); \
	164	(bx) = (stack)->e[(top) - 2].u.v; \
	165	(top)--; \
	166	} while (0)
	167
	168	const char *lttng_filter_print_op(enum filter_op op);
	169
	170	int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode);
	171	int lttng_filter_specialize_bytecode(struct bytecode_runtime *bytecode);
	172
	173	uint64_t lttng_filter_false(void *filter_data,
	174	const char *filter_stack_data);
	175	uint64_t lttng_filter_interpret_bytecode(void *filter_data,
	176	const char *filter_stack_data);
	177
	178	#endif /* _LTTNG_FILTER_H */