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

/* SPDX-License-Identifier: MIT
 *
 * lttng/filter.h
 *
 * LTTng modules filter header.
 *
 * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#ifndef _LTTNG_FILTER_H
#define _LTTNG_FILTER_H

#include <linux/kernel.h>

#include <lttng/events.h>
#include <lttng/filter-bytecode.h>

/* Filter stack length, in number of entries */
#define FILTER_STACK_LEN	10	/* includes 2 dummy */
#define FILTER_STACK_EMPTY	1

#define FILTER_MAX_DATA_LEN	65536

#ifdef DEBUG
#define dbg_printk(fmt, args...)				\
	printk(KERN_DEBUG "LTTng: [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 "LTTng: [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;
	size_t data_len;
	size_t data_alloc_len;
	char *data;
	uint16_t len;
	char code[0];
};

enum entry_type {
	REG_S64,
	REG_DOUBLE,
	REG_STRING,
	REG_STAR_GLOB_STRING,
	REG_TYPE_UNKNOWN,
	REG_PTR,
};

enum load_type {
	LOAD_ROOT_CONTEXT,
	LOAD_ROOT_APP_CONTEXT,
	LOAD_ROOT_PAYLOAD,
	LOAD_OBJECT,
};

enum object_type {
	OBJECT_TYPE_S8,
	OBJECT_TYPE_S16,
	OBJECT_TYPE_S32,
	OBJECT_TYPE_S64,
	OBJECT_TYPE_U8,
	OBJECT_TYPE_U16,
	OBJECT_TYPE_U32,
	OBJECT_TYPE_U64,

	OBJECT_TYPE_DOUBLE,
	OBJECT_TYPE_STRING,
	OBJECT_TYPE_STRING_SEQUENCE,

	OBJECT_TYPE_SEQUENCE,
	OBJECT_TYPE_ARRAY,
	OBJECT_TYPE_STRUCT,
	OBJECT_TYPE_VARIANT,

	OBJECT_TYPE_DYNAMIC,
};

struct filter_get_index_data {
	uint64_t offset;	/* in bytes */
	size_t ctx_index;
	size_t array_len;
	struct {
		size_t len;
		enum object_type type;
		bool rev_bo;	/* reverse byte order */
	} elem;
};

/* Validation stack */
struct vstack_load {
	enum load_type type;
	enum object_type object_type;
	const struct lttng_event_field *field;
	bool rev_bo;	/* reverse byte order */
};

struct vstack_entry {
	enum entry_type type;
	struct vstack_load load;
};

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 "LTTng: filter: 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 "LTTng: filter: Stack empty\n");
		return -EINVAL;
	}
	stack->top--;
	return 0;
}

/* Execution stack */
enum estack_string_literal_type {
	ESTACK_STRING_LITERAL_TYPE_NONE,
	ESTACK_STRING_LITERAL_TYPE_PLAIN,
	ESTACK_STRING_LITERAL_TYPE_STAR_GLOB,
};

struct load_ptr {
	enum load_type type;
	enum object_type object_type;
	const void *ptr;
	bool rev_bo;
	/* Temporary place-holders for contexts. */
	union {
		int64_t s64;
		uint64_t u64;
		double d;
	} u;
	/*
	 * "field" is only needed when nested under a variant, in which
	 * case we cannot specialize the nested operations.
	 */
	const struct lttng_event_field *field;
};

struct estack_entry {
	enum entry_type type;
	union {
		int64_t v;

		struct {
			const char *str;
			const char __user *user_str;
			size_t seq_len;
			enum estack_string_literal_type literal_type;
			int user;		/* is string from userspace ? */
		} s;
		struct load_ptr ptr;
	} 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_t	ax_t
#define estack_bx_t	bx_t

#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, ax_t, bx_t)		\
	do {							\
		BUG_ON((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 {							\
		BUG_ON((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 *lttng_filter_print_op(enum filter_op op);

int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode);
int lttng_filter_specialize_bytecode(const struct lttng_event_desc *event_desc,
		struct bytecode_runtime *bytecode);

uint64_t lttng_filter_false(void *filter_data,
		struct lttng_probe_ctx *lttng_probe_ctx,
		const char *filter_stack_data);
uint64_t lttng_filter_interpret_bytecode(void *filter_data,
		struct lttng_probe_ctx *lttng_probe_ctx,
		const char *filter_stack_data);

#endif /* _LTTNG_FILTER_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: MIT
	2	*
	3	* lttng/filter.h
	4	*
	5	* LTTng modules filter header.
	6	*
	7	* Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	*/
	9
	10	#ifndef _LTTNG_FILTER_H
	11	#define _LTTNG_FILTER_H
	12
	13	#include <linux/kernel.h>
	14
	15	#include <lttng/events.h>
	16	#include <lttng/filter-bytecode.h>
	17
	18	/* Filter stack length, in number of entries */
	19	#define FILTER_STACK_LEN 10 /* includes 2 dummy */
	20	#define FILTER_STACK_EMPTY 1
	21
	22	#define FILTER_MAX_DATA_LEN 65536
	23
	24	#ifdef DEBUG
	25	#define dbg_printk(fmt, args...) \
	26	printk(KERN_DEBUG "LTTng: [debug bytecode in %s:%s@%u] " fmt, \
	27	__FILE__, __func__, __LINE__, ## args)
	28	#else
	29	#define dbg_printk(fmt, args...) \
	30	do { \
	31	/* do nothing but check printf format */ \
	32	if (0) \
	33	printk(KERN_DEBUG "LTTng: [debug bytecode in %s:%s@%u] " fmt, \
	34	__FILE__, __func__, __LINE__, ## args); \
	35	} while (0)
	36	#endif
	37
	38	/* Linked bytecode. Child of struct lttng_bytecode_runtime. */
	39	struct bytecode_runtime {
	40	struct lttng_bytecode_runtime p;
	41	size_t data_len;
	42	size_t data_alloc_len;
	43	char *data;
	44	uint16_t len;
	45	char code[0];
	46	};
	47
	48	enum entry_type {
	49	REG_S64,
	50	REG_DOUBLE,
	51	REG_STRING,
	52	REG_STAR_GLOB_STRING,
	53	REG_TYPE_UNKNOWN,
	54	REG_PTR,
	55	};
	56
	57	enum load_type {
	58	LOAD_ROOT_CONTEXT,
	59	LOAD_ROOT_APP_CONTEXT,
	60	LOAD_ROOT_PAYLOAD,
	61	LOAD_OBJECT,
	62	};
	63
	64	enum object_type {
	65	OBJECT_TYPE_S8,
	66	OBJECT_TYPE_S16,
	67	OBJECT_TYPE_S32,
	68	OBJECT_TYPE_S64,
	69	OBJECT_TYPE_U8,
	70	OBJECT_TYPE_U16,
	71	OBJECT_TYPE_U32,
	72	OBJECT_TYPE_U64,
	73
	74	OBJECT_TYPE_DOUBLE,
	75	OBJECT_TYPE_STRING,
	76	OBJECT_TYPE_STRING_SEQUENCE,
	77
	78	OBJECT_TYPE_SEQUENCE,
	79	OBJECT_TYPE_ARRAY,
	80	OBJECT_TYPE_STRUCT,
	81	OBJECT_TYPE_VARIANT,
	82
	83	OBJECT_TYPE_DYNAMIC,
	84	};
	85
	86	struct filter_get_index_data {
	87	uint64_t offset; /* in bytes */
	88	size_t ctx_index;
	89	size_t array_len;
	90	struct {
	91	size_t len;
	92	enum object_type type;
	93	bool rev_bo; /* reverse byte order */
	94	} elem;
	95	};
	96
	97	/* Validation stack */
	98	struct vstack_load {
	99	enum load_type type;
	100	enum object_type object_type;
	101	const struct lttng_event_field *field;
	102	bool rev_bo; /* reverse byte order */
	103	};
	104
	105	struct vstack_entry {
	106	enum entry_type type;
	107	struct vstack_load load;
	108	};
	109
	110	struct vstack {
	111	int top; /* top of stack */
	112	struct vstack_entry e[FILTER_STACK_LEN];
	113	};
	114
	115	static inline
	116	void vstack_init(struct vstack *stack)
	117	{
	118	stack->top = -1;
	119	}
	120
	121	static inline
	122	struct vstack_entry vstack_ax(struct vstack stack)
	123	{
	124	if (unlikely(stack->top < 0))
	125	return NULL;
	126	return &stack->e[stack->top];
	127	}
	128
	129	static inline
	130	struct vstack_entry vstack_bx(struct vstack stack)
	131	{
	132	if (unlikely(stack->top < 1))
	133	return NULL;
	134	return &stack->e[stack->top - 1];
	135	}
	136
	137	static inline
	138	int vstack_push(struct vstack *stack)
	139	{
	140	if (stack->top >= FILTER_STACK_LEN - 1) {
	141	printk(KERN_WARNING "LTTng: filter: Stack full\n");
	142	return -EINVAL;
	143	}
	144	++stack->top;
	145	return 0;
	146	}
	147
	148	static inline
	149	int vstack_pop(struct vstack *stack)
	150	{
	151	if (unlikely(stack->top < 0)) {
	152	printk(KERN_WARNING "LTTng: filter: Stack empty\n");
	153	return -EINVAL;
	154	}
	155	stack->top--;
	156	return 0;
	157	}
	158
	159	/* Execution stack */
	160	enum estack_string_literal_type {
	161	ESTACK_STRING_LITERAL_TYPE_NONE,
	162	ESTACK_STRING_LITERAL_TYPE_PLAIN,
	163	ESTACK_STRING_LITERAL_TYPE_STAR_GLOB,
	164	};
	165
	166	struct load_ptr {
	167	enum load_type type;
	168	enum object_type object_type;
	169	const void *ptr;
	170	bool rev_bo;
	171	/* Temporary place-holders for contexts. */
	172	union {
	173	int64_t s64;
	174	uint64_t u64;
	175	double d;
	176	} u;
	177	/*
	178	* "field" is only needed when nested under a variant, in which
	179	* case we cannot specialize the nested operations.
	180	*/
	181	const struct lttng_event_field *field;
	182	};
	183
	184	struct estack_entry {
	185	enum entry_type type;
	186	union {
	187	int64_t v;
	188
	189	struct {
	190	const char *str;
	191	const char __user *user_str;
	192	size_t seq_len;
	193	enum estack_string_literal_type literal_type;
	194	int user; /* is string from userspace ? */
	195	} s;
	196	struct load_ptr ptr;
	197	} u;
	198	};
	199
	200	struct estack {
	201	int top; /* top of stack */
	202	struct estack_entry e[FILTER_STACK_LEN];
	203	};
	204
	205	#define estack_ax_v ax
	206	#define estack_bx_v bx
	207
	208	#define estack_ax_t ax_t
	209	#define estack_bx_t bx_t
	210
	211	#define estack_ax(stack, top) \
	212	({ \
	213	BUG_ON((top) <= FILTER_STACK_EMPTY); \
	214	&(stack)->e[top]; \
	215	})
	216
	217	#define estack_bx(stack, top) \
	218	({ \
	219	BUG_ON((top) <= FILTER_STACK_EMPTY + 1); \
	220	&(stack)->e[(top) - 1]; \
	221	})
	222
	223	#define estack_push(stack, top, ax, bx, ax_t, bx_t) \
	224	do { \
	225	BUG_ON((top) >= FILTER_STACK_LEN - 1); \
	226	(stack)->e[(top) - 1].u.v = (bx); \
	227	(stack)->e[(top) - 1].type = (bx_t); \
	228	(bx) = (ax); \
	229	(bx_t) = (ax_t); \
	230	++(top); \
	231	} while (0)
	232
	233	#define estack_pop(stack, top, ax, bx, ax_t, bx_t) \
	234	do { \
	235	BUG_ON((top) <= FILTER_STACK_EMPTY); \
	236	(ax) = (bx); \
	237	(ax_t) = (bx_t); \
	238	(bx) = (stack)->e[(top) - 2].u.v; \
	239	(bx_t) = (stack)->e[(top) - 2].type; \
	240	(top)--; \
	241	} while (0)
	242
	243	const char *lttng_filter_print_op(enum filter_op op);
	244
	245	int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode);
	246	int lttng_filter_specialize_bytecode(const struct lttng_event_desc *event_desc,
	247	struct bytecode_runtime *bytecode);
	248
	249	uint64_t lttng_filter_false(void *filter_data,
	250	struct lttng_probe_ctx *lttng_probe_ctx,
	251	const char *filter_stack_data);
	252	uint64_t lttng_filter_interpret_bytecode(void *filter_data,
	253	struct lttng_probe_ctx *lttng_probe_ctx,
	254	const char *filter_stack_data);
	255
	256	#endif /* _LTTNG_FILTER_H */