[lttng-modules.git] / 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 <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 "[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;
	size_t data_len;
	size_t data_alloc_len;
	char *data;
	uint16_t len;
	char code[];
};

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 */
		bool user;	/* from userspace */
	} 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 */
	bool user;	/* from userspace */
};

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 "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 */
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;
	bool user;	/* from userspace */
	/* 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 {
	union {
		int64_t v;

		struct {
			const char *str;
			const char __user *user_str;
			size_t seq_len;
			enum estack_string_literal_type literal_type;
			bool 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(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_validate_bytecode_load(struct bytecode_runtime *bytecode);
int lttng_filter_specialize_bytecode(struct lttng_event *event,
		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
9f36eaed MJ	1	/* SPDX-License-Identifier: MIT
9f36eaed MJ	2	*
07dfc1d0 MD	3	* lttng-filter.h
	4	*
	5	* LTTng modules filter header.
	6	*
bbf3aef5	7	* Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
07dfc1d0 MD	8	*/
07dfc1d0 MD	9
9f36eaed MJ	10	#ifndef _LTTNG_FILTER_H
	11	#define _LTTNG_FILTER_H
	12
07dfc1d0 MD	13	#include <linux/kernel.h>
07dfc1d0 MD	14
bbd023d6 MD	15	#include <lttng-events.h>
bbd023d6 MD	16	#include <filter-bytecode.h>
07dfc1d0 MD	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
3834b99f MD	22	#define FILTER_MAX_DATA_LEN 65536
3834b99f MD	23
07dfc1d0 MD	24	#ifdef DEBUG
	25	#define dbg_printk(fmt, args...) \
	26	printk(KERN_DEBUG "[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 "[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;
3834b99f MD	41	size_t data_len;
	42	size_t data_alloc_len;
	43	char *data;
07dfc1d0	44	uint16_t len;
ad48a5c0	45	char code[];
07dfc1d0 MD	46	};
	47
	48	enum entry_type {
	49	REG_S64,
	50	REG_DOUBLE,
	51	REG_STRING,
02aca193	52	REG_STAR_GLOB_STRING,
07dfc1d0	53	REG_TYPE_UNKNOWN,
3834b99f MD	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 */
c89271d4	94	bool user; /* from userspace */
3834b99f	95	} elem;
07dfc1d0 MD	96	};
	97
	98	/* Validation stack */
3834b99f MD	99	struct vstack_load {
	100	enum load_type type;
	101	enum object_type object_type;
	102	const struct lttng_event_field *field;
	103	bool rev_bo; /* reverse byte order */
c89271d4	104	bool user; /* from userspace */
3834b99f MD	105	};
3834b99f MD	106
07dfc1d0 MD	107	struct vstack_entry {
07dfc1d0 MD	108	enum entry_type type;
3834b99f	109	struct vstack_load load;
07dfc1d0 MD	110	};
	111
	112	struct vstack {
	113	int top; /* top of stack */
	114	struct vstack_entry e[FILTER_STACK_LEN];
	115	};
	116
	117	static inline
	118	void vstack_init(struct vstack *stack)
	119	{
	120	stack->top = -1;
	121	}
	122
	123	static inline
	124	struct vstack_entry vstack_ax(struct vstack stack)
	125	{
	126	if (unlikely(stack->top < 0))
	127	return NULL;
	128	return &stack->e[stack->top];
	129	}
	130
	131	static inline
	132	struct vstack_entry vstack_bx(struct vstack stack)
	133	{
	134	if (unlikely(stack->top < 1))
	135	return NULL;
	136	return &stack->e[stack->top - 1];
	137	}
	138
	139	static inline
	140	int vstack_push(struct vstack *stack)
	141	{
	142	if (stack->top >= FILTER_STACK_LEN - 1) {
	143	printk(KERN_WARNING "Stack full\n");
	144	return -EINVAL;
	145	}
	146	++stack->top;
	147	return 0;
	148	}
	149
	150	static inline
	151	int vstack_pop(struct vstack *stack)
	152	{
	153	if (unlikely(stack->top < 0)) {
	154	printk(KERN_WARNING "Stack empty\n");
	155	return -EINVAL;
	156	}
	157	stack->top--;
	158	return 0;
	159	}
	160
	161	/* Execution stack */
02aca193 PP	162	enum estack_string_literal_type {
	163	ESTACK_STRING_LITERAL_TYPE_NONE,
	164	ESTACK_STRING_LITERAL_TYPE_PLAIN,
	165	ESTACK_STRING_LITERAL_TYPE_STAR_GLOB,
	166	};
	167
3834b99f MD	168	struct load_ptr {
	169	enum load_type type;
	170	enum object_type object_type;
	171	const void *ptr;
	172	bool rev_bo;
c89271d4	173	bool user; /* from userspace */
3834b99f MD	174	/* Temporary place-holders for contexts. */
	175	union {
	176	int64_t s64;
	177	uint64_t u64;
	178	double d;
	179	} u;
	180	/*
	181	* "field" is only needed when nested under a variant, in which
	182	* case we cannot specialize the nested operations.
	183	*/
	184	const struct lttng_event_field *field;
	185	};
	186
07dfc1d0 MD	187	struct estack_entry {
	188	union {
	189	int64_t v;
	190
	191	struct {
	192	const char *str;
f127e61e	193	const char __user *user_str;
07dfc1d0	194	size_t seq_len;
02aca193	195	enum estack_string_literal_type literal_type;
c89271d4	196	bool user; /* is string from userspace ? */
07dfc1d0	197	} s;
3834b99f	198	struct load_ptr ptr;
07dfc1d0 MD	199	} u;
	200	};
	201
	202	struct estack {
	203	int top; /* top of stack */
	204	struct estack_entry e[FILTER_STACK_LEN];
	205	};
	206
	207	#define estack_ax_v ax
	208	#define estack_bx_v bx
	209
	210	#define estack_ax(stack, top) \
	211	({ \
5f12cb8d	212	BUG_ON((top) <= FILTER_STACK_EMPTY); \
07dfc1d0 MD	213	&(stack)->e[top]; \
	214	})
	215
	216	#define estack_bx(stack, top) \
	217	({ \
5f12cb8d	218	BUG_ON((top) <= FILTER_STACK_EMPTY + 1); \
07dfc1d0 MD	219	&(stack)->e[(top) - 1]; \
	220	})
	221
	222	#define estack_push(stack, top, ax, bx) \
	223	do { \
5f12cb8d	224	BUG_ON((top) >= FILTER_STACK_LEN - 1); \
07dfc1d0 MD	225	(stack)->e[(top) - 1].u.v = (bx); \
	226	(bx) = (ax); \
	227	++(top); \
	228	} while (0)
	229
	230	#define estack_pop(stack, top, ax, bx) \
	231	do { \
5f12cb8d	232	BUG_ON((top) <= FILTER_STACK_EMPTY); \
07dfc1d0 MD	233	(ax) = (bx); \
	234	(bx) = (stack)->e[(top) - 2].u.v; \
	235	(top)--; \
	236	} while (0)
	237
	238	const char *lttng_filter_print_op(enum filter_op op);
	239
	240	int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode);
ce5579a7	241	int lttng_filter_validate_bytecode_load(struct bytecode_runtime *bytecode);
3834b99f MD	242	int lttng_filter_specialize_bytecode(struct lttng_event *event,
3834b99f MD	243	struct bytecode_runtime *bytecode);
07dfc1d0 MD	244
07dfc1d0 MD	245	uint64_t lttng_filter_false(void *filter_data,
79150a49	246	struct lttng_probe_ctx *lttng_probe_ctx,
07dfc1d0 MD	247	const char *filter_stack_data);
07dfc1d0 MD	248	uint64_t lttng_filter_interpret_bytecode(void *filter_data,
79150a49	249	struct lttng_probe_ctx *lttng_probe_ctx,
07dfc1d0 MD	250	const char *filter_stack_data);
	251
	252	#endif /* _LTTNG_FILTER_H */