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

/*
 * lttng-filter.c
 *
 * LTTng modules filter code.
 *
 * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/list.h>
#include <linux/slab.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",

	/* load userspace field ref */
	[ FILTER_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
	[ FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",

	/*
	 * load immediate star globbing pattern (literal string)
	 * from immediate.
	 */
	[ FILTER_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",

	/* globbing pattern binary operator: apply to */
	[ FILTER_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
	[ FILTER_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",
};

const char *lttng_filter_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_printk("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_struct:		/* Unsupported. */
		case atype_array_compound:	/* Unsupported. */
		case atype_sequence_compound:	/* Unsupported. */
		case atype_variant:		/* Unsupported. */
		default:
			return -EINVAL;
		}
	}
	if (!field)
		return -EINVAL;

	/* Check if field offset is too large for 16-bit offset */
	if (field_offset > LTTNG_KERNEL_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:
		if (field->user)
			op->op = FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE;
		else
			op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
		break;
	case atype_string:
		if (field->user)
			op->op = FILTER_OP_LOAD_FIELD_REF_USER_STRING;
		else
			op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
		break;
	case atype_struct:		/* Unsupported. */
	case atype_array_compound:	/* Unsupported. */
	case atype_sequence_compound:	/* Unsupported. */
	case atype_variant:		/* Unsupported. */
	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;

	dbg_printk("Apply context reloc: %u %s\n", reloc_offset, context_name);

	/* Get context index */
	idx = lttng_get_context_index(lttng_static_ctx, context_name);
	if (idx < 0)
		return -ENOENT;

	/* Check if idx is too large for 16-bit offset */
	if (idx > LTTNG_KERNEL_FILTER_BYTECODE_MAX_LEN - 1)
		return -EINVAL;

	/* Get context return type */
	ctx_field = &lttng_static_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:
		BUG_ON(ctx_field->event_field.user);
		op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
		break;
	case atype_struct:	/* Unsupported. */
	case atype_array_compound:	/* Unsupported. */
	case atype_sequence_compound:	/* Unsupported. */
	case atype_variant:		/* Unsupported. */
	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_printk("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:
		printk(KERN_WARNING "Unknown reloc op type %u\n", op->op);
		return -EINVAL;
	}
	return 0;
}

static
int bytecode_is_linked(struct lttng_filter_bytecode_node *filter_bytecode,
		struct lttng_event *event)
{
	struct lttng_bytecode_runtime *bc_runtime;

	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_filter_bytecode_node *filter_bytecode,
		struct 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_printk("Linking...\n");

	/* We don't need the reloc table in the runtime */
	runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
	runtime = kzalloc(runtime_alloc_len, GFP_KERNEL);
	if (!runtime) {
		ret = -ENOMEM;
		goto alloc_error;
	}
	runtime->p.bc = filter_bytecode;
	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;
	list_add_rcu(&runtime->p.node, insert_loc);
	dbg_printk("Linking successful.\n");
	return 0;

link_error:
	runtime->p.filter = lttng_filter_false;
	runtime->p.link_failed = 1;
	list_add_rcu(&runtime->p.node, insert_loc);
alloc_error:
	dbg_printk("Linking failed.\n");
	return ret;
}

void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
{
	struct lttng_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_filter_bytecode_node *bc;
	struct lttng_bytecode_runtime *runtime;

	/* Can only be called for events with desc attached */
	WARN_ON_ONCE(!event->desc);

	/* Link each bytecode. */
	list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
		int found = 0, ret;
		struct list_head *insert_loc;

		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.
		 */
		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_printk("linking bytecode\n");
		ret = _lttng_filter_event_link_bytecode(event, bc,
				insert_loc);
		if (ret) {
			dbg_printk("[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_filter_bytecode_node *filter_bytecode)
{
	list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
	return 0;
}

void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
{
	struct lttng_filter_bytecode_node *filter_bytecode, *tmp;

	list_for_each_entry_safe(filter_bytecode, tmp,
			&enabler->filter_bytecode_head, node) {
		kfree(filter_bytecode);
	}
}

void lttng_free_event_filter_runtime(struct lttng_event *event)
{
	struct bytecode_runtime *runtime, *tmp;

	list_for_each_entry_safe(runtime, tmp,
			&event->bytecode_runtime_head, p.node) {
		kfree(runtime);
	}
}
Commit	Line	Data
07dfc1d0 MD	1	/*
	2	* lttng-filter.c
	3	*
	4	* LTTng modules filter code.
	5	*
bbf3aef5	6	* Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
07dfc1d0	7	*
bbf3aef5 MD	8	* Permission is hereby granted, free of charge, to any person obtaining a copy
	9	* of this software and associated documentation files (the "Software"), to deal
	10	* in the Software without restriction, including without limitation the rights
	11	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	12	* copies of the Software, and to permit persons to whom the Software is
	13	* furnished to do so, subject to the following conditions:
07dfc1d0	14	*
bbf3aef5 MD	15	* The above copyright notice and this permission notice shall be included in
bbf3aef5 MD	16	* all copies or substantial portions of the Software.
07dfc1d0	17	*
bbf3aef5 MD	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	21	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	22	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	23	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	24	* SOFTWARE.
07dfc1d0 MD	25	*/
	26
	27	#include <linux/list.h>
	28	#include <linux/slab.h>
	29
241ae9a8	30	#include <lttng-filter.h>
07dfc1d0 MD	31
	32	static const char *opnames[] = {
	33	[ FILTER_OP_UNKNOWN ] = "UNKNOWN",
	34
	35	[ FILTER_OP_RETURN ] = "RETURN",
	36
	37	/* binary */
	38	[ FILTER_OP_MUL ] = "MUL",
	39	[ FILTER_OP_DIV ] = "DIV",
	40	[ FILTER_OP_MOD ] = "MOD",
	41	[ FILTER_OP_PLUS ] = "PLUS",
	42	[ FILTER_OP_MINUS ] = "MINUS",
	43	[ FILTER_OP_RSHIFT ] = "RSHIFT",
	44	[ FILTER_OP_LSHIFT ] = "LSHIFT",
	45	[ FILTER_OP_BIN_AND ] = "BIN_AND",
	46	[ FILTER_OP_BIN_OR ] = "BIN_OR",
	47	[ FILTER_OP_BIN_XOR ] = "BIN_XOR",
	48
	49	/* binary comparators */
	50	[ FILTER_OP_EQ ] = "EQ",
	51	[ FILTER_OP_NE ] = "NE",
	52	[ FILTER_OP_GT ] = "GT",
	53	[ FILTER_OP_LT ] = "LT",
	54	[ FILTER_OP_GE ] = "GE",
	55	[ FILTER_OP_LE ] = "LE",
	56
	57	/* string binary comparators */
	58	[ FILTER_OP_EQ_STRING ] = "EQ_STRING",
	59	[ FILTER_OP_NE_STRING ] = "NE_STRING",
	60	[ FILTER_OP_GT_STRING ] = "GT_STRING",
	61	[ FILTER_OP_LT_STRING ] = "LT_STRING",
	62	[ FILTER_OP_GE_STRING ] = "GE_STRING",
	63	[ FILTER_OP_LE_STRING ] = "LE_STRING",
	64
	65	/* s64 binary comparators */
	66	[ FILTER_OP_EQ_S64 ] = "EQ_S64",
	67	[ FILTER_OP_NE_S64 ] = "NE_S64",
	68	[ FILTER_OP_GT_S64 ] = "GT_S64",
	69	[ FILTER_OP_LT_S64 ] = "LT_S64",
	70	[ FILTER_OP_GE_S64 ] = "GE_S64",
	71	[ FILTER_OP_LE_S64 ] = "LE_S64",
	72
	73	/* double binary comparators */
	74	[ FILTER_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
	75	[ FILTER_OP_NE_DOUBLE ] = "NE_DOUBLE",
	76	[ FILTER_OP_GT_DOUBLE ] = "GT_DOUBLE",
	77	[ FILTER_OP_LT_DOUBLE ] = "LT_DOUBLE",
	78	[ FILTER_OP_GE_DOUBLE ] = "GE_DOUBLE",
	79	[ FILTER_OP_LE_DOUBLE ] = "LE_DOUBLE",
	80
	81	/* Mixed S64-double binary comparators */
	82	[ FILTER_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
	83	[ FILTER_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
	84	[ FILTER_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
	85	[ FILTER_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
	86	[ FILTER_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
	87	[ FILTER_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
	88
	89	[ FILTER_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
	90	[ FILTER_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
	91	[ FILTER_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
	92	[ FILTER_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
	93	[ FILTER_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
	94	[ FILTER_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
95
96	/* unary */
97	[ FILTER_OP_UNARY_PLUS ] = "UNARY_PLUS",
98	[ FILTER_OP_UNARY_MINUS ] = "UNARY_MINUS",
99	[ FILTER_OP_UNARY_NOT ] = "UNARY_NOT",
100	[ FILTER_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
101	[ FILTER_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
102	[ FILTER_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
103	[ FILTER_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
104	[ FILTER_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
105	[ FILTER_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
106
107	/* logical */
108	[ FILTER_OP_AND ] = "AND",
109	[ FILTER_OP_OR ] = "OR",
110
111	/* load field ref */
112	[ FILTER_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
113	[ FILTER_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
114	[ FILTER_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
115	[ FILTER_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
116	[ FILTER_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
117
118	/* load from immediate operand */
119	[ FILTER_OP_LOAD_STRING ] = "LOAD_STRING",
120	[ FILTER_OP_LOAD_S64 ] = "LOAD_S64",
121	[ FILTER_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
122
123	/* cast */
124	[ FILTER_OP_CAST_TO_S64 ] = "CAST_TO_S64",
125	[ FILTER_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
126	[ FILTER_OP_CAST_NOP ] = "CAST_NOP",
127
128	/* get context ref */
129	[ FILTER_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
130	[ FILTER_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
131	[ FILTER_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
132	[ FILTER_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
f127e61e MD	133
	134	/* load userspace field ref */
	135	[ FILTER_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
	136	[ FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",
83fb57ab MD	137
	138	/*
	139	* load immediate star globbing pattern (literal string)
	140	* from immediate.
	141	*/
	142	[ FILTER_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",
	143
	144	/* globbing pattern binary operator: apply to */
	145	[ FILTER_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
	146	[ FILTER_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",
07dfc1d0 MD	147	};
	148
	149	const char *lttng_filter_print_op(enum filter_op op)
	150	{
	151	if (op >= NR_FILTER_OPS)
	152	return "UNKNOWN";
	153	else
	154	return opnames[op];
	155	}
	156
	157	static
	158	int apply_field_reloc(struct lttng_event *event,
	159	struct bytecode_runtime *runtime,
	160	uint32_t runtime_len,
	161	uint32_t reloc_offset,
	162	const char *field_name)
	163	{
	164	const struct lttng_event_desc *desc;
	165	const struct lttng_event_field fields, field = NULL;
	166	unsigned int nr_fields, i;
	167	struct field_ref *field_ref;
	168	struct load_op *op;
	169	uint32_t field_offset = 0;
	170
	171	dbg_printk("Apply field reloc: %u %s\n", reloc_offset, field_name);
	172
	173	/* Lookup event by name */
	174	desc = event->desc;
	175	if (!desc)
	176	return -EINVAL;
	177	fields = desc->fields;
	178	if (!fields)
	179	return -EINVAL;
	180	nr_fields = desc->nr_fields;
	181	for (i = 0; i < nr_fields; i++) {
	182	if (!strcmp(fields[i].name, field_name)) {
	183	field = &fields[i];
	184	break;
	185	}
	186	/* compute field offset */
	187	switch (fields[i].type.atype) {
	188	case atype_integer:
	189	case atype_enum:
	190	field_offset += sizeof(int64_t);
	191	break;
	192	case atype_array:
	193	case atype_sequence:
	194	field_offset += sizeof(unsigned long);
	195	field_offset += sizeof(void *);
	196	break;
	197	case atype_string:
	198	field_offset += sizeof(void *);
	199	break;
f513b2bf MD	200	case atype_struct: /* Unsupported. */
	201	case atype_array_compound: /* Unsupported. */
	202	case atype_sequence_compound: /* Unsupported. */
65c85aa6	203	case atype_variant: /* Unsupported. */
07dfc1d0 MD	204	default:
	205	return -EINVAL;
	206	}
	207	}
	208	if (!field)
	209	return -EINVAL;
	210
	211	/* Check if field offset is too large for 16-bit offset */
f127e61e	212	if (field_offset > LTTNG_KERNEL_FILTER_BYTECODE_MAX_LEN - 1)
07dfc1d0 MD	213	return -EINVAL;
	214
	215	/* set type */
	216	op = (struct load_op *) &runtime->data[reloc_offset];
	217	field_ref = (struct field_ref *) op->data;
	218	switch (field->type.atype) {
	219	case atype_integer:
	220	case atype_enum:
	221	op->op = FILTER_OP_LOAD_FIELD_REF_S64;
	222	break;
	223	case atype_array:
	224	case atype_sequence:
f127e61e MD	225	if (field->user)
	226	op->op = FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE;
	227	else
	228	op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
07dfc1d0 MD	229	break;
07dfc1d0 MD	230	case atype_string:
f127e61e MD	231	if (field->user)
	232	op->op = FILTER_OP_LOAD_FIELD_REF_USER_STRING;
	233	else
	234	op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
07dfc1d0	235	break;
f513b2bf MD	236	case atype_struct: /* Unsupported. */
	237	case atype_array_compound: /* Unsupported. */
	238	case atype_sequence_compound: /* Unsupported. */
65c85aa6	239	case atype_variant: /* Unsupported. */
07dfc1d0 MD	240	default:
	241	return -EINVAL;
	242	}
	243	/* set offset */
	244	field_ref->offset = (uint16_t) field_offset;
	245	return 0;
	246	}
	247
	248	static
	249	int apply_context_reloc(struct lttng_event *event,
	250	struct bytecode_runtime *runtime,
	251	uint32_t runtime_len,
	252	uint32_t reloc_offset,
	253	const char *context_name)
	254	{
	255	struct field_ref *field_ref;
	256	struct load_op *op;
	257	struct lttng_ctx_field *ctx_field;
	258	int idx;
	259
	260	dbg_printk("Apply context reloc: %u %s\n", reloc_offset, context_name);
	261
	262	/* Get context index */
	263	idx = lttng_get_context_index(lttng_static_ctx, context_name);
	264	if (idx < 0)
	265	return -ENOENT;
	266
	267	/* Check if idx is too large for 16-bit offset */
f127e61e	268	if (idx > LTTNG_KERNEL_FILTER_BYTECODE_MAX_LEN - 1)
07dfc1d0 MD	269	return -EINVAL;
	270
	271	/* Get context return type */
	272	ctx_field = &lttng_static_ctx->fields[idx];
	273	op = (struct load_op *) &runtime->data[reloc_offset];
	274	field_ref = (struct field_ref *) op->data;
	275	switch (ctx_field->event_field.type.atype) {
	276	case atype_integer:
	277	case atype_enum:
	278	op->op = FILTER_OP_GET_CONTEXT_REF_S64;
	279	break;
	280	/* Sequence and array supported as string */
	281	case atype_string:
	282	case atype_array:
	283	case atype_sequence:
f127e61e	284	BUG_ON(ctx_field->event_field.user);
07dfc1d0 MD	285	op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
07dfc1d0 MD	286	break;
f513b2bf MD	287	case atype_struct: /* Unsupported. */
	288	case atype_array_compound: /* Unsupported. */
	289	case atype_sequence_compound: /* Unsupported. */
65c85aa6	290	case atype_variant: /* Unsupported. */
07dfc1d0 MD	291	default:
	292	return -EINVAL;
	293	}
	294	/* set offset to context index within channel contexts */
	295	field_ref->offset = (uint16_t) idx;
	296	return 0;
	297	}
	298
	299	static
	300	int apply_reloc(struct lttng_event *event,
	301	struct bytecode_runtime *runtime,
	302	uint32_t runtime_len,
	303	uint32_t reloc_offset,
	304	const char *name)
	305	{
	306	struct load_op *op;
	307
	308	dbg_printk("Apply reloc: %u %s\n", reloc_offset, name);
	309
	310	/* Ensure that the reloc is within the code */
	311	if (runtime_len - reloc_offset < sizeof(uint16_t))
	312	return -EINVAL;
	313
	314	op = (struct load_op *) &runtime->data[reloc_offset];
	315	switch (op->op) {
	316	case FILTER_OP_LOAD_FIELD_REF:
	317	return apply_field_reloc(event, runtime, runtime_len,
	318	reloc_offset, name);
	319	case FILTER_OP_GET_CONTEXT_REF:
	320	return apply_context_reloc(event, runtime, runtime_len,
	321	reloc_offset, name);
	322	default:
	323	printk(KERN_WARNING "Unknown reloc op type %u\n", op->op);
	324	return -EINVAL;
	325	}
	326	return 0;
	327	}
	328
	329	static
	330	int bytecode_is_linked(struct lttng_filter_bytecode_node *filter_bytecode,
	331	struct lttng_event *event)
	332	{
	333	struct lttng_bytecode_runtime *bc_runtime;
	334
	335	list_for_each_entry(bc_runtime,
	336	&event->bytecode_runtime_head, node) {
	337	if (bc_runtime->bc == filter_bytecode)
	338	return 1;
	339	}
	340	return 0;
	341	}
	342
	343	/*
	344	* Take a bytecode with reloc table and link it to an event to create a
	345	* bytecode runtime.
	346	*/
	347	static
	348	int _lttng_filter_event_link_bytecode(struct lttng_event *event,
	349	struct lttng_filter_bytecode_node *filter_bytecode,
	350	struct list_head *insert_loc)
	351	{
	352	int ret, offset, next_offset;
	353	struct bytecode_runtime *runtime = NULL;
	354	size_t runtime_alloc_len;
355
356	if (!filter_bytecode)
357	return 0;
358	/* Bytecode already linked */
359	if (bytecode_is_linked(filter_bytecode, event))
360	return 0;
361
362	dbg_printk("Linking...\n");
363
364	/* We don't need the reloc table in the runtime */
365	runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
366	runtime = kzalloc(runtime_alloc_len, GFP_KERNEL);
367	if (!runtime) {
368	ret = -ENOMEM;
369	goto alloc_error;
370	}
371	runtime->p.bc = filter_bytecode;
372	runtime->len = filter_bytecode->bc.reloc_offset;
373	/* copy original bytecode */
374	memcpy(runtime->data, filter_bytecode->bc.data, runtime->len);
375	/*
376	* apply relocs. Those are a uint16_t (offset in bytecode)
377	* followed by a string (field name).
378	*/
379	for (offset = filter_bytecode->bc.reloc_offset;
380	offset < filter_bytecode->bc.len;
381	offset = next_offset) {
382	uint16_t reloc_offset =
383	(uint16_t ) &filter_bytecode->bc.data[offset];
384	const char *name =
385	(const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
386
387	ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
388	if (ret) {
389	goto link_error;
390	}
391	next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
392	}
393	/* Validate bytecode */
394	ret = lttng_filter_validate_bytecode(runtime);
395	if (ret) {
396	goto link_error;
397	}
398	/* Specialize bytecode */
399	ret = lttng_filter_specialize_bytecode(runtime);
400	if (ret) {
401	goto link_error;
402	}
403	runtime->p.filter = lttng_filter_interpret_bytecode;
404	runtime->p.link_failed = 0;
405	list_add_rcu(&runtime->p.node, insert_loc);
406	dbg_printk("Linking successful.\n");
407	return 0;
408
409	link_error:
410	runtime->p.filter = lttng_filter_false;
411	runtime->p.link_failed = 1;
412	list_add_rcu(&runtime->p.node, insert_loc);
413	alloc_error:
414	dbg_printk("Linking failed.\n");
415	return ret;
416	}
417
418	void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
419	{
420	struct lttng_filter_bytecode_node *bc = runtime->bc;
421
422	if (!bc->enabler->enabled \|\| runtime->link_failed)
423	runtime->filter = lttng_filter_false;
424	else
425	runtime->filter = lttng_filter_interpret_bytecode;
426	}
427
428	/*
429	* Link bytecode for all enablers referenced by an event.
430	*/
431	void lttng_enabler_event_link_bytecode(struct lttng_event *event,
432	struct lttng_enabler *enabler)
433	{
434	struct lttng_filter_bytecode_node *bc;
435	struct lttng_bytecode_runtime *runtime;
436
437	/* Can only be called for events with desc attached */
438	WARN_ON_ONCE(!event->desc);
439
440	/* Link each bytecode. */
441	list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
442	int found = 0, ret;
443	struct list_head *insert_loc;
444
445	list_for_each_entry(runtime,
446	&event->bytecode_runtime_head, node) {
447	if (runtime->bc == bc) {
448	found = 1;
449	break;
450	}
451	}
452	/* Skip bytecode already linked */
453	if (found)
454	continue;
455
456	/*
457	* Insert at specified priority (seqnum) in increasing
458	* order.
459	*/
460	list_for_each_entry_reverse(runtime,
461	&event->bytecode_runtime_head, node) {
462	if (runtime->bc->bc.seqnum < bc->bc.seqnum) {
463	/* insert here */
464	insert_loc = &runtime->node;
465	goto add_within;
466	}
467	}
468	/* Add to head to list */
469	insert_loc = &event->bytecode_runtime_head;
470	add_within:
471	dbg_printk("linking bytecode\n");
472	ret = _lttng_filter_event_link_bytecode(event, bc,
473	insert_loc);
474	if (ret) {
475	dbg_printk("[lttng filter] warning: cannot link event bytecode\n");
476	}
477	}
478	}
479
480	/*
481	* We own the filter_bytecode if we return success.
482	*/
483	int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
484	struct lttng_filter_bytecode_node *filter_bytecode)
485	{
486	list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
487	return 0;
488	}
489
490	void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
491	{
492	struct lttng_filter_bytecode_node filter_bytecode, tmp;
493
494	list_for_each_entry_safe(filter_bytecode, tmp,
495	&enabler->filter_bytecode_head, node) {
496	kfree(filter_bytecode);
497	}
498	}
499
500	void lttng_free_event_filter_runtime(struct lttng_event *event)
501	{
502	struct bytecode_runtime runtime, tmp;
503
504	list_for_each_entry_safe(runtime, tmp,
505	&event->bytecode_runtime_head, p.node) {
506	kfree(runtime);
507	}
508	}