X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-filter.c;fp=lttng-filter.c;h=6cd750cd6934c2a7a75d3e519950f99e995a5851;hb=07dfc1d0e4b093ad02682499a702dc11e54e8302;hp=0000000000000000000000000000000000000000;hpb=4ecb5ad551c82311205afbcda492739a08d6b132;p=lttng-modules.git

diff --git a/lttng-filter.c b/lttng-filter.c
new file mode 100644
index 00000000..6cd750cd
--- /dev/null
+++ b/lttng-filter.c
@@ -0,0 +1,471 @@
+/*
+ * lttng-filter.c
+ *
+ * LTTng modules filter code.
+ *
+ * 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/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",
+};
+
+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;
+		default:
+			return -EINVAL;
+		}
+	}
+	if (!field)
+		return -EINVAL;
+
+	/* Check if field offset is too large for 16-bit offset */
+	if (field_offset > 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:
+		op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
+		break;
+	case atype_string:
+		op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
+		break;
+	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 > 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:
+		op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
+		break;
+	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);
+	}
+}