4 * LTTng modules filter code.
6 * Copyright (C) 2010-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include <linux/list.h>
24 #include <linux/slab.h>
26 #include "lttng-filter.h"
28 static const char *opnames
[] = {
29 [ FILTER_OP_UNKNOWN
] = "UNKNOWN",
31 [ FILTER_OP_RETURN
] = "RETURN",
34 [ FILTER_OP_MUL
] = "MUL",
35 [ FILTER_OP_DIV
] = "DIV",
36 [ FILTER_OP_MOD
] = "MOD",
37 [ FILTER_OP_PLUS
] = "PLUS",
38 [ FILTER_OP_MINUS
] = "MINUS",
39 [ FILTER_OP_RSHIFT
] = "RSHIFT",
40 [ FILTER_OP_LSHIFT
] = "LSHIFT",
41 [ FILTER_OP_BIN_AND
] = "BIN_AND",
42 [ FILTER_OP_BIN_OR
] = "BIN_OR",
43 [ FILTER_OP_BIN_XOR
] = "BIN_XOR",
45 /* binary comparators */
46 [ FILTER_OP_EQ
] = "EQ",
47 [ FILTER_OP_NE
] = "NE",
48 [ FILTER_OP_GT
] = "GT",
49 [ FILTER_OP_LT
] = "LT",
50 [ FILTER_OP_GE
] = "GE",
51 [ FILTER_OP_LE
] = "LE",
53 /* string binary comparators */
54 [ FILTER_OP_EQ_STRING
] = "EQ_STRING",
55 [ FILTER_OP_NE_STRING
] = "NE_STRING",
56 [ FILTER_OP_GT_STRING
] = "GT_STRING",
57 [ FILTER_OP_LT_STRING
] = "LT_STRING",
58 [ FILTER_OP_GE_STRING
] = "GE_STRING",
59 [ FILTER_OP_LE_STRING
] = "LE_STRING",
61 /* s64 binary comparators */
62 [ FILTER_OP_EQ_S64
] = "EQ_S64",
63 [ FILTER_OP_NE_S64
] = "NE_S64",
64 [ FILTER_OP_GT_S64
] = "GT_S64",
65 [ FILTER_OP_LT_S64
] = "LT_S64",
66 [ FILTER_OP_GE_S64
] = "GE_S64",
67 [ FILTER_OP_LE_S64
] = "LE_S64",
69 /* double binary comparators */
70 [ FILTER_OP_EQ_DOUBLE
] = "EQ_DOUBLE",
71 [ FILTER_OP_NE_DOUBLE
] = "NE_DOUBLE",
72 [ FILTER_OP_GT_DOUBLE
] = "GT_DOUBLE",
73 [ FILTER_OP_LT_DOUBLE
] = "LT_DOUBLE",
74 [ FILTER_OP_GE_DOUBLE
] = "GE_DOUBLE",
75 [ FILTER_OP_LE_DOUBLE
] = "LE_DOUBLE",
77 /* Mixed S64-double binary comparators */
78 [ FILTER_OP_EQ_DOUBLE_S64
] = "EQ_DOUBLE_S64",
79 [ FILTER_OP_NE_DOUBLE_S64
] = "NE_DOUBLE_S64",
80 [ FILTER_OP_GT_DOUBLE_S64
] = "GT_DOUBLE_S64",
81 [ FILTER_OP_LT_DOUBLE_S64
] = "LT_DOUBLE_S64",
82 [ FILTER_OP_GE_DOUBLE_S64
] = "GE_DOUBLE_S64",
83 [ FILTER_OP_LE_DOUBLE_S64
] = "LE_DOUBLE_S64",
85 [ FILTER_OP_EQ_S64_DOUBLE
] = "EQ_S64_DOUBLE",
86 [ FILTER_OP_NE_S64_DOUBLE
] = "NE_S64_DOUBLE",
87 [ FILTER_OP_GT_S64_DOUBLE
] = "GT_S64_DOUBLE",
88 [ FILTER_OP_LT_S64_DOUBLE
] = "LT_S64_DOUBLE",
89 [ FILTER_OP_GE_S64_DOUBLE
] = "GE_S64_DOUBLE",
90 [ FILTER_OP_LE_S64_DOUBLE
] = "LE_S64_DOUBLE",
93 [ FILTER_OP_UNARY_PLUS
] = "UNARY_PLUS",
94 [ FILTER_OP_UNARY_MINUS
] = "UNARY_MINUS",
95 [ FILTER_OP_UNARY_NOT
] = "UNARY_NOT",
96 [ FILTER_OP_UNARY_PLUS_S64
] = "UNARY_PLUS_S64",
97 [ FILTER_OP_UNARY_MINUS_S64
] = "UNARY_MINUS_S64",
98 [ FILTER_OP_UNARY_NOT_S64
] = "UNARY_NOT_S64",
99 [ FILTER_OP_UNARY_PLUS_DOUBLE
] = "UNARY_PLUS_DOUBLE",
100 [ FILTER_OP_UNARY_MINUS_DOUBLE
] = "UNARY_MINUS_DOUBLE",
101 [ FILTER_OP_UNARY_NOT_DOUBLE
] = "UNARY_NOT_DOUBLE",
104 [ FILTER_OP_AND
] = "AND",
105 [ FILTER_OP_OR
] = "OR",
108 [ FILTER_OP_LOAD_FIELD_REF
] = "LOAD_FIELD_REF",
109 [ FILTER_OP_LOAD_FIELD_REF_STRING
] = "LOAD_FIELD_REF_STRING",
110 [ FILTER_OP_LOAD_FIELD_REF_SEQUENCE
] = "LOAD_FIELD_REF_SEQUENCE",
111 [ FILTER_OP_LOAD_FIELD_REF_S64
] = "LOAD_FIELD_REF_S64",
112 [ FILTER_OP_LOAD_FIELD_REF_DOUBLE
] = "LOAD_FIELD_REF_DOUBLE",
114 /* load from immediate operand */
115 [ FILTER_OP_LOAD_STRING
] = "LOAD_STRING",
116 [ FILTER_OP_LOAD_S64
] = "LOAD_S64",
117 [ FILTER_OP_LOAD_DOUBLE
] = "LOAD_DOUBLE",
120 [ FILTER_OP_CAST_TO_S64
] = "CAST_TO_S64",
121 [ FILTER_OP_CAST_DOUBLE_TO_S64
] = "CAST_DOUBLE_TO_S64",
122 [ FILTER_OP_CAST_NOP
] = "CAST_NOP",
124 /* get context ref */
125 [ FILTER_OP_GET_CONTEXT_REF
] = "GET_CONTEXT_REF",
126 [ FILTER_OP_GET_CONTEXT_REF_STRING
] = "GET_CONTEXT_REF_STRING",
127 [ FILTER_OP_GET_CONTEXT_REF_S64
] = "GET_CONTEXT_REF_S64",
128 [ FILTER_OP_GET_CONTEXT_REF_DOUBLE
] = "GET_CONTEXT_REF_DOUBLE",
131 const char *lttng_filter_print_op(enum filter_op op
)
133 if (op
>= NR_FILTER_OPS
)
140 int apply_field_reloc(struct lttng_event
*event
,
141 struct bytecode_runtime
*runtime
,
142 uint32_t runtime_len
,
143 uint32_t reloc_offset
,
144 const char *field_name
)
146 const struct lttng_event_desc
*desc
;
147 const struct lttng_event_field
*fields
, *field
= NULL
;
148 unsigned int nr_fields
, i
;
149 struct field_ref
*field_ref
;
151 uint32_t field_offset
= 0;
153 dbg_printk("Apply field reloc: %u %s\n", reloc_offset
, field_name
);
155 /* Lookup event by name */
159 fields
= desc
->fields
;
162 nr_fields
= desc
->nr_fields
;
163 for (i
= 0; i
< nr_fields
; i
++) {
164 if (!strcmp(fields
[i
].name
, field_name
)) {
168 /* compute field offset */
169 switch (fields
[i
].type
.atype
) {
172 field_offset
+= sizeof(int64_t);
176 field_offset
+= sizeof(unsigned long);
177 field_offset
+= sizeof(void *);
180 field_offset
+= sizeof(void *);
189 /* Check if field offset is too large for 16-bit offset */
190 if (field_offset
> FILTER_BYTECODE_MAX_LEN
- 1)
194 op
= (struct load_op
*) &runtime
->data
[reloc_offset
];
195 field_ref
= (struct field_ref
*) op
->data
;
196 switch (field
->type
.atype
) {
199 op
->op
= FILTER_OP_LOAD_FIELD_REF_S64
;
203 op
->op
= FILTER_OP_LOAD_FIELD_REF_SEQUENCE
;
206 op
->op
= FILTER_OP_LOAD_FIELD_REF_STRING
;
212 field_ref
->offset
= (uint16_t) field_offset
;
217 int apply_context_reloc(struct lttng_event
*event
,
218 struct bytecode_runtime
*runtime
,
219 uint32_t runtime_len
,
220 uint32_t reloc_offset
,
221 const char *context_name
)
223 struct field_ref
*field_ref
;
225 struct lttng_ctx_field
*ctx_field
;
228 dbg_printk("Apply context reloc: %u %s\n", reloc_offset
, context_name
);
230 /* Get context index */
231 idx
= lttng_get_context_index(lttng_static_ctx
, context_name
);
235 /* Check if idx is too large for 16-bit offset */
236 if (idx
> FILTER_BYTECODE_MAX_LEN
- 1)
239 /* Get context return type */
240 ctx_field
= <tng_static_ctx
->fields
[idx
];
241 op
= (struct load_op
*) &runtime
->data
[reloc_offset
];
242 field_ref
= (struct field_ref
*) op
->data
;
243 switch (ctx_field
->event_field
.type
.atype
) {
246 op
->op
= FILTER_OP_GET_CONTEXT_REF_S64
;
248 /* Sequence and array supported as string */
252 op
->op
= FILTER_OP_GET_CONTEXT_REF_STRING
;
257 /* set offset to context index within channel contexts */
258 field_ref
->offset
= (uint16_t) idx
;
263 int apply_reloc(struct lttng_event
*event
,
264 struct bytecode_runtime
*runtime
,
265 uint32_t runtime_len
,
266 uint32_t reloc_offset
,
271 dbg_printk("Apply reloc: %u %s\n", reloc_offset
, name
);
273 /* Ensure that the reloc is within the code */
274 if (runtime_len
- reloc_offset
< sizeof(uint16_t))
277 op
= (struct load_op
*) &runtime
->data
[reloc_offset
];
279 case FILTER_OP_LOAD_FIELD_REF
:
280 return apply_field_reloc(event
, runtime
, runtime_len
,
282 case FILTER_OP_GET_CONTEXT_REF
:
283 return apply_context_reloc(event
, runtime
, runtime_len
,
286 printk(KERN_WARNING
"Unknown reloc op type %u\n", op
->op
);
293 int bytecode_is_linked(struct lttng_filter_bytecode_node
*filter_bytecode
,
294 struct lttng_event
*event
)
296 struct lttng_bytecode_runtime
*bc_runtime
;
298 list_for_each_entry(bc_runtime
,
299 &event
->bytecode_runtime_head
, node
) {
300 if (bc_runtime
->bc
== filter_bytecode
)
307 * Take a bytecode with reloc table and link it to an event to create a
311 int _lttng_filter_event_link_bytecode(struct lttng_event
*event
,
312 struct lttng_filter_bytecode_node
*filter_bytecode
,
313 struct list_head
*insert_loc
)
315 int ret
, offset
, next_offset
;
316 struct bytecode_runtime
*runtime
= NULL
;
317 size_t runtime_alloc_len
;
319 if (!filter_bytecode
)
321 /* Bytecode already linked */
322 if (bytecode_is_linked(filter_bytecode
, event
))
325 dbg_printk("Linking...\n");
327 /* We don't need the reloc table in the runtime */
328 runtime_alloc_len
= sizeof(*runtime
) + filter_bytecode
->bc
.reloc_offset
;
329 runtime
= kzalloc(runtime_alloc_len
, GFP_KERNEL
);
334 runtime
->p
.bc
= filter_bytecode
;
335 runtime
->len
= filter_bytecode
->bc
.reloc_offset
;
336 /* copy original bytecode */
337 memcpy(runtime
->data
, filter_bytecode
->bc
.data
, runtime
->len
);
339 * apply relocs. Those are a uint16_t (offset in bytecode)
340 * followed by a string (field name).
342 for (offset
= filter_bytecode
->bc
.reloc_offset
;
343 offset
< filter_bytecode
->bc
.len
;
344 offset
= next_offset
) {
345 uint16_t reloc_offset
=
346 *(uint16_t *) &filter_bytecode
->bc
.data
[offset
];
348 (const char *) &filter_bytecode
->bc
.data
[offset
+ sizeof(uint16_t)];
350 ret
= apply_reloc(event
, runtime
, runtime
->len
, reloc_offset
, name
);
354 next_offset
= offset
+ sizeof(uint16_t) + strlen(name
) + 1;
356 /* Validate bytecode */
357 ret
= lttng_filter_validate_bytecode(runtime
);
361 /* Specialize bytecode */
362 ret
= lttng_filter_specialize_bytecode(runtime
);
366 runtime
->p
.filter
= lttng_filter_interpret_bytecode
;
367 runtime
->p
.link_failed
= 0;
368 list_add_rcu(&runtime
->p
.node
, insert_loc
);
369 dbg_printk("Linking successful.\n");
373 runtime
->p
.filter
= lttng_filter_false
;
374 runtime
->p
.link_failed
= 1;
375 list_add_rcu(&runtime
->p
.node
, insert_loc
);
377 dbg_printk("Linking failed.\n");
381 void lttng_filter_sync_state(struct lttng_bytecode_runtime
*runtime
)
383 struct lttng_filter_bytecode_node
*bc
= runtime
->bc
;
385 if (!bc
->enabler
->enabled
|| runtime
->link_failed
)
386 runtime
->filter
= lttng_filter_false
;
388 runtime
->filter
= lttng_filter_interpret_bytecode
;
392 * Link bytecode for all enablers referenced by an event.
394 void lttng_enabler_event_link_bytecode(struct lttng_event
*event
,
395 struct lttng_enabler
*enabler
)
397 struct lttng_filter_bytecode_node
*bc
;
398 struct lttng_bytecode_runtime
*runtime
;
400 /* Can only be called for events with desc attached */
401 WARN_ON_ONCE(!event
->desc
);
403 /* Link each bytecode. */
404 list_for_each_entry(bc
, &enabler
->filter_bytecode_head
, node
) {
406 struct list_head
*insert_loc
;
408 list_for_each_entry(runtime
,
409 &event
->bytecode_runtime_head
, node
) {
410 if (runtime
->bc
== bc
) {
415 /* Skip bytecode already linked */
420 * Insert at specified priority (seqnum) in increasing
423 list_for_each_entry_reverse(runtime
,
424 &event
->bytecode_runtime_head
, node
) {
425 if (runtime
->bc
->bc
.seqnum
< bc
->bc
.seqnum
) {
427 insert_loc
= &runtime
->node
;
431 /* Add to head to list */
432 insert_loc
= &event
->bytecode_runtime_head
;
434 dbg_printk("linking bytecode\n");
435 ret
= _lttng_filter_event_link_bytecode(event
, bc
,
438 dbg_printk("[lttng filter] warning: cannot link event bytecode\n");
444 * We own the filter_bytecode if we return success.
446 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
447 struct lttng_filter_bytecode_node
*filter_bytecode
)
449 list_add(&filter_bytecode
->node
, &enabler
->filter_bytecode_head
);
453 void lttng_free_enabler_filter_bytecode(struct lttng_enabler
*enabler
)
455 struct lttng_filter_bytecode_node
*filter_bytecode
, *tmp
;
457 list_for_each_entry_safe(filter_bytecode
, tmp
,
458 &enabler
->filter_bytecode_head
, node
) {
459 kfree(filter_bytecode
);
463 void lttng_free_event_filter_runtime(struct lttng_event
*event
)
465 struct bytecode_runtime
*runtime
, *tmp
;
467 list_for_each_entry_safe(runtime
, tmp
,
468 &event
->bytecode_runtime_head
, p
.node
) {