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97b58163 MD |
1 | #ifndef _LTTNG_FILTER_H |
2 | #define _LTTNG_FILTER_H | |
3 | ||
4 | /* | |
5 | * lttng-filter.h | |
6 | * | |
7 | * LTTng UST filter header. | |
8 | * | |
9 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
10 | * | |
11 | * This library is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU Lesser General Public | |
13 | * License as published by the Free Software Foundation; only | |
14 | * version 2.1 of the License. | |
15 | * | |
16 | * This library is distributed in the hope that it will be useful, | |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | * Lesser General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU Lesser General Public | |
22 | * License along with this library; if not, write to the Free Software | |
23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
24 | */ | |
25 | ||
26 | #include <errno.h> | |
27 | #include <stdio.h> | |
28 | #include <helper.h> | |
29 | #include <lttng/ust-events.h> | |
53569322 | 30 | #include <lttng/ust-context-provider.h> |
97b58163 | 31 | #include <stdint.h> |
0305960f | 32 | #include <assert.h> |
97b58163 MD |
33 | #include <errno.h> |
34 | #include <string.h> | |
35 | #include <inttypes.h> | |
36 | #include <limits.h> | |
37 | #include <usterr-signal-safe.h> | |
38 | #include "filter-bytecode.h" | |
39 | ||
0305960f | 40 | /* Filter stack length, in number of entries */ |
9b33aac4 MD |
41 | #define FILTER_STACK_LEN 10 /* includes 2 dummy */ |
42 | #define FILTER_STACK_EMPTY 1 | |
97b58163 MD |
43 | |
44 | #ifndef min_t | |
45 | #define min_t(type, a, b) \ | |
46 | ((type) (a) < (type) (b) ? (type) (a) : (type) (b)) | |
47 | #endif | |
48 | ||
49 | #ifndef likely | |
50 | #define likely(x) __builtin_expect(!!(x), 1) | |
51 | #endif | |
52 | ||
53 | #ifndef unlikely | |
54 | #define unlikely(x) __builtin_expect(!!(x), 0) | |
55 | #endif | |
56 | ||
57 | #ifdef DEBUG | |
f488575f MD |
58 | #define dbg_printf(fmt, args...) \ |
59 | printf("[debug bytecode in %s:%s@%u] " fmt, \ | |
60 | __FILE__, __func__, __LINE__, ## args) | |
97b58163 MD |
61 | #else |
62 | #define dbg_printf(fmt, args...) \ | |
63 | do { \ | |
64 | /* do nothing but check printf format */ \ | |
65 | if (0) \ | |
f488575f MD |
66 | printf("[debug bytecode in %s:%s@%u] " fmt, \ |
67 | __FILE__, __func__, __LINE__, ## args); \ | |
97b58163 MD |
68 | } while (0) |
69 | #endif | |
70 | ||
f488575f | 71 | /* Linked bytecode. Child of struct lttng_bytecode_runtime. */ |
97b58163 | 72 | struct bytecode_runtime { |
f488575f | 73 | struct lttng_bytecode_runtime p; |
97b58163 MD |
74 | uint16_t len; |
75 | char data[0]; | |
76 | }; | |
77 | ||
0305960f | 78 | enum entry_type { |
97b58163 MD |
79 | REG_S64, |
80 | REG_DOUBLE, | |
81 | REG_STRING, | |
53569322 | 82 | REG_UNKNOWN, |
97b58163 MD |
83 | }; |
84 | ||
0305960f MD |
85 | /* Validation stack */ |
86 | struct vstack_entry { | |
87 | enum entry_type type; | |
97b58163 MD |
88 | }; |
89 | ||
0305960f MD |
90 | struct vstack { |
91 | int top; /* top of stack */ | |
92 | struct vstack_entry e[FILTER_STACK_LEN]; | |
93 | }; | |
94 | ||
95 | static inline | |
96 | void vstack_init(struct vstack *stack) | |
97 | { | |
98 | stack->top = -1; | |
99 | } | |
100 | ||
101 | static inline | |
102 | struct vstack_entry *vstack_ax(struct vstack *stack) | |
103 | { | |
104 | if (unlikely(stack->top < 0)) | |
105 | return NULL; | |
106 | return &stack->e[stack->top]; | |
107 | } | |
108 | ||
109 | static inline | |
110 | struct vstack_entry *vstack_bx(struct vstack *stack) | |
111 | { | |
112 | if (unlikely(stack->top < 1)) | |
113 | return NULL; | |
114 | return &stack->e[stack->top - 1]; | |
115 | } | |
116 | ||
117 | static inline | |
118 | int vstack_push(struct vstack *stack) | |
119 | { | |
120 | if (stack->top >= FILTER_STACK_LEN - 1) { | |
121 | ERR("Stack full\n"); | |
122 | return -EINVAL; | |
123 | } | |
124 | ++stack->top; | |
125 | return 0; | |
126 | } | |
127 | ||
128 | static inline | |
129 | int vstack_pop(struct vstack *stack) | |
130 | { | |
131 | if (unlikely(stack->top < 0)) { | |
132 | ERR("Stack empty\n"); | |
133 | return -EINVAL; | |
134 | } | |
135 | stack->top--; | |
136 | return 0; | |
137 | } | |
138 | ||
139 | /* Execution stack */ | |
140 | struct estack_entry { | |
53569322 | 141 | enum entry_type type; /* For dynamic typing. */ |
0305960f MD |
142 | union { |
143 | int64_t v; | |
144 | double d; | |
145 | ||
146 | struct { | |
147 | const char *str; | |
9b33aac4 MD |
148 | size_t seq_len; |
149 | int literal; /* is string literal ? */ | |
0305960f MD |
150 | } s; |
151 | } u; | |
152 | }; | |
97b58163 | 153 | |
0305960f MD |
154 | struct estack { |
155 | int top; /* top of stack */ | |
156 | struct estack_entry e[FILTER_STACK_LEN]; | |
97b58163 MD |
157 | }; |
158 | ||
53569322 MD |
159 | /* |
160 | * Always use aliased type for ax/bx (top of stack). | |
161 | * When ax/bx are S64, use aliased value. | |
162 | */ | |
9b33aac4 MD |
163 | #define estack_ax_v ax |
164 | #define estack_bx_v bx | |
53569322 MD |
165 | #define estack_ax_t ax_t |
166 | #define estack_bx_t bx_t | |
9b33aac4 | 167 | |
53569322 MD |
168 | /* |
169 | * ax and bx registers can hold either integer, double or string. | |
170 | */ | |
9b33aac4 MD |
171 | #define estack_ax(stack, top) \ |
172 | ({ \ | |
173 | assert((top) > FILTER_STACK_EMPTY); \ | |
174 | &(stack)->e[top]; \ | |
175 | }) | |
176 | ||
177 | #define estack_bx(stack, top) \ | |
178 | ({ \ | |
179 | assert((top) > FILTER_STACK_EMPTY + 1); \ | |
180 | &(stack)->e[(top) - 1]; \ | |
181 | }) | |
182 | ||
53569322 MD |
183 | /* |
184 | * Currently, only integers (REG_S64) can be pushed into the stack. | |
185 | */ | |
186 | #define estack_push(stack, top, ax, bx, ax_t, bx_t) \ | |
9b33aac4 MD |
187 | do { \ |
188 | assert((top) < FILTER_STACK_LEN - 1); \ | |
189 | (stack)->e[(top) - 1].u.v = (bx); \ | |
53569322 | 190 | (stack)->e[(top) - 1].type = (bx_t); \ |
9b33aac4 | 191 | (bx) = (ax); \ |
53569322 | 192 | (bx_t) = (ax_t); \ |
9b33aac4 MD |
193 | ++(top); \ |
194 | } while (0) | |
195 | ||
53569322 | 196 | #define estack_pop(stack, top, ax, bx, ax_t, bx_t) \ |
9b33aac4 MD |
197 | do { \ |
198 | assert((top) > FILTER_STACK_EMPTY); \ | |
199 | (ax) = (bx); \ | |
53569322 | 200 | (ax_t) = (bx_t); \ |
9b33aac4 | 201 | (bx) = (stack)->e[(top) - 2].u.v; \ |
53569322 | 202 | (bx_t) = (stack)->e[(top) - 2].type; \ |
9b33aac4 MD |
203 | (top)--; \ |
204 | } while (0) | |
0305960f | 205 | |
97b58163 MD |
206 | const char *print_op(enum filter_op op); |
207 | ||
208 | int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode); | |
209 | int lttng_filter_specialize_bytecode(struct bytecode_runtime *bytecode); | |
210 | ||
8a92ed2a | 211 | uint64_t lttng_filter_false(void *filter_data, |
97b58163 | 212 | const char *filter_stack_data); |
8a92ed2a | 213 | uint64_t lttng_filter_interpret_bytecode(void *filter_data, |
97b58163 MD |
214 | const char *filter_stack_data); |
215 | ||
216 | #endif /* _LTTNG_FILTER_H */ |