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07dfc1d0 MD |
1 | #ifndef _LTTNG_FILTER_H |
2 | #define _LTTNG_FILTER_H | |
3 | ||
4 | /* | |
5 | * lttng-filter.h | |
6 | * | |
7 | * LTTng modules filter header. | |
8 | * | |
bbf3aef5 | 9 | * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
07dfc1d0 | 10 | * |
bbf3aef5 MD |
11 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
12 | * of this software and associated documentation files (the "Software"), to deal | |
13 | * in the Software without restriction, including without limitation the rights | |
14 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
15 | * copies of the Software, and to permit persons to whom the Software is | |
16 | * furnished to do so, subject to the following conditions: | |
07dfc1d0 | 17 | * |
bbf3aef5 MD |
18 | * The above copyright notice and this permission notice shall be included in |
19 | * all copies or substantial portions of the Software. | |
07dfc1d0 | 20 | * |
bbf3aef5 MD |
21 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
22 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
23 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
24 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
25 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
26 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
27 | * SOFTWARE. | |
07dfc1d0 MD |
28 | */ |
29 | ||
30 | #include <linux/kernel.h> | |
31 | ||
bbd023d6 MD |
32 | #include <lttng-events.h> |
33 | #include <filter-bytecode.h> | |
07dfc1d0 MD |
34 | |
35 | /* Filter stack length, in number of entries */ | |
36 | #define FILTER_STACK_LEN 10 /* includes 2 dummy */ | |
37 | #define FILTER_STACK_EMPTY 1 | |
38 | ||
39 | #ifdef DEBUG | |
40 | #define dbg_printk(fmt, args...) \ | |
41 | printk(KERN_DEBUG "[debug bytecode in %s:%s@%u] " fmt, \ | |
42 | __FILE__, __func__, __LINE__, ## args) | |
43 | #else | |
44 | #define dbg_printk(fmt, args...) \ | |
45 | do { \ | |
46 | /* do nothing but check printf format */ \ | |
47 | if (0) \ | |
48 | printk(KERN_DEBUG "[debug bytecode in %s:%s@%u] " fmt, \ | |
49 | __FILE__, __func__, __LINE__, ## args); \ | |
50 | } while (0) | |
51 | #endif | |
52 | ||
53 | /* Linked bytecode. Child of struct lttng_bytecode_runtime. */ | |
54 | struct bytecode_runtime { | |
55 | struct lttng_bytecode_runtime p; | |
56 | uint16_t len; | |
57 | char data[0]; | |
58 | }; | |
59 | ||
60 | enum entry_type { | |
61 | REG_S64, | |
62 | REG_DOUBLE, | |
63 | REG_STRING, | |
64 | REG_TYPE_UNKNOWN, | |
65 | }; | |
66 | ||
67 | /* Validation stack */ | |
68 | struct vstack_entry { | |
69 | enum entry_type type; | |
70 | }; | |
71 | ||
72 | struct vstack { | |
73 | int top; /* top of stack */ | |
74 | struct vstack_entry e[FILTER_STACK_LEN]; | |
75 | }; | |
76 | ||
77 | static inline | |
78 | void vstack_init(struct vstack *stack) | |
79 | { | |
80 | stack->top = -1; | |
81 | } | |
82 | ||
83 | static inline | |
84 | struct vstack_entry *vstack_ax(struct vstack *stack) | |
85 | { | |
86 | if (unlikely(stack->top < 0)) | |
87 | return NULL; | |
88 | return &stack->e[stack->top]; | |
89 | } | |
90 | ||
91 | static inline | |
92 | struct vstack_entry *vstack_bx(struct vstack *stack) | |
93 | { | |
94 | if (unlikely(stack->top < 1)) | |
95 | return NULL; | |
96 | return &stack->e[stack->top - 1]; | |
97 | } | |
98 | ||
99 | static inline | |
100 | int vstack_push(struct vstack *stack) | |
101 | { | |
102 | if (stack->top >= FILTER_STACK_LEN - 1) { | |
103 | printk(KERN_WARNING "Stack full\n"); | |
104 | return -EINVAL; | |
105 | } | |
106 | ++stack->top; | |
107 | return 0; | |
108 | } | |
109 | ||
110 | static inline | |
111 | int vstack_pop(struct vstack *stack) | |
112 | { | |
113 | if (unlikely(stack->top < 0)) { | |
114 | printk(KERN_WARNING "Stack empty\n"); | |
115 | return -EINVAL; | |
116 | } | |
117 | stack->top--; | |
118 | return 0; | |
119 | } | |
120 | ||
121 | /* Execution stack */ | |
122 | struct estack_entry { | |
123 | union { | |
124 | int64_t v; | |
125 | ||
126 | struct { | |
127 | const char *str; | |
f127e61e | 128 | const char __user *user_str; |
07dfc1d0 MD |
129 | size_t seq_len; |
130 | int literal; /* is string literal ? */ | |
f127e61e | 131 | int user; /* is string from userspace ? */ |
07dfc1d0 MD |
132 | } s; |
133 | } u; | |
134 | }; | |
135 | ||
136 | struct estack { | |
137 | int top; /* top of stack */ | |
138 | struct estack_entry e[FILTER_STACK_LEN]; | |
139 | }; | |
140 | ||
141 | #define estack_ax_v ax | |
142 | #define estack_bx_v bx | |
143 | ||
144 | #define estack_ax(stack, top) \ | |
145 | ({ \ | |
5f12cb8d | 146 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
147 | &(stack)->e[top]; \ |
148 | }) | |
149 | ||
150 | #define estack_bx(stack, top) \ | |
151 | ({ \ | |
5f12cb8d | 152 | BUG_ON((top) <= FILTER_STACK_EMPTY + 1); \ |
07dfc1d0 MD |
153 | &(stack)->e[(top) - 1]; \ |
154 | }) | |
155 | ||
156 | #define estack_push(stack, top, ax, bx) \ | |
157 | do { \ | |
5f12cb8d | 158 | BUG_ON((top) >= FILTER_STACK_LEN - 1); \ |
07dfc1d0 MD |
159 | (stack)->e[(top) - 1].u.v = (bx); \ |
160 | (bx) = (ax); \ | |
161 | ++(top); \ | |
162 | } while (0) | |
163 | ||
164 | #define estack_pop(stack, top, ax, bx) \ | |
165 | do { \ | |
5f12cb8d | 166 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
167 | (ax) = (bx); \ |
168 | (bx) = (stack)->e[(top) - 2].u.v; \ | |
169 | (top)--; \ | |
170 | } while (0) | |
171 | ||
172 | const char *lttng_filter_print_op(enum filter_op op); | |
173 | ||
174 | int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode); | |
175 | int lttng_filter_specialize_bytecode(struct bytecode_runtime *bytecode); | |
176 | ||
177 | uint64_t lttng_filter_false(void *filter_data, | |
79150a49 | 178 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
179 | const char *filter_stack_data); |
180 | uint64_t lttng_filter_interpret_bytecode(void *filter_data, | |
79150a49 | 181 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
182 | const char *filter_stack_data); |
183 | ||
184 | #endif /* _LTTNG_FILTER_H */ |