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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, | |
02aca193 | 64 | REG_STAR_GLOB_STRING, |
07dfc1d0 MD |
65 | REG_TYPE_UNKNOWN, |
66 | }; | |
67 | ||
68 | /* Validation stack */ | |
69 | struct vstack_entry { | |
70 | enum entry_type type; | |
71 | }; | |
72 | ||
73 | struct vstack { | |
74 | int top; /* top of stack */ | |
75 | struct vstack_entry e[FILTER_STACK_LEN]; | |
76 | }; | |
77 | ||
78 | static inline | |
79 | void vstack_init(struct vstack *stack) | |
80 | { | |
81 | stack->top = -1; | |
82 | } | |
83 | ||
84 | static inline | |
85 | struct vstack_entry *vstack_ax(struct vstack *stack) | |
86 | { | |
87 | if (unlikely(stack->top < 0)) | |
88 | return NULL; | |
89 | return &stack->e[stack->top]; | |
90 | } | |
91 | ||
92 | static inline | |
93 | struct vstack_entry *vstack_bx(struct vstack *stack) | |
94 | { | |
95 | if (unlikely(stack->top < 1)) | |
96 | return NULL; | |
97 | return &stack->e[stack->top - 1]; | |
98 | } | |
99 | ||
100 | static inline | |
101 | int vstack_push(struct vstack *stack) | |
102 | { | |
103 | if (stack->top >= FILTER_STACK_LEN - 1) { | |
104 | printk(KERN_WARNING "Stack full\n"); | |
105 | return -EINVAL; | |
106 | } | |
107 | ++stack->top; | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static inline | |
112 | int vstack_pop(struct vstack *stack) | |
113 | { | |
114 | if (unlikely(stack->top < 0)) { | |
115 | printk(KERN_WARNING "Stack empty\n"); | |
116 | return -EINVAL; | |
117 | } | |
118 | stack->top--; | |
119 | return 0; | |
120 | } | |
121 | ||
122 | /* Execution stack */ | |
02aca193 PP |
123 | enum estack_string_literal_type { |
124 | ESTACK_STRING_LITERAL_TYPE_NONE, | |
125 | ESTACK_STRING_LITERAL_TYPE_PLAIN, | |
126 | ESTACK_STRING_LITERAL_TYPE_STAR_GLOB, | |
127 | }; | |
128 | ||
07dfc1d0 MD |
129 | struct estack_entry { |
130 | union { | |
131 | int64_t v; | |
132 | ||
133 | struct { | |
134 | const char *str; | |
f127e61e | 135 | const char __user *user_str; |
07dfc1d0 | 136 | size_t seq_len; |
02aca193 | 137 | enum estack_string_literal_type literal_type; |
f127e61e | 138 | int user; /* is string from userspace ? */ |
07dfc1d0 MD |
139 | } s; |
140 | } u; | |
141 | }; | |
142 | ||
143 | struct estack { | |
144 | int top; /* top of stack */ | |
145 | struct estack_entry e[FILTER_STACK_LEN]; | |
146 | }; | |
147 | ||
148 | #define estack_ax_v ax | |
149 | #define estack_bx_v bx | |
150 | ||
151 | #define estack_ax(stack, top) \ | |
152 | ({ \ | |
5f12cb8d | 153 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
154 | &(stack)->e[top]; \ |
155 | }) | |
156 | ||
157 | #define estack_bx(stack, top) \ | |
158 | ({ \ | |
5f12cb8d | 159 | BUG_ON((top) <= FILTER_STACK_EMPTY + 1); \ |
07dfc1d0 MD |
160 | &(stack)->e[(top) - 1]; \ |
161 | }) | |
162 | ||
163 | #define estack_push(stack, top, ax, bx) \ | |
164 | do { \ | |
5f12cb8d | 165 | BUG_ON((top) >= FILTER_STACK_LEN - 1); \ |
07dfc1d0 MD |
166 | (stack)->e[(top) - 1].u.v = (bx); \ |
167 | (bx) = (ax); \ | |
168 | ++(top); \ | |
169 | } while (0) | |
170 | ||
171 | #define estack_pop(stack, top, ax, bx) \ | |
172 | do { \ | |
5f12cb8d | 173 | BUG_ON((top) <= FILTER_STACK_EMPTY); \ |
07dfc1d0 MD |
174 | (ax) = (bx); \ |
175 | (bx) = (stack)->e[(top) - 2].u.v; \ | |
176 | (top)--; \ | |
177 | } while (0) | |
178 | ||
179 | const char *lttng_filter_print_op(enum filter_op op); | |
180 | ||
181 | int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode); | |
182 | int lttng_filter_specialize_bytecode(struct bytecode_runtime *bytecode); | |
183 | ||
184 | uint64_t lttng_filter_false(void *filter_data, | |
79150a49 | 185 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
186 | const char *filter_stack_data); |
187 | uint64_t lttng_filter_interpret_bytecode(void *filter_data, | |
79150a49 | 188 | struct lttng_probe_ctx *lttng_probe_ctx, |
07dfc1d0 MD |
189 | const char *filter_stack_data); |
190 | ||
191 | #endif /* _LTTNG_FILTER_H */ |